The Microbe (Sep 2024)
First report on a wonder endophyte Coma circularis from Basella rubra L. stem: a house of pharmaceutically active compounds
Abstract
Basella rubra L. is a tremendous source of biologically active compounds with proven therapeutic properties. Endophytes facilitate many of these properties. The selected fresh stems were surface sterilized, cut into small bits and cultured on potato dextrose agar plate for 7–10 days. Microscopic and molecular methods were used to characterize the fungi. This study isolated Coma circularis for the first time as an endophyte and inoculated it into potato dextrose broth for fermentation for 14 days. The broth was filtered, lyophilized, and tested. The filtrate showed antibacterial activity against antimicrobial resistant human pathogens of both Gram-positive (Methicillin-resistant Staphylococcus aureus, Minimum Inhibitory Concentration 5 mg/ml) and Gram-negative bacteria (Klebsiella pneumoniae, 5 mg/ml and Acinetobacter sp., Minimum Inhibitory Concentration 2.5 mg/ml). The outcomes of time kill kinetics assay depended on duration of exposure and concentration of filtrate. Filtrate potentially inhibited the tested bacteria at 2X MIC and 1X MIC, till 30 h; and at 1/2X MIC, up to 18 h. Furthermore, it damaged the cell membrane, which led to significant protein and nucleic acid leakage in treated cells at early hours (2 h). MTT assay analyzed the anti-proliferative effect on MCF7, MDA-MB-231, SKBR3, and MCF 10A cell lines. The measured IC50 values were 224.31, 326.28, 382.89 and 701.21 µg/ml respectively. In silico analysis predicted that a few compounds have antimicrobial and anticancer properties and fall within in Lipinski’s rule of five. Based on BOILED Egg prediction, except two, all are absorbed in GI or entered to brain. Therapeutic bioactive molecules in LCFS can be a good source and can open a door in new drug development to overcome the threats of AMR. As C. circularis has been isolated and identified as an endophyte from Basella rubra for the first time and no other findings have been publicly available, in-depth research is needed on the organism and its mode of action. Further, detailed studies should be carried out to determine the mode of cytotoxicity and pathways involved in in vivo models.
