Study of Sinapic Acid, Caffeic Acid, Vanillic Acid and Bougainvillea Extracts: Evaluating Their Effect on Proliferation of Chick Embryo Fibroblast Cells and Determining Their Ability to Reduce MTT Reagent

Plant polyphenols exhibit antioxidant and anticancer activities, and their cytotoxic effects are evaluated by MTT assay. Some polyphenols and plant extracts have potential to reduce the MTT reagent, thereby influencing experimental outcomes. This study aims to evaluate the effects of sinapic acid (SA), caffeic acid (CA), vanillic acid (VA) and bougainvillea extracts (BEE yellow flower[YF] and BEE white flower [WF]), on the growth of chick embryo fibroblast cells (CEF cells), and to investigate their interaction with the MTT reagent. The MTT readings of SA and CA treated cells increased with increasing concentration, suggesting cell growth, whereas for BEE (YF) and BEE (WF), readings decreased, indicating growth inhibition. However, the morphology of CA and BEE (WF) treated cells appeared rounded, indicating potential cytotoxic effects. In contrast, cells treated with SA, VA, and BEE (YF) did not show any noticeable changes in morphology. Cell-free MTT assays were performed to investigate the interaction of polyphenols and plant extracts with the MTT reagent. The MTT absorbance readings for SA and CA exhibited a dose-dependent increase, suggesting their capacity to effectively reduce the MTT reagent compared to VA. Both bougainvillea extracts also demonstrated the capacity to reduce the MTT reagent in a dose-dependent manner in the cell-free system. The MTT reduction potential of polyphenols followed the order CA > SA > VA, while for bougainvillea extracts, it was BEE (WF) > BEE (YF). The IC50 values were 21.15 µM for SA, 17.3 µM for CA, >1000 µM for VA, 46.03 µg/ml for BEE (YF) and 21.08 µg/ml for BEE (WF).