The aqueous tuber extract of Pueraria tuberosa (Willd.) D.C. caused cytotoxic effect on HT 29 cell lines with down regulation of nuclear factor-kappa B (NF-κB)

Abstract

Abstract Background Pueraria tuberosa (Willd) D.C. (Fabaceae) tubers are already used in traditional medicine by Ayurvedic physicians for the management of fertility disorders, general weakness, and also as anti-ageing therapies. Other known pharmacological properties include: anti-hyperglycemics, hepatoprotective, anti-hyperlipidemic, diuretic, nutritive, and anti-fertility agents in male rats. Methods The anti-proliferative effect of the aqueous tuberous root extract of Pueraria tuberosa on vascular smooth muscle cells (VSMCs) and Human Colorectal Adenocarcinoma Cell lines (HT-29) was investigated using the Cell Titer 96 MTT Proliferation Assay where the viable cells were seeded at a density of 5 × 104 (100 µL/well). For VSMC, log concentrations of the extract at 200 and 800 µg/mL were added and incubated for 24 and 48 h time points. Incubation of the extract in the presence of vascular endothelial growth factor (VEGF) and ET-1 was also conducted at different times. Concentrations of the extract (200, 400 and 700 µg/mL) were also added and incubated with the HT 29 cell lines for 24, 48 and 72 h time points. The effect of the tuber aqueous extract of the plant on nuclear factor-κB (NF-κB) expression after 2 h was also carried out using immunoblotting technique. Results The result showed that after 24 h, the effect of the extract in the presence of the mitogens and on the VSMC was more of proliferation. However, at 48 h, the 200 µg/mL dose, both alone and in the presence of VEGF caused 11.1% and 25.9% decreases respectively, in cell proliferation. In the HT 29 cytotoxic study the 200 µg/mL concentration caused the greatest cytotoxic effect at 77.1% cell inhibition followed by 400 µg/mL concentration at 71.4% after 72 h. The immunoblotting assay showed a down regulation of NF-κB expressions with 0.7 µg/mL concentration showing the greatest effect. NF-κB, a pro-inflammatory agent is increasingly recognized as a crucial player in many steps of cancer initiation and progression. Conclusions It could therefore be concluded that the aqueous root extract of Pueraria tuberosa possesses cytotoxic effect and could serve as a lead compound for anticancer and anti-inflammatory agents.