Evaluation of antioxidant and analgesic activities of three medicinal plants

Abstract

Background: Medicinal plant species with antioxidant and pro-oxidant properties contemplate in high number of flavonoids, carotenoids, and phenolic acids. This present study has been designed to evaluate antioxidant and analgesic activities of three Bangladeshi medicinal plants. Materials and Methods: In this study, after the phytochemical screening, antioxidant activity of the crude methanol extracts of three medicinal species naming Bougainvillea glabra (Nyctaginaceae ), Licuala grandis (Arecaceae ), and Anthurium crystallinum (Araceae ) were evaluated using the spectrophotometric 1,1-diphenyl-2-picrylhydrazyl-free radical scavenging assay. In addition, total phenolic and total tannin contents have also been determined using standard gallic acid. Finally, analgesic activities of these plants have also been evaluated by acetic acid writhing inhibition and tail flick test in mice. Results: The inhibitory concentration 50% values of methanol crude extract of B. glabra , L. grandis , and A. crystallinum were 1.72, 2.18, and 13.21 μg/mL, whereas the standard (ascorbic acid) showed the value 3.90 μg/mL. The extracts of B. glabra , L. grandis , and A. crystallinum also showed the total phenolic contents as 40.97 ± 0.004, 247.272 ± 0.016, and 302.22 ± 0.011 mg gallic acid equivalent (GAE)/100 g, and the total tannin contents as 2172 ± 0.002, 435.7 ± 0.01, and 2414.98 ± 0.028 mg GAE/100 g of dried plant extract, respectively. The three-plant extracts have reduced the pain by both these methods in mice in a dose-dependent manner. Conclusion: In sum, it can be said that the three-plant species showed potent antioxidant and analgesic activities.