In Vitro Antiproliferative Efficacy, Antioxidant Activity and LC MS Based Metabolite Profiling of Premna Barbata Stem Bark

Abstract

Premna barbata Wall. ex Schauer is used traditionally as folkloric medicines for the treatment of different
pathological conditions. The first reported constituent from the bark of the plant was an iridoid glycoside premnosidic acid having antioxidant activity. Other species of this genus i.e., Premna latifolia, Premna tomentosa has shown to have antioxidant and cytotoxic activities. Despite the ethnomedicinal uses, no scientific evidence in support of antitumor activity on the stem bark of Premna barbata is reported so far. Hence, the current work aims to assess anticancer potentiality of different extracts of P. barbata on various cancer cell lines. Different extracts i.e., Petroleum ether extract (PBPE), Chloroform extract (PBCE), Ethyl acetate extract (PBEE) and Alcoholic extract (PBAE) were prepared and on each extract in-vitro antiproliferative activity was performed by using SRB assay. The most potent extract i.e., PBEE was then evaluated for antioxidant activity. Qualitative phytochemical investigation of different extracts indicates the presence of proteins, carbohydrates, steroids/triterpenoids, alkaloids, glycosides, flavonoids, and phenolic constituents. Ethyl acetate extract of Premna barbata gives potent cytotoxic activity in all cancer cell lines but more selectively to human colon cancer cell line (COLO-205) with GI 50 44.6 μg/ml. The phenolic and flavonoid content in ethyl acetate extract was 3.43±0.09 mg GE/g and 4.28±0.18mg QE/g respectively. Nineteen compounds were observed in positive (+) ESI mode chromatograms when LC-MS analysis was carried out. The LC-MS analysis by positive ionization mode, the predicted compounds such as Geniposidic acid (synonym: Premnosidic acid) and Rutin were detected. The cytotoxicity observed on cancerous cell lines in our study may be due to the presence of observed compounds. So, it can be concluded that Premna barbata stembark has remarkable cytotoxic activity against different tumor cell lines but the effect is more on colon cell lines as compared to others.