Caffeic acid, morin hydrate and quercetin partially attenuate sulfur mustard-induced cell death by inhibiting the lipoxygenase pathway

The effect of quercetin supplementation on clinical outcomes in COVID-19 patients: A systematic review and meta-analysis

Coronavirus disease (COVID-19) affects both the respiratory system and the body as a whole. Natural molecules, such as flavonoid quercetin, as potential treatment methods to help patients combat COVID-19. The aim of this systematic review and meta-analysis is to give a comprehensive overview of the impact of quercetin supplementation on inflammatory factors, hospital admission, and mortality of patients with COVID-19. The search has been conducted on PubMed, Scopus, Web of Science, EMBASE, and the Cochrane Library using relevant keywords until August 25, 2023. We included randomized controlled trials (RCTs) comparing COVID-19 patients who received quercetin supplementation versus controls. We included five studies summarizing the evidence in 544 patients. Meta-analysis showed that quercetin administration significantly reduced LDH activity (standard mean difference (SMD): -0.42, 95% CI: -0.82, -0.02, I 2 = 48.86%), decreased the risk of hospital admission by 70% (RR: 0.30, 95% CI: 0.14, 0.62, I 2 = 00.00%), ICU admission by 73% (RR: 0.27, 95% CI: 0.09, 0.78, I 2 = 20.66%), and mortality by 82% (RR: 0.18, 95% CI: 0.03, 0.98, I 2 = 00.00%). No significant changes in CRP, D-dimmer, and ferritin were found between groups. Quercetin was found to significantly reduce LDH levels and decrease the risk of hospital and ICU admission and mortality in patients with COVID-19 infection.

Natural Inhibitors against Potential Targets of Cyclooxygenase, Lipoxygenase and Leukotrienes

BACKGROUND

Cyclooxygenase (COX) and Lipoxygenase (LOX) enzymes catalyze the production of pain mediators like Prostaglandins (PGs) and Leukotrienes (LTs), respectively from arachidonic acid.

INTRODUCTION

The COX and LOX enzyme modulators are responsible for the major PGs and LTs mediated complications like asthma, osteoarthritis, rheumatoid arthritis, cancer, Alzheimer's disease, neuropathy and Cardiovascular Syndromes (CVS). Many synthetic Nonsteroidal Anti- Inflammatory Drugs (NSAIDs) used in the treatment have serious side effects like nausea, vomiting, hyperacidity, gastrointestinal ulcers, CVS, etc. Methods: The natural inhibitors of pain mediators have great acceptance worldwide due to fewer side effects on long-term uses. The present review is an extensive study of the advantages of plantbased vs synthetic inhibitors.

RESULTS

These natural COX and LOX inhibitors control inflammatory response without causing side-effect-related complicacy.

CONCLUSION

Therefore, the natural COX and LOX inhibitors may be used as alternative medicines for the management of pain and inflammation due to their less toxicity and resistivity.

Experimental and Clinical Studies on the Effects of Natural Products on Noxious Agents-Induced Lung Disorders, a Review

The harmful effects of various noxious agents (NA) are well-known and there are reports regarding the induction of various lung disorders due to exposure to these agents both in animal and human studies. In addition, various studies have shown the effects of natural products (NP) on NA-induced lung disorders. The effects of various NP, including medicinal plants and their derivatives, on lung injury induced by NA, were reviewed in this study. The improving effects of various NP including medicinal plants, such as Aloe vera, Anemarrhena asphodeloides, Avena sativa, Crocus sativus, Curcuma longa, Dioscorea batatas, Glycyrrhiza glabra, Gentiana veitchiorum, Gentiopicroside, Houttuynia cordata, Hibiscus sabdariffa, Hochu-ekki-to, Hippophae rhamnoides, Juglans regia, Melanocarpa fruit juice, Mikania glomerata, Mikania laevigata, Moringa oleifera, Myrtus communis L., Lamiaceae, Myrtle, Mosla scabra leaves, Nectandra leucantha, Nigella sativa, Origanum vulgare L, Pulicaria petiolaris, Paulownia tomentosa, Pomegranate seed oil, Raphanus sativus L. var niger, Rosa canina, Schizonepeta tenuifolia, Thymus vulgaris, Taraxacum mongolicum, Tribulus Terrestris, Telfairia occidentalis, Taraxacum officinale, TADIOS, Xuebijing, Viola yedoensis, Zataria multiflora, Zingiber officinale, Yin-Chiao-San, and their derivatives, on lung injury induced by NA were shown by their effects on lung inflammatory cells and mediators, oxidative stress markers, immune responses, and pathological changes in the experimental studies. Some clinical studies also showed the therapeutic effects of NP on respiratory symptoms, pulmonary function tests (PFT), and inflammatory markers. Therefore, the results of this study showed the possible therapeutic effects of various NP on NA-induced lung disorders by the amelioration of various features of lung injury. However, further clinical studies are needed to support the therapeutic effects of NP on NA-induced lung disorders for clinical practice purposes.

Vitamin C (Ascorbate) and Redox Topics in Cancer

Significance: Vitamin C (ascorbate), in regard to its effectiveness against malignancies, has had a controversial history in cancer treatment. It has been shown that in vitro and in vivo anticancer efficacy of ascorbate relies on its pro-oxidant effect mainly from an increased generation of reactive oxygen species (ROS). A growing understanding of its anticancer activities and pharmacokinetic properties has prompted scientists to re-evaluate the significance of ascorbate in cancer treatment. Recent Advances: A recent resurge in ascorbate research emerged after discovering that, at high doses, ascorbate preferentially kills Kirsten-Ras (K-ras)- and B-raf oncogene (BRAF)-mutant cancer cells. In addition, some of the main hallmarks of cancer cells, such as redox homeostasis and oxygen-sensing regulation (through inhibition of hypoxia-inducible factor-1 alpha [HIF-1α] activity), are affected by vitamin C. Critical Issues: Currently, there is no clear consensus from the literature in regard to the beneficial effects of antioxidants. Results from both human and animal studies provide no clear evidence about the benefit of antioxidant treatment in preventing or suppressing cancer development. Since pro-oxidants may affect both normal and tumor cells, the extremely low toxicity of ascorbate represents a main advantage. This guarantees the safe inclusion of ascorbate in clinical protocols to treat cancer patients. Future Directions: Current research could focus on elucidating the wide array of reactions between ascorbate and reactive species, namely ROS, reactive nitrogen species as well as reactive sulfide species, and their intracellular molecular targets. Unraveling these mechanisms could allow researchers to assess what could be the optimal combination of ascorbate with standard treatments.

Interactive Effects of Wide-Spectrum Monochromatic Lights on Phytochemical Production, Antioxidant and Biological Activities of Solanum xanthocarpum Callus Cultures

Solanum xanthocarpum is considered an important traditional medicinal herb because of its unique antioxidant, and anti-diabetic, anti-aging, and anti-inflammatory potential. Because of the over exploitation linked to its medicinal properties as well as destruction of its natural habitat, S. xanthocarpum is now becoming endangered and its supply is limited. Plant in vitro culture and elicitation are attractive alternative strategies to produce biomass and stimulate biosynthesis of medicinally important phytochemicals. Here, we investigated the potential influence of seven different monochromatic light treatments on biomass and secondary metabolites accumulation in callus culture of S. xanthocarpum as well as associated biological activities of the corresponding extracts. Among different light treatments, highest biomass accumulation was observed in white light-treated callus culture. Optimum accumulation of total flavonoid contents (TFC) and total phenolic contents (TPC) were observed in callus culture kept under continuous white and blue light respectively than control. Quantification of phytochemicals through HPLC revealed that optimum production of caffeic acid (0.57 ± 0.06 mg/g DW), methyl-caffeate (17.19 mg/g ± 1.79 DW), scopoletin (2.28 ± 0.13 mg/g DW), and esculetin (0.68 ± 0.07 mg/g DW) was observed under blue light callus cultures. Compared to the classic photoperiod condition, caffeic acid, methyl-caffeate, scopoletin, and esculetin were accumulated 1.7, 2.5, 1.1, and 1.09-folds higher, respectively. Moreover, high in vitro cell free antioxidant, anti-diabetic, anti-aging, and anti-inflammatory activities were closely associated with the production of these secondary metabolites. These results clearly showed the interest to apply multispectral light as elicitor of in vitro callus cultures S. xanthocarpum to promote the production of important phytochemicals, and allow us to propose this system as an alternative for the collection of this endangered species from the wild.