The current study aimed to screen the preliminary phytochemicals in the leaf extract of the medicinal plant Simarouba glauca and to analyze its potential antimicrobial, antioxidant and anticancer properties. The phytochemical profile of the methanol extract was analyzed, and bioactive compounds were identified using chromatography, FTIR and GCMS. Antimicrobial activity and Minimum Inhibitory Concentration (MIC) were determined against 14 bacterial and 6 fungal strains. Moreover, the synergistic effect of a plant extract with commercially available antibiotics was also evaluated using the checkerboard method. The ethanolic and methanolic extracts showed exclusive activity against S. aureus and profound activity against E. coli and S. marcescens. Upon comparing breakpoints, methanolic extract demonstrated higher antimicrobial activity with a MIC value of 3.2 mg/mL against the test pathogens. Furthermore, the extracts demonstrated potential antioxidant activity; methanol extract had higher antioxidant potential compared to the ethanol extract. The major proactive bioactive compound with maximum antioxidant capacity was observed to be terpenoids. The methanol extract of S. glauca showed significant cytotoxicity against the MCF-7 breast cancer cell line with an IC50 value of 16.12 µg/mL. The overall results of our work provide significant evidence for the usage of methanolic extract of S. glauca as an efficient ethnomedicinal agent and a potential candidate for relieving many human ailments.

In the present study, the anti-proliferative and apoptotic potential of Tabebuia roseo-alba in lung cancer was assessed. Silver nanoparticles (AgNPs) of T. roseo-alba were synthesized using an ethanolic extract and characterized by adopting various parameters. Herein, the eco-friendly, cost-effective, and green synthesis of AgNPs was evaluated using an ethanolic extract of T. roseo-alba. The as-synthesized AgNPs were then characterized using various characterization techniques, such as UV-visible spectroscopy (UV-vis), X-ray powder diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The AgNPs are crystalline, spherical, and highly stable AgNPs of varying sizes in the range of 5–20 nm. The anticancer activity of the ethanolic extract of T. roseo-alba and its AgNPs was determined using an MTT assay. The results indicated that, although both samples showed prominent anti-proliferative activity on lung cancer cell lines, the AgNPs of T. roseo-alba were found to be more potent than the ethanolic extract. Further, apoptosis induction ability was evaluated by FITC Annexin V and PI staining, the results of which demonstrated the efficiency of the ethanolic extract of T. roseo-alba and its AgNPs in causing oxidative stress and subsequent cellular death. This was subsequently further confirmed by measuring the mitochondrial membrane potential after staining the cells with JC1. The apoptotic mode of cell death was further confirmed by DNA fragmentation and caspase assays using Western blot analysis.

The pigments are the coloured substances obtained from various organic and inorganic sources. Due to the negative impact of chemically synthesized dyes and pigments, there is a significant demand for microbially derived natural colourants. Microorganisms secrete pigments as their secondary metabolites. Microbial pigments are found as an alternative to synthetic pigments as they are produced significantly in higher quantities through biotechnological processes. Microbial pigments replaced by artificial colourants are easily decomposable and do not cause hazardous effects on the ecosystem. Different microbes like bacteria, fungi and actinomycetes could be exploited in pigment production. Despite varied groups of microorganisms acting as a source of pigment, bacteria are predominant source for pigment production because of their genetic simplicity. Moreover, bacterial pigments are recognized for their biological activities which accomplish their usage as colourants and therapeutics in various industries. Regarding bacterial pigment production, fermentation strategies are essential to overcome the market demand, which is applied in the pharmaceutical, chemical and food industries. The importance of bacterial pigments over synthetic pigments in various industrial applications and their production strategies is well narrated in this review.