Phenolic content, flavonoid content and antioxidant activity of some medicinal plants used for traditional maternal healthcare in Katsina State, Nigeria

Abstract

An ethnobotanical study of medicinal plants used for traditional maternal healthcare in Katsina State, Nigeria revealed that Artemisia annua, Euphorbia balsamifera, Guiera senegalensis, Ipomoea asarifolia and Mitragyana inermis are the most common herbs used by women to treat and prevent ailments associated with oxidative stress during pregnancy. In this study, the phenolic flavonoid content and antioxidant activities of those herbs were investigated to justify their folkloric use. Phenolic and flavonoid contents were respectively assessed by evaluating total phenolic content (TPC) and total flavonoid Content (TFC) while antioxidant activity was determined using ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC) and 2,2ꞌ- diphenyl-1- picrylhydrazyl (DPPH) assays. G. senegalensis showed the highest TPC, TFC, FRAP, TAC and lowest DPPH IC₅₀ (136.07mg GAE/g DW, 158.80mg QE/g DW, 34.25mg AAE/g DW 424.73mg AAE/g DW and 442.82μg/ml, respectively) followed by M. inermis (113.69mg GAE/g DW, 87.50mg QE/g DW, 19.37mg AAE/g DW, 332.30mg AAE/g DW and 609μg/ml, respectively). Correlation analyses revealed strong positive linear correlations between phenolic antioxidants (TPC and TFC) and antioxidant assays (FRAP, TAC and DPPH) with regression coefficient (R²) ranging from 0.695 to 0.867 implying that phenolic compounds are responsible for the antioxidant properties observed in these herbs.

Keywords: Antioxidant activity, Katsina state, maternal healthcare, medicinal plants, Nigeria, traditional