Phytochemical screening for antimicrobial and antioxidant activity of periwinkle

Abstract

To perform preliminary phytochemical screening, investigate total flavonoids, phenolic, and antioxidants, and evaluate the antimicrobial potential of Catharanthus roseus, the chemical composition of the various crude extracts from the leaves was determined by GC-MS analysis. The dried leaves of C. roseus were powdered and subjected to extraction using three different solvents. All prepared extracts were then subjected to detect flavonoid and phenolic contents as per Folin-Ciocalteu and aluminium chloride methods, respectively. Various assays like SOD, POD, CAT, ABTS, and DPPH were used to analyze in vitro antioxidant activity. All plant extracts were further used to determine antimicrobial activity against five selected bacterial strains. Each section was subjected further to GC-MS. Preliminary phytochemical analysis showed that the maximum phytoconstituents were found in methanolic extract. The lowest IC50 value was exhibited by the methanolic extract, followed by the ethanolic extract. The activity levels of antioxidant enzymes in the plant extracts were satisfactory. The antimicrobial potential of the plant extracts was found to be positively correlated with the total phenolics and flavonoid contents. Fifteen different phytoconstituents were in methanolic, seven in ethanolic, while five compounds were identified in the petroleum ether extract by GC-MS. Some of these compounds are known to possess antimicrobial and antioxidant properties.