In vitro photoprotective, antioxidant and antibacterial activity of Vernonia squarrosa (D. Don) Less

Abstract

Vernonia squarrosa (D. Don) Less. (Asteraceae) is an ethnomedicinally important plant of unexplored medicinal potential. The Hydro-Methanolic Leaf Extract (HMLE) reveals presence of alkaloids, terpenoid, tannins, phenols, flavonoids, saponins and also cardiac glycosides with notable amount of phenol, flavonoid, β carotene and lycopene. The high antioxidant activity of HMLE when assessed by 2, 2 diphenyl 1-picrylhydrazyl (DPPH) shows significant EC50value of 11.63 ± 2.60 μg/ml. Photoprotection efficiency of HMLE was determined and expressed as Sun Protection Factor (SPF). Reasonably high SPF value of 38 (SPF=38 at 200 μg/ml) provides UV blockage up to 98%. HMLE extract was also screened for antibacterial activity against four human pathogenic bacterial strains, Staphylococcus aureus (MTCC 2940), Pseudomonas aeruginosa (MTCC 2453), Bacillus subtilis (MTCC 441), Escherichia coli (MTCC 739). Results showed prominent antibacterial impact on these tested bacteria. Lupeol, a pentacyclic triterpenoid was found to be present as a dominant member in Gas chromatography-mass spectrometry (GC-MS) analysis of HMLE. Lupeol is a pentacyclic triterpenoid compound with diverse pharmaceutical applications. This is the maiden report of bioactive compounds from V. squarrosa highlighting their antibacterial, photoprotective and antioxidant activities.