The Effects of Vernonia amygdalina on Vascular Smooth Muscle Cell Proliferation and Cytotoxicity in HT 29 Cell Lines

Abstract

Using the Cell Titer 96 MTT Proliferation Assay, the antiproliferative effects of methanol leaf extracts of Vernonia 
amygdalina (V. amygdalina) Del (Asteraceae) on Vascular Smooth Muscle Cells (VSMC) and Human Colorectal 
Adenocarcinoma Cell line (HT 29) were examined. The extract was administered to VSMC at log doses of 200 and 
800 g/mL and incubated for 24 and 48 hours. Extracts were also incubated for varying amounts of time with VEGF 
and ET-1 (the mitogens). The HT 29 cell line was treated with varying concentrations of extract (200, 400, and 700 
g/mL) for 24, 48, and 72 hours.  After 24 hours, both the plant extract and the mitogens had a greater impact on 
VSMC proliferation than the plant extract alone or in the presence of mitogens (except at 200 g/mL, when there was 
no proliferation in the presence of ET-1). The increase in growth was much more noticeable after 48 hours. Increase 
of 153.3% was seen, for instance, when 800 g/mL of V. amygdalina was combined with VEGF. In the cytotoxic 
trial with HT 29, the extract was cytotoxic throughout the whole dosage range. At 72 hours, 69.2% of cells were 
inhibited by a V. amygdalina dose of 200 g/mL. However, it should be pointed out that the extract's impact was 
most evident and persistent at the 24-hour time point. From these results, we may infer that although the extract 
stimulates VSMC proliferation, it has the opposite impact on the HT 29 cell line. Since the extract was shown to 
have inhibitory effects on the HT 29 cell line, this suggests that it displays a cytotoxic impact and might potentially 
serve as lead agents in the quest for an anticancer medication derived from natural sources.