Assessment of Antioxidant Effect of 2,5-Dihydroxybenzoic Acid and Vitamin A in Brains of Rats with Induced Hyperoxia

Gentisic acid ameliorates cisplatin-induced reprotoxicity through suppressing endoplasmic reticulum stress and upregulating Nrf2 pathway

Reproductive toxicity is a serious side effect of cisplatin (CP) chemotherapy. Gentisic acid (GTA) is a phenolic acid with strong antioxidant properties. Here, we aimed to determine therapeutic effect of GTA against CP-induced testicular toxicity in rats for the first time. Male Sprague-Dawley rats received a single dose of CP (5 mg/kg; intraperitoneal) and treated with GTA (1.5 and 3 mg/kg; intraperitoneal; 3 consecutive days). The levels of oxidative stress (OS), inflammation, endoplasmic reticulum stress (ERS) and apoptosis biomarkers were assessed in the testicular tissue of rats. In addition, how CP affects the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway and the effect of GTA on this situation were also addressed in the testicular tissue. CP administration induced histopathological changes in testicular tissue of rats with a significant increase in OS, inflammation, ERS and apoptosis biomarkers and a decrease in antioxidant capacity and Nrf2 expression levels. Administrations of GTA resulted in an amelioration of these altered parameters. These data suggest that GTA may be a potential therapeutic agent against CP-induced testicular toxicity. Activation of the Nrf2 pathway plays a key role of this therapeutic effect of GTA.

The Genus Alternanthera: Phytochemical and Ethnopharmacological Perspectives

Ethnopharmacological relevance: The genus Alternanthera (Amaranthaceae) comprises 139 species including 14 species used traditionally for the treatment of various ailments such as hypertension, pain, inflammation, diabetes, cancer, microbial and mental disorders.

Aim of the review: To search research gaps through critical assessment of pharmacological activities not performed to validate traditional claims of various species of Alternanthera. This review will aid natural product researchers in identifying Alternanthera species with therapeutic potential for future investigation.

Materials and methods: Scattered raw data on ethnopharmacological, morphological, phytochemical, pharmacological, toxicological, and clinical studies of various species of the genus Alternanthera have been compiled utilizing search engines like SciFinder, Google Scholar, PubMed, Science Direct, and Open J-Gate for 100 years up to April 2021.

Results: Few species of Alternanthera genus have been exhaustively investigated phytochemically, and about 129 chemical constituents related to different classes such as flavonoids, steroids, saponins, alkaloids, triterpenoids, glycosides, and phenolic compounds have been isolated from 9 species. Anticancer, antioxidant, antibacterial, CNS depressive, antidiabetic, analgesic, anti-inflammatory, and immunomodulator effects have been explored in the twelve species of the genus. A toxicity study has been conducted on 3 species and a clinical study on 2 species.

Conclusions: The available literature on pharmacological studies of Alternanthera species reveals that few species have been selected based on ethnobotanical surveys for scientific validation of their traditional claims. But most of these studies have been conducted on uncharacterized and non-standardized crude extracts. A roadmap of research needs to be developed for the isolation of new bioactive compounds from Alternanthera species, which can emerge out as clinically potential medicines.

Targeting cellular batteries for the therapy of neurological diseases

The mitochondria, apart from being known as the cell's "powerhouse," are crucial in the viability of nerve cells. Any damage to these cellular organelles can result in their cellular level dysfunction which includes rapidly multiplying reactive oxygen species (ROS) from the mitochondrial membrane, impaired calcium ion homeostasis, and disturbed mitochondrial dynamics by the formation of permeability transition pore in mitochondria. All these impaired biochemical changes lead to various neurological disorders such as progressive supranuclear palsy (PSP), Parkinson's disease (PD), and Alzheimer's disease (AD). Moreover, impaired mitochondrial functions are particularly prone to damage owing to prolonged lifespan and stretched length of the neurons. At the same time, neurons are highly dependent on ATP, and thus, the mitochondria play a central role in the pathogenesis pertaining to neuronal disorders. Dysfunction in the mitochondria is an early pathological hallmark of neurological disorders, and its early detection with the help of suitable biomarkers can lead to promising treatment in this area. Thus, the drugs which are targeting mitochondrial dysfunctions are the emerging area of research in connection with neurological disorders. This can be evidenced by the great opportunities for mitigation, diagnosis, and treatment of numerous human disorders that entail mitochondrial dysfunction at the nexus of their pathogenesis. Here, we throw light at the mitochondrial pathologies and indications of dysfunctional mitochondria in PD, AD, and PSP. There is also an insight into the possible therapeutic strategies highlighting the need for mitochondria-based medicine and made an attempt for claiming the prerequisite for the therapy of neurological diseases.

Erucic acid, a nutritional PPARδ-ligand may influence Huntington's disease pathogenesis

Increasing recent evidence suggests a key role of oligodendroglial injury and demyelination in the pathophysiology of Huntington's Disease (HD) and the transcription factor PPARδ is critical for oligodendroglial regeneration and myelination. PPARδ directly involves in the pathogenesis of HD and treatment with a brain-permeable PPARδ-agonist (KD3010) alleviates its severity in mice. Erucic acid (EA) is also a PPARδ-ligand ω9 fatty acid which is highly consumed in Asian countries through ingesting cruciferous vegetables such as rapeseed (Brassica napus) and indian mustard (Brassica juncea). EA is also an ingredient of Lorenzo's oil employed in the medical treatment of adrenoleukodystrophy and can be converted to nervonic acid, a component of myelin. HD pathogenesis also involves oxidative and inflammatory injury and EA exerts antioxidative and antiinflammatory efficacies including inhibition of thrombin and elastase. Consumption of rapeseed, indian mustard, and Canola oils (containing EA) improves cognitive parameters in animal models, as well as treatment with pure EA. Moreover, erucamide, an endogenous EA-amide derivative regulating angiogenesis and water balance, exerts antidepressive and anxiolytic effects in mice. Hitherto, no study has investigated the therapeutic potential of EA in HD and we believe that it strongly merits to be studied in animal models of HD as a potential therapeutic.

A review on gentisic acid as a plant derived phenolic acid and metabolite of aspirin: Comprehensive pharmacology, toxicology, and some pharmaceutical aspects

Beneficial therapeutic effects of phenolic acids have been proven in various research projects including in vivo and in vitro studies. Gentisic acid (GA) is a phenolic acid that has been associated with useful effects on human health, such as antiinflammatory, antigenotoxic, hepatoprotective, neuroprotective, antimicrobial, and especially antioxidant activities. It is an important metabolite of aspirin and also widely distributed in plants as a secondary plant product such as Gentiana spp., Citrus spp., Vitis vinifera, Pterocarpus santalinus, Helianthus tuberosus, Hibiscus rosa-sinensis, Olea europaea, and Sesamum indicum and in fruits such as avocados, batoko plum, kiwi fruits, apple, bitter melon, black berries, pears, and some mushrooms. This study was undertaken to review the pharmacological effects, pharmacokinetic properties as well as toxicity and pharmaceutical applications of GA.

Effect of long-term normobaric hyperoxia on oxidative stress in mitochondria of the guinea pig brain

Normobaric hyperoxia (NBO) is applied for treatment of various clinical conditions related to hypoxia, but it can potentially also induce generation of reactive oxygen species, causing cellular damage. In this study, we examined the effects of 60 h NBO treatment on lipid and protein oxidative damage and activity of superoxide dismutase (Mn-SOD) in brain mitochondria of guinea pigs. Despite significant stimulation of Mn-SOD expression and activity the NBO treatment resulted in accumulation of markers of oxidative lesions, including lipid peroxidation (conjugated dienes, thiobarbituric acid reactive substances) and protein modification (bityrosines, adducts with lipid peroxidation products, oxidized thiols). When inhaled O(2) was enriched with oxygen cation, O (2) (•+) , the Mn-SOD expression and activity were stimulated to similar extend, but lipid peroxidation and protein oxidation were prevented. These results suggest that long-term NBO treatment causes oxidative stress, but enrichment of inhaled oxygen by oxygen cation can protect the brain again adverse effects of hyperoxia.

Mitochondrial medicine for neurodegenerative diseases

Mitochondrial dysfunction has been reported in a wide array of neurological disorders ranging from neuromuscular to neurodegenerative diseases. Recent studies on neurodegenerative diseases have revealed that mitochondrial pathology is generally found in inherited or sporadic neurodegenerative diseases and is believed to be involved in the pathophysiological process of these diseases. Commonly seen types of mitochondrial dysfunction in neurodegenerative diseases include excessive free radical generation, lowered ATP production, mitochondrial permeability transition, mitochondrial DNA lesions, perturbed mitochondrial dynamics and apoptosis. Mitochondrial medicine as an emerging therapeutic strategy targeted to mitochondrial dysfunction in neurodegenerative diseases has been proven to be of value, though this area of research is still at in its early stage. In this article, we report on recent progress in the development of several mitochondrial therapies including antioxidants, blockade of mitochondrial permeability transition, and mitochondrial gene therapy as evidence that mitochondrial medicine has promise in the treatment of neurodegenerative diseases.

Simultaneous determination of flavones and phenolic acids in the leaves of Ricinus communis Linn. by capillary electrophoresis with amperometric detection

Capillary electrophoresis (CE) with amperometric detection (AD) has been developed for the separation and determination of disaccharide glycoside rutin, gentistic acid, quercetin, and gallic acid in the leaves of Ricinus communis Linn. for the first time. The effects of the acidity and the concentration of the running buffer, separation voltage, injection time, and detection potential were investigated to acquire the optimum conditions for the determination of the four analytes. The detection electrode was a 300microm diameter carbon disc electrode at a detection potential of +0.90V (versus saturated calomel electrode (SCE)). The four analytes could be well separated within 10min in a 40cm length fused silica capillary at a separation voltage of 15kV in a 50mM borate buffer (pH 9.0). The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with detection limits (S/N=3) ranging from 0.8 to 2.9microM for all the analytes. The proposed method has been successfully applied to monitor flavones and phenolic acids in the real plant samples with satisfactory assay results.