Determination of total phenolic and flavonoid content of Ghontoghe (Kleinhovia hospita L.) leaves: in vitro antioxidant study

Abstract

The Ghontohge plant (Kleinhovia hospita L.) has been used as a traditional medicine to treat scurvy, lice, eye pain, jaundice and hepatitis, cholesterol, diabetes, hypertension and treat pneumonia. Therefore, it is possible that plants can be used as antioxidants and redox signalling sourced from natural materials. The purpose of this study was to investigate the antioxidant potential and evaluate the total phenolic and flavonoid content of Ghontoghe leaves and investigate the most potent fraction as an antioxidant from the extract and fractions of Ghontoghe leaves. Ghontoghe leaf powder was extracted using the maceration method. Antioxidant activity was evaluated using 2,2-diphenyl-1-picryhidrazyl (DPPH) and 2,2-Azinobis 3-ethyl benzothiazoline 6-sulfonic acid radicals (ABTS). The total phenolic content was determined using the Folin-Ciocalteau method. Meanwhile, the total flavonoid content was determined using the aluminium chloride complex colourimetric method. The ethyl acetate fraction showed the strongest antioxidant activity on both DPPH radicals and ABTS radicals with IC50 values of 6.253±0.008 g/mL and 6.486±0.023 g/mL, respectively. The ethyl acetate fraction also showed high phenolic and flavonoid content with values of 26.92±0.10 mg GAE/g sample and 95±0.69 mg QE/g sample, respectively. The ethyl acetate fraction has the potential to be used as a source of natural antioxidants and has the potential to be used as a functional food.