Abstract

A COMPARATIVE ASSESSMENT OF ANTIOXIDANT AND ANTIBACTERIAL PROPERTIES OF FOUR COMMON EDIBLE HERBS OF BANGLADESH

Shams Ara Khan*, Liton Sikder, Md Roich Khan, Muhammad Torequl Islam

ABSTRACT

Edible herbs are important source of nutrients and very common in the daily diet of Bangladeshi people. Hence the present study was undertaken with an overall objective of assessing antioxidant and antibacterial potentials of four common Bangladeshi edible herbs (leafy vegetables). The total phenolic content (TPC), total flavonoid content (TFC) and total tannin content (TTC) of the analyzed herbs ranged from 80.35 to 210.34 mg gallic acid equivalent per 100g dry weight, 110.83 to 220.90 mg quercetin per 100g dry weight and 100.00 to 260.47 mg gallic acid equivalent per 100g dry weight respectively. All the four extracts showed different level of antioxidant activities as evaluated by three in vitro assays such as DPPH radical scavenging, hydrogen peroxide radical scavenging and ferric ion reducing power activity. The results reveled that, Amaranthus viridis showed highest DPPH and hydrogen peroxide radical scavenging (IC50 ~52 μg/ml and ~101 μg/ml respectively) with highest phenol and flavonoid content(210.34 mg GAE/100g dw and 220.90 mg QE/100g dw respectively). But, Amaranthus lividus presented the better reducing power activity than the other three plants. In antimicrobial assay, two doses (250μg and 500μg) of four plant extracts were tested against eleven bacterial species. Piper longum exhibited strong antibacterial activity against all species whereas Amaranthus viridis showed no activity against any single strain. Interestingly, Piper longum presented the highest TTC value (260.47 mg GAE/100g dw). The study findings concluded that the consumption of these herbs could exert several beneficial effects by virtue of their antioxidant and antibacterial activity.

Keywords: Bangladeshi edible herbs; Antioxidant; TPC; TFC; TTC; DPPH; Hydrogen peroxide; Reducing power; Bacterial strain.