In vitro antibacterial and anticancer properties of Helicteres hirsuta Lour. leaf and stem extracts and their fractions.

Helicteres hirsuta Lour. (H. hirsuta) has been considered as a herbal medicine for the treatment of malaria and diabetes but limited studies have been conducted on its anticancer and antibacterial properties. In this study, the in vitro antibacterial and anticancer properties of the leaf and stem extracts and their two sub-fractions (aqueous and saponin-enriched butanol fractions) prepared from H. hirsuta were elucidated. MTT and CCK-8 assays were employed to assess their in vitro anticancer properties against various cancer cell lines. The antibacterial activity was assessed using the disc diffusion method and minimum inhibitory concentration (MIC) values were determined. The results revealed that the saponin-enriched fractions from H. hirsuta leaves and stems showed the highest antibacterial activity against E. coli (MIC values of 2.50 and 5.00 mg/mL, respectively) and S. lugdunensis (MIC values of 0.35 and 0.50 mg/mL, respectively). Importantly, these saponin-enriched fractions possessed strong anticancer activity in vitro towards a range of cancer cell lines including MIA PaCa-2 (pancreas); A2780 (ovarian); H460 (lung); A431 (skin); Du145 (prostate); HT29 (colon); MCF-7 (breast); SJ-G2, U87, SMA (glioblastoma) and BE2-C (neuroblastoma) at low doses (GI50 values of 0.36-11.17 µg/mL). They especially revealed potent anti-pancreatic cancer activity in vitro against MIA PaCa-2, BxPC-3 and CFPAC-1 cells with IC50 values of 1.80-6.43 µg/mL. This finding provides scientific evidence of the cytotoxic activity of the extracts prepared from H. hirsuta leaves and stems, and suggests further studies to isolate active compounds for development of new anticancer agents from these plant extracts.