Caffeic Acid Genotoxicity: Correlation of the Pig-a Assay with Regulatory Genetic Toxicology In Vivo Endpoints

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.

Polyphenols and Their Impact on the Prevention of Neurodegenerative Diseases and Development

It is well known that neurodegenerative diseases' development and progression are accelerated due to oxidative stress and inflammation, which result in impairment of mitochondrial function, cellular damage, and dysfunction of DNA repair systems. The increased consumption of antioxidants can postpone the development of these disorders and improve the quality of patients' lives who have already been diagnosed with neurodegenerative diseases. Prolonging life span in developed countries contributes to an increase in the incidence ratio of chronic age-related neurodegenerative disorders, such as PD (Parkinson's disease), AD (Alzheimer's disease), or numerous forms of age-related dementias. Dietary supplementation with neuroprotective plant-derived polyphenols might be considered an important element of healthy aging. Some polyphenols improve cognition, mood, visual functions, language, and verbal memory functions. Polyphenols bioavailability differs greatly from one compound to another and is determined by solubility, degree of polymerization, conjugation, or glycosylation resulting from chemical structure. It is still unclear which polyphenols are beneficial because their potential depends on efficient transport across the BBB (blood-brain barrier), bioavailability, and stability in the CNS (central nervous system). Polyphenols improve brain functions by having a direct impact on cells and processes in the CNS. For a direct effect, polyphenolic compounds must be able to overcome the BBB and accumulate in brain tissue. In this review, the latest achievements in studies (animal models and clinical trials) on the effect of polyphenols on brain activity and function are described. The beneficial impact of plant polyphenols on the brain may be summarized by their role in increasing brain plasticity and related cognition improvement. As reversible MAO (monoamine oxidase) inhibitors, polyphenols are mood modulators and improve neuronal self-being through an increase in dopamine, serotonin, and noradrenaline amounts in the brain tissue. After analyzing the prohealth effects of various eating patterns, it was postulated that their beneficial effects result from synergistic interactions between individual dietary components. Polyphenols act on the brain endothelial cells and improve the BBB's integrity and reduce inflammation, thus protecting the brain from additional injury during stroke or autoimmune diseases. Polyphenolic compounds are capable of lowering blood pressure and improving cerebral blood flow. Many studies have revealed that a nutritional model based on increased consumption of antioxidants has the potential to ameliorate the cognitive impairment associated with neurodegenerative disorders. Randomized clinical trials have also shown that the improvement of cognitive functions resulting from the consumption of foods rich in flavonoids is independent of age and health conditions. For therapeutic use, sufficient quantities of polyphenols must cross the BBB and reach the brain tissue in active form. An important issue in the direct action of polyphenols on the CNS is not only their penetration through the BBB, but also their brain metabolism and localization. The bioavailability of polyphenols is low. The most usual oral administration also conflicts with bioavailability. The main factors that limit this process and have an effect on therapeutic efficacy are: selective permeability across BBB, gastrointestinal transformations, poor absorption, rapid hepatic and colonic metabolism, and systemic elimination. Thus, phenolic compounds have inadequate bioavailability for human applications to have any beneficial effects. In recent years, new strategies have been attempted in order to exert cognitive benefits and neuroprotective effects. Converting polyphenols into nanostructures is one of the theories proposed to enhance their bioavailability. The following nanoscale delivery systems can be used to encapsulate polyphenols: nanocapsules, nanospheres, micelles, cyclodextrins, solid lipid nanoparticles, and liposomes. It results in great expectations for the wide-scale and effective use of polyphenols in the prevention of neurodegenerative diseases. Thus far, only natural polyphenols have been studied as neuroprotectors. Perhaps some modification of the chemical structure of a given polyphenol may increase its neuroprotective activity and transportation through the BBB. However, numerous questions should be answered before developing neuroprotective medications based on plant polyphenols.

Cytotoxic and Genotoxic Evaluation of the Aqueous and Hydroalcoholic Leaf and Bark Extracts of Crataegus oxyacantha in Murine Model

Crataegus oxyacantha has been mainly used in traditional medicine for the treatment of cardiovascular diseases. However, its safety profile has not been fully established, since only the genotoxic effects of C. oxyacantha fruit have been described. Therefore, the objective of this work was evaluating the cytotoxicity and genotoxicity of the aqueous and hydroalcoholic leaf and bark extracts of C. oxyacantha by means of the micronucleus test in a murine model. Doses of 2000, 1000, and 500 mg/kg of both extracts were administered orally for 5 days in mice of the Balb-C strain. Peripheral blood smears were performed at 0, 24, 48, 72, and 96 h after each administration. The number of polychromatic erythrocytes (PCEs), micronucleated polychromatic erythrocytes (MNPCEs), and micronucleated erythrocytes (MNEs) was determined at the different sampling times. Our results showed that the leaf and bark of C. oxyacantha increase the number of MNEs at the 2000 mg/kg dose, and only the aqueous leaf extract decreases the number of PCEs at the same dose. Therefore, the aqueous and hydroalcoholic leaf and bark extracts of C. oxyacantha showed genotoxic effects, and only the aqueous leaf extract exhibited cytotoxic effects.

Caffeic acid: an antioxidant with novel antisickling properties

It is well documented that caffeic acid (3,4‐dihydroxycinnamic acid) (CA) interacts with and inhibits the oxidative reactions of myoglobin (Mb) and hemoglobin (Hb), and this interaction underlies its antioxidative action in meat. Sickle cell hemoglobin (HbS) is known for its tendency to oxidize more readily than normal HbA in the presence of hydrogen peroxide (H₂O₂), which leads to a more persistent and highly oxidizing ferryl Hb (HbFe⁴⁺). We have investigated the effects of CA on HbS oxidation intermediates, specifically on the ferric/ferryl forms. At a low concentration of H₂O₂ (0.5‐fold over heme), we observed a fivefold reduction in the amount of HbFe⁴⁺ accumulated in a mixture of ferric and H₂O₂ solution. Higher levels of H₂O₂ (onefold and twofold over heme) led to a lesser threefold and twofold reduction in the content of HbFe⁴⁺, respectively, possibly due to the saturation of the binding sites on the Hb molecule. The most intriguing finding was that when 5‐molar excess CA over heme was used, and a considerable increase in the delay time of HbS polymerization to approximately 200 s was observed. This delay in polymerization of HbS is theoretically sufficient to avoid microcapillary blockage and prevent vasoconstrictions in vivo. Mass spectrometry analysis indicated that CA was more extensively covalently bonded to βCys⁹³ than to βCys¹¹² and αCys¹⁰⁴. The dual antioxidant and antisickling properties of CA may be explored further to maximize its therapeutic potential in SCD.

Evaluation of cellular safety and the chemical composition of the peanut (Arachis hypogaea L.) ethanolic extracts

Arachis hypogaea L. (Leguminosae) is distributed in tropical and subtropical areas. Peanut has high nutritional and commercial value. Scientific research showed that peanut has biological properties such as anticancer, antioxidant, antiinflammatory. However, it is necessary to know if consumption of peanut, either as food or as a phytopharmaceutical implies a health risk. The aim was to evaluate cytotoxicity and genotoxicity of ethanolic extracts from A. hypogaea. Also, chemical characterization of these extracts was performed. Cytotoxicity was evaluated by MTT and Neutral Red Uptake (NRU) assays on Vero cells. Genotoxicity was studied by Micronuclei and comet assays on Balb/C mice. Qualitative and quantitative chemical analysis of extracts were performed. Results showed that extracts have low cytotoxicity. Tegument ethanolic extract (TEE) and Seed ethanolic extract (SEE) were not genotoxic. The treatments with TEE at 250 mg/kg and SEE at 2000 mg/kg revealed (highest concentrations evaluated) some toxicity on blood marrow cells of mice. Chemical characterization indicated that TEE had 74.33 ± 1.10 mg GAE/g of dried extract and SEE had 15.05 ± 0.06 mg GAE/g of dried extract of total phenolic content. Also, proanthocyanidins (O.D. at 550 nm 1.39 ± 0.15) and caffeic acid (2.46%) were identified in TEE. While, linoleic acid (58.84%) oleic acid (11.31%) and palmitic acid (8.37%) were major compounds of SEE. In conclusion, peanut consumption is safe at concentrations recommended for healthy uses, such as nutrition, and phytomedicine.