Quantitation of β-carboline and quercetin in alligator weed (Alternanthera philoxeroides (Mart.) Griseb.) by LC-MS/MS and evaluation of cardioprotective effects of the methanol extracts

Revealing the potential bioactive components and mechanism of Qianhua Gout Capsules in the treatment of gouty arthritis through network pharmacology, molecular docking and pharmacodynamic study strategies

Recent clinical studies have confirmed the effectiveness of Qianhua Gout Capsules (QGC) in the treatment of gouty arthritis (GA). However, the specific regulatory targets and mechanisms of action of QGC are still unclear. To address this gap, we utilized network pharmacology, molecular docking, and pharmacodynamic approaches to investigate the bioactive components and associated mechanisms of QGC in the treatment of GA. By employing UPLC-Q Exactive-MS, we identified the compounds present in QGC, with active ingredients defined as those with oral bioavailability ≥30 % and drug similarity ≥0.18. Subsequently, the targets of these active compounds were determined using the TCMSP database, while GA-related targets were identified from DisGeNET, GeneCards, TTD, OMIM, and DrugBank databases. Further analysis including PPI analysis, GO analysis, and KEGG pathway enrichment was conducted on the targets. Validation of the predicted results was performed using a GA rat model, evaluating pathological changes, inflammatory markers, and pathway protein expression. Our results revealed a total of 130 components, 44 active components, 16 potential shared targets, GO-enriched terms, and 47 signaling pathways related to disease targets. Key active ingredients included quercetin, kaempferol, β-sitosterol, luteolin, and wogonin. The PPI analysis highlighted five targets (PPARG, IL-6, MMP-9, IL-1β, CXCL-8) with the highest connectivity, predominantly enriched in the IL-17 signaling pathway. Molecular docking experiments demonstrated strong binding of CXCL8, IL-1β, IL-6, MMP9, and PPARG targets with the top five active compounds. Furthermore, animal experiments confirmed the efficacy of QGC in treating GA in rats, showing reductions in TNF-α, IL-6, and MDA levels, and increases in SOD levels in serum. In synovial tissues, QGC treatment upregulated CXCL8 and PPARG expression, while downregulating IL-1β, MMP9, and IL-6 expression. In conclusion, this study applied a network pharmacology approach to uncover the composition of QGC, predict its pharmacological interactions, and demonstrate its in vivo efficacy, providing insights into the anti-GA mechanisms of QGC. These findings pave the way for future investigations into the therapeutic mechanisms underlying QGC's effectiveness in the treatment of GA.

Dual role of quercetin in enhancing the efficacy of cisplatin in chemotherapy and protection against its side effects: a review

Chemotherapy has opened a new window in cancer therapy. However, the resistance of cancer cells has dramatically reduced the efficacy of chemotherapy. Cisplatin is a chemotherapeutic agent and its potential in cancer therapy has been restricted by resistance of cancer cells. As a consequence, the scientists have attempted to find new strategies in elevating chemotherapy efficacy. Due to great anti-tumour activity, naturally occurring compounds are of interest in polychemotherapy. Quercetin is a flavonoid with high anti-tumour activity against different cancers that can be used with cisplatin to enhance its efficacy and also are seen to sensitise cancer cells into chemotherapy. Furthermore, cisplatin has side effects such as nephrotoxicity and ototoxicity. Administration of quercetin is advantageous in reducing the adverse effects of cisplatin without compromising its anti-tumour activity. In this review, we investigate the dual role of quercetin in enhancing anti-tumour activity of cisplatin and simultaneous reduction in its adverse effects.

Catalytic potential of a fungal indole prenyltransferase toward β-carbolines, harmine and harman, and their prenylation effects on antibacterial activity

The prenylation of compounds has attracted much attention, since it often adds bioactivity to non-prenylated compounds. We employed an enzyme assay with CdpNPT, an indole prenyltransferase from Aspergillus fumigatus with two naturally occurring β-carbolines, harmine (3) and harman (4) as prenyl acceptors, in the presence of dimethylallyl diphosphate (DMAPP) as the prenyl donor. The enzyme accepted these two prenyl acceptor substrates to produce 6-(3',3'-dimethylallyl)harmine (5) from 3 and 9-(3',3'-dimethylallyl)harman (6) and 6-(3',3'-dimethylallyl)harman (7) from 4. The X-ray crystal structure analysis of the CdpNPT (38-440) truncated mutant complexed with 4, and docking simulation studies of DMAPP to the crystal structure of the CdpNPT (38-440) mutant, suggested that CdpNPT could employ the two-step prenylation mechanism to produce 7, while the enzyme produced 6 with either one- or two-step prenylation mechanisms. Furthermore, the antibacterial assays revealed that the 3',3'-dimethylallylation of 3 and 4, as well as harmol (1), at C-6 enhanced the activities against Staphylococcus aureus and Bacillus subtilis.

“Malancha” [Alternanthera philoxeroides (Mart.) Griseb.]: A Potential Therapeutic Option against Viral Diseases

Alternanthera philoxeroides (Mart.) Griseb., commonly known as “Alligator weed” in English, and “Malancha” in Bengali, is a leafy vegetable from the family Amaranthaceae A. L. de Jussieu. This species is native to China, particularly to the provinces around the Yangtze River, other Far East and South-East Asian countries, and countries from other continents (e.g., South America). This plant also grows in certain areas in Australia, New Zealand, and the USA. While in Bangladesh the leaves of this plant are consumed as a vegetable, in China, this plant has been used widely as a traditional remedy for the treatment of various viral diseases (e.g., measles, influenza, and haemorrhagic fever). Flavonoids and saponins are the two largest groups of phytochemicals produced by this plant, and the antiviral property of this plant and its compounds has been studied extensively. This review article reviews all published literature on this plant and critically appraises its phytochemical profile linking to biomolecular interactions and therapeutic potential, particularly, against viral diseases.

The Genus Alternanthera: Phytochemical and Ethnopharmacological Perspectives

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

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

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

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

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

Quercetin: A Bioactive Compound Imparting Cardiovascular and Neuroprotective Benefits: Scope for Exploring Fresh Produce, Their Wastes, and By-Products

Quercetin, a bioactive secondary metabolite, holds incredible importance in terms of bioactivities, which has been proved by in vivo and in vitro studies. The treatment of cardiovascular and neurological diseases by quercetin has been extensively investigated over the past decade. Quercetin is present naturally in appreciable amounts in fresh produce (fruits and vegetables). However, today, corresponding to the growing population and global demand for fresh fruits and vegetables, a paradigm shift and focus is laid towards exploring industrial food wastes and/or byproducts as a new resource to obtain bioactive compounds such as quercetin. Based on the available research reports over the last decade, quercetin has been suggested as a reliable therapeutic candidate for either treating or alleviating health issues, mainly those of cardiovascular and neurological diseases. In the present review, we have summarized some of the critical findings and hypotheses of quercetin from the available databases foreseeing its future use as a potential therapeutic agent to treat cardiovascular and neurological diseases. It is anticipated that this review will be a potential reference material for future research activities to be undertaken on quercetin obtained from fresh produce as well as their respective processing wastes/byproducts that rely on the circular concept.

Potential Implications of Quercetin and its Derivatives in Cardioprotection

Quercetin (QCT) is a natural polyphenolic compound enriched in human food, mainly in vegetables, fruits and berries. QCT and its main derivatives, such as rhamnetin, rutin, hyperoside, etc., have been documented to possess many beneficial effects in the human body including their positive effects in the cardiovascular system. However, clinical implications of QCT and its derivatives are still rare. In the current paper we provide a complex picture of the most recent knowledge on the effects of QCT and its derivatives in different types of cardiac injury, mainly in ischemia-reperfusion (I/R) injury of the heart, but also in other pathologies such as anthracycline-induced cardiotoxicity or oxidative stress-induced cardiac injury, documented in in vitro and ex vivo, as well as in in vivo experimental models of cardiac injury. Moreover, we focus on cardiac effects of QCT in presence of metabolic comorbidities in addition to cardiovascular disease (CVD). Finally, we provide a short summary of clinical studies focused on cardiac effects of QCT. In general, it seems that QCT and its metabolites exert strong cardioprotective effects in a wide range of experimental models of cardiac injury, likely via their antioxidant, anti-inflammatory and molecular pathways-modulating properties; however, ageing and presence of lifestyle-related comorbidities may confound their beneficial effects in heart disease. On the other hand, due to very limited number of clinical trials focused on cardiac effects of QCT and its derivatives, clinical data are inconclusive. Thus, additional well-designed human studies including a high enough number of patients testing different concentrations of QCT are needed to reveal real therapeutic potential of QCT in CVD. Finally, several negative or controversial effects of QCT in the heart have been reported, and this should be also taken into consideration in QCT-based approaches aimed to treat CVD in humans.