A neuroprotective role of kaempferol against chlorpyrifos-induced oxidative stress and memory deficits in rats via GSK3β-Nrf2 signaling pathway

Deciphering the mechanisms underlying the neuroprotective potential of kaempferol: a comprehensive investigation

Neurodegenerative disorders are characterized by neuronal degradation, dysfunction, or death within the CNS. Oxidative and inflammatory stress play crucial roles in the pathogenesis of various neurodegenerative diseases. The interplay between these stressors and dysregulated cellular signaling pathways contributes to neurodegeneration. Downregulation of NRF-2 compromises antioxidant defense, exacerbating neuronal damage, while increased TLR-4/MAPK and TLR-4/NF-κB signaling promotes neuroinflammation. Excessive ROS production by NADPH oxidase leads to oxidative damage and neuronal apoptosis. The strategies targeting NRF-2, TLR-4-mediated inflammatory stress, and NADPH oxidase activity promise to mitigate neuronal damage and halt the progression of the disease. Kaempferol is a flavonoid polyphenol antioxidant found abundantly in various fruits and vegetables, including apples, grapes, tomatoes, and broccoli. It is widely found in medicinal plants including Equisetum spp., Sophora japonica, Ginkgo biloba, and Euphorbia pekinensis (Rupr.). A substantial body of in vitro and in vivo evidences have demonstrated the neuroprotective potential of kaempferol against neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Kaempferol demonstrates multifaceted potential in mitigating neuroinflammation, apoptosis, and oxidative stress in different neurodegenerative diseases through the modulation of various pathways including NRF-2, NADPH oxidase, TLR-4/MAPK, and TLR-4/NF-κB. This review article was developed through a comprehensive analysis and interpretation of research published between 2009 and 2024, sourced from multiple scientific databases, including PubMed, Scopus, ScienceDirect, and Web of Science. This review aims to provide an in-depth overview of the neuroprotective effects of kaempferol, focusing on its underlying molecular mechanisms. A total of 24 research evidence were included to elucidate the molecular pathways by which kaempferol exerts its protective effects against neurodegenerative diseases.

Improvement of chlorpyrifos-induced cognitive impairment by mountain grape anthocyanins based on PI3K/Akt signaling pathway

The organophosphorus insecticide Chlorpyrifos (CPF) is widely used worldwide due to its high effectiveness. However, when ingested through the mouth and nose, it can cause severe neurotoxic effects and cognitive impairment. Natural anthocyanins show great potential in improving cognitive impairment. In this paper, we will delve into the protective effect of anthocyanins on CPF-induced cognitive impairment and its mechanism through the PI3K/Akt signaling pathway. Morris water maze, histopathological, ELISA and western blot analyses showed that anthocyanins effectively ameliorated CPF-induced spatial learning memory impairment in mice by ameliorating CPF-induced AChE inhibition, oxidative stress, and neuroinflammation and by modulating the levels of apoptosis (Caspase-3, Caspase-9) and autophagy (LC3II/ LC3I, Beclin1, p62, mTOR) biomarkers, in order to restore damaged hippocampal tissue morphology, neuron and synapse structures. To identify the action pathway of anthocyanins, we used KEGG and GO pathway enrichment analysis for screening prediction and western blot and molecular docking to verify that anthocyanins improve CPF-induced cognitive impairment by activating the PI3K/Akt pathway.

Optimization and pharmacological evaluation of phytochemical-rich Cuscuta reflexa seed extract for its efficacy against chlorpyrifos-induced hepatotoxicity in murine models

The popular organophosphorus (OP) compound chlorpyrifos (CP) has recently gained significant attention due to its health risks, particularly among farmers exposed to OP pesticides. This study aimed to evaluate the acute toxicity of Cuscuta reflexa seed extract (CRSE) and its efficacy of mitigating the adverse effects of CP in albino male mice. For acute toxicity analysis, the first group was served as the control group, while the second group was received CRSE (200 mg/kg/bw) on the first day of the 14-day experiment. For hepatotoxicity analysis, the first group was the control group, the second group (vehicle control) received corn oil (CO) (2 mL/kg/bw), the third group was given CP (20 mg/kg/bw) dissolved in corn oil and the fourth group was given CP (20 mg/kg/bw) along-with CRSE (200 mg/kg/bw) orally via gavage once daily for 21 days. The acute toxicity examination revealed no statistically significant differences between the CRSE-treated and control groups in serum biochemical indicators and histopathological analyses of various organs, suggesting that CRSE as safe at a dosage of 200 mg/kg/bw, with an oral LD50 in mice higher than 200 mg/kg. The hepatotoxicity study demonstrated that the CP administration resulted in liver damage and oxidative stress, while CRSE acted as an antioxidant and attenuated the signs of oxidative stress in liver damage. Hence, a promising therapeutic approach for lowering CP hepatotoxicity is co-treatment with CRSE.

Fluoxetine attenuates chlorpyrifos-induced neuronal injury through the PPARγ, SIRT1, NF-κB, and JAK1/STAT3 signals

Chlorpyrifos (CPF) is a widely used organophosphate insecticide in agriculture and homes. Exposure to organophosphates is associated with neurotoxicity. Fluoxetine (FLX) is a selective serotonin reuptake inhibitor (SSRI) that is widely prescribed for depression and anxiety disorders. Studies have shown that FLX has neuroprotective, anti-inflammatory, antioxidant, and antiapoptotic effects. The molecular mechanisms underlying FLX are not fully understood. This work aimed to investigate the potential neuroprotective effect of FLX on CPF-induced neurotoxicity and the underlying molecular mechanisms involved. Thirty-two rats were randomly divided into four groups: (I) the vehicle control group; (II) the FLX-treated group (10 mg/kg/day for 28 days, p.o); (III) the CPF-treated group (10 mg/kg for 28 days); and (IV) the FLX+CPF group. FLX attenuated CPF-induced neuronal injury, as evidenced by a significant decrease in Aβ and p-Tau levels and attenuation of cerebral and hippocampal histological abrasion injury induced by CPF. FLX ameliorated neuronal oxidative stress, effectively reduced MDA production, and restored SOD and GSH levels through the coactivation of the PPARγ and SIRT1 proteins. FLX counteracted the neuronal inflammation induced by CPF by decreasing MPO, NO, TNF-α, IL-1β, and IL-6 levels by suppressing NF-κB and JAK1/STAT3 activation. The antioxidant and anti-inflammatory properties of FLX help to prevent CPF-induced neuronal intoxication.

Neuroprotective effects of Tradescantia spathacea tea bioactives in Parkinson's disease: In vivo proof-of-concept

Background and aim

Tradescantia spathacea (T. spathacea) is a traditional medicinal plant from Central America and its tea, obtained by infusion, has been recognized as a functional food. The aim of this work was to investigate the effects of dry tea containing biocompounds from T. spathacea tea on motor and emotional behavior, as well as tyrosine hydroxylase (TH) and glial fibrillary acidic protein (GFAP) expression in 6-hydroxydopamine (6-OHDA)-lesioned rats.

Experimental procedure

Bioactives were identified by Ultra Performance Liquid Chromatography (UPLC) and an in vivo study in male Wistar rats was run as proof of concept of neuroprotective effects of DTTS.

Results and conclusion

We found 15 biocompounds that had not been previously reported in T. spathacea: the UPLC-QTOF-MS/MS allowed identification five phenolic acids, one coumarin, two flavonoids, one iridoid, one phenylpropanoid glycoside, and six fatty acid derivatives. The dry tea of T. spathacea (DTTS) presented significant antioxidant activity and high contents of phenolic compounds and flavonoids. Doses of 10, 30, and 100 mg/kg of DTTS were protective against dopaminergic neurodegeneration and exhibited modulatory action on the astrocyte-mediated neuroinflammatory response. Behavioral tests showed that 30 mg/kg of DTTS counteracted motor impairment, while 100 mg/kg produced an anxiolytic effect. The DTTS could be, therefore, a promising strategy for the management of Parkinson's disease.

Vitamin E alleviates chlorpyrifos induced glutathione depletion, lipid peroxidation and iron accumulation to inhibit ferroptosis in hepatocytes and mitigate toxicity in zebrafish

Organophosphates, a widely used group of pesticides, can cause severe toxicity in human beings and other non-target organisms. Liver, being the primary site for xenobiotic metabolism, is extremely vulnerable to xenobiotic-induced toxicity. Considering the numerous vital functions performed by the liver, including xenobiotic detoxification, protecting this organ from the ubiquitous pesticides in our food and environment is essential for maintaining homeostasis. In this study, we have investigated the impact of the organophosphate pesticide, Chlorpyrifos (CPF), on zebrafish liver at a concentration (300 μg/L) which is environmentally realistic. We have also demonstrated the role of dietary supplementation of α-tocopherol or Vitamin E (Vit E) (500 mg/kg feed) in mitigating pesticide-induced liver toxicity. Mechanistically, we showed that Vit E resulted in significant elevation of the Nrf2 and its downstream antioxidant enzyme activities and gene expressions, especially that of GST and GPx, resulting in reduction of CPF-induced intracellular lipid ROS and hepatic LPO. Further interrogation, such as analysis of GSH: GSSG ratio, intracellular iron concentration, iron metabolizing genes, mitochondrial dysfunction etc. revealed that CPF induces ferroptosis which can be reversed by Vit E supplementation. Ultimately, reduced concentration of CPF in zebrafish serum and flesh highlighted the role of Vit E in ameliorating CPF toxicity.

Oral administration of phytochemicals protects honey bees against cognitive and motor impairments induced by the insecticide fipronil

Pollution produced by exposure to pesticides is a major concern for food security because the negative impacts on pollinators. Fipronil, an insecticide broadly used around the globe has been associated with the ongoing decline of bees. With a characteristic neuroactive toxicodynamic, fipronil leads to cognitive and motor impairments at sublethal dosages. Despite of regional bans, multilevel strategies are necessary for the protection of pollinators. Recent evidence suggests that specific nutrients in the diets of bees may induce protection against insecticides. Here, we evaluated whether the administration of three phytochemicals, namely rutin, kaempferol and p-coumaric acid provide protection to the Africanized honey bee Apis mellifera against oral administration of realistic dosages of fipronil. We tested the potential impairment produced by fipronil and the protection induced by the phytochemicals in learning, 24h memory, sucrose sensitivity and motor control. We found that the administration of fipronil induced a concentration-dependent impairment in learning and motor control, but not 24h memory or sucrose sensitivity across a 24h window. We also found that the administration of rutin, p-coumaric acid, kaempferol and the mixture was innocuous and generally offered protection against the impairments induced by fipronil. Overall, our results indicate that bees can be prophylactically protected against insecticides via nutrition, providing an alternative to the ongoing conflict between the use of insecticides and the decline of pollinators. As the studied phytochemicals are broadly present in nectar and pollen, our results suggest that the nutritional composition, and not only its production, should be considered when implementing strategies of conservation via gardens and co-cropping.

Therapeutic potential of salidroside in preserving rat cochlea organ of corti from gentamicin-induced injury through modulation of NRF2 signaling and GSK3β/NF-κB pathway

Salidroside (SAL) is a phenol glycoside compound found in plants of the Rhodiola genus which has natural antioxidant and free radical scavenging properties. SAL are able to protect against manganese-induced ototoxicity. However, the molecular mechanism by which SAL reduces levels of reactive oxygen species (ROS) is unclear. Here, we established an in vitro gentamicin (GM) ototoxicity model to observe the protective effect of SAL on GM-induced hair cells (HC) damage. Cochlear explants of postnatal day 4 rats were obtained and randomly divided into six groups: two model groups (treatment with 0.2 mM or 0.4 mM GM for 24 h); two 400 μmol/L SAL-pretreated groups pretreatment with SAL for 3 h followed by GM treatment (0.2 mM or 0.4 mM) for 24 h; 400 μmol/L SAL group (treatment with SAL for 24 h); control group (normal cultured cochlear explants). The protective effects of SAL on GM-induced HC damage, and on mRNA and protein levels of antioxidant enzymes were observed. HC loss occurred after 24 h of GM treatment. Pretreatment with SAL significantly reduced GM-induced OHC loss. In cochlear tissues, mRNA and protein levels of NRF2 and HO-1 were enhanced in the GM alone group compared with the SAL pretreatment GM treatment group. SAL may protect against GM-induced ototoxicity by regulating the antioxidant defense system of cochlear tissues; SAL can activate NRF2/HO-1 signaling, inhibit NF-κB activation, activate AKT, and increase inhibitory phosphorylation of GSK3β to decrease GSK3 activity, all of which exert antioxidant effects.

Berberine alleviates chlorpyrifos-induced nephrotoxicity in rats via modulation of Nrf2/HO-1 axis

Chlorpyrifos (CPS), an organophosphorus insecticide, is widely used for agricultural and non-agricultural purposes with hazardous health effects. Berberine (BBR) is a traditional Chinese medicine and a phytochemical with anti-inflammatory and anti-oxidative properties. The present study evaluated the effects of BBR against kidney damage induced by CPS and the underlying mechanisms. An initial study indicated that BBR 50 mg/kg was optimal under our experimental conditions. Then, 24 rats (6/group) were randomized into: control, BBR (50 mg/kg/day), CPS (10 mg/kg/day), and CPS + BBR. BBR was administration 1 h prior to CPS. Each treatment was delivered daily for a period of 28 consecutive days using a gastric gavage tube. Compared to CPS-alone treated rats, BBR effectively improved renal function by preventing the rise in serum urea, creatinine, and uric levels. The reno-protective effects of BBR were confirmed through a histological examination of kidney tissues. BBR restored oxidant-antioxidant balance in renal tissues mediated by Keap1/Nrf2/HO-1 axis modulation. In addition, BBR decreased nitric oxide (NO) and myeloperoxidase (MPO) activity. This was paralleled with the potent down-regulation of NF-κB. Furthermore, BBR exhibited anti-apoptotic activities supported by the upregulation of Bcl-2 and down-regulation of Bax and caspase-3 expression. In conclusion, our data suggest that BBR attenuates CPS-induced nephrotoxicity in rats by restoring oxidant-antioxidant balance and inhibiting inflammatory response and apoptosis in renal tissue. This is mediated, at least partly, by modulation of the Nrf2/HO-1 axis.

An Update of Kaempferol Protection against Brain Damage Induced by Ischemia-Reperfusion and by 3-Nitropropionic Acid

Kaempferol, a flavonoid present in many food products, has chemical and cellular antioxidant properties that are beneficial for protection against the oxidative stress caused by reactive oxygen and nitrogen species. Kaempferol administration to model experimental animals can provide extensive protection against brain damage of the striatum and proximal cortical areas induced by transient brain cerebral ischemic stroke and by 3-nitropropionic acid. This article is an updated review of the molecular and cellular mechanisms of protection by kaempferol administration against brain damage induced by these insults, integrated with an overview of the contributions of the work performed in our laboratories during the past years. Kaempferol administration at doses that prevent neurological dysfunctions inhibit the critical molecular events that underlie the initial and delayed brain damage induced by ischemic stroke and by 3-nitropropionic acid. It is highlighted that the protection afforded by kaempferol against the initial mitochondrial dysfunction can largely account for its protection against the reported delayed spreading of brain damage, which can develop from many hours to several days. This allows us to conclude that kaempferol administration can be beneficial not only in preventive treatments, but also in post-insult therapeutic treatments.

Effect of quercetin-loaded poly (lactic-co-glycolic) acid nanoparticles on lipopolysaccharide-induced memory decline, oxidative stress, amyloidogenesis, neurotransmission, and Nrf2/HO-1 expression

Neuroinflammation contributes to the pathogenesis of several neurodegenerative disorders. This study examined the neuroprotective effect of quercetin (QUR)-loaded poly (lactic-co-glycolic) acid (PLGA) nanoparticles (QUR NANO) against the neurotoxicity induced by lipopolysaccharide (LPS) in mice. A QUR NANO formulation was prepared and characterized by differential scanning calorimetry, X-ray diffraction, entrapment efficiency (EE), high-resolution transmission electron microscopy, field emission scanning electron microscopy, and in vitro drug release profile. Levels of glutathione, malondialdehyde, catalase, inducible nitric oxide synthase (iNOS), amyloid beta 42 (Aβ42), β-secretase, gamma-aminobutyric acid (GABA), and acetylcholine esterase (AChE) were measured in the mouse brain tissues. The gene expression of nuclear factor erythroid-related factor 2 (Nrf-2) and heme oxygenase-1 (HO-1) were also determined. The prepared QUR NANO formulation showed 92.07 ± 3.21% EE and drug loading of 4.62 ± 0.55. It exhibited clusters of nano-spherical particles with smooth surface areas, and the loading process was confirmed. In vivo, the QUR NANO preserved the spatial memory of mice and protected the hippocampus from LPS-induced histological lesions. The QUR NANO significantly reduced the levels of malondialdehyde, iNOS, Aβ42, β-secretase, and AChE in brain tissue homogenates. Conversely, QUR NANO increased the glutathione, catalase, and GABA concentrations and upregulated the expression of Nrf-2 and HO-1 genes. Remarkably, the neuroprotective effect of QUR NANO was significantly greater than that of herbal QUR. In summary, the prepared QUR NANO formulation was efficient in mitigating LPS-induced neurotoxicity by reducing memory loss, oxidative stress, and amyloidogenesis while preserving neurotransmission and upregulating the expression of Nrf2 and HO-1 genes. This study addresses several key factors in neuroinflammatory disorders and explores the potential of QUR-loaded nanoparticles as a novel therapeutic approach to alleviate these factors.

Lipid Carrier Nanostructured Astilbin Ameliorates Rotenone-Induced Neurodegeneration in Mice Brain via Modulation of GSK3β-Nrf2 Signaling Pathways

Astilbin is a flavanonol, found in St John's wort (Hypericum perforatum) and many other plants. It has been demonstrated that astilbin contains anti-inflammatory, antioxidant, and immune-suppressive properties. However, the bioavailability of astilbin remains a question for which drug delivery-based nanoparticles can be utilized. We formulated a nanostructured lipid carrier loaded with astilbin (NLC-AS) and tested its effects on the rotenone exposed PC12 cells and in a neurodegenerative mice model of Parkinson's disease (PD) induced by rotenone. Results show that rotenone caused dose-dependent inhibition of PC12 cell growth with about 50% cell death at 2 µM rotenone. Rotenone caused apoptosis in PC12 cells which was reduced to a notable level by NLC-AS through suppression of oxidative stress, especially via elevation of GSH and total antioxidant capacity, and inhibition of monoamine oxidase. Rotenone significantly augmented neurodegeneration in mouse brains by triggering apoptosis and oxidative damage, while NLC-AS treatment halted these processes. Rotenone-exposed mice showed neuronal deficits and impaired neurocognitive functions like loss of memory and learning restrictions which were restored to a remarkable level by NLC-AS administration. The protective effect of NLC-AS was mediated through the inhibition of GSK3β and induction of Nrf2 genes in the brain tissues. These findings suggest that NLC-AS administration may efficiently regulate the signs of PD in mice and prevent neurodegeneration and neurocognitive dysfunctions.

Natural products for the treatment of neurodegenerative diseases

BACKGROUND

Neurodegenerative diseases are among the most common diseases in older adults worldwide. Alzheimer's disease (AD) and Parkinson's disease (PD) are two of the most common neurodegenerative diseases, and are accompanied by cerebral cortical atrophy, neuronal loss, protein accumulation, and excessive accumulation of metal ions. Natural products exhibit outstanding performance in improving cerebral circulatory disorders, promoting cerebral haematoma absorption, repairing damaged nerve tissue, and improving damaged nerve function. In recent years, studies have shown that neuroinflammatory mechanisms and signalling pathways closely related to the occurrence and development of neurological diseases include microglial activation, nuclear factor-κB (NF-κB) pathway, mitogen activated protein kinases (MAPK) pathway, reactive oxygen pathway, nucleotide binding oligomerisation domain-like receptor protein3 (NLRP3) inflammasomes, toll-like receptor4 (TLR4) pathway, nuclear factor erythroid 2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) pathway, phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway, and intestinal flora. Therefore, this study considered the mechanism of neurological diseases as the starting point to review the mechanism of action of natural products in the prevention and treatment of AD and PD in recent years to provide a theoretical basis for clinical prevention and treatment.

AIM

Natural products are a promising source of novel lead structures that have long been used to treat various nervous system diseases.

METHODOLOGY

This review collected literature on neurological diseases and natural products from 2012 to 2022, which were mainly searched through databases such as ScienceDirect, Springer, PubMed, SciFinder, China National Knowledge Infrastructure (CNKI), Wanfang, Google Scholar, and Baidu Academic. The following keywords were searched: neurological disorders, natural products, signalling pathway, mechanism of action.

RESULTS

This review summarises the pathogenesis of degenerative neurological diseases, recent findings on natural products used in neurodegenerative diseases, and the molecular mechanisms underlying these effects.

Polyherbal and Multimodal Treatments: Kaempferol- and Quercetin-Rich Herbs Alleviate Symptoms of Alzheimer's Disease

Alzheimer's Disease (AD) is a progressive neurodegenerative disorder impairing cognition and memory in the elderly. This disorder has a complex etiology, including senile plaque and neurofibrillary tangle formation, neuroinflammation, oxidative stress, and damaged neuroplasticity. Current treatment options are limited, so alternative treatments such as herbal medicine could suppress symptoms while slowing cognitive decline. We followed PRISMA guidelines to identify potential herbal treatments, their associated medicinal phytochemicals, and the potential mechanisms of these treatments. Common herbs, including Ginkgo biloba, Camellia sinensis, Glycyrrhiza uralensis, Cyperus rotundus, and Buplerum falcatum, produced promising pre-clinical results. These herbs are rich in kaempferol and quercetin, flavonoids with a polyphenolic structure that facilitate multiple mechanisms of action. These mechanisms include the inhibition of Aβ plaque formation, a reduction in tau hyperphosphorylation, the suppression of oxidative stress, and the modulation of BDNF and PI3K/AKT pathways. Using pre-clinical findings from quercetin research and the comparatively limited data on kaempferol, we proposed that kaempferol ameliorates the neuroinflammatory state, maintains proper cellular function, and restores pro-neuroplastic signaling. In this review, we discuss the anti-AD mechanisms of quercetin and kaempferol and their limitations, and we suggest a potential alternative treatment for AD. Our findings lead us to conclude that a polyherbal kaempferol- and quercetin-rich cocktail could treat AD-related brain damage.

Influence of chlorpyrifos exposure on UVB irradiation induced toxicity in human skin cells

BACKGROUND

Although chlorpyrifos (CPS) has been banned in many developed countries, it still remains one of the best-selling pesticides in the world. Widespread environmental and occupational exposure to CPS pose a serious risk to human health. Another environmental factor that can adversely affect human health is ultraviolet radiation B (UVB, 280-315 nm wave length). Here we attempt determine if exposure to CPS can modify toxic effects of UVB. Such situation might be a common phenomenon in agriculture workers, where exposure to both factors takes place.

METHODS

Two skin cell lines; namely human immortalized keratinocytes HaCaT and BJ human fibroblasts were used in this study. Cytotoxicity was investigated using a cell membrane damage detection assay (LDH Cytotoxicity Assay), a DNA damage detection assay (Comet Assay), an apoptosis induction detection assay (Apo-ONE Homogeneous Caspase-3/7 Assay) and a cell reactive oxygen species detection assay (ROS-Glo H2O2 assay). Cytokine IL-6 production was also measured in cells using an ELISA IL-6 Assay.

RESULTS

Pre-incubation of skin cells with CPS significantly increased UVB-induced toxicity at the highest UVB doses (15 and 20 mJ/cm2). Also pre-exposure of BJ cells to CPS significantly increased the level of DNA damage, except for 20 mJ/cm2 UVB. In contrast, pre-exposure of HaCaT cells, to CPS prior to UVB radiation did not cause any significant changes. A decrease in caspase 3/7 activity was observed in HaCaT cells pre-exposed to 250 µM CPS and 5 mJ/cm2 UVB. Meanwhile, no statistically significant changes were observed in fibroblasts. In HaCaT cells, pre-exposure to CPS resulted in a statistically significant increase in ROS production. Also, in BJ cells, similar results were obtained except for 20 mJ/cm2. Interestingly, CPS seems to inhibited IL-6 production in HaCaT and BJ cells exposed to UVB (in the case of HaCaT cells for all UVB doses, while for BJ cells only at 15 and 20 mJ/cm2).

CONCLUSIONS

In conclusion, the present study indicates that CPS may contribute to the increased UVB-induced toxicity in skin cells, which was likely due to the induction of ROS formation along with the generation of DNA damage. However, further studies are required to gain better understanding of the mechanisms involved.

Involvement of oxidative stress-related apoptosis in chlorpyrifos-induced cytotoxicity and the ameliorating potential of the antioxidant vitamin E in human glioblastoma cells

Organophosphate pesticides (OPs), which are among the most widely used synthetic chemicals for the control of a wide variety of pests, are however associated with various adverse reactions in animals and humans. Chlorpyrifos, an OP, has been shown to cause various health complications due to ingestion, inhalation, or skin absorption. The mechanisms underlying the adverse effect of chlorpyrifos on neurotoxicity have not been elucidated. Therefore, we aimed to determine the mechanism of chlorpyrifos-induced cytotoxicity and to examine whether the antioxidant vitamin E (VE) ameliorated these cytotoxic effects using DBTRG-05MG, a human glioblastoma cell line. The DBTRG-05MG cells were treated with chlorpyrifos, VE, or chlorpyrifos plus VE and compared with the untreated control cells. Chlorpyrifos induced a significant decrease in cell viability and caused morphological changes in treated cultures. Furthermore, chlorpyrifos led to the increased production of reactive oxygen species (ROS) accompanied by a decrease in the level of reduced glutathione. Additionally, chlorpyrifos induced apoptosis by upregulating the protein levels of Bax and cleaved caspase-9/caspase-3 and by downregulating the protein levels of Bcl-2. Moreover, chlorpyrifos modulated the antioxidant response by increasing the protein levels of Nrf2, HO-1, and NQO1. However, VE reversed the cytotoxicity and oxidative stress induced by chlorpyrifos treatment in DBTRG-05MG cells. Overall, these findings suggest that chlorpyrifos causes cytotoxicity through oxidative stress, a process that may play an important role in the development of chlorpyrifos-associated glioblastoma.

A review of how the saffron (Crocus sativus) petal and its main constituents interact with the Nrf2 and NF-κB signaling pathways

The primary by-product of saffron (Crocus sativus) processing is saffron petals, which are produced in large quantities but are discarded. The saffron petals contain a variety of substances, including alkaloids, anthocyanins, flavonoids, glycosides, kaempferol, and minerals. Pharmacological investigations revealed the antibacterial, antidepressant, antidiabetic, antihypertensive, antinociceptive, antispasmodic, antitussive, hepatoprotective, immunomodulatory, and renoprotective properties of saffron petals, which are based on their antioxidant, anti-inflammatory, and antiapoptotic effects. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway protects against oxidative stress, carcinogenesis, and inflammation. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB) is a protein complex involved in approximately all animal cells and participates in different biological procedures such as apoptosis, cell growth, development, deoxyribonucleic acid (DNA) transcription, immune response, and inflammation. The pharmacological properties of saffron and its compounds are discussed in this review, along with their associated modes of action, particularly the Nrf2 and NF-ĸB signaling pathways. Without considering a time constraint, our team conducted this review using search engines or electronic databases like PubMed, Scopus, and Web of Science. Saffron petals and their main constituents may have protective effects in numerous organs such as the brain, colon, heart, joints, liver, lung, and pancreas through several mechanisms, including the Nrf2/heme oxygenase-1 (HO-1)/Kelch-like ECH-associated protein 1 (Keap1) signaling cascade, which would then result in its antioxidant, anti-inflammatory, antiapoptotic, and therapeutic effects.

Correlation between total phenolic and flavonoid contents and biological activities of 12 ethanolic extracts of Iranian propolis

Propolis is a resinous substance produced by honey bees that is very popular as a natural remedy in traditional medicine. The current research is the first study on the biological properties of ethanolic extracts of propolis (EEP) from several different regions (12) of Iran. Total phenolic and flavonoid contents (TPC and TFC) of Iranian EEPs were variable between 26.59-221.38 mg GAE/g EEP and 4.8-100.03 mg QE/g EEP. The DPPH scavenging assay showed all the studied EEP samples, except for the sample with the lowest TPC and TFC (P6), have suitable antioxidant activity. All the EEPs inhibited both cholinesterase enzymes (acetylcholinesterase: AChE, butyrylcholinesterase: BuChE) but most of them exhibited a distinct selectivity over BuChE. Evaluation of the antibacterial activity of the EEP samples using four pathogenic bacteria (B. cereus, S. aureus, A. baumannii, and P. aeruginosa) demonstrated that the antibacterial properties of propolis are more effective on the gram-positive bacterium. Spearman correlation analysis showed a strong positive correlation between TPC and TFC of the Iranian EEPs and their antioxidant, anticholinesterase, and antibacterial activities. Considering that there is ample evidence of anticholinesterase activity of flavonoids and a significant correlation between the anticholinesterase activity of the studied Iranian EEPs and their total flavonoid content was observed, the interaction of 17 well-known propolis flavonoids with AChE and BuChE was explored using molecular docking. The results indicated that all the flavonoids interact with the active site gorge of both enzymes with high affinity. Summing up, the obtained results suggest that Iranian propolis possesses great potential for further studies.

Neurobehavioral Responses and Toxic Brain Reactions of Juvenile Rats Exposed to Iprodione and Chlorpyrifos, Alone and in a Mixture

Herein, male juvenile rats (23th postnatal days (PND)) were exposed to chlorpyrifos (CPS) (7.5 mg/kg b.wt) and/or iprodione (IPD) (200 mg IPD /kg b.wt) until the onset of puberty (60th day PND). Our results demonstrated that IPD and/or CPS exposure considerably reduced locomotion and exploration. However, CPS single exposure induced anxiolytic effects. Yet, neither IPD nor IPD + CPS exposure significantly affected the anxiety index. Of note, IPD and/or CPS-exposed rats showed reduced swimming time. Moreover, IPD induced significant depression. Nonetheless, the CPS- and IPD + CPS-exposed rats showed reduced depression. The individual or concurrent IPD and CPS exposure significantly reduced TAC, NE, and AChE but increased MDA with the maximum alteration at the co-exposure. Moreover, many notable structural encephalopathic alterations were detected in IPD and/or CPS-exposed rat brain tissues. The IPD + CPS co-exposed rats revealed significantly more severe lesions with higher frequencies than the IPD or CPS-exposed ones. Conclusively, IPD exposure induced evident neurobehavioral alterations and toxic reactions in the brain tissues. IPD and CPS have different neurobehavioral effects, particularly regarding depression and anxiety. Hence, co-exposure to IPD and CPS resulted in fewer neurobehavioral aberrations relative to each exposure. Nevertheless, their simultaneous exposure resulted in more brain biochemistry and histological architecture disturbances.

Neuroprotective Effect of Propolis Polyphenol-Based Nanosheets in Cellular and Animal Models of Rotenone-Induced Parkinson's Disease

Considering the central role of oxidative stress in the onset and progress of Parkinson's diseases (PD), search for compounds with antioxidant properties has attracted a growing body of attention. Here, we compare the neuroprotective effect of bulk and nano forms of the polyphenolic fraction of propolis (PFP) against rotenone-induced cellular and animal models of PD. Mass spectrometric analysis of PFP confirmed the presence of multiple polyphenols including kaempferol, naringenin, coumaric acid, vanillic acid, and ferulic acid. In vitro cellular experiments indicate the improved efficiency of the nano form, compared to the bulk form, of PFP in attenuating rotenone-induced cytotoxicity characterized by a decrease in cell viability, release of lactate dehydrogenase, increased ROS generation, depolarization of the mitochondrial membrane, decreased antioxidant enzyme activity, and apoptosis induction. In vivo experiments revealed that while no significant neuroprotection was observed relating to the bulk form, PFP nanosheets were very effective in protecting animals, as evidenced by the improved behavioral and neurochemical parameters, including decreased lipid peroxidation, increased GSH content, and antioxidant enzyme activity enhancement. We suggest that improved neuroprotective effects of PFP nanosheets may be attributed to their increased water solubility and enrichment with oxygen-containing functional groups (such as OH and COOH), leading to increased antioxidant activity of these compounds.

Neuroprotective effect of piracetam-loaded magnetic chitosan nanoparticles against thiacloprid-induced neurotoxicity in albino rats

Thiacloprid (TH) is a neurotoxic agricultural insecticide and potential food contaminant. The purpose of this study was to investigate the relationship between TH exposure and memory dysfunction in rats, as well as the potential protective effect of piracetam and piracetam-loaded magnetic chitosan nanoparticles (PMC NPs). Rats were divided into five equal groups (six rats/group). The control group received saline. Group II was treated with PMC NPs at a dose level of 200 mg/kg body weight (Bwt); Group III was treated with 1/10 LD₅₀ of TH (65 mg/kg Bwt); Group IV was treated with TH (65 mg/kg Bwt) and piracetam (200 mg/kg Bwt); Group V was co-treated with TH (65 mg/kg Bwt) and PMC NPs (200 mg/kg Bwt). All animal groups were dosed daily for 6 weeks by oral gavage. Footprint analysis, hanging wire test, open field test, and Y-maze test were employed to assess behavioral deficits. Animals were euthanized, and brain tissues were analyzed for oxidative stress biomarkers, proinflammatory cytokines, and gene expression levels of glial fibrillary acidic protein (GFAP), amyloid-beta precursor protein (APP), B-cell lymphoma 2 (Bcl-2), and caspase-3. Brain and sciatic nerve tissues were used for the evaluation of histopathological changes and immunohistochemical expression of tau protein and nuclear factor kappa B (NF-κB), respectively. The results revealed that TH-treated rats suffered from oxidative damage and inflammatory effect on the central and peripheral nerves. The administration of PMC NPs considerably protected against TH-induced neuronal damage, increased antioxidant enzyme activity, decreased inflammatory markers, and improved behavioral performance than the group treated with piracetam. The neuroprotective effect of PMC NPs was mediated through the inhibition of GFAP, APP, caspase-3, Tau, and NF-κB gene expression with induction of Bcl-2 expression. In conclusion, TH could induce oxidative stress, inflammatory and neurobehavior impairment in rats. However, PMC NPs administration markedly mitigated TH-induced brain toxicity, possibly via oxidative and inflammatory modulation rather than using piracetam alone.

Pesticides as a risk factor for cognitive impairment: Natural substances are expected to become alternative measures to prevent and improve cognitive impairment

Pesticides are the most effective way to control diseases, insects, weeds, and fungi. The central nervous system (CNS) is damaged by pesticide residues in various ways. By consulting relevant databases, the systemic relationships between the possible mechanisms of pesticides damage to the CNS causing cognitive impairment and related learning and memory pathways networks, as well as the structure-activity relationships between some natural substances (such as polyphenols and vitamins) and the improvement were summarized in this article. The mechanisms of cognitive impairment caused by pesticides are closely related. For example, oxidative stress, mitochondrial dysfunction, and neuroinflammation can constitute three feedback loops that interact and restrict each other. The mechanisms of neurotransmitter abnormalities and intestinal dysfunction also play an important role. The connection between pathways is complex. NMDAR, PI3K/Akt, MAPK, Keap1/Nrf2/ARE, and NF-κB pathways can be connected into a pathway network by targets such as Ras, Akt, and IKK. The reasons for the improvement of natural substances are related to their specific structure, such as polyphenols with different hydroxyl groups. This review's purpose is to lay a foundation for exploring and developing more natural substances that can effectively improve the cognitive impairment caused by pesticides.

Mentha rotundifolia (L.) Huds. aqueous extract attenuates H2O2 induced oxidative stress and neurotoxicity

Introduction

Oxidative stress plays a causal role in neurodegenerative diseases. The aim of this study is to evaluate the antioxidant and neuroprotective effects of Mentha rotundifolia (L.) Huds (M. rotundifolia), a widely used Moroccan plant in traditional medicine.

Methods

The chemical composition of M. rotundifolia aqueous extract was analyzed by liquid chromatography coupled to mass spectrometry (LC-MS). 2,2-diphenyl 1-picrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺) assays were used to assess its in vitro antioxidant activity. H₂O₂ was utilized to induce oxidative stress and neurotoxicity in vivo. Behavioral changes were evaluated using Open Field, Y-maze and Rotarod tests. Hyperalgesia was assessed using the tail immersion test.

Results and discussion

The LC-MS/MS analysis revealed high content of kaempferol glucuronide (85%) at the extract. IC₅₀ values of the DPPH and ABTS were 26.47 and 41.21 μg/mL, respectively. Pre-treatments with M. rotundifolia extract attenuated the behavioral changes induced by H₂O₂. In addition, the latency of tail withdrawal increased significantly in the treated groups suggesting central analgesic effect of M. rotundifolia extract. Moreover, the extract attenuated the deleterious effects of H₂O₂ and improved all liver biomarkers. The obtained results suggested that M. rotundifolia had remarkable antioxidant and neuroprotective effects and may prevent oxidative stress related disorders.

Potential molecular mechanisms of Erlongjiaonang action in idiopathic sudden hearing loss: A network pharmacology and molecular docking analyses

Background

Idiopathic sudden hearing loss (ISHL) is characterized by sudden unexplainable and unilateral hearing loss as a clinically emergent symptom. The use of the herb Erlongjiaonang (ELJN) in traditional Chinese medicine is known to effectively control and cure ISHL. This study explored the underlying molecular mechanisms using network pharmacology and molecular docking analyses.

Method

The Traditional Chinese Medicine System Pharmacological database and the Swiss Target Prediction database were searched for the identification of ELJN constituents and potential gene targets, respectively, while ISHL-related gene abnormality was assessed using the Online Mendelian Inheritance in Man and Gene Card databases. The interaction of ELJN gene targets with ISHL genes was obtained after these databases were cross-screened, and a drug component-intersecting target network was constructed, and the gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes, and protein-protein interaction networks were analyzed. Cytoscape software tools were used to map the active components-crossover target-signaling pathway network and screened targets were then validated by establishing molecular docking with the corresponding components.

Result

Erlongjiaonang contains 85 components and 250 corresponding gene targets, while ISHL has 714 disease-related targets, resulting in 66 cross-targets. The bioinformatical analyses revealed these 66 cross-targets, including isorhamnetin and formononetin on NOS3 expression, baicalein on AKT1 activity, and kaempferol and quercetin on NOS3 and AKT1 activity, as potential ELJN-induced anti-ISHL targets.

Conclusion

This study uncovered potential ELJN gene targets and molecular signaling pathways in the control of ISHL, providing a molecular basis for further investigation of the anti-ISHL activity of ELJN.

Flavonoids and saponins: What have we got or missed?

BACKGROUND

Flavonoids and saponins are important bioactive compounds that have attracted wide research interests. This review aims to summarise the state of the art of the pharmacology, toxicology and clinical efficacy of these compounds.

METHODS

Data were retrieved from PubMed, Cochrane Library, Web of Science, Proquest, CNKI, Chongqing VIP, Wanfang, NPASS and HIT 2.0 databases. Meta-analysis and systematic reviews were evaluated following the PRISMA guideline. Statistical analyses were conducted using SPSS23.0.

RESULTS

Rising research trends on flavonoids and saponins were observed since the 1990s and the 2000s, respectively. Studies on pharmacological targets and activities of flavonoids and saponins represent an important area of research advances over the past decade, and these important resources have been documented in open-access specialised databases and can be retrieved with ease. The rising research on flavonoids and saponins can be attributed, at least in part, to their links with some highly investigated fields of research, e.g., oxidative stress, inflammation and cancer; i.e., 6.88% and 3.03% of publications on oxidative stress cited by PubMed in 1990 - 2021 involved flavonoids and saponins, respectively, significantly higher than the percentage involving alkaloids (1.88%). The effects of flavonoids concern chronic venous insufficiency, cervical lesions, diabetes, rhinitis, dermatopathy, prostatitis, menopausal symptoms, angina pectoris, male pattern hair loss, lymphocytic leukaemia, gastrointestinal diseases and traumatic cerebral infarction, etc, while those of saponins may have impact on venous oedema in chronic deep vein incompetence, erectile dysfunction, acute impact injuries and systemic lupus erythematosus, etc. The volume of in vitro research appears way higher than in vivo and clinical studies, with only 10 meta-analyses and systematic reviews (involving 290 interventional and observational studies), and 36 clinical studies on flavonoids and saponins. Data are sorely needed on pharmacokinetics, in vitro pan-assay interferences, purity of tested compounds, interactions in complex herbal extracts, real impact of anti-oxidative strategies, and mid- and long-term toxicities. To fill these important gaps, further investigations are warranted. On the other hand, drug interactions may cause adverse effects but might also be useful for synergism, with the goals of enhancing effects or of detoxifying. Furthermore, the interactions between phytochemicals and the intestinal microbiota are worth investigating as the field may present a promising potential for novel drug development.

A comprehensive and mechanistic review on protective effects of kaempferol against natural and chemical toxins: Role of NF-κB inhibition and Nrf2 activation

Different toxins, including chemicals and natural, can be entered from various routes and influence human health. Herbal medicines and their active components can attenuate the toxicity of agents via multiple mechanisms. For example, kaempferol, as a flavonoid, can be found in fruits and vegetables, and has an essential role in improving disorders such as cardiovascular disorders, neurological diseases, cancer, pain, and inflammation situations. The beneficial effects of kaempferol may be related to the inhibition of oxidative stress, attenuation of inflammatory factors such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and nuclear factor ĸB (NF-ĸB) as well as the modulation of apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways. This flavonoid boasts a wide spectrum of toxin targeting effects in tissue fibrosis, inflammation, and oxidative stress thus shows promising protective effects against natural and chemical toxin induced hepatotoxicity, nephrotoxicity, cardiotoxicity, neurotoxicity, lung, and intestinal in the in vitro and in vivo setting. The most remarkable aspect of kaempferol is that it does not focus its efforts on just one organ or one molecular pathway. Although its significance as a treatment option remains questionable and requires more clinical studies, it seems to be a low-risk therapeutic option. It is crucial to emphasize that kaempferol's poor bioavailability is a significant barrier to its use as a therapeutic option. Nanotechnology can be a promising way to overcome this challenge, reviving optimism in using kaempferol as a viable treatment agent against toxin-induced disorders.

Piceatannol protects rat neuron cells from oxygen-glucose deprivation reperfusion injury via regulation of GSK-3β/Nrf2 signaling pathway

OBJECTIVE

To investigate the effect and mechanism of piceatannol on cerebral ischemia-reperfusion injury.

METHODS

The oxygen-glucose deprivation reperfusion (OGD/R) model was constructed in primary cultured suckling rat cortical neuron cells. After 2 h of oxygen-glucose deprivation, the cells were treated with piceatannol for 24 h. The cell survival rate was detected by MTT assay, and the degree of cell damage was detected by intracellular lactate dehydrogenase (LDH) release assay. The activity of superoxide dismutase (SOD) and the content of adenosine triphosphate (ATP) were detected by colorimetric method. The content of reactive oxygen species (ROS) was detected by flow cytometry or observed with inverted fluorescence microscope. The ultrastructure of mitochondria was observed with transmission electron microscopy. Western blotting was used to detect the phosphorylation levels of protein kinase B (AKT) and glycogen synthase kinase (GSK)-3β. Immunofluorescence staining was used to observe the nuclear localization of nuclear factor-erythroid 2-related factor (Nrf) 2. After OGD/R neuron cells were pretreated with Nrf2 inhibitor ML385 for 24 h, the effect of Nrf2 on the improvement of cell activity and antioxidant activity of piceatannol were investigated. Western blotting was used to detect the protein expression levels of Nrf2, heme oxygenase (HO) 1 and NADPH quinone oxidoreductase (NQO) 1.

RESULTS

Piceatannol significantly increased the survival rate of OGD/R neurons, decreased LDH release and reactive oxygen species content, increased SOD activity, ameliorated mitochondrial ultrastructural damage, increased mitochondrial membrane potential and ATP level (all P<0.05), increased phosphorylation of AKT and GSK-3β protein, up-regulated the expression of Nrf2, HO-1 and NQO1 protein, increased the nuclear-to-plasma ratio of Nrf2, and promoted the nuclear transfer of Nrf2 (all P<0.05). ML385 could significantly reverse the rescue effect of paclitaxel on the model cells and the regulatory activities of SOD, ROS and LDH (all P<0.05).

CONCLUSION

Piceatannol can regulate Nrf2 by activating GSK-3β signaling pathway, promote its nuclear translocation, exert corresponding antioxidant effect, and protect mitochondrial structure and function in rat neuron cells.

Neuroprotective efficacy of berberine following developmental exposure to chlorpyrifos in F1 generation of Wistar rats: Apoptosis-autophagy interplay

Chlorpyrifos (CPF), an organophosphate insecticide commonly used in agriculture and household applications, is considered a developmental neurotoxicant. This study aimed to explain the neuroprotective role of Berberine (BBR) against CPF-induced autophagy dysfunction and apoptotic neurodegeneration in the developing hippocampus. F1 generation of Wistar rats was exposed to CPF (3 mg/kg b.wt.) and co-treated with BBR (10 mg/kg b.wt) in two different exposure regimens, gestational (GD9-12 and GD17-21) and lactational (PND1-20). Our results demonstrated that CPF intoxication instigated cognitive and neurobehavioral impairment, oxidant-antioxidant imbalance, and histomorphological alterations in CA1, CA3, and DG regions of the offsprings. Furthermore, mRNA expression of pro-apoptotic genes (caspase3 and Bax) was upregulated, and that of anti-apoptotic BCl₂ was downregulated. In addition, exposure to CPF also activated the autophagy inhibitor (mTOR) transcription and subsequently downregulated the expression of autophagy markers beclin1 and LC3-II. In contrast, gestational and lactational co-treatment of BBR significantly upregulated the enzymatic anti-oxidant bar of the hippocampus and attenuated histological alterations. Moreover, BBR co-treatments reduced apoptotic neurodegeneration in the hippocampal region by regulating the expression of apoptotic genes and upregulated the levels of autophagy, confirmed by ultrastructural studies, decreased gene expression and immunostaining of mTOR and increased, and increased expression gene expression and immunostaining of LC3-II positive cells. Our results confirm that treatment with BBR induces autophagy, which plays a neuroprotective role in CPF-induced developmental neuronal apoptosis in the F1 generation of Wistar rats by regulating the balance between autophagy and apoptosis.

Toxicity Profiles of Kleeb Bua Daeng Formula, a Traditional Thai Medicine, and Its Protective Effects on Memory Impairment in Animals

Kleeb Bua Daeng (KBD) formula has long been used in Thailand as a traditional herbal medicine for promoting brain health. Our recent reports illustrated that KBD demonstrates multiple modes of action against several targets in the pathological cascade of Alzheimer’s disease (AD). The main purpose of the present study was to determine the protective effect and mechanism of KBD in amyloid beta (Aβ)-induced AD rats and its toxicity profiles. Pretreatment with the KBD formula for 14 days significantly improved the short- and long-term memory performance of Aβ-induced AD rats as assessed by the Morris Water Maze (MWM) and object-recognition tests. KBD treatment increased the activities of the antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase; reduced the malondialdehyde content, and; decreased the acetylcholinesterase activity in the rat brain. An acute toxicity test revealed that the maximum dose of 2000 mg/kg did not cause any mortality or symptoms of toxicity. An oral, subchronic toxicity assessment of KBD at doses of 125, 250, and 500 mg/kg body weight/day for 90 days showed no adverse effects on behavior, mortality, hematology, or serum biochemistry. Our investigations indicate that KBD is a nontoxic traditional medicine with good potential for the prevention and treatment of AD.

Phenolic Characterization Using cLC-DAD Analysis and Evaluation of In Vitro and In Vivo Pharmacological Activities of Ruta tuberculata Forssk

The perennial aromatic plant Ruta tuberculata Forssk (Rutaceae) has been traditionally used by Mediterranean peoples as folk medicine against several types of disease to treat diverse illness. The objective of this work is to evaluate the in vitro and in vivo pharmacological activities of the aqueous (RAE) and methanolic (MeOH) 80% (RME) extracts of Algerian R. tuberculata aerial parts. Antioxidant potential, neuro-protective and anti-arthritic activities were investigated in vitro using six antioxidant approaches and by determining acetyl-cholinesterase and bovine albumin denaturation inhibitory capacities, respectively. Furthermore, in vivo anti-ulcer and anti-inflammatory activities were evaluated on EtOH-induced gastric mucosal damage and carrageenan-induced paw edema models in mice. Moreover, bio-compounds’ contents were also quantified using spectrophotometric and cLC-DAD methods. Both in vivo and in vitro investigations showed remarkable antioxidant activity of Ruta tuberculata Forssk, while methanolic extract (RME) of Ruta tuberculata Forssk exhibited more significant neuro-protective and anti-inflammatory effects. However, the antiulcer activity was more pronounced with RAE of R. tuberculata, which suggests that this plant can be considered as a natural resource of potent bioactive compounds that may act as antioxidant and anti-inflammatory agents, which underlines the importance of incorporating them in therapies in order to treat various diseases linked to oxidative stress, and they may also provide crucial data for the development of new anticholinesterase drugs to improve neurodegenerative diseases, such as Alzheimer’s.

The Therapeutic Potential of Kaemferol and Other Naturally Occurring Polyphenols Might Be Modulated by Nrf2-ARE Signaling Pathway: Current Status and Future Direction

Kaempferol is a natural flavonoid, which has been widely investigated in the treatment of cancer, cardiovascular diseases, metabolic complications, and neurological disorders. Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor involved in mediating carcinogenesis and other ailments, playing an important role in regulating oxidative stress. The activation of Nrf2 results in the expression of proteins and cytoprotective enzymes, which provide cellular protection against reactive oxygen species. Phytochemicals, either alone or in combination, have been used to modulate Nrf2 in cancer and other ailments. Among them, kaempferol has been recently explored for its anti-cancer and other anti-disease therapeutic efficacy, targeting Nrf2 modulation. In combating cancer, diabetic complications, metabolic disorders, and neurological disorders, kaempferol has been shown to regulate Nrf2 and reduce redox homeostasis. In this context, this review article highlights the current status of the therapeutic potential of kaempferol by targeting Nrf2 modulation in cancer, diabetic complications, neurological disorders, and cardiovascular disorders. In addition, we provide future perspectives on kaempferol targeting Nrf2 modulation as a potential therapeutic approach.

Kaempferol: A flavonoid with wider biological activities and its applications

Kaempferol and its derivatives are naturally occurring phytochemicals with promising bioactivities. This flavonol can reduce the lipid oxidation in the human body, prevent the organs and cell structure from deterioration and protect their functional integrity. This review has extensively highlighted the antioxidant, antimicrobial, anticancer, neuroprotective, and hepatoprotective activity of kaempferol. However, poor water solubility and low bioavailability of kaempferol greatly limit its applications. The utilization of advanced delivery systems can improve its stability, efficacy, and bioavailability. This is the first review that aimed to comprehensively collate some of the vital information published on biosynthesis, mechanism of action, bioactivities, bioavailability, and toxicological potential of kaempferol. Besides, it provides insights into the future direction on the improvement of bioavailability of kaempferol for wide applications.

Modulatory Effect of Papaya Extract against Chlorpyrifos-Induced Oxidative Stress, Immune Suppression, Endocrine Disruption, and DNA Damage in Female Clarias gariepinus

Chlorpyrifos (CPF) is one of the widely used organophosphorus pesticides in agriculture activities and its presence in the aquatic environment has been broadly recorded. In the present study, we investigated the effect of CPF exposure on oxidative stress, innate immunity, sexual hormones, and DNA integrity of female African catfish, Clarias gariepinus, in addition to the potential use of dietary supplementation of papaya, Carica papaya (CP), extract against CPF toxicity. Apparent healthy female catfish (300 ± 10 g) were divided into four groups with three replicates each. The first group served as the negative control (fed on a basal diet) and the other groups exposed to CPF (8.75 µg/L) with or without CP extract (250 mg/kg body weight) for six weeks. The results revealed that CPF exposure exhibited marked elevations in stress markers (glucose and cortisol), serum aspartate aminotransferase, alanine aminotransferase activities, testosterone, and luteinizing hormone level. Moreover, CPF increased the percentage of hepatic DNA damage. In addition, catfish exposed to CPF experienced significant decline in serum total protein, albumin, follicles stimulating hormone, estradiol hormone levels, AChE, immunoglobulin, and lysozyme activity. CPF induced significantly oxidative stress in hepatic and renal tissues. The dietary supplementation with CP extract at a level of 250 mg/kg body weight succeeded to alleviate the negative effects of CPF on the physiological, immunological, and antioxidant status of female catfish. In addition, CP extract alleviated the endocrine disruption and hepatic DNA damage and counteracted the subchronic CPF toxicity in female African catfish. Finally, the CP extract may be used as a feed additive in the aquatic diet.

Protective Effect of Portulaca oleracea Extract Against Lipopolysaccharide-Induced Neuroinflammation, Memory Decline, and Oxidative Stress in Mice: Potential Role of miR-146a and miR-let 7

Neuroinflammation is an adaptive immune response to the central nervous system (CNS) injury induced by infection or toxins. MicroRNAs (miRs) showed critical roles in neuroinflammation as either proinflammatory or anti-inflammatory molecules. Interestingly, Portulaca oleracea (purslane) is an edible plant capable of ameliorating several diseases, including headache, burns, and diabetes; however, its effect on the neuroinflammation-associated miRs was not previously investigated. This study aimed to investigate the effect of aqueous purslane extract on the neuroinflammation induced by lipopolysaccharide (LPS) in mice and to identify its effect on animal cognition, oxidative stress, and expressions of miR-146a and miR-let 7. Adult mice were divided into the following groups: Normal group, LPS group, and Purslane+LPS group. Novel target recognition test, brain histopathology, and measurement of oxidative stress and inflammatory markers were performed. The results showed that LPS group exhibited significant decline in the cognitive memory, brain histopathological injury and a decrease in the number of intact neurons compared to the normal group. Furthermore, the LPS group showed a significant increase in malondialdehyde concentration, whereas superoxide dismutase and catalase activities were decreased. The LPS group also showed an increase in the inflammatory markers tumor necrosis factor-α and nuclear factor kappa B and downregulation of miR-146a and miR-let 7 expressions in the brain cells compared to the normal group, P value <.05. Interestingly, all these changes were reversed by administration of the aqueous purslane extract. In conclusion, the aqueous purslane extract protected from LPS-induced neuroinflammation and memory decline in mice through antioxidant and anti-inflammatory effect where upregulation of miR-146a and miR-1et 7 expressions was involved.

Kaempferol prevents cadmium chloride-induced liver damage by upregulating Nrf2 and suppressing NF-κB and keap1

This study evaluated the protective effect of kaempferol, a natural flavonoid, against cadmium chloride (CdCl₂)-induced liver damage and examined the possible anti-inflammatory and antioxidant mechanisms of protection. Adult male rats were divided into 4 groups (each of 8 rats) as control, kaempferol (50 mg/kg/day orally), CdCl₂ (15 ppm/day), and CdCl₂ (15 ppm/day) + kaempferol (50 mg/kg/day). All treatments were given for 30 days. With no effect on attenuating the reduced food intake, kaempferol significantly increased body weight and lowered serum levels of liver injury markers including bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase 1 (γ-GTT1) in the CdCl₂-treated rats. It also restored normal liver architectures, prevented hepatocyte, loss, and swelling and reduced inflammatory cell infiltration. These effects were associated with a reduction in mitochondrial permeability transition pore, as well as in the expression of cytochrome-c and cleaved caspase-3, markers of mitochondrial damage, and intrinsic cell death. In both the control positive and CdCl₂-treated rats, kaempferol significantly lowered the hepatic levels of reactive oxygen species, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), Interleukine-6 (IL-6), and the nuclear activity and localization of NF-κB p65. Besides, kaempferol significantly increased the hepatic total and nuclear levels of the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1, as well as levels of superoxide dismutase (SOD) and reduced glutathione (GSH) but reduced the cytoplasmic protein levels of keap1. In conclusion, the protective effect of kaempferol against CdCl₂-induced hepatic damage is mediated by antioxidant and anti-inflammatory effects driven by upregulating Nrf2/HO-1 axis and suppressing the NF-κB p65 and keap1.

Therapeutic Strategies Targeting Mitochondrial Calcium Signaling: A New Hope for Neurological Diseases?

Calcium (Ca²⁺) is a versatile secondary messenger involved in the regulation of a plethora of different signaling pathways for cell maintenance. Specifically, intracellular Ca²⁺ homeostasis is mainly regulated by the endoplasmic reticulum and the mitochondria, whose Ca²⁺ exchange is mediated by appositions, termed endoplasmic reticulum-mitochondria-associated membranes (MAMs), formed by proteins resident in both compartments. These tethers are essential to manage the mitochondrial Ca²⁺ influx that regulates the mitochondrial function of bioenergetics, mitochondrial dynamics, cell death, and oxidative stress. However, alterations of these pathways lead to the development of multiple human diseases, including neurological disorders, such as amyotrophic lateral sclerosis, Friedreich's ataxia, and Charcot-Marie-Tooth. A common hallmark in these disorders is mitochondrial dysfunction, associated with abnormal mitochondrial Ca²⁺ handling that contributes to neurodegeneration. In this work, we highlight the importance of Ca²⁺ signaling in mitochondria and how the mechanism of communication in MAMs is pivotal for mitochondrial maintenance and cell homeostasis. Lately, we outstand potential targets located in MAMs by addressing different therapeutic strategies focused on restoring mitochondrial Ca²⁺ uptake as an emergent approach for neurological diseases.

Neurodegenerative Diseases and Flavonoids: Special Reference to Kaempferol

Neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, Huntington's disease, Multiple Sclerosis and Ischemic stroke have become a major health problem worldwide. Pre-clinical studies have demonstrated the beneficial effects of flavonoids on neurodegenerative diseases and suggest them to be used as therapeutic agents. Kaempferol is found in many plants such as tea, beans, broccoli, strawberries, and neuroprotective effects against the development of many neurodegenerative diseases such as Parkinson, Alzheimer's disease and Huntington's disease. The present study summarizes the neuroprotective effects of kaempferol in various models of neurodegenerative diseases. Kaempferol delays the initiation as well as the progression of neurodegenerative disorders by acting as a scavenger of free radicals and preserving the activity of various antioxidant enzymes. Kaempferol can cross the Blood-Brain Barrier (BBB), and therefore results in an enhanced protective effect. The multi-target property of kaempferol makes it a potential dietary supplement in preventing and treating neurodegenerative diseases.

Kaemperfol alleviates pyroptosis and microglia-mediated neuroinflammation in Parkinson's disease via inhibiting p38MAPK/NF-κB signaling pathway

The study aims to investigate whether kaemperfol (KAE) inhibits microglia pyroptosis and subsequent neuroinflammatory response to exert neuroprotective effects, along with the underlying mechanisms. The results showed KAE could ameliorate the behavioral deficits of Parkinson's disease (PD) rats, inhibit the activation of microglia and astrocytes, reduce the loss of TH-positive neurons, down-regulate levels of pyroptosis-related NOD-like receptor family pyrin domain containing 3 (NLRP3), GasderminD-N Term (GSDMD-NT), caspase1, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), interleukin (IL)-1β, and IL-18, and decrease the levels of inflammatory molecules (inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2)) and p38 mitogen-activated protein kinase/nuclear factor-kappaB (p38MAPK/NF-κB) signaling pathway molecules (p38MAPK, p-p38MAPK, NF-κB, and p-NF-κB) in the substantia nigra of PD rats. Further in vitro study indicated that KAE reversed the activation of BV2 cells and down-regulated the expressions of pyrolytic proteins, inflammatory mediators and key molecules in p38MAPK/NF-κB signaling pathway. Collectively, KAE inhibits the microglia pyroptosis and subsequent neuroinflammatory response to exert neuroprotective effects on 6-hydroxydopamine (6-OHDA)-induced PD rats and lipopolysaccharide (LPS)-induced BV2 inflammatory cells through inhibiting p38MAPK/NF-κB signaling pathway.

Jeopardy of COVID-19: Rechecking the Perks of Phytotherapeutic Interventions

The novel coronavirus disease (COVID-19), the reason for worldwide pandemic, has already masked around 220 countries globally. This disease is induced by Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2). Arising environmental stress, increase in the oxidative stress level, weak immunity and lack of nutrition deteriorates the clinical status of the infected patients. Though several researches are at its peak for understanding and bringing forward effective therapeutics, yet there is no promising solution treating this disease directly. Medicinal plants and their active metabolites have always been promising in treating many clinical complications since time immemorial. Mother nature provides vivid chemical structures, which act multi-dimensionally all alone or synergistically in mitigating several diseases. Their unique antioxidant and anti-inflammatory activity with least side effects have made them more effective candidate for pharmacological studies. These medicinal plants inhibit attachment, encapsulation and replication of COVID-19 viruses by targeting various signaling molecules such as angiotensin converting enzyme-2, transmembrane serine protease 2, spike glycoprotein, main protease etc. This property is re-examined and its potency is now used to improve the existing global health crisis. This review is an attempt to focus various antiviral activities of various noteworthy medicinal plants. Moreover, its implications as prophylactic or preventive in various secondary complications including neurological, cardiovascular, acute kidney disease, liver disease are also pinpointed in the present review. This knowledge will help emphasis on the therapeutic developments for this novel coronavirus where it can be used as alone or in combination with the repositioned drugs to combat COVID-19.

Iprodione and/or chlorpyrifos exposure induced testicular toxicity in adult rats by suppression of steroidogenic genes and SIRT1/TERT/PGC-1α pathway

There is cumulative evidence that iprodione (IPR) fungicide and chlorpyrifos (CPF) insecticide are endocrine disruptors that can evoke reproductive toxicity. Yet, the underlying mechanisms are still unclear. Besides, the outcomes of their co-exposure to male sexual behavior and male fertility are still unknown. The effects of IPR (200 mg/kg b.wt) and CPF (7.45 mg/kg b.wt) single or mutual exposure for 65 days on sexual behavior, sex hormones, testicular enzymes, testis, and accessory sex gland histomorphometric measurements, apoptosis, and oxidative stress biomarkers were investigated. In addition, expression of nuclear receptor subfamily group A (NR5A1), 17β-hydroxysteroid dehydrogenase (HSD17B3), silent information regulator type-1 (SIRT1), telomerase reverse transcriptase (TERT), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) genes has been assessed. Our results revealed that the individual or concurrent IPR and CPF exposure significantly disturb the sexual behavior, semen characteristics, testicular enzymes, and male hormones level. Oxidative stress caused by IPR and CPF activates apoptosis by inducing Caspase-3 and reducing Bcl-2. Downregulation of HSD17B3, NR5A1, and SIRT1/TERT/PGC-1α pathway was evident. Of note, most of these disturbances were exaggerated in rats co-exposed to IPR and CPF compared to IPR or CPF alone. Conclusively, our findings verified that IPR and CPF possibly damage the male reproductive system, and concurrent exposure should be avoided.

Antioxidant and Anti-Inflammatory Potential of Thymoquinone and Lycopene Mitigate the Chlorpyrifos-Induced Toxic Neuropathy

CPF (chlorpyrifos) is an organophosphate pesticide used in agricultural and veterinary applications. Our experiment aimed to explore the effects of thymoquinone (TQ) and/or lycopene (LP) against CPF-induced neurotoxicity. Wistar rats were categorized into seven groups: first group served as a control (corn oil only); second group, TQ (10 mg/kg); third group, LP (10 mg/kg); fourth group, CPF (10 mg/kg) and deemed as CPF toxic control; fifth group, TQ + CPF; sixth group, (LP + CPF); and seventh group, (TQ + LP + CPF). CPF intoxication inhibited acetylcholinesterase (AchE), decreased glutathione (GSH) content, and increased levels of malondialdehyde (MDA), an oxidative stress biomarker. Furthermore, CPF impaired the activity of antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT) along with enhancement of the level of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β. CPF evoked apoptosis in brain tissue. TQ or LP treatment of CPF-intoxicated rats greatly improved AchE activity, oxidative state, inflammatory responses, and cell death. Co-administration of TQ and LP showed better restoration than their sole treatment. In conclusion, TQ or LP supplementation may alleviate CPF-induced neuronal injury, most likely due to TQ or LPs' antioxidant, anti-inflammatory, and anti-apoptotic effects.

Study on the Antianxiety Mechanism of Suanzaoren Decoction Based on Network Pharmacology and Molecular Docking

Objective. Suanzaoren Decoction (SZRT) is a classic decoction to calm the nerves in traditional Chinese medicine (TCM). It has been extensively treated as an antianxiety drug in modern times, but the material basis and pharmacological mechanisms are still unclear. To explore the material basis and corresponding potential targets, as well as to elucidate the mechanism of SZRT, network pharmacology and molecular docking methods were utilized. Methods. The main chemical compounds and potential targets of SZRT were collected from the pharmacological database analysis platform (TCMSP). Anxiety targets were obtained from the GeneCards database. Then, a target compound network was established using overlapping genes and the corresponding potential compounds. Protein interaction analysis, GO enrichment, and KEGG pathway enrichment were performed using the STRING database, DAVID database, and KOBAS database. Finally, molecular docking was conducted between MAOB and its corresponding active compound in SZRT to further verify the results. Results. A total of 137 active components in SZRT were screened from the TCMSP database, and 210 corresponding targets were predicted. A total of 5434 anxiety-related targets were obtained from the disease target database, and finally 22 potential targets of SZRT on antianxiety were obtained. The constructed C-T network showed that the average degree of active components was 5.4, and four of them interacted with six or more targets. PPI analysis shows that key genes such as MAOA, MAOB, IL1B, TNF, NR3CI, and HTR3A were identified as potential therapeutic targets. A pathway analysis showed that SZRT may participate in neurotransmitter regulation and immunoregulation in a synergistic way to treat anxiety. The binding energy between the active compounds and MAOB was low, indicating good binding. The results of molecular docking showed that all the 10 active ingredients were able to successfully dock with MAOB, and the binding energy of coumaroyltyramine with MAOB was the lowest, that is, −9.6 kcal/mol, and the binding method was hydrogen bonding. Conclusions. SZRT produces antianxiety effects mainly by affecting the neurotransmitter release, transmission, and immunoregulation. This study provides a new approach to elucidating the molecular mechanism and material basis of SZRT in the treatment of anxiety, and it will also benefit the application of TCM in modern medicine.

Elucidation of glycosylation sites of kaempferol di-O-glycosides from methanolic extract of the leaves of Prunus domestica subsp. syriaca

RATIONALE

Flavonol glycosides containing the glycosylation patterns 3,4'-di-O and 4',7-di-O are rare in nature and they have not yet been studied in detail by electrospray ionization mass spectrometry (ESI-MS(+/-), in contrast to the flavonol glycosides containing the glycosylation pattern 3,7-di-O.

METHOD

The leaves from Prunus domestica L. subsp. syriaca were extracted with pure methanol or, in order to perform hydrolysis and extraction simultaneously, with a 5% methanolic solution of hydrochloric acid. The high-performance liquid chromatography (HPLC)/ESI-MS(+/-) analyses were performed using a Waters model 2690 HPLC pump and a Waters/Micromass ZQ2000 mass spectrometer.

RESULTS

Three kinds of kaempferol di-O-glycosides have been identified, namely kaempferol-3-O-hexoside-7-O-rhamnosides, kaempferol-3-O-pentoside-4'-O-rhamnosides and kaempferol 4',7-di-O-rhamnoside. The identification was performed on the basis of the abundances of the respective Y-type product ions.

CONCLUSIONS

The abundances of [Yⁿ ₀ - H]^-· , Yⁿ ₀ ^- and Yⁿ ₀ ⁺ product ions were of crucial importance for the determination of glycosylation patterns. The obtained results can be useful for HPLC/ESI-MS identification of rare flavonol-di-O-glycosides.

Investigation of possible neuroprotective effects of some plant extracts on brain in bile duct ligated rats

This study aimed to investigate the possible neuroprotective effects of bitter melon (BM), chard, and parsley extracts on oxidative damage that may occur in the brain of rats with bile duct ligation (BDL)-induced biliary cirrhosis. It was observed that lipid peroxidation (LPO), sialic acid (SA), and nitric oxide (NO) levels increased; glutathione (GSH) levels, catalase (CAT) activity, and tissue factor (TF) activity decreased significantly in the BDL group. However, in groups with BDL given BM, chard, and parsley extracts LPO, SA, NO levels decreased; GSH levels and CAT activities increased significantly. No significant differences were observed between groups in total protein, glutathione-S-transferase, superoxide dismutase, and boron. Histological findings were supported by the biochemical results. BM, chard, and parsley extracts were effective in the regression of oxidant damage caused by cirrhosis in the brain tissues. PRACTICAL APPLICATIONS: Bitter melon (BM), chard, and parsley have antioxidant properties due to their bioactive compounds which are involved in scavenging free radicals, suppressing their production, and stimulating the production of endogenous antioxidant compounds. Since BM, chard, and parsley extracts were found to be effective in the regression of oxidant damage caused by cirrhosis in the brain tissues, these plant extracts may be an alternative in the development of different treatment approaches against brain damage in cirrhosis. At the same time, these species have been used as food by the people for many years. Therefore, they can be used safely as neuroprotective agents in treatment.

Poria cocos polysaccharide attenuates damage of nervus in Alzheimer's disease rat model induced by D-galactose and aluminum trichloride

Poria cocos polysaccharide (PCP) is a compound from Poria cocos, and which is used as a classical tonic agent. This article aims to investigate the effects of PCP on neuronal damage of hippocampus and cognitive function in a rat model of Alzheimer's disease induced by D-galactose and aluminum trichloride. Oxiracetam (ORC) was used as a positive drug in this experiment. The rats were treated with PCP at doses of 100, 200 and 300 mg/kg/day for 30 days and ORC at dose of 346 mg/kg/day after modeling. The results of behavioral test showed that PCP could prevent cognitive decline in Alzheimer's disease rats as assessed by Y-maze test and Morris water maze test. Results of hippocampus slices showed that neurons were integrated and regularly arranged in the groups, which were administered along with PCP. Moreover, PCP could reduce neuronal apoptosis in hippocampus of Alzheimer's disease rats. Furthermore, the activities of superoxide dismutase in the hippocampus were elevated by PCP administration, while acetyl cholinesterase, reactive oxygen, malondialdehyde and inflammatory factors levels were reduced. In addition, we found PCP could attenuate MAPK/NF-κB signal pathway in the hippocampus. All results illustrated that PCP could exert neuroprotective effects at least partly through alleviating oxidative stress, apoptosis, inflammation and inhibiting the MAPK/NF-κB pathway in Alzheimer's disease rats induced by D-galactose and aluminum trichloride.

A review of dietary phytochemicals and their relation to oxidative stress and human diseases

Phytochemicals refer to active substances in plant-based diets. Phytochemicals found in for example fruits, vegetables, grains and seed oils are considered relatively safe for consumption due to mammal-plant co-evolution and adaptation. A number of human diseases are related to oxidative stress caused by for example chemical environmental contaminants in air, water and food; while also lifestyle including smoking and lack of exercise and dietary preferences are important factors for disease development in humans. Here we explore the dietary sources of antioxidant phytochemicals that have beneficial effects on oxidative stress, cardiovascular and neurological diseases as well as cancer. Plant-based diets usually contain phenolic acids, flavonoids and carotenoids, which have strong antioxidant properties, and therefore remove the excess of active oxygen in the body, and protect cells from damage, reducing the risk of cardiovascular and Alzheimer's disease. In most cases, obesity is related to diet and inactivity and plant-based diets change lipid composition and metabolism, which reduce obesity related hazards. Cruciferous and Allium vegetables are rich in organic sulphides that can act on the metabolism of carcinogens and therefore used as anti-cancer and suppressing agents while dietary fibres and plant sterols may improve intestinal health and prevent intestinal diseases. Thus, we recommend a diet rich in fruits, vegetables, and grains as its content of phytochemicals may have the potential to prevent or improve a broad sweep of various diseases.

Neuroprotective and Antioxidant Enhancing Properties of Selective Equisetum Extracts

The sterile stems belonging to the Equisetum species are often used in traditional medicine of various nations, including Romanians. They are highly efficient in treating urinary tract infections, cardiovascular diseases, respiratory tract infections, and medical skin conditions due to their content of polyphenolic derivatives that have been isolated. In this regard, this study aimed to provide the chemical composition of the extracts obtained from the Equisetum species (E. pratense, E. sylvaticum, E. telmateia) and to investigate the biological action in vitro and in vivo. For the chemical characterization of the analyzed Equisetum species extracts, studies were performed by using ultra-high-performance liquid chromatography (UHPLC-DAD). In vitro evaluation of the antioxidant activity of the plant extracts obtained from these species of Equisetum genus was determined. The neuroprotective activity of these three ethanolic extracts from the Equisetum species using zebrafish tests was determined in vivo. All obtained results were statistically significant. The results indicate that E. sylvaticum extract has a significant antioxidant activity; whereas, E. pratense extract had anxiolytic and antidepressant effects significantly higher than the other two extracts used. All these determinations indicate promising results for the antioxidant in vitro tests and neuroprotective activity of in vivo tests, particularly mediated by their active principles.

Role of natural plant products against Alzheimer's disease

Alzheimer's disease (AD) is one of the major neurodegenerative disorder. Deposition of amyloid fibrils and tau protein are associated with various pathological symptoms. Currently limited medication is available for AD treatment. Most of the drugs are basically cholinesterase inhibitors and associated with various side effects. Natural plant products have shown potential as a therapeutic agent for the treatment of AD symptoms. Variety of secondary metabolites like flavonoids, tannins, terpenoids, alkaloids and phenols are used to reduce the progression of the disease. Plant products have less or no side effect and are easily available. The present review gives a detailed account of the potential of natural plant products against the AD symptoms.

A comprehensive review on phytochemistry, bioactivities, toxicity studies, and clinical studies on Ficus carica Linn. leaves

The leaves of Ficus carica Linn. (FC) have been widely used for medicine purposes since ancient times, and its decoction is consumed as tea. Many scientific papers have been published in the literature and the researchers across the world are still exploring the health benefits of FC leaves. In this review, we have collected the literature published since 2010 in the databases: Pubmed, Scopus, Web of Science, SciFinder, Google Scholar, Baidu Scholar and local classic herbal literature. The summary of the chemical constituents in FC leaves, biological activities, toxicity studies, and clinical studies carried out on FC leaves is provided in this review. In addition, the molecular mechanisms of the active constituents in FC leaves are also comprehended. FC leaves are reported to 126 constituents out of which the polyphenolic compounds are predominant. Many scientific studies have proven the antidiabetic, antioxidant, anti-inflammatory, anticancer, anticholinesterase, antimicrobial, hepatoprotective, and renoprotective activities. Many studies have carried out to provide the insights on molecular pathways involved in the biological activities of FC leaves. The toxicity studies have suggested that FC leaves exhibit toxicity only at very high doses. We believe this review serve as a comprehensive resource for those who are interested to understand the scientific evidence that support the medicinal values of FC leaves and also the research gaps to further improve the commercial value and health benefits of FC leaves.

The Nrf2 pathway in psychiatric disorders: pathophysiological role and potential targeting

Introduction: All psychiatric disorders exhibit excitotoxicity, mitochondrial dysfunction, inflammation, oxidative stress, and neural damage as their common characteristic. The endogenous nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is implicated in the defense mechanism against oxidative stress and has a significant role in psychiatric disorders.Areas covered: We explore the role of Nrf2 pathway and its modulators in psychiatric disorders. The literature was searched utilizing various databases such as Embase, Medline, Web of Science, Pub-Med, and Google Scholar from 2010 to 2020. The search included research articles, clinical reports, systematic reviews, and meta-analyses.Expert opinion: Environmental factors and genetic predisposition can be a trigger for the development of psychiatric disorders. Nrf2 downregulates certain inflammatory pathways and upregulates various antioxidant enzymes to maintain a balance. However, its intricate balance with NF-Kβ (Nuclear factor kappa light chain enhancer of activated B cells) and its crosstalk with the transcription factor Nrf2 is critical in severe oxidative stress. Several Nrf2 modulators are now in clinical trials and can help reduce oxidative stress and neuroinflammation. There are immense potential opportunities for these modulators to become a novel therapeutic option.