α-Glucosidase Inhibition and Antioxidant Properties of Streptomyces sp.: In Vitro

Streptomyces-Derived Metabolites with Potential Photoprotective Properties-A Systematic Literature Review and Meta-Analysis on the Reported Chemodiversity

Sun overexposure is associated with the development of diseases that primarily affect the skin, which can lead to skin cancer. Among the main measures of photoprotection is the use of sunscreens. However, there is currently concern about the reported harmful effects to both humans and the environment due to several of the sunscreen ingredients available on the market. For this reason, the search for and development of new agents with photoprotective properties is required. In searching for these metabolites, researchers have turned their attention to microbial sources, especially the microbiota in unusual hostile environments. Among the diverse microorganisms available in nature, Actinobacteria and specifically Streptomyces, have been shown to be a source of metabolites with various biological activities of interest, such as antimicrobial, antitumor and immunomodulator activities. Herein, we present the results of a systematic review of the literature in which Streptomyces isolates were studied as a source of compounds with photoprotective properties. A meta-analysis of the structure-property and structure-activity relationships of those metabolites identified in the qualitative analysis phase was also carried out. These findings indicate that Streptomyces are a source of metabolites with potential applications in the development of new, safe and more eco-friendly sunscreens.

In vitro α-glucosidase inhibition, antioxidant, anticancer, and antimycobacterial properties of ethyl acetate extract of Aegle tamilnadensis Abdul Kader (Rutaceae) leaf

The present study was aimed to investigate in vitro α-glucosidase inhibition, antioxidant, anticancer, and antimycobacterial activities of the ethyl acetate extract of A. tamilnadensis leaves. The extract recorded strong α-glucosidase inhibition with an IC50 value of 100 μg/ml. The antioxidant potential of the extract was evaluated by nitric oxide radical inhibition, lipid peroxidation inhibition, ferric thiocyanate, and ABTS radical scavenging assay, and the extract recorded significant antioxidant activity. The ferric thiocyanate activity of extract was superior to butylated hydroxyl anisol (BHA), the standard antioxidant agent. The anticancer activity of the extract was evaluated against (1) breast cancer cell lines (MDAM B-231), (2) cervical cancer cell lines (HeLa), and (3) lung cancer cell line (A 549) using MTT assay, and significant activity was recorded against A 549 with an IC50 value of 64 μg/ml. Further studies on the morphology, acridine orange/ethidium bromide staining, and cell cycle analysis by flow cytometry confirm the extract-induced apoptosis in A 549. This extract also recorded significant anti-tuberculosis activity against Mycobacterium smegmatis. The current study suggests that the ethyl acetate extract of A. tamilnadensis is a potential source of natural α-glucosidase inhibitor and antioxidant for protection as well as prevention of life-threatening diseases like cancer.