Antioxidant properties, radical scavenging activity and biomolecule protection capacity of flavonoid naringenin and its glycoside naringin: a comparative study

Food Containing Bioactive Flavonoids and Other Phenolic or Sulfur Phytochemicals With Antiviral Effect: Can We Design a Promising Diet Against COVID-19?

Since in late 2019, when the coronavirus 2 (SARS-CoV-2) pathogen of coronavirus disease 2019 (COVID-19) started to spread all over the world, causing the awful global pandemic we are still experiencing, an impressive number of biologists, infectious disease scientists, virologists, pharmacologists, molecular biologists, immunologists, and other researchers working in laboratories of all the advanced countries focused their research on the setting up of biotechnological tools, namely vaccines and monoclonal antibodies, as well as of rational design of drugs for therapeutic approaches. While vaccines have been quickly obtained, no satisfactory anti-Covid-19 preventive, or therapeutic approach has so far been discovered and approved. However, among the possible ways to achieve the goal of COVID-19 prevention or mitigation, there is one route, i.e., the diet, which until now has had little consideration. In fact, in the edible parts of plants supplying our food, there are a fair number of secondary metabolites mainly belonging to the large class of the flavonoids, endowed with antiviral or other health beneficial activities such as immunostimulating or anti-inflammatory action that could play a role in contributing to some extent to prevent or alleviate the viral infection and/or counteract the development of SARS induced by the novel coronavirus. In this review, a number of bioactive phytochemicals, in particular flavonoids, proven to be capable of providing some degree of protection against COVID-19, are browsed, illustrating their beneficial properties and mechanisms of action as well as their distribution in cultivated plant species which supply food for the human diet. Furthermore, room is also given to information regarding the amount in food, the resistance to cooking processes and, as a very important feature, the degree of bioavailability of these compounds. Concluding, remarks and perspectives for future studies aimed at increasing and improving knowledge and the possibility of using this natural complementary therapy to counteract COVID-19 and other viral pathologies are discussed.

Hydrogen peroxide is necessary during tail regeneration in juvenile axolotl

BACKGROUND

Hydrogen peroxide (H₂ O₂ ) is a key reactive oxygen species (ROS) generated during appendage regeneration among vertebrates. However, its role during tail regeneration in axolotl as redox signaling molecule is unclear.

RESULTS

Treatment with exogenous H₂ O₂ rescues inhibitory effects of apocynin-induced growth suppression in tail blastema cells leading to cell proliferation. H₂ O₂ also promotes recruitment of immune cells, regulate the activation of AKT kinase and Agr2 expression during blastema formation. Additionally, ROS/H₂ O₂ regulates the expression and transcriptional activity of Yap1 and its target genes Ctgf and Areg.

CONCLUSIONS

These results show that H₂ O₂ is necessary and sufficient to promote tail regeneration in axolotls. Additionally, Akt signaling and Agr2 were identified as ROS targets, suggesting that ROS/H₂ O₂ is likely to regulate epimorphic regeneration through these signaling pathways. In addition, ROS/H₂ O₂ -dependent-Yap1 activity is required during tail regeneration.

A metabolomic study on the anti-depressive effects of two active components from Chrysanthemum morifolium

Chrysanthemum morifolium (Chr) is a traditional Chinese medicine (TCM) that has been used in the treatment of inflammation-linked diseases for hundreds of years. Naringenin (Nar) and apigenin (Api) are the major active components in aqueous extracts of C. morifolium. The aim of our study was to clarify the roles of Chr, Nar and Api in ameliorating depression-like behaviour induced by corticosterone. First, the behavioural and biochemical indicators closely related to depression were examined to evaluate the therapeutic effects of Chr/Nar/Api on a depression model. Then, a metabolomics approach was utilized to screen for biomarkers and related pathways between a control group and Chr/Nar/Api groups. The comprehensive results revealed that Chr/Nar/Api exerted anti-depressant effects through interfering with tryptophan metabolism, arginine and prolinemetabolism, citrate cycle, niacin and niacinamide metabolism, phenylalanine metabolism, and alanine, aspartate and glutamate metabolism. The mechanism of Chr/Api/Nar in the treatment of depression was elucidated based on material and energy metabolism. Moreover, Nar could be used as a substitute for Chr for reversing depression-like behaviour, and Api was similar to a positive drug in terms of function on depression. The integrated metabolomics approach demonstrated here should be an effective method for interpreting the function of herbs from TCM and clarifying the mechanism of their components in future studies.

Bioactivity and Delivery Strategies of Phytochemical Compounds in Bone Tissue Regeneration

Plant-derived secondary metabolites represent a reservoir of phytochemicals for regenerative medicine application because of their varied assortment of biological properties including anti-oxidant, anti-inflammatory, antibacterial, and tissue remodeling properties. In addition, bioactive phytochemicals can be easily available, are often more cost-effective in large-scale industrialization, and can be better tolerated compared to conventional treatments mitigating the long-lasting side effects of synthetic compounds. Unfortunately, their poor bioavailability and lack of long-term stability limit their clinical impact. Nanotechnology-based delivery systems can overcome these limitations increasing bioactive molecules’ local effectiveness with reduction of the possible side effects on healthy bone. This review explores new and promising strategies in the area of delivery systems with particular emphasis on solutions that enhance bioavailability and/or health effects of plant-derived phytochemicals such as resveratrol, quercetin, epigallocatechin-3-gallate, and curcumin in bone tissue regeneration.

Naringin attenuates cerebral ischemia-reperfusion injury in rats by inhibiting endoplasmic reticulum stress

Objective

This investigation was carried out with an aim of exploring neuroprotection by naringin (Nar) in rats with cerebral ischemia-reperfusion (CI/R) injury and its mechanism.

Methods

Rats were grouped into ischemia-reperfusion (I/R), sham operation (Sham), nimodipine control (NIM), and different doses of Nar (Nar-L, Nar-M, Nar-H) groups. With Zea Longa score for assessment of neurological deficits, dry and wet method for measurement of brain tissue water content, and (2,3,5-triphenyltetrazolium chloride) TTC staining for determination of cerebral infarction volume, the related parameters were obtained and compared. Subsequently, ELISA was introduced to detect levels of proinflammatory cytokines (TNF-α, IL-8) and anti-inflammatory cytokine (IL-10) in the serum as well as superoxide dismutase (SOD) and malondialdehyde (MDA) activities in brain tissue. Western blot was applied to evaluate endoplasmic reticulum stress (ERS)-related proteins expression, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), caspase-12, and activating transcription factor 6 (ATF-6).

Results

Nar significantly alleviated nerve injury and decreased brain tissue water content and brain infraction volume in CI/R injury rats in a concentration-dependent manner. Reduction of TNF-α, IL-8 as well as MDA content and elevation of IL-10 as well as SOD activity were confirmed to be caused by Nar treatment in a concentration-dependent manner. Meanwhile, ERS-related proteins also markedly decreased in the Nar groups.

Conclusion

Nar may achieve neuroprotection and alleviation of CI/R injury by anti-inflammation, anti-oxidation, and inhibiting ERS, and its efficacy is concentration-dependent.

Current Advances in the Use of Nanophytomedicine Therapies for Human Cardiovascular Diseases

Considering the high prevalence of cardiovascular diseases (CVDs), the primary cause of death during the last several decades, it is necessary to develop proper strategies for the prevention and treatment of CVDs. Given the excessive side effects of current therapies, alternative therapeutic approaches like medicinal plants and natural products are preferred. Lower toxicity, chemical diversity, cost-effectiveness, and proven therapeutic potentials make natural products superior compared to other products. Nanoformulation methods improve the solubility, bioavailability, circulation time, surface area-to-volume ratio, systemic adverse side effects, and drug delivery efficiency of these medications. This study intended to review the functionality of the most recent nanoformulated medicinal plants and/or natural products against various cardiovascular conditions such as hypertension, atherosclerosis, thrombosis, and myocardial infarction. Literature review revealed that curcumin, quercetin, and resveratrol were the most applied natural products, respectively. Combination therapy, conjugation, or fabrication of nanoparticles and nanocarriers improved the applications and therapeutic efficacy of herbal- or natural-based nanoformulations. In the context of CVDs prevention and/or treatment, available data suggest that natural-based nanoformulations are considerably efficient, alone or in blend with other herbal/synthetic medicines. However, clinical trials are mandatory to elucidate the safety, cardioprotective effect, and mechanism of actions of nanophytomedicines.

Chemical characterization and in vivo antioxidant activity of parsley (Petroselinum crispum) aqueous extract

Twenty-nine flavonoid glycosides were identified in the aqueous extract (PC) of Petroselinum crispum var. crispum leaves and apiin, the major compound, was isolated thereof. Apigenin was obtained (90% purity) by the hydrolysis of apiin. A high content of phenolics (12.49 ± 1.70 mg GAE per g of parsley extract - Folin-Ciocalteu method) and total flavonoids (15.05 ± 2.20 mg of quercetin equivalents per g of parsley extract - aluminum chloride method) was quantified in P. crispum, as well as high antioxidant activity ((EC50 - 15.50 mg mL-1, DPPH method) and (189.8 mM Fe(ii) per mg of dry plant aqueous extract - FRAP method)). In vivo analysis with Saccharomyces cerevisiae cells showed low toxicity of the aqueous extract of parsley, however, it revealed a high dose-dependent antioxidant potential, mainly in the lipoperoxidation assay. In addition, flavonoid apiin also showed antioxidant action on yeast cells under oxidative stress in the cell viability assay (0.1 mM) and lipid peroxidation (0.01 and 0.1 mM), while apigenin was slightly antioxidant. Therefore, it is likely that the antioxidant activity of apiin is related to the total antioxidant capacity of parsley.

Phyllosilicate-content influence on the spectroscopic properties and antioxidant capacity of Iberian Cretaceous clays

Kaolinite-rich Cretaceous clay sediment samples from Burgos (Spain) have been analyzed by elemental analysis, X-ray fluorescence, inductively coupled plasma mass spectrometry, X-ray diffraction and different spectroscopic techniques, as Fourier Transform Infrared, ultraviolet-visible and electron paramagnetic resonance. The clay sediment samples mainly contain quartz, muscovite and kaolinite. Different radicals, as A- and B-Centers in kaolinite and organic paramagnetic species, are detected. An illite/kaolinite FTIR band ratio parameter (IKB) is proposed to infer the illite/kaolinite proportion, which can be useful to graphically visualize the iron-substituted Al(III) sites. Studies of the activity as scavengers of DPPH and ABTS radicals show that samples with a larger amount of orthorhombic Fe(III) ions replacing Al(III) ions exhibit a higher antioxidant capacity.

Naringenin Attenuates Toxicity and Oxidative Stress Induced by Lambda-cyhalothrin in Liver of Male Rats

BACKGROUND AND OBJECTIVES

Extensive use of Lambda-cyhalothrin (LTC), a synthetic pyrethroid insecticide, has been associated with serious health problems to the non-target organisms including mammals. The present study investigated the protective effect of naringenin (NGN), an antioxidant flavonoid, against the toxicity induced LTC in the liver of male rats.

MATERIALS AND METHODS

Five groups of rats were assigned as follows; control group, LTC group (6.12 mg kg-1, 1/10 LD50), LTC-NGN group (6.12 mg kg-1 LTC and 50 mg kg-1 NGN), NGN-LTC group (50 mg kg-1 NGN and 6.12 mg kg-1 LTC) and NGN group (50 mg kg-1). Doses were administrated orally for 21 consecutive days.

RESULTS

Administration of LTC induced liver damage as indicated by the increase in the activities of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase and in the level of total bilirubin in serum. LTC also induced a significant elevation in the levels of serum total lipids, total cholesterol, triglycerides and low-density lipoproteins while high-density lipoproteins decreased. Furthermore, LTC significantly disturbed the oxidant/antioxidant balance in the liver as shown by the elevation in lipid peroxidation, lipid hydroperoxides, protein carbonyl content and conjugated dienes with a concomitant inhibition in the major antioxidants such as reduced glutathione and the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase. Both post-treatment and pre-treatment with NGN significantly modulated the LTC-induced hepatotoxicity and oxidative stress in rat's liver and pretreatment was found to be more effective in improving most of the studied parameters in both serum and liver tissue.

CONCLUSION

NGN could be used as a safe dietary supplement to protect against the toxicity and oxidative stress associated with the use of LTC.

Green extraction techniques from fruit and vegetable waste to obtain bioactive compounds-A review

Food wastes imply significant greenhouse gas emissions, that increase the challenge of climate change and impact food security. According to FAO (2019), one of the main food wastes come from fruit and vegetables, representing 0.5 billion tons per year, of the 1.3 billion tons of total waste. The wastes obtained from fruit and vegetables have plenty of valuable components, known as bioactive compounds, with many properties that impact positively in human health. Some bioactive compounds hold antioxidant, anti-inflammatory, and anti-cancer properties and they have the capacity of modulating metabolic processes. Currently, the use of fruit and vegetable waste is studied to obtain bioactive compounds, through non-conventional techniques, also known as green extraction techniques. These extraction techniques report higher yields, reduce the use of solvents, employ less extraction time, and improve the efficiency of the process for obtaining bioactive compounds. Once extracted, these compounds can be used in the cosmetic, pharmaceutical, or food industry, the last one being focused on improving food quality.

Molecular Docking Studies of Naringenin and its Protective Efficacy against Methotrexate Induced Oxidative Tissue Injury

BACKGROUND

Although Methotrexate (MTX) possesses a wide clinical spectrum of activity, its toxic side effects on normal cells and drug resistance often hamper its successful outcome. Naringenin (NG) one of the promising bioactive flavonoids that are extensively found in grapes, citrus fruits, and fruit arils of Pithecellobium dulce.

OBJECTIVE

Only a few experimental in vivo studies on the efficacy of NG against chemotherapeutic drugs have been carried out. Aiming to fill this gap, the present study was carried out to characterize and identify its possible therapeutic targets and also to explore its protective efficacy against MTX induced tissue damage.

METHODS

Oxidative stress was induced in mice with MTX (20 mg/kg B.wt) and animals were orally administered with 10 mg/kg B.wt NG for 10 consecutive days. On day 11, all animals were sacrificed, and hematological and serum biochemical parameters were analyzed. The antioxidant efficacy of NG against MTX was evaluated by quantifying tissue superoxide dismutase (SOD), glutatione peroxidase (GPx), reduced glutathione (GSH) and catalase along with oxidative stress markers [malondialdehyde (MDA) and nitric oxide (NO)]. Further, the histopathological analysis was performed to confirm the protective efficacy of FPD. In silico docking studies were also performed to exploring antioxidant enzyme-based targets.

RESULTS

Our results showed that concurrent administration of NG counteracted oxidative stress induced by MTX, as evidenced by increased expression of antioxidant markers, decreased expression of renal and hepatotoxicity serum marker enzymes (p <0.05). Molecular docking study was performed using Auto dock vina to understand the mechanism of ligand binding (S-NG and R-NG) with antioxidant enzymes. The binding affinity of S-NG with catalase, GPx, ALP, and SGPT was -10.1, -7.1, -7.1, and -7.3 kcal/mol respectively, whereas for R-NG was -10.8, -7.1, -7.6, and -7.4 kcal/mol respectively. Further, histopathological analysis affirmed the protective efficacy of NG against MTX induced hepatic and renal toxicities.

CONCLUSION

Treatment with NG significantly reduced MTX induced pancytopenia, renal, and hepatic toxicity.

Marama bean [Tylosema esculentum (Burch.) A. Schreib.]: an indigenous plant with potential for food, nutrition, and economic sustainability

Developing countries need to explore undervalued indigenous plants to fully enhance their food and nutrition security, health, and economic viability. This review explores the nutritional, phytochemical, and economic potential of marama bean (Tylosema esculentum, Fabaceae), a non-nodulating indigenous legume that can be cultivated in and is well-adapted to dry or low moisture conditions. Marama bean is popularly referred to as 'green gold' due to the considerable value derived from its above ground and underground organs. The seeds have nutritional value comparable to legumes such as groundnut and soybean. In addition, the seeds are a rich source of phytochemicals such as phenolic acids, phytosterols, flavonoids, behenic acid and griffonilide while carbohydrates are abundant in the tubers. Based on the existing literature, marama bean remains poorly explored, mainly anecdotal with limited scientific evidence available to support its nutritional and medicinal uses as well as economic benefits. This has been ascribed to a shortage of clear research goals and limited resources specifically directed to this underutilized indigenous plant. From an economic and commercial perspective, the high phytochemical content suggests the possibility of developing a functional health drink and associated value-added products. However, efficient cultivation protocols for marama bean, especially to ensure the sustainable supply of the plant material, remain crucial. Furthermore, novel approaches, especially the use of molecular techniques that can facilitate rapid selection of desired traits in marama, are recommended. These anticipated improved agronomical traits will enhance the commercial and economical potential of marama and also contribute to rural-urban food-nutrition sustainability globally.

Chemical Composition of Tomato Seed Flours, and Their Radical Scavenging, Anti-Inflammatory and Gut Microbiota Modulating Properties

In the current study, the chemical composition and total phenolic content of tomato seed flours, along with potential health beneficial properties, including free radical scavenging capacities, anti-inflammatory capacities, and gut microbiota profile modulation, were examined using two different batches. Eight compounds were identified in the tomato seed flour, including malic acid, 2-hydroxyadipic acid, salicylic acid, naringin, N-acetyl-tryptophan, quercetin-di-O-hexoside, kaempferol-di-O-hexoside, and azelaic acid. The total phenolic contents of tomato seed flour were 1.97-2.00 mg gallic acid equivalents/g. Oxygen radical absorbing capacities (ORAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacities (DPPH), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical scavenging capacities (ABTS) were 86.32-88.57, 3.57-3.81, and 3.39-3.58 µmoles Trolox equivalents/g, respectively, on a per flour dry weight basis. The mRNA expression of the pro-inflammatory markers, interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), were dose-dependently suppressed by tomato seed flour extracts. The extracts altered five of the eight bacterial phyla and genera evaluated. The results may provide some scientific support for the use of tomato seed flour as value-added food ingredients.

Protective Effects of 6,7,4'-Trihydroxyflavanone on Hypoxia-Induced Neurotoxicity by Enhancement of HO-1 through Nrf2 Signaling Pathway

Since hypoxia-induced neurotoxicity is one of the major causes of neurodegenerative disorders, including the Alzheimer’s disease, continuous efforts to find a novel antioxidant from natural products are required for public health. 6,7,4′-trihydroxyflavanone (THF), isolated from Dalbergia odorifera, has been shown to inhibit osteoclast formation and have an antibacterial activity. However, no evidence has reported whether THF has a protective role against hypoxia-induced neurotoxicity. In this study, we found that THF is not cytotoxic, but pre-treatment with THF has a cytoprotective effect on CoCl₂-induced hypoxia by restoring the expression of anti-apoptotic proteins in SH-SY5y cells. In addition, pre-treatment with THF suppressed CoCl₂-induced hypoxia-related genes including HIF1α, p53, VEGF, and GLUT1 at the mRNA and protein levels. Pre-treatment with THF also attenuated the oxidative stress occurred by CoCl₂-induced hypoxia by preserving antioxidant proteins, including SOD and CAT. We revealed that treatment with THF promotes HO-1 expression through Nrf2 nuclear translocation. An inhibitor assay using tin protoporphyrin IX (SnPP) confirmed that the enhancement of HO-1 by pre-treatment with THF protects SH-SY5y cells from CoCl₂-induced neurotoxicity under hypoxic conditions. Our results demonstrate the advantageous effects of THF against hypoxia-induced neurotoxicity through the HO-1/Nrf2 signaling pathway and provide a therapeutic insight for neurodegenerative disorders.

Naringenin Nano-Delivery Systems and Their Therapeutic Applications

Naringenin (NRG) is a polyphenolic phytochemical belonging to the class of flavanones and is widely distributed in citrus fruits and some other fruits such as bergamot, tomatoes, cocoa, and cherries. NRG presents several interesting pharmacological properties, such as anti-cancer, anti-oxidant, and anti-inflammatory activities. However, the therapeutic potential of NRG is hampered due to its hydrophobic nature, which leads to poor bioavailability. Here, we review a wide range of nanocarriers that have been used as delivery systems for NRG, including polymeric nanoparticles, micelles, liposomes, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), nanosuspensions, and nanoemulsions. These nanomedicine formulations of NRG have been applied as a potential treatment for several diseases, using a wide range of in vitro, ex vivo, and in vivo models and different routes of administration. From this review, it can be concluded that NRG is a potential therapeutic option for the treatment of various diseases such as cancer, neurological disorders, liver diseases, ocular disorders, inflammatory diseases, skin diseases, and diabetes when formulated in the appropriate nanocarriers.

Antioxidant and Antibacterial Activity of Essential Oils and Hydroethanolic Extracts of Greek Oregano (O. vulgare L. subsp. hirtum (Link) Ietswaart) and Common Oregano (O. vulgare L. subsp. vulgare)

Greek oregano and common oregano were compared in respect of the antioxidant and antibacterial activity of the corresponding essential oils and hydroethanolic extracts in relation with their chemical profile. The chemical composition of essential oils was determined by GC-MS and GC-FID, while extracts (phenolic acids and flavonoids fractions) were analyzed by HPLC-DAD. Based on given volatiles, the investigated subspecies represented two chemotypes: a carvacrol/γ-terpinene/p-cymene type in the case of Greek oregano and a sabinyl/cymyl type rich in terpinen-4-ol in common oregano. Within non-volatile phenolic compounds, rosmarinic acid appeared to dominate in both subspecies. Lithospermic acid B, chlorogenic acid and isovitexin were present only in Greek oregano extracts. However, the total content of flavonoids was higher in common oregano extracts. The essential oil and extract of Greek oregano revealed visibly stronger antibacterial activity (expressed as MIC and MBC) than common oregano, whereas the antioxidant potential (determined by DPPH, ABTS and FRAP) of these extracts was almost equal for both subspecies. In the case of Origanum plants, the potential application of essential oils and extracts as antiseptic and antioxidant agents in the food industry should be preceded by subspecies identification followed by recognition of their chemotype concerning both terpene and phenolics composition.

The Role of Polyphenols in Abiotic Stress Response: The Influence of Molecular Structure

Abiotic stressors such as extreme temperatures, drought, flood, light, salt, and heavy metals alter biological diversity and crop production worldwide. Therefore, it is important to know the mechanisms by which plants cope with stress conditions. Polyphenols, which are the largest group of plant-specialized metabolites, are generally recognized as molecules involved in stress protection in plants. This diverse group of metabolites contains various structures, from simple forms consisting of one aromatic ring to more complex ones consisting of large number of polymerized molecules. Consequently, all these molecules, depending on their structure, may show different roles in plant growth, development, and stress protection. In the present review, we aimed to summarize data on how different polyphenol structures influence their biological activity and their roles in abiotic stress responses. We focused our review on phenolic acids, flavonoids, stilbenoids, and lignans.

The Strategy of Boosting the Immune System Under the COVID-19 Pandemic

The novel coronavirus (SARS-CoV-2) infection (COVID-19) has raised considerable concern on the entire planet. On March 11, 2020, COVID-19 was categorized by the World Health Organization (WHO) as a pandemic infection, and by March 18, 2020, it has spread to 146 countries. The first internal defense line against numerous diseases is personalized immunity. Although it cannot be claimed that personalized nutrition will have an immediate impact on a global pandemic, as the nutritional interventions required a long time to induce beneficial outcomes on immunity development, nutritional strategies are still able to clarify and have a beneficial influence on the interplay between physiology and diet, which could make a positive contribution to the condition in the next period. As such, a specific goal for every practitioner is to evaluate different tests to perceive the status of the patient, such as markers of inflammation, insulin regulation, and nutrient status, and to detect possible imbalances or deficiencies. During the process of disease development, the supplementation and addition of different nutrients and nutraceuticals can influence not only the viral replication but also the cellular mechanisms. It is essential to understand that every patient has its individual needs. Even though many nutrients, nutraceuticals, and drugs have beneficial effects on the immune response and can prevent or ameliorate viral infections, it is essential to detect at what stage in COVID-19 progression the patient is at the moment and decide what kind of nutrition intervention is necessary. Furthermore, understanding the pathogenesis of coronavirus infection is critical to make proper recommendations.

Combination therapy of flaxseed and hesperidin enhances the effectiveness of lifestyle modification in cardiovascular risk control in prediabetes: a randomized controlled trial

BACKGROUND

Regarding the increasing prevalence of cardiometabolic abnormalities, and its association with non-communicable chronic diseases, providing preventive and therapeutic strategies is a priority. A randomized placebo-controlled study was conducted to assess the effects of combination therapy of milled brown flaxseed and hesperidin during lifestyle intervention on controlling cardiovascular risk in prediabetes.

METHODS

A total of forty-eight subjects were randomly assigned to receive lifestyle intervention plus combination therapy of brown flaxseed (30 g milled) and hesperidin (two 500 mg capsules) or lifestyle modification alone for 12 weeks. Changes from baseline in anthropometric measures, lipid profile and atherogenic indices, glucose homeostasis parameters, and inflammatory biomarkers was assessed as a primary end point.

RESULTS

Anthropometric data comparison between the two groups showed a significant reduction in weight (p = 0.048). Waist circumference reduction was about twice that of the control group (- 6.75 cm vs - 3.57 cm), but this difference was not statistically significant. Comparison of blood pressure changes throughout the study indicated a greater reduction in blood pressure in the intervention group rather than control group (- 5.66 vs. - 1.56 mmHg, P = 0.049). Improvements of lipid profile and atherogenic indices, glucose homeostasis parameters, and inflammatory biomarkers in flaxseed-hesperidin group was significantly more than the control group after 12 weeks of intervention (p < 0.05).

CONCLUSION

Our results indicate that co-administration of flaxseed and hesperidin as an adjunct to lifestyle modification program is more effective than lifestyle modification alone in the metabolic abnormalities remission of prediabetic patients.

TRIAL REGISTRATION

 The trial was registered with ClinicalTrials.gov, number NCT03737422. Registered 11 November 2018. Retrospectively registered, https://clinicaltrials.gov/ct2/results?cond=&term=NCT03737422&cntry=&state=&city=&dist= .

The simultaneous determination of naringenin and its valine carbamate prodrug in rat plasma using supercritical fluid chromatography -tandem mass spectrometric method

To enhance the oral bioavailability of naringenin, a valine carbamate prodrug was firstly synthesized. It is essential to measure naringenin and its carbamate prodrug simultaneously for evaluating their pharmacokinetic behavior in Sprague-Dawley rats. Here, the samples were analyzed by a supercritical fluid chromatography-tandem mass spectrometric (SFC-MS/MS) method after extracting by liquid-liquid extraction with ethyl acetate. The analytes were eluted completely on an ACQUITY UPC^2TM BEH 2-EP column (3.0 × 100 mm, 1.7 μm) within 2.5 min by gradient elution. The mass transition ion pairs were m/z 273.2→153.0, 416.0→153.1, and 271.2→91.0 for naringenin, the prodrug, and genistein (the internal standard), respectively. Naringenin and the prodrug had excellent linear correlations over the range of 2-1000 ng/mL (r > 0.995) and 4-2000 ng/mL (r > 0.998), with lower limits of quantification of 2 ng/mL and 4 ng/mL, respectively. The intra-day and inter-day precision and accuracy for all quality control samples were within ± 15 %. The high-throughput, sensitive, and economical SFC-MS/MS method was successfully applied to the pharmacokinetic study of naringenin and its carbamate prodrug for the first time. The pharmacokinetic study results showed the total C_max of naringenin in prodrug group was 4.14-fold higher than naringenin group. The higher total AUC value observed with prodrug group indicated increased bioavailability of naringenin as compared to naringenin suspension. The present work provides some helpful information for future studies of naringenin and its carbamate prodrug.

Naringenin improves depressive- and anxiety-like behaviors in mice exposed to repeated hypoxic stress through modulation of oxido-inflammatory mediators and NF-kB/BDNF expressions

Oxidative and inflammatory signaling pathways have been identified as important targets for mitigating hypoxic stress-induced neurological complications. Thus, the effects of naringenin, a potent antioxidant, anti-inflammatory and neuroprotective bioflavonoid on hypoxic stress-induced depressive-like and anxiety-related behaviors in mice, and the underlying molecular mechanisms were evaluated in this study. Thirty-five male Swiss mice were distributed into 5 groups (n = 7). Mice in group I (non-stress control) and group 2 (stress-control) both had vehicle (5 % DMSO), while groups 3-5 received naringenin (10, 25 and 50 mg/kg), intraperitonally. Thirty minutes later, mice in groups 2-5 were subjected to 15 min hypoxic stress, daily for 14 days. Locomotor activity, anxiety and depression were evaluated on day 15. The mice brains were processed for malondialdehyde, glutathione, superoxide-dismutase (SOD), catalase, tumor necrosis factor-alpha (TNF-α) and interleukin-1β assays. The serum corticosterone concentration and expressions of the brain immunopositive cells of inducible nitric oxide synthase (iNOS), nuclear factor kappa-B (NF-kB) and brain derived neurotrophic factor (BDNF) as well as histomorphological changes of the amygdala were also determined. Naringenin (25-50 mg/kg) ameliorated the hypolocomotion, depressive- and anxiety-like behaviors in hypoxic mice. The increased brain contents of malondialdehyde, TNF-α, interleukin-1β, and decreased antioxidant (glutathione and SOD) status were attenuated by naringenin. Naringenin (10 mg/kg) increases BDNF expression but did not significantly (p < 0.05) alter corticosterone and catalase contents. The increased expressions of iNOS and NF-kB as well as loss of amygdala neuronal cells were reduced by naringenin (10 mg/kg). Overall, these findings suggest that naringenin improves depressive- and anxiety-like behaviors in mice exposed to hypoxic stress by modulating oxido-inflammatory insults and NF-kB/BDNF expressions.

Enzymatic treatment, unfermented and fermented fruit-based products: current state of knowledge

In recent years, food manufacturers are increasingly utilizing enzymes in the production of fruit-based (unfermented and fermented) products to increase yield and maximize product quality in a cost-effective manner. Depending on the fruits and desired product characteristics, different enzymes (e.g. pectinase, cellulase, hemicellulase, amylase, and protease) are used alone or in combinations to achieve optimized processing conditions and improve nutritional and sensorial quality. In this review, the mechanisms of action and sources of different enzymes, as well as their effects on the physicochemical, nutritional, and organoleptic properties of unfermented and fermented fruit-based products are summarized and discussed, respectively. In general, the application of enzymatic hydrolysis treatment (EHT) in unfermented fruit-based product helps to achieve four main purposes: (i) viscosity reduction (easy to filter), (ii) clarification (improved appearance/clarity), (iii) better nutritional quality (increase in polyphenolics) and (iv) enhanced organoleptic characteristic (brighter color and complex aroma profile). In addition, EHT provides numerous other advantages to fermented fruit-based products such as better fermentation efficiency and enrichment in aroma. To meet the demand for new market trends, researchers and manufacturers are increasingly employing non-Saccharomyces yeast (with enzymatic activities) alone or in tandem with Saccharomyces cerevisiae to produce complex flavor profile in fermented fruit-based products. Therefore, this review also evaluates the potential of some non-Saccharomyces yeasts with enzymatic activities and how their utilization helps to tailor wines with unique aroma profile. Lastly, in view of an increase in lactose-intolerant individuals, the potential of fermented probiotic fruit juice as an alternative to dairy-based probiotic products is discussed.

Phytochemical Characterization of Dillenia indica L. Bark by Paper Spray Ionization-Mass Spectrometry and Evaluation of Its Antioxidant Potential Against t-BHP-Induced Oxidative Stress in RAW 264.7 Cells

The antioxidant effects of the ethyl acetate fraction of Dillenia indica bark (DIBEt) and the underlying mechanisms were investigated in tert-butyl hydroperoxide (t-BHP)-stimulated oxidative stress in RAW 264.7 cells. Paper spray ionization-mass spectroscopy with positive-ion mode tentatively revealed 27 secondary metabolites in D. indica bark extract; predominant among them were alkaloids, phenolic acids, and flavonoids. A new triterpenoid (nutriacholic acid) was confirmed in DIBEt for the first time. DIBEt had strong free radical-scavenging capabilities and was also able to reduce t-BHP-induced cellular reactive oxygen species (ROS) generation in RAW 264.7 cells. DIBEt was found to prevent oxidative stress by boosting the levels of heme oxygenase-1 (HO-1) through the up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) via the regulation of extracellular signal-regulated kinase (ERK) phosphorylation in RAW 264.7 cells. These results support the potential of DIBEt for defense against oxidative stress-stimulated diseases.

Quercetin and Naringenin Provide Functional and Antioxidant Protection to Stored Boar Semen

In this study, we evaluated the impact of 5-50 μM quercetin (QUE) and naringenin (NAR) on extended boar spermatozoa in the BTS (Beltsville Thawing Solution) medium for 72 h. Spermatozoa motion, membrane, acrosome, and DNA integrity were investigated immediately after sample dilution (0 h) as well as after 24 h, 48 h, and 72 h of semen storage. Furthermore, reactive oxygen species (ROS) and superoxide production, as well as the extent of oxidative damage to the sperm proteins and lipids, were assessed to determine the potential of QUE and NAR to prevent a potential loss of sperm vitality due to oxidative stress development. Our results indicate that the most notable parameter influenced by QUE was the mitochondrial activity, which remained significantly higher throughout the experiment (p < 0.001 and p < 0.0001; 10 μM), and which correlated with the most prominent maintenance of sperm motility (p < 0.01, 48 h; p < 0.05, 72 h). A significant membrane stabilization (p < 0.01, 24 h and 48 h; p < 0.0001, 72 h) and prevention of lipid peroxidation (p < 0.05, 24 h and 48 h; p < 0.01, 72 h) was primarily observed following administration of 10 and 25 μM NAR; respectively. Administration of 10 μM QUE led to a significant decrease of superoxide (p < 0.0001, 48 h and 72 h) while the most notable decline of ROS generation was recorded in the case of 10 and 25 μM NAR (p < 0.001). This study may provide new information on the specific mechanisms of action involved in the favorable effects of natural biomolecules on spermatozoa.

Flavonoids in adipose tissue inflammation and atherosclerosis: one arrow, two targets

Flavonoids are polyphenolic compounds naturally occurring in fruits and vegetables, in addition to beverages such as tea and coffee. Flavonoids are emerging as potent therapeutic agents for cardiovascular as well as metabolic diseases. Several studies corroborated an inverse relationship between flavonoid consumption and cardiovascular disease (CVD) or adipose tissue inflammation (ATI). Flavonoids exert their anti-atherogenic effects by increasing nitric oxide (NO), reducing reactive oxygen species (ROS), and decreasing pro-inflammatory cytokines. In addition, flavonoids alleviate ATI by decreasing triglyceride and cholesterol levels, as well as by attenuating inflammatory mediators. Furthermore, flavonoids inhibit synthesis of fatty acids and promote their oxidation. In this review, we discuss the effect of the main classes of flavonoids, namely flavones, flavonols, flavanols, flavanones, anthocyanins, and isoflavones, on atherosclerosis and ATI. In addition, we dissect the underlying molecular and cellular mechanisms of action for these flavonoids. We conclude by supporting the potential benefit for flavonoids in the management or treatment of CVD; yet, we call for more robust clinical studies for safety and pharmacokinetic values.

The role of polyphenols in poultry nutrition

In the last two decades, poultry and animal industries became increasingly interested in using plant-based feed supplements, herbs and their derivatives to retain or enhance their health and productivity. These health benefits for the host mainly attributed to the secondary plant metabolites, namely polyphenols. Polyphenols are renowned for their antioxidant, immunomodulatory, anti-mutagenic and anti-inflammatory properties. However, despite these advantages of polyphenols, they have been characterized by poor absorption in the gut and low concentration in target cells that compromise their role as effective antioxidants. The low bioavailability of polyphenols necessitates the need for further investigations to harness their full potential in poultry farms. This review is existing evidence about the bioavailability of polyphenols and their antioxidant, immunomodulatory, antimicrobial, detoxification properties and their impacts on poultry performance.

A Comprehensive Systematic Review of the Effects of Naringenin, a Citrus-Derived Flavonoid, on Risk Factors for Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of liver dysfunction worldwide. Recently, some natural compounds have attracted growing interest in the treatment of NAFLD. In this context, most attention has been paid to natural products derived from fruits, vegetables, and medicinal herbs. Naringenin, a natural flavanone, has been revealed to have pharmacological effects in the treatment of obesity and associated metabolic disorders such as NAFLD. The aim of this study was to examine the therapeutic effects of naringenin and its possible mechanisms of action in the management of NAFLD and related risk factors. The current systematic review was performed according to the guidelines of the 2015 PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) statements. We searched PubMed/Medline, Science Direct, Scopus, ProQuest, and Google Scholar databases up until February 2020. Of 1217 full-text articles assessed, 36 studies met the inclusion criteria. The evidence reviewed in the present study indicates that naringenin modulates several biological processes related to NAFLD including energy balance, lipid and glucose metabolism, inflammation, and oxidative stress by different mechanisms. Overall, the favorable effects of naringenin along with its more potency and efficacy, compared with other antioxidants, indicate that naringenin may be a promising therapeutic approach for the management of NAFLD and associated complications. However, due to the lack of clinical trials, future robust human randomized clinical trials that address the effects of naringenin on NAFLD and other liver-related diseases are crucial. Further careful human pharmacokinetic studies are also needed to establish dosage ranges, as well as addressing preliminary safety and tolerability of naringenin, before proceeding to larger-scale endpoint trials.

Phenolic Profiles, Antioxidant, and Inhibitory Activities of Kadsura heteroclita (Roxb.) Craib and Kadsura coccinea (Lem.) A.C. Sm

Kadsura spp. in the Schisandraceae family are woody vine plants, which produce edible red fruits that are rich in nutrients and antioxidant activities. Despite their valuable food applications, Kadsura spp. are only able to grow naturally in the forest, and reproduction handled by botanists is still in progress with a very low growth rate. Subsequently, Kadsura spp. were listed as endangered species by the International Union for Conservation of Nature and Natural Resources (IUCN) in 2011. Two different Kadsura spp., including Kadsura coccinea (Lem.) A.C. Sm. and Kadsura heteroclita (Roxb.) Craib, are mostly found in northern Thailand. These rare, wild fruits are unrecognizable to outsiders, and there have only been limited investigations into its biological properties. This study, therefore, aimed to comparatively investigate the phenolic profiles, antioxidant activities, and inhibitory activities against the key enzymes involved in diabetes (α-glucosidase and α-amylase) and Alzheimer's disease (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and beta-secretase 1 (BACE-1)) in different fruit parts (exocarp, mesocarp (edible part), seed, and core) of Kadsura coccinea (Lem.) A.C. Sm. and Kadsura heteroclita (Roxb.) Craib. The results suggested that Kadsura spp. extracts were rich in flavonol (quercetin), flavanone (naringenin), anthocyanidins (cyanidin and delphinidin), and anthocyanins (cyanidin 3-O-glucoside (kuromanin), cyanidin 3-O-galactoside (ideain), cyanidin 3-O-rutinoside (keracyanin), and cyanidin 3,5-di-O-glucoside (cyanin)). These flavonoids were found to be responsible for the high antioxidant activities and key enzyme inhibitions detected in Kadsura spp. extracts. The findings of the present study can support further development of Kadsura spp. as a potential source of phenolics and anti-oxidative agents with health benefits against diabetes and Alzheimer's disease. Besides, exocarp and the core of Kadsura spp. exhibited higher phenolic contents, antioxidant activities, and key enzyme inhibitory activities compared to the mesocarp and seeds, respectively. This information can promote the use of fruit parts other than the edible mesocarp for future food applications using Kadsura spp. rather than these being wasted.

Flavonoids in Agriculture: Chemistry and Roles in, Biotic and Abiotic Stress Responses, and Microbial Associations

The current world of climate change, global warming and a constantly changing environment have made life very stressful for living entities, which has driven the evolution of biochemical processes to cope with stressed environmental and ecological conditions. As climate change conditions continue to develop, we anticipate more frequent occurrences of abiotic stresses such as drought, high temperature and salinity. Living plants, which are sessile beings, are more exposed to environmental extremes. However, plants are equipped with biosynthetic machinery operating to supply thousands of bio-compounds required for maintaining internal homeostasis. In addition to chemical coordination within a plant, these compounds have the potential to assist plants in tolerating, resisting and escaping biotic and abiotic stresses generated by the external environment. Among certain biosynthates, flavonoids are an important example of these stress mitigators. Flavonoids are secondary metabolites and biostimulants; they play a key role in plant growth by inducing resistance against certain biotic and abiotic stresses. In addition, the function of flavonoids as signal compounds to communicate with rhizosphere microbes is indispensable. In this review, the significance of flavonoids as biostimulants, stress mitigators, mediators of allelopathy and signaling compounds is discussed. The chemical nature and biosynthetic pathway of flavonoid production are also highlighted.

Naringenin, a flavanone with antiviral and anti-inflammatory effects: A promising treatment strategy against COVID-19

At the end of 2019, a novel flu-like coronavirus named COVID-19 (coronavirus disease 2019) was recognized by World Health Organization. No specific treatments exist for COVID-19 at this time. New evidence suggests that therapeutic options focusing on antiviral agents may alleviate COVID-19 symptoms as well as those that lead to the decrease in the inflammatory responses. Flavonoids, as phenolic compounds, have attracted considerable attention due to their various biological properties. In this review, the promising effects and possible mechanisms of action of naringenin, a citrus-derived flavonoid, against COVID-19 were discussed. We searched PubMed/Medline, Science direct, Scopus, and Google Scholar databases up to March 2020 using the definitive keywords. The evidence reviewed here indicates that naringenin might exert therapeutic effects against COVID-19 through the inhibition of COVID-19 main protease, 3-chymotrypsin-like protease (3CLpro), and reduction of angiotensin converting enzyme receptors activity. One of the other mechanisms by which naringenin might exert therapeutic effects against COVID-19 is, at least partly, by attenuating inflammatory responses. The antiviral activity of the flavanone naringenin against some viruses has also been reported. On the whole, the favorable effects of naringenin lead to a conclusion that naringenin may be a promising treatment strategy against COVID-19.

Naringenin-Functionalized Multi-Walled Carbon Nanotubes: A Potential Approach for Site-Specific Remote-Controlled Anticancer Delivery for the Treatment of Lung Cancer Cells

Multi-walled carbon nanotubes functionalized with naringenin have been developed as new drug carriers to improve the performance of lung cancer treatment. The nanocarrier was characterized by Transmission Electron Microscopy (TEM), Fourier-Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy, Raman Spectroscopy, and Differential Scanning Calorimetry (DSC). Drug release rates were determined in vitro by the dialysis method. The cytotoxic profile was evaluated using the MTT assay, against a human skin cell line (hFB) as a model for normal cells, and against an adenocarcinomic human alveolar basal epithelial (A569) cell line as a lung cancer in vitro model. The results demonstrated that the functionalization of carbon nanotubes with naringenin occurred by non-covalent interactions. The release profiles demonstrated a pH-responsive behavior, showing a prolonged release in the tumor pH environment. The naringenin-functionalized carbon nanotubes showed lower cytotoxicity on non-malignant cells (hFB) than free naringenin, with an improved anticancer effect on malignant lung cells (A549) as an in vitro model of lung cancer.

Naringin nano-ethosomal novel sunscreen creams: Development and performance evaluation

Long term exposure of skin to UV rays produces detrimental effects such as premature skin-ageing and skin cancer. Although, zinc oxide (ZnO) and titanium dioxide (TiO₂) are good sunscreen agents, they do not provide highly efficient UV radiation protection and antioxidant and anti-aging effects. The present study was aimed at developing and characterizing ethosomes loaded with naringin and then to incorporate them into sunscreen creams containing nano-ZnO and -TiO₂ to achieve adequate skin penetration and skin retention so as to scavenge the free radicals by virtue of naringin's antioxidant property. Ethosomes were prepared and optimized with respect to concentrations of ethanol and cholesterol, time of sonication, drug and lipid ratio and amount of drug. The ethosomes were evaluated for size, zeta potential (ZP), polydispersity index (PDI), encapsulation efficiency and surface morphology. Ethosomal sunscreen creams were evaluated for physicochemical tests, spreadability, antioxidant, cytotoxicity and skin permeation studies. Optimized ethosomal formulation exhibited average vesicle size, PDI, ZP and drug encapsulation efficiency of 142.5 ± 5.6 nm, 0.199 ± 0.007, -72.5 ± 2.9 mV and 33.79 ± 1.35%, respectively. Naringin ethosomes showed enhanced retention in the skin (403.44 ± 15.33 μg/cm²) compared to naringin suspension (202.81 ± 9.45 μg/cm²). The optimized sunscreen cream exhibited SPF of 21.21 ± 0.62 with negligible permeation of naringin across the skin. Ethosomes showed pronounced skin permeation for naringin and optimized cream containing naringin ethosomes along with nano- ZnO and TiO2 showed good skin retention for naringin.

The Genoprotective Role of Naringin

Since ancient times, fruits and edible plants have played a special role in the human diet for enhancing health and maintaining youthfulness. The aim of our work was to determine the interactions between naringin, a natural ingredient of grapefruits, and DNA using an electrochemical biosensor. Electrochemical methods allow analyzing the damages occurring in the structure of nucleic acids and their interactions with xenobiotics. Our study showed that the changes in the location of electrochemical signals and their intensity resulted from the structural alterations in DNA. The signal of adenine was affected at lower concentrations of naringin, but the signal of guanine was unaffected in the same condition. The dynamics of changes occurring in the peak height and surface of adenine related to naringin concentration was also significantly lower. The complete binding of all adenine bases present in the tested double-stranded DNA solution was observed at naringin concentrations ranging from 8.5 to 10.0 µM. At larger concentrations, this active compound exerted an oxidizing effect on DNA. However, the critical concentrations of naringin were found to be more than twice as high as the dose absorbable in an average human (4 µM). The results of our work might be helpful in the construction of electrochemical sensors for testing the content of polyphenols and would allow determining their genoprotective functionality.

Hepatoprotective and Anti-Oxidative Effects of Total Flavonoids From Qu Zhi Qiao (Fruit of Citrus Paradisi cv.Changshanhuyou) on Nonalcoholic Steatohepatitis In Vivo and In Vitro Through Nrf2-ARE Signaling Pathway

Nonalcoholic steatohepatitis (NASH) is a liver disease defined as the dynamic condition of hepatocellular injury during the progress of nonalcoholic fatty liver disease (NAFLD). Total flavonoids from the dry and immature fruits of Citrus Paradisi cv.Changshanhuyou (accepted species name: Citrus × aurantium L) (Qu Zhi Qiao, QZQ) are purified and named TFCH. This study was purposed to investigate and analyze the effect of TFCH on NASH model through Nuclear factor erythroid 2-related factor 2 (Nrf2)- antioxidant response elements pathway in vivo and in vitro. In vivo study was performed using male C57BL/6 mice fed with high fat diet 16 weeks for NASH model. After 7-week modeling, mice in TFCH-treated group were daily treated with intragastric administration of TFCH at 25 mg/kg, 50 mg/kg, 200 mg/kg, respectively, for successive 8 weeks. Histopathological and immunohistochemical analyses were conducted for evaluating severity of NASH-mice model and the effect of TFCH treatment. In vitro experiment was performed by using human LX-2 cells and cultured with Free fatty acid (FFA) (Oleic acid: palmitic: l: 0.5 mmol/L) for 24 h and then treated with TFCH at different concentrations (0, 25, 50, 100, 200 mg/ml) for 6 h,12 h, and 24 h. Anti-apoptosis effect of TFCH on LX-2 cells cultured with FFA was revealed by the CCK-8 assay. Lipid parameters and oxidative stress markers were measured in vivo and in vitro, results showed that TFCH dose-dependently and greatly increased the antioxidant ability and reduced the oxidative damage in NASH model. The protein expression of Nrf2 and the downstream target genes in mice liver and human LX-2 cells were tested by Western blot analysis to investigate the possible molecular mechanisms of TFCH. Our results indicated that TFCH up-regulated protein expression of these genes and have the significant influence in activating the Nrf2-ARE signaling pathway. This study shows Nrf2-ARE signaling pathway may provide novel therapeutic opportunities for NASH therapy in the future.

Citrus fruit-derived flavonoid naringenin and the expression of hepatic organic cation transporter 1 protein in diabetic rats treated with metformin

Naringenin possesses many pharmacological effects and may modulate metformin disposition. The purpose of this study was to evaluate the role of naringenin on hepatic expression of organic cation transporter 1 (OCT1) protein and its associated effects on metformin-associated hyperlactataemia in diabetes. Forty-nine male Sprague Dawley rats randomly assigned to seven groups (n = 7) were orally treated daily with 3.0 mL/kg body-weight (BW) of distilled water (group 1) or 60 mg/kg BW of naringenin (groups 2 and 5) or 250 mg/kg BW of metformin (groups 3 and 6), respectively, dissolved in distilled water. Similarly, group 7 was given metformin and naringenin. Groups 4, 5, 6 and 7 were administered intraperitoneally with streptozotocin at a single dose of 60 mg/kg BW to induce diabetes. Glucose tolerance tests were performed. The animals were killed after 8 weeks of treatment, blood was collected, and livers excised for further biochemical analysis. Lowered body-weight, increased polydipsia and reduced hepatic glycogen concentrations were observed in diabetic rats compared to controls. Naringenin only significantly decreased plasma lactate levels, while metformin only or with naringenin significantly increased plasma lactate levels in diabetic compared to non-treated diabetic animals. Metformin only but not naringenin significantly increased plasma lactate levels in non-diabetic compared to control rats. Furthermore, naringenin with or without metformin but not metformin only significantly increased hepatic organic cation transporter 1 (OCT1) expression in diabetic compared to non-treated diabetic rats. Contrastingly, metformin only but not naringenin significantly increased hepatic OCT1 expression in non-diabetic rats compared to controls. Diabetic rats treated with metformin exhibited significantly increased plasma metformin concentrations compared to non-diabetic but naringenin significantly dropped this parameter. Conversely, hepatic metformin concentrations were significantly lower in diabetic rats treated with metformin compared to non-diabetic rats but significantly increased when naringenin was added. These results suggest that naringenin ameliorated hyperglycaemia-induced reduction in hepatic OCT1 expression leading to metformin accumulation and increased lactic acid production.

Naringin protects against Bisphenol-A induced oculopathy as implication of cataract in hypertensive rat model

People who have experienced high blood pressure are at greater risk of susceptibility to other health problems including oculopathy. The patients with these experiences do not have adequate treatment and those who do; spend much funds on the drug purchase. The study examines the protective effect of naringin (NRG) against ocular impairment in _L-NAME induced hypertensive rat on exposure to a cellular disruptor. Fifty-six adult male albino rats were randomly distributed into eight (n = 7) groups. Group I: control animals, Group II was treated with Nω-nitro-L-arginine methyl ester hydrochloride (_L-NAME), Group III was treated with 50 mg/kg Bisphenol-A, Group IV was treated with _L-NAME +50 mg/kg Bisphenol-A. Group V was administered with _L-NAME +80 mg/kg NRG. Group VI was administered with 50 Mg/kg BPA + 80 mg/kg NRG. Group VII was administered with _L-NAME+50 mg/kg Bisphenol-A +80 mg/kg NRG. Lastly, group VIII was treated with 80 mg/kg NRG alone for 14 days. Naringin prevented hypertension and ocular dysfunction by depleting the activities of angiotensin-converting enzymes, arginase, aldose-reductase and phosphodiesterase-5¹ (PDE-5¹) with corresponding down-regulation of inflammatory markers including TNF-α and IL-B. Moreover, ocular impairment was remarkably reduced by NRG as manifested by the decreased activities of AChE, BuChE, MAO-A and enzymes of ATP hydrolysis (ATPase, ADPase, AMPase) and adenosine deaminase with resultant increased NO level. Also, ocular expression of CD43 transcript, caspaace-9 and tumor suppressor P53 proteins were suppressed on treatment with NRG. This study corroborates the view that NRG may be a useful therapy in alleviating inflammatory markers, apoptosis and metabolic nucleotides disorders via the NOS/cGMP/PKG signaling pathways in hypertensive rat model on exposure to a cellular disruptor.

Potential therapeutic antipsychotic effects of Naringin against ketamine-induced deficits in rats: Involvement of Akt/GSK-3β and Wnt/β-catenin signaling pathways

AIM

Schizophrenia is a chronic, disabling and one of the major neurological illnesses affecting nearly 1% of the global population. Currently available antipsychotic medications possess limited effects. The current research aimed at investigating potential therapeutic add-on benefit to enhance the effects of clozapine anti-schizophrenic.

MAIN METHODS

To induce schizophrenia, ketamine was administered at a dose of 25 mg/kg i.p. for 14 consecutive days. Naringin was administered to Wistar rats at a dose of 100 mg/kg orally, alone or in combination with clozapine 5 mg/kg i.p from day 8 to day 14. Furthermore, behavioral tests were conducted to evaluate positive, negative and cognitive symptoms of schizophrenia. In addition, neurotransmitters' levels were detected using HPLC. Moreover, oxidative stress markers were assessed using spectrophotometry. Furthermore, apoptotic and wnt/β-catenin pathway markers were determined using western blotting (Akt, GSK-3β and β-catenin), colorimetric methods (Caspase-3) and immunohistochemistry (Bax, Bcl2 and cytochrome c).

KEY FINDINGS

Ketamine induced positive, negative and cognitive schizophrenia symptoms together with neurotransmitters' imbalance. In addition, ketamine treatment caused significant glutathione depletion, lipid peroxidation and reduction in catalase activity. Naringin and/or clozapine treatment significantly attenuated ketamine-induced schizophrenic symptoms and oxidative injury. Additionally, ketamine provoked apoptosis via increasing Bax/Bcl2 expression, caspase-3 activity, and Cytochrome C and Akt protein expression while naringin/clozapine treatment significantly inhibited this apoptotic effect. Moreover, naringin activated the neurodevelopmental wnt/β-catenin signaling pathway evidenced by increasing pGSK-3β and reducing pβ-catenin protein expression.

SIGNIFICANCE

These findings may suggest that naringin possesses a potential therapeutic add-on effect against ketamine-induced schizophrenia.

Metabolism and Pharmacokinetics of Phytochemicals in the Human Body

Background:

Phytochemicals are obtained from various plants and used for the treatment of diseases as both traditional and modern medicines. Poor bioavailability of phytochemicals is a major concern in applying phytochemicals as a therapeutic agent. It is, therefore, necessary to understand the metabolism and pharmacokinetics of phytochemicals for its implication as a therapeutic agent.

Methods:

Articles on the metabolism of phytochemicals from the PubMed database. The articles were classified into the digestion, absorption, metabolism, excretion, toxicity, and bioavailability of phytochemicals and the effect of gut microbiota on the metabolism of phytochemicals.

Results:

The metabolism of each phytochemical is largely dependent on the individual's digestive ability, membrane transporters, metabolizing enzymes and gut microbiota. Further, the form of the phytochemical and genetic make-up of the individual greatly influences the metabolism of phytochemicals.

Conclusion:

The metabolism of phytochemicals is mostly depended on the form of phytochemicals and individualspecific variations in the metabolism of phytochemicals. Understanding the metabolism and pharmacokinetics of phytochemicals might help in applying plant-based medicines for the treatment of various diseases.

Natural antioxidants' effects on endoplasmic reticulum stress-related diseases

Endoplasmic reticulum (ER) stress is a normal molecular process induced by the over-accumulation of misfolded or unfolded proteins. ER stress induces the unfolded protein response (UPR), which reduces global protein synthesis, increases ER capacity and protein degradation, to restart ER homeostasis, allowing cell survival. However, the over-induction of UPR can also trigger inflammatory processes, tissue damage and cell death. ER stress is involved in several pathologies, like endothelial dysfunction, diabetes and heart, liver, kidney or neurological diseases. Although the progression of these diseases is the result of several pathological mechanisms, oxidative stress has been widely related to these pathologies. Moreover, ER stress can establish a progressive pathological cycle with oxidative stress. Therefore, the use of natural antioxidants, able to modulate both oxidative and ER stress, can be a new strategy to mitigate these diseases. This review is focused on the effects of natural antioxidant compounds on ER stress in endothelial dysfunction, diabetes and heart, liver, kidney or neurological diseases.

Influence of the Chitosan and Rosemary Extract on Fungal Biodegradation of Some Plasticized PLA-Based Materials

The fungal degradation of the complex polymeric systems based on poly(lactic acid) (PLA) and natural bioactive compounds (chitosan and powdered rosemary alcoholic extract) was studied. Two fungal strains, Chaetomium globosum and Phanerochaete chrysosporium were tested. Both fungi characteristics and changes in morphology, structure and thermal properties were monitored. Biochemical parameters as superoxide dismutase, catalase, soluble protein and malondialdehyde have been determined at different time periods of fungal degradation. The fungi extracellular enzyme activities are slightly decreased in the case of composites containing bioactive compounds. The presence of natural compounds in the PLA-based polymeric system determines an acceleration of fungal degradation and probably the chemical hydrolysis, which further helps the attachment of fungi on the surface of polymeric samples. Significant decreases in average molecular mass of the polymeric samples were observed by fungi action; accompanied by structural changes, increase in crystallinity and decrease of thermal properties and the loss of the physical integrity and finally to degradation and integration of fungal degradation products into environmental medium. It was found that both fungi tested are efficient for PLA-based materials degradation, the most active from them being Chaetomium globosum fungus.