Sub-acute toxicity profile of a modified resveratrol supplement

Assessment of Acute and Chronic Toxicity in Wistar Rats (Rattus norvegicus) and New Zealand Rabbits (Oryctolagus cuniculus) of an Enriched Polyphenol Extract Obtained from Caesalpinia spinosa

Although herbal drugs are often considered safe for consumption, there is increasing evidence that some can generate undesirable health effects. However, polyphenols found in certain plants have been shown to provide a range of benefits for human health. In previous work, a standardized and quantified extract (P2Et) obtained from Caesalpinia spinosa (Dividivi) plant showed promising antioxidant, immunomodulatory, and anti-inflammatory properties in animal models of cancer and COVID-19 patients. The extract has also been subjected to genotoxicity, mutagenicity, and 28-day oral chronic toxicity evaluations, demonstrating a good safety profile. To advance preclinical and clinical development, further acute and chronic toxicity evaluations of the P2Et extract were performed. Acute toxicity tests were performed orally in Wistar rats at a dose of 2000 mg/kg, indicating that the lethal dose 50% (LD50) value exceeded 2000 mg/kg and classifying the P2Et extract as category 5 according to the Globally Harmonized System of Classification (GHS). In this work, chronic toxicity tests were conducted for 180 days on Wistar rats and New Zealand rabbits at a dose of 1000 mg/kg under Good Laboratory Practice (GLP) conditions. No weight loss or alterations in biochemical and hematological parameters associated with treatment were observed in the animals, suggesting the absence of toxicity in the assessed parameters. These results indicate that the P2Et extract is safe for oral administration at doses up to 1000 mg/kg body weight over a six-month period.

Phytochemical profiling, in vitro biological activities, and in silico (molecular docking and absorption, distribution, metabolism, excretion, toxicity) studies of Polygonum cognatum Meissn

Polygonum cognatum Meissn, a perennial herbaceous belonging to the Polygonaceae family, is an aromatic plant. High-performance liquid chromatography/diode array detector method was developed and validated for the phytochemical analysis of the plant. Also, various methods were used to investigate the antioxidant, antimicrobial, and cytotoxic activities of the methanolic extracts. Antioxidant activities were researched by 2,2'-diphenyl-1-picrylhydrazyl and cupric reducing antioxidant capacity methods. Among the tested standard microbial strains, Candida albicans was found to be more sensitive with a 24.60 ± 0.55 mm inhibition zone according to the diffusion tests. In the microdilution tests, the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration values were 4.75 and ≥ 4.75 mg/mL, respectively, for all tested pathogens. Human colon carcinoma cells were used to investigate cytotoxicity by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide analysis (IC50  = 2891 μg/mL for Plant A, IC50  = 3291 μg/mL for Plant B). Molecular docking and absorption, distribution, metabolism, excretion, and toxicity analysis were used to explain inhibition mechanisms of major phenolic compounds of plants against Tankyrase 1, Tankyrase 2 enzymes, and deoxyribonucleic acid gyrase subunit B and found compatible with experimental results.

A Review of Medicinal Plants and Phytochemicals for the Management of Gout

Gout, characterized by elevated uric acid levels, is a common inflammatory joint disease associated with pain, joint swelling, and bone erosion. Existing treatments for gout often result in undesirable side effects, highlighting the need for new, safe, and cost-effective anti-gout drugs. Natural products, including medicinal plants and phytochemicals, have gained attention as potential sources of anti-gout compounds. In this review, we examined articles from 2000 to 2020 using PubMed and Google Scholar, focusing on the effectiveness of medicinal plants and phyto-chemicals in managing gout. Our findings identified 14 plants and nine phytochemicals with anti-gout properties. Notably, Teucrium polium, Prunus avium, Smilax riparia, Rhus coriaria, Foenic-ulum vulgare, Allium cepa, Camellia japonica, and Helianthus annuus exhibited the highest xa-thine oxidase inhibitory activity, attributed to their unique natural bioactive compounds such as phenolics, tannins, coumarins, terpenoids, and alkaloids. Herbal plants and their phytochemicals have demonstrated promising effects in reducing serum urate and inhibiting xanthine. This review aims to report recent studies on plants/phytochemicals derived from herbs beneficial in gout and their different mechanisms.

Uncovering the mechanism of resveratrol in the treatment of diabetic kidney disease based on network pharmacology, molecular docking, and experimental validation

BACKGROUND

Diabetic kidney disease (DKD) has been the leading cause of chronic kidney disease in developed countries. Evidence of the benefits of resveratrol (RES) for the treatment of DKD is accumulating. However, comprehensive therapeutic targets and underlying mechanisms through which RES exerts its effects against DKD are limited.

METHODS

Drug targets of RES were obtained from Drugbank and SwissTargetPrediction Databases. Disease targets of DKD were obtained from DisGeNET, Genecards, and Therapeutic Target Database. Therapeutic targets for RES against DKD were identified by intersecting the drug targets and disease targets. GO functional enrichment analysis, KEGG pathway analysis, and disease association analysis were performed using the DAVID database and visualized by Cytoscape software. Molecular docking validation of the binding capacity between RES and targets was performed by UCSF Chimera software and SwissDock webserver. The high glucose (HG)-induced podocyte injury model, RT-qPCR, and western blot were used to verify the reliability of the effects of RES on target proteins.

RESULTS

After the intersection of the 86 drug targets and 566 disease targets, 25 therapeutic targets for RES against DKD were obtained. And the target proteins were classified into 6 functional categories. A total of 11 cellular components terms and 27 diseases, and the top 20 enriched biological processes, molecular functions, and KEGG pathways potentially involved in the RES action against DKD were recorded. Molecular docking studies showed that RES had a strong binding affinity toward PPARA, ESR1, SLC2A1, SHBG, AR, AKR1B1, PPARG, IGF1R, RELA, PIK3CA, MMP9, AKT1, INSR, MMP2, TTR, and CYP2C9 domains. The HG-induced podocyte injury model was successfully constructed and validated by RT-qPCR and western blot. RES treatment was able to reverse the abnormal gene expression of PPARA, SHBG, AKR1B1, PPARG, IGF1R, MMP9, AKT1, and INSR.

CONCLUSIONS

RES may target PPARA, SHBG, AKR1B1, PPARG, IGF1R, MMP9, AKT1, and INSR domains to act as a therapeutic agent for DKD. These findings comprehensively reveal the potential therapeutic targets for RES against DKD and provide theoretical bases for the clinical application of RES in the treatment of DKD.

Fabrication and Evaluation of Quercetin Nanoemulsion: A Delivery System with Improved Bioavailability and Therapeutic Efficacy in Diabetes Mellitus

The current study was intended to fabricate and evaluate ultrasonically assisted quercetin nanoemulsion (Que-NE) for improved bioavailability and therapeutic effectiveness against diabetes mellitus in rats. Ethyl oleate, Tween 20, and Labrasol were chosen as oil, surfactant, and cosurfactant, respectively. Box–Behnken design (BBD) was employed to study the influence of process variables such as % surfactant and cosurfactant mixture (Smix) (5 to 7%), % amplitude (20–30%) and sonication time (2.5–7.5 min) on droplet size, polydispersibility index (PDI), and % entrapment efficiency (%EE) were studied. The optimization predicted that 9% Smix at 25% amplitude for 2.5 min would produce Que-NE with a droplet size of 125.51 nm, 0.215 PDI, and 87.04% EE. Moreover, the optimized Que-NE exhibited appreciable droplet size and PDI when stored at 5, 30, and 40 °C for 45 days. Also, the morphological characterization by transmission electron microscope (TEM) indicated the spherical shape of the optimized nanoemulsion. Furthermore, the Que-NE compared to pure quercetin exhibited superior release and enhanced oral bioavailability. The streptozocin-induced antidiabetic study in rats revealed that the Que-NE had remarkable protective and therapeutic properties in managing body weight, blood glucose level, lipid profile, and tissue injury markers, alongside the structure of pancreatic β-cells and hepatocytes being protected. Thus, the developed Que-NE could be of potential use as a substitute strategy for diabetes.

Applications of Fruit Polyphenols and Their Functionalized Nanoparticles Against Foodborne Bacteria: A Mini Review

The ingestion of contaminated water and food is known to cause food illness. Moreover, on assessing the patients suffering from foodborne disease has revealed the role of microbes in such diseases. Concerning which different methods have been developed for protecting food from microbes, the treatment of food with chemicals has been reported to exhibit an unwanted organoleptic effect while also affecting the nutritional value of food. Owing to these challenges, the demand for natural food preservatives has substantially increased. Therefore, the interest of researchers and food industries has shifted towards fruit polyphenols as potent inhibitors of foodborne bacteria. Recently, numerous fruit polyphenols have been acclaimed for their ability to avert toxin production and biofilm formation. Furthermore, various studies have recommended using fruit polyphenols solely or in combination with chemical disinfectants and food preservatives. Currently, different nanoparticles have been synthesized using fruit polyphenols to curb the growth of pathogenic microbes. Hence, this review intends to summarize the current knowledge about fruit polyphenols as antibacterial agents against foodborne pathogens. Additionally, the application of different fruit extracts in synthesizing functionalized nanoparticles has also been discussed.

Bioactivity, bioavailability, and gut microbiota transformations of dietary phenolic compounds: implications for COVID-19

The outbreak of mysterious pneumonia at the end of 2019 is associated with widespread research interest worldwide. The coronavirus disease-19 (COVID-19) targets multiple organs through inflammatory, immune, and redox mechanisms, and no effective drug for its prophylaxis or treatment has been identified until now. The use of dietary bioactive compounds, such as phenolic compounds (PC), has emerged as a putative nutritional or therapeutic adjunct approach for COVID-19. In the present study, scientific data on the mechanisms underlying the bioactivity of PC and their usefulness in COVID-19 mitigation are reviewed. In addition, antioxidant, antiviral, anti-inflammatory, and immunomodulatory effects of dietary PC are studied. Moreover, the implications of digestion on the putative benefits of dietary PC against COVID-19 are presented by addressing the bioavailability and biotransformation of PC by the gut microbiota. Lastly, safety issues and possible drug interactions of PC and their implications in COVID-19 therapeutics are discussed.

Genotoxicity and mutagenicity assessment of a standardized extract (P2Et) obtained from Caesalpinia spinosa

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The P2Et extract was assessed for genotoxicity and mutagenicity activity.

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The P2Et extract showed no genotoxicity in Micronucleus assay.

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The P2Et extract showed no mutagenicity in Ames test.

The standardized P2Et extract obtained from Caesalpinia spinosa has shown antioxidant, and direct antitumor activity, but also activation of specific immune response through the induction of tumor immunogenic cell death in breast and melanoma cancer models. The present work evaluated the mutagenicity and genotoxicity profile of P2Et to continue the development of the P2Et. Genotoxicity was evaluated by OECD 1997 a guideline and mutagenicity by OECD 2016. At P2Et’s doses of 500, 1000, and 2000 mg/kg body weight in mice (Mus musculus), the difference between the number of micronuclei in PCE of the groups were not statistically significant (17 (negative control), 15 (500 mg/kg), 15 (1000 mg/kg), 19 (2000 mg/kg) and 271 (positive control). Similarly, P2Et did not induce gene mutations by base pair changes or frameshifts in the genome of Salmonella Typhimurium strains TA98, TA100, TA102, TA1535 and TA1537 at the tested range of concentrations up to 5000 μg/plate in the absence and presence of metabolic activation. Therefore, the P2Et was considered as non- mutagenic and non-genotoxic at the conditions of the tests.

Polyphenols from Food and Natural Products: Neuroprotection and Safety

Polyphenols are naturally occurring micronutrients that are present in many food sources. Besides being potent antioxidants, these molecules may also possess anti-inflammatory properties. Many studies have highlighted their potential role in the prevention and treatment of various pathological conditions connected to oxidative stress and inflammation (e.g., cancer, and cardiovascular and neurodegenerative disorders). Neurodegenerative diseases are globally one of the main causes of death and represent an enormous burden in terms of human suffering, social distress, and economic costs. Recent data expanded on the initial antioxidant-based mechanism of polyphenols’ action by showing that they are also able to modulate several cell-signaling pathways and mediators. The proposed benefits of polyphenols, either as protective/prophylactic substances or as therapeutic molecules, may be achieved by the consumption of a natural polyphenol-enriched diet, by their use as food supplements, or with formulations as pharmaceutical drugs/nutraceuticals. It has also been proved that the health effects of polyphenols depend on the consumed amount and their bioavailability. However, their overconsumption may raise safety concerns due to the accumulation of high levels of these molecules in the organism, particularly if we consider the loose regulatory legislation regarding the commercialization and use of food supplements. This review addresses the main beneficial effects of food polyphenols, and focuses on neuroprotection and the safety issues related to overconsumption.

Evaluation of garlic oil in nano-emulsified form: Optimization and its efficacy in high-fat diet induced dyslipidemia in Wistar rats

Garlic oil nanoemulsion was formulated using ultrasonic emulsification and the optimized garlic oil nanoemulsion ratio (1:2) of oil: surfactant showed spherical, with tiny droplet size 24.9 ± 1.11 nm. It was observed that the prepared nanoemulsion has the zeta potential of -42.63 ± 1.58 mV and a low polydispersity index of 0.2 ± 0.09 with excellent stability. The formulation was subjected to in vivo acute and sub-acute toxicity. In acute toxicity study, single oral administration of 18.63 ml of garlic oil nanoemulsion/kg resulted in immediate mortality. However, garlic oil nanoemulsion (0.46 ml/kg) and tween 80 (0.5 ml/kg) administered rats did not exhibit any toxicity and showed no changes in hematological and histological parameters. Further, both preventive and curative studies of garlic oil nanoemulsion were evaluated in high-fat diet fed dyslipidemic Wistar rats. Garlic oil nanoemulsion administered groups showed a significant effect in reducing the levels of lipid profiles (p < 0.001) compared to atorvastatin and garlic oil. Evaluation of lipid deposits in hepatic tissues was analyzed by Oil Red O staining, which revealed that garlic oil nanoemulsion administered rats markedly reduced the fat depots. Our findings suggest that garlic oil nano-emulsified form reduced toxicity and improved efficacy in preventing and treating dyslipidemia.

Targeting arachidonic acid pathway by natural products for cancer prevention and therapy

Arachidonic acid (AA) pathway, a metabolic process, plays a key role in carcinogenesis. Hence, AA pathway metabolic enzymes phospholipase A₂s (PLA₂s), cyclooxygenases (COXs) and lipoxygenases (LOXs) and their metabolic products, such as prostaglandins and leukotrienes, have been considered novel preventive and therapeutic targets in cancer. Bioactive natural products are a good source for development of novel cancer preventive and therapeutic drugs, which have been widely used in clinical practice due to their safety profiles. AA pathway inhibitory natural products have been developed as chemopreventive and therapeutic agents against several cancers. Curcumin, resveratrol, apigenin, anthocyans, berberine, ellagic acid, eugenol, fisetin, ursolic acid, [6]-gingerol, guggulsteone, lycopene and genistein are well known cancer chemopreventive agents which act by targeting multiple pathways, including COX-2. Nordihydroguaiaretic acid and baicalein can be chemopreventive molecules against various cancers by inhibiting LOXs. Several PLA₂s inhibitory natural products have been identified with chemopreventive and therapeutic potentials against various cancers. In this review, we critically discuss the possible utility of natural products as preventive and therapeutic agents against various oncologic diseases, including prostate, pancreatic, lung, skin, gastric, oral, blood, head and neck, colorectal, liver, cervical and breast cancers, by targeting AA pathway. Further, the current status of clinical studies evaluating AA pathway inhibitory natural products in cancer is reviewed. In addition, various emerging issues, including bioavailability, toxicity and explorability of combination therapy, for the development of AA pathway inhibitory natural products as chemopreventive and therapeutic agents against human malignancy are also discussed.

Diffusion Efficiency and Bioavailability of Resveratrol Administered to Rat Brain by Different Routes: Therapeutic Implications

Resveratrol possesses anti-tumor activities against central nervous system (CNS) tumors in vitro but has not yet been used clinically due to its low bioavailability, particularly in the CNS. This study thus aimed to elucidate brain bioavailability of trans-resveratrol by monitoring brain concentrations and dwell times following administration of resveratrol through intragastric, intraperitoneal, external carotid artery/ECA and intrathecal routes. In parallel, we evaluated the biological responses of rat RG2 glioblastoma cells as well as RG2-formed rat intracranial glioblastomas treated with resveratrol via intrathecal administration. The results revealed that resveratrol was detected in rat brains except when administered systemically. Intrathecal administration of reseveratrol led to abundant apoptotic foci and increased staining of the autophagy proteins, LC-3 and Beclin-1 and shrinkage of the intracranial tumors. In conclusion, the BBB penetrability of resveratrol is remarkably increased by intracthecal administration. Regular short-term resveratrol treatments suppress growth and enhance autophagic and apoptotic activities of rat RG2 glioblastoma cells in vitro and in vivo. Therefore, intrathecal administration of resveratrol could be an optimal intervention approach in the adjuvant management of brain malignancies.

Resveratrol based oral nutritional supplement produces long-term beneficial effects on structure and visual function in human patients

Background: Longevinex^® (L/RV) is a low dose hormetic over-the-counter (OTC) oral resveratrol (RV) based matrix of red wine solids, vitamin D₃ and inositol hexaphosphate (IP6) with established bioavailability, safety, and short-term efficacy against the earliest signs of human atherosclerosis, murine cardiac reperfusion injury, clinical retinal neovascularization, and stem cell survival. We previously reported our short-term findings for dry and wet age-related macular degeneration (AMD) patients. Today we report long term (two to three year) clinical efficacy. Methods: We treated three patients including a patient with an AMD treatment resistant variant (polypoidal retinal vasculature disease). We evaluated two clinical measures of ocular structure (fundus autofluorescent imaging and spectral domain optical coherence extended depth choroidal imaging) and qualitatively appraised changes in macular pigment volume. We further evaluated three clinical measures of visual function (Snellen visual acuity, contrast sensitivity, and glare recovery to a cone photo-stress stimulus). Results: We observed broad bilateral improvements in ocular structure and function over a long time period, opposite to what might be expected due to aging and the natural progression of the patient’s pathophysiology. No side effects were observed. Conclusions: These three cases demonstrate that application of epigenetics has long-term efficacy against AMD retinal disease, when the retinal specialist has exhausted other therapeutic modalities.

Resveratrol and calcium signaling: molecular mechanisms and clinical relevance

Resveratrol is a naturally occurring compound contributing to cellular defense mechanisms in plants. Its use as a nutritional component and/or supplement in a number of diseases, disorders, and syndromes such as chronic diseases of the central nervous system, cancer, inflammatory diseases, diabetes, and cardiovascular diseases has prompted great interest in the underlying molecular mechanisms of action. The present review focuses on resveratrol, specifically its isomer trans-resveratrol, and its effects on intracellular calcium signaling mechanisms. As resveratrol's mechanisms of action are likely pleiotropic, its effects and interactions with key signaling proteins controlling cellular calcium homeostasis are reviewed and discussed. The clinical relevance of resveratrol's actions on excitable cells, transformed or cancer cells, immune cells and retinal pigment epithelial cells are contrasted with a review of the molecular mechanisms affecting calcium signaling proteins on the plasma membrane, cytoplasm, endoplasmic reticulum, and mitochondria. The present review emphasizes the correlation between molecular mechanisms of action that have recently been identified for resveratrol and their clinical implications.