ABSTRACT
Medicinal plants are being used as an alternative source of health management to cure various human ailments. The healing role is attributed to the hidden dynamic groups of various phytoconstituents, most of which have been recorded from plants and their derivatives. Nowadays, medicinal plants have gained more attention due to their pharmacological and industrial potential. Aromatic compounds are one of the dynamic groups of secondary metabolites (SM) naturally present in plants; and anthraquinones of this group are found to be attractive due to their high bioactivity and low toxicity. They have been reported to exhibit anticancer, antimicrobial, immune-suppressive, antioxidant, antipyretic, diuretic and anti-inflammatory activities. Anthraquinones have been also shown to exhibit potent antiviral effects against different species of viruses. Though, it has been reported that a medicinal plant with antiviral activity against one viral infection may be used to combat other types of viral infections. Therefore, in this review, we explored and highlighted the antiviral properties of anthraquinones of Polygonaceae, Rubiaceae and Asphodelaceae families. Anthraquinones from these plant families have been reported for their effects on human respiratory syncytial virus and influenza virus. They are hence presumed to have antiviral potential against SARS-CoV as well. Thus, anthraquinones are potential candidates that need to be screened thoroughly and developed as drugs to combat COVID-19. The information documented in this review could therefore serve as a starting point in developing novel drugs that may help to curb the SARS-COVID-19 pandemic.
ABSTRACT
Many people in different African countries are suffering from different diseases many of which result in serious life threat and public health problems with high risk of infection and mortality. Due to less accessibility and high cost of modern drugs, people of this continent often depend on traditional medicine using medicinal plants to manage the diseases. Africa has large tropical rain forests, which are very rich in medicinal plants. Many of them have been scientifically proven for their medicinal values. These medicinal plants which constitute a large repertoire of endophytes have not been significantly explored for the isolation of these microorganisms and their bioactive secondary metabolites. This review summarizes the research on endophytes isolated from medicinal plants of Africa, their pharmacological potential and some of their biotechnological aspects. Novel compounds reported from endophytes from Africa with their biological activities have also been reviewed. Information documented in this review might serve as starting point for future researches on endophytes in different African countries.
Subject(s)
Plants, Medicinal , Endophytes/genetics , HumansABSTRACT
PURPOSE: Despite the fact that hyper-activation of Wnt/ß-catenin signaling pathway has been seen in many cancers, including liver, colorectal and lung carcinoma, no small molecule inhibitors are available that specifically target this pathway. In this study, we analyzed the impact of dinactin (DA), an antibiotic ionophore produced by Streptomyces species, as an effective small molecule targeting Wnt/ß-catenin signaling pathway in cancer cells. METHODS: We performed MTT assays to investigate cell viability and proliferation after exposure to small molecules. Protein expression analysis was carried out by western blotting. Top-Flash reporter assays were used to score for ß-catenin signaling and cell cycle analysis was carried out by flow cytometry. RESULTS: In the first set of experiments, DA was seen to selectively inhibit the proliferation of HCT-116 and HepG2 cancer cells, unlike HEK-293 cells (a low tumorigenic cell line), in apoptosis-independent manner. Further, DA was seen to block the G1/S progression and decrease the expression of cyclin D1 in cancer cells. Since cyclin D1 is the downstream target gene of Wnt/ß-catenin signaling, we examined the impact of DA on TCF-dependent ß-catenin activity using Top-Flash reporter assay. Interestingly, DA significantly decreased Top-Flash activity at lower nano-molar concentrations when compared with salinomycin in HCT-116 and HepG2 cells. CONCLUSION: We report the identification of dinactin as a natural product-based small molecule that effectively blocks the Wnt/ß-catenin signaling pathway in cancer cells at nano-molar concentration. We anticipate that DA could be developed as a novel drug for anti-cancer therapy and for the management of neuropathic pain.
