Phytochemical Screening and Characterization of Foeniculum vulgare Seeds Ethanol Extract as Potential Medicine for COVID-19.

Abstract

Since coronavirus disease 19 (COVID-19) was first found in China on 12 December 2019, finding potential treatments for this virus have always been pushed by many countries. The polyphenolic compound contained in Foeniculum vulgare seeds extract has been found to have antioxidant activity and is linked to the protection of diseases. Thus, the aim of this project is to perform extraction of Foeniculum vulgare seeds, phytochemical screening and characterization of Foeniculum vulgare seeds ethanol extract as potential source of herbal medicine for COVID-19. The extraction was carried out by using a maceration method in 96% ethanol with 1:5 sample-to-solvent ratio in three cycles. The secondary metabolites contained in the extract were checked via phytochemical screening, followed by determining the total phenolic and flavonoid content. The antioxidant activity was then evaluated by using DPPH, ABTS and FRAP assay. The obtained yield of fennel seeds ethanol extract was found to be 38.75%, in which the main secondary metabolites contained in the extract showed positive results for alkaloids, carbohydrates, saponin, cholesterol, flavonoids, tannins and quinones. The ethanolic extract of fennel seeds showed higher content of phenolic rather than the flavonoid content, with 7.8375 mg GAE/gram of extract and 0.1719 mg QE/gram of extract, which contributes to its high antioxidant properties. The IC50 of seeds extract was found to be 738.8 ± 24.48 (SE) μg/mL in DPPH assay and 404.7 ± 47.30 (SE) μg/mL in ABTS assay, while the antioxidant capacity of the extract was found to be 0.0479 in DPPH assay and 0.1367 in ABTS assay. Meanwhile the antioxidant power was measured by using FRAP assay, in which the fennel seeds ethanol extract contained 230.192 mg TE/gram of extract, which indicated a high antioxidant power properties of this extract.