Asian Pacific Journal of Tropical Biomedicine

327-334

Authors: Mohammad Reza Khazdair, Akbar Anaeigoudari, Gabriel A Agbor

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a novel coronavirus identified at the end of 2019. It is recognized as the causative agent of coronavirus disease 2019 (COVID-19). Flavonoids have been shown to exhibit therapeutical effect on complications related to COVID-19. The present study reviews possible therapeutic benefits of flavonoids on SARS-CoV-2. The Web of Science, PubMed, Scopus, and Google Scholar were searched using keywords: “COVID-19”, “SARS-CoV-2”, “Kaempferol” and “Quercetin” in the Title/Abstract. Relevant published articles in the English language until August 2020 were considered. Kaempferol and quercetin showed antiviral properties such as inhibition of protein kinase B and phosphorylation of protein kinase and blocking effects on a selective channel (3a channel) expressed in SARS-CoV infected cells. They also reduced the level of reactive oxygen species, expression of inducible nitric oxide synthase, pro-inflammatory mediators including TNF-α, IL-1α, IL-1β, IL-6, IL-10, and IL-12 p70, and chemokines. Kaempferol and quercetin might exert beneficial effects in the control or treatment of COVID-19 because of their antiviral, antioxidant, anti-inflammatory, and immunomodulatory effects.

344-352

Authors: Saber Mohamed Eweda, Mennatallah Ahmed Ali, Hala Mohamed Abd El-Bary, Nahed Hussein El-Sokkary, Madiha Hassan Helmy, Maher Abdel-Nabi Kamel

Objective: To investigate the modulatory effects of bitter gourd extract on the insulin signaling pathway in the liver and skeletal muscle tissues of diabetic rats. Methods: The ethanolic extract of bitter gourd was prepared and its contents of total polyphenols and flavonoids were assayed. A neonatal streptozotocin-induced diabetic rat model was established and the diabetic rats were assigned into different groups and were treated with different doses of bitter gourd extract (100, 200, 400, or 600 mg/kg) or with glibenclamide (0.1 mg/kg) for 30 d. Fasting blood glucose, insulin, and lipid profile were evaluated and the insulin signaling pathway in the liver and skeletal muscle of rats was investigated. The correlations between homeostasis model assessment (HOMA) and the components of insulin signaling pathway were also evaluated. Results: Different doses of bitter gourd extract significantly ameliorated fasting blood glucose level and HOMA index for insulin resistance. Moreover, bitter gourd extract increased serum insulin and improved disrupted serum lipid profile. The levels of insulin receptor substrate-1 (IRS-1), p-insulin receptor β (p-IR-β), protein kinase C (PKC), GLUT2, and GLUT4 were improved by treatment with bitter gourd extract. The best results were obtained with 400 mg/kg dose of the extract, the effect of which was equivalent to that of glibenclamide. HOMA in the bitter gourd treated rats was negatively correlated with p-IR-β, IRS-1 and PKC in hepatic and skeletal muscle. HOMA was also negatively correlated with skeletal muscle GLUT4. Conclusions: Bitter gourd extract improves glucose homeostasis and lipid profile in diabetic rats via enhancement of insulin secretion and sensitivity. Therefore, bitter gourd can be used as a potential pharmacological agent for the treatment of type 2 diabetes mellitus.

363-374

Authors: Anish Nag, Ritesh Banerjee, Priya Goswami, Maumita Bandyopadhyay, Anita Mukherjee

Objective: To compare the antioxidant and anti-genotoxic properties of Alpinia (A.) galanga, Curcuma (C.) amada, and C. caesia. Methods: Cytotoxicity of ethanolic extracts of A. galanga, C. amada, and C. caesia at selected doses was evaluated by trypan blue, MTT, and flow cytometry-based assays. Genotoxicity and anti-genotoxicity (against methyl methanesulfonate, 35 μM and H2O2, 250 μM) of these plants were studied by comet assay in human lymphocytes in vitro. Furthermore, DPPH, ABTS, FRAP, lipid peroxidation, and hydroxyl radical scavenging assays were performed to study the antioxidant potentials of the plants. Finally, anti-genotoxic potential of C. amada was validated in Swiss albino mice using comet assay. Phytochemical composition of C. amada was determined by GC/MS and HPLC. Results: The selected doses (2.5, 5, and 10 μg/mL) of A. galanga, C. amada, and C. caesia were non-toxic by cytotoxicity tests. All three ethanolic extracts of plant rhizomes demonstrated antioxidant and anti-genotoxic properties against methyl methanesulfonate-and H2O2-induced oxidative stress in human peripheral blood lymphocytes in vitro. Multivariate analysis revealed that various antioxidant properties of these extracts in DPPH, ABTS, and FRAP assays were strongly correlated with their total phenolic constituents. C. amada extract conferred protection against cyclophosphamide-induced DNA damage in the bone marrow cells of mice and DNA damage was significantly inhibited by 2.5 mg/kg C. amada extract. Conclusions: C. amada is rich in potentially bioactive molecules and exhibits potent antioxidant activities. Its anti-genotoxicity against cyclophosphamide-induced oxidative stress is also confirmed in this study.