Phytocompound profiling and assessment of antioxidant antibacterial, anti-inflammatory, and cytotoxic activities of Momordica balsamina leaf extracts

Abstract

Background: The use of medicinal herbs has raised considerable interest worldwide attributed to their health-promoting effects. Momordica balsamina (M. balsamina) is a medicinal herb that has long been used to treat various ailments. Therefore, this study aims to profile the phytocompounds and assess antioxidant, antibacterial, anti-inflammatory, and cytotoxic activities of M. balsamina leaf extracts. Methodology: Methanol and water were used as extraction solvents. Profiling of phytochemical constituents of M. balsamina extracts was done using TLC, phytochemical screening tests, UV-Vis, FTIR, and UHPLC-qTOF-MS analysis. Biological activities were assessed using in vitro bioactivity screening (cytotoxicity and anti-inflammatory) assays, an antioxidant assay using free radical scavenging (DPPH) activity, and determination of minimum inhibitory concentration using the serial micro broth dilution technique. Results: Phytochemical screening revealed the presence of cardiac glycosides, flavonoids, saponins, tannins, and terpenoids in both extracts. The UV-VIS profile revealed various absorption bands ranging from 200 – 750 nm indicating the presence of flavonoids, phenolic compounds, tannins, terpenoids, carotenoids, chlorophyll, and alkaloids. FTIR spectra confirmed the presence of alkaloids, flavonoids, terpenes, anthraquinones, and phenolic compounds. The UHPLC-qTOF-MS detected flavonoid aglyclones such as quercetin, isorhamnetin, and kaempferol as well as dicaffeoylquinic, feruloyl isocitric and pseudolaroside A acids in the methanolic extract. Based on our knowledge, this is the first report on the presence of pseudolaroside A and feruloyl isocitric acid in M. balsamina leaves. UHPLC-qTOF-MS could not identify the compounds in the water extract. Both extracts had antioxidant potential and exhibited no antibacterial activity on gut-associated bacteria. In vitro cytotoxicity results showed that extracts were non-toxic against human colorectal adenocarcinoma (HT29 and Caco2), Vero, and RAW 264.7 cells. Methanolic extract showed anti-inflammatory activity on RAW 264.7 cells and water extract exhibited no activity. Conclusion: M. balsamina leaves contain plethora secondary metabolites with no cytotoxic potential and may be used as antioxidant and anti-inflammatory agents.