Variation in chemical constituents, in-vitro bioactivity and toxicity profile among different parts of Clerodendrum glandulosum Lindl. (C. colebrookianum Walp.)

In this study, chemical, biological and toxicity profile of hydromethanolic extracts of different parts (leaf, stem and root) of Clerodendrum glandulosum Lindl. were investigated simultaneously for the first time. Total phenolic and flavonoid contents were estimated spectrophotometrically. Untargeted metabolomics was performed using GC–MS and HPLC-PDA-MS to identify the individual secondary metabolites. Antioxidant potentials (DPPH, ABTS, FRAP, phosphomolybdenum, superoxide ion scavenging assay) were estimated and enzyme inhibition assays (α-glucosidase, α-amylase, pancreatic lipase, xanthine oxidase, angiotensin-converting enzyme) were performed. Cytotoxicity of the extracts in HepG2 and L6 cell lines along with acute oral toxicity was carried out. Leaf extract exhibited the highest phenolic (282.02 ± 5.87 mg GAE/g) and flavonoid (276.74 ± 5.08 mg QCE/g) content. Significantly (p<0.05) high antioxidant and enzyme inhibition potential was found in leaf extract as compared to stem and root. Leaf extract (IC₅₀: 104.11 ± 0.36 μg/mL) exhibited comparatively better inhibition potential than standard inhibitor acarbose (IC₅₀: 232.57 ± 3.28 μg/mL) against α-glucosidase enzyme. Chemical analysis confirmed the presence of verbascoside in all the three parts, whereas caffeic acid, other verbascoside derivatives, scutellarin, luteolin, and apigenin were identified in leaf. No cytotoxicity was demonstrated except by stem extract at higher concentration (1000 µg/mL). However, no in-vivo toxicity was demonstrated by extracts of any parts. These findings provides a brief overview on the chemical and biological propensities of C. glandulosum Lindl. with possibility of its use in the management of various ailments.