Chemical composition, cytotoxic and pro-inflammatory enzyme inhibitory properties of Withania somnifera (L.) Dunal root extracts
Shivraj Hariram Nile, Yi Liang, Zengyuan Wang, Jiayi Zheng, Chengtao Sun, Arti Nile, Gopal Patel, Guoyin Kai
Abstract
Ashwagandha W. somnifera (L.) Dunal is a popular ethnomedicinal herb endowed with potential pharmacotherapeutic properties. In this study the ethanol extract (EE) and water extract (WE) of ashwagandha roots were qualitatively analysed using high performance liquid chromatography (HPLC), the results showed EE containing withanoside IV (a), physagulin D (b), 27-hydroxywithanone (c), withanoside V (d), withaferin A (e), withastramonolide (f), withanolide A (g), withanone (h), and withanolide B (i) as major bioactive compounds. Antioxidant potential was studied using four in vitro free radical scavenging assays and EE displayed higher antioxidant effect compared to WE for all assays. The EE also showed enzyme inhibitory effect against lipoxygenase (5-LOX) >cyclooxygenases-1 (COX-1) compared to cyclooxygenases-2 (COX-2) and to that of WE. Furthermore, EE demonstrated a potential cytotoxic effect on proliferation of A549 cells in vitro, showing IC50 values, 394.8 (24 h), 171.9 (48 h) and 126.1 (72 h) μg/mL, respectively. EE extract also exhibited induction of apoptosis in dose dependent manner confirmed with the production of ROS in A549 cells through flow cytometric analysis. The obtained results demonstrated that ashwagandha EE with high concentration of bioactive compounds could act as potential drug candidates against pro-inflammatory enzymes involved in development of inflammation and progression of lung cancer. Further, extensive research is needed to investigate the ashwagandha bioactive compounds responsible for treating inflammation, oxidative stress and lung cancer.