Antioxidant and free radical scavenging properties of twelve traditionally used Indian medicinal plants.
Farrukh Aqil, Iqbal Ahmad, Zafar Mehmood
Author Affiliation: Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, 202 002, India.
Turkish Journal of Biology 30 : 177-183
Abstract : The methanolic crude extracts of 12 traditionally used Indian medicinal plants were screened for their antioxidant and free radical scavenging properties using ?-tocopherol and butylated hydroxy toluene (BHT) as standard antioxidants. The plants were: Allium sativum, Camellia sinensis, Delonix regia, Lawsonia inermis, Mangifera indica, Ocimum sanctum [O. tenuiflorum], Piper cubeba, Punica granatum, Terminalia bellirica, Terminalia chebula and Trigonella foenum-graecum. Antioxidant activity was measured by ferric thiocyanate (FTC) assay and compared with the thiobarbituric acid (TBA) method. Free radical scavenging activity was evaluated using diphenyl picryl hydrazyl (DPPH) radicals. The overall antioxidant activity of Lawsonia inermis was the strongest, followed in descending order by Ocimum sanctum, Cichorium intybus, Piper cubeba, Punica granatum, Allium sativum, Delonix regia, Terminalia chebula, Terminalia bellirica, Mangifera indica, Camellia sinensis, and Trigonella foenum-graecum. Seven plants, Terminalia chebula, Mangifera indica, Terminalia bellirica, Punica granatum, Ocimum sanctum, Cichorium intybus, and Camellia sinensis, showed strong free radical scavenging activity with the DPPH method. Phytochemical analysis of plant extracts indicated the presence of major phytocompounds, including phenolics, alkaloids, glycosides, flavonoids, and tannins. The phenolic concentrations in the above plants ranged from 28.66 to 169.67 mg/g of dry plant extract. A fair correlation between antioxidant/free radical scavenging activity and phenolic content was observed among 9 plants; however, in 3 plants (Piper cubeba, Lawsonia inermis and Trigonella foenum-graecum), no such relationship was observed. The tested plant extracts showed promising antioxidant and free radical scavenging activity, thus justifying their traditional use.