Characterization and Cytoxicity Evaluation of Crude Ethanol Extract of the Herbal Plant Gynura Divaricata

Abstract

Gynura divaricata has been widely used as traditional Chinese medicine for treating a variety of diseases. The bioactive compounds of G. divaricata, especially its rich flavonoid and phenolic acid contents make the plant has potential to be used as an antimalarial. In order for a substance to be used as an antimalarial, it needs to have low toxicity against human cells. This study aims to obtain the crude ethanolic extract of G. divaricata, characterize its phenolic and flavonoid contents, and examine its cytotoxic activity in human cell lines. Extraction of G. divaricata was done using reflux extraction with 60% ethanol as the solvent. The characterization of G. divaricata crude ethanolic extract flavonoid and phenolic content were measured using aluminum chloride and gallic acid colorimetric assays. MTT assay was utilized to evaluate the cytotoxicity of the crude ethanolic extract in the human cell line (HEK-293). In this study, the extraction of G. divaricata leaves resulted in a yield of 17%. Moreover, the phenolic and flavonoid content was measured to be 4.4 ± 0.49 mgGAE/g and 6.026 ± 0.09 mQE/g, respectively. The low yield of phenolic content was suspected due to the degradation of gallic acid that was used. Unexpectedly, the crude ethanolic extract of G. divaricata was shown to exert high cytotoxic activity in human endothelial kidney (HEK-293) cells with an IC value of 1.0646 mg/ml. G. divaricata have been successfully extracted and its flavonoid and phenolic contents were measured, even though the yield was lower than expected. Future studies can be conducted to investigate the cytotoxicity activity of different crude extracts of G. divaricata. It is also highly recommended to do other cytotoxic or viability assays to ensure reliability and avoid false-positive results that were owned by the MTT assay.