Phytochemical constituents and free radical scavenging activity of four Terminalia species

Terminalia is an important genus of trees, used in ‘Ayurvedic’ system of medicine. Four species of Terminalia (arjuna, bellarica, chebula and muelleri) were studied for their total phenolic contents (TPC), antioxidant activity (AOA) and free radical scavenging activities (FRSA). The TPC varied from 110.1 to 275.5 mg/g GAE, AOA from 62.3% to 92.1% and FRSA showed in terms of IC₅₀ (inhibitory concentration) from 0.031 to 0.110 mg/ml, EC₅₀ (efficient concentration) from 1.34 to 4.78 mg/mg_DPPH and antiradical power (ARP) from 20.91 to 74.62 in four species of Terminalia. TPC in fruits of all species were found highest from other parts. The fruits of T. arjuna showed better inhibition of lipid peroxidation assayed by ammonium thiocyanate. On the other hand, ferric ion chelating capacity (FICC) of fruits of T. chebula was highest. Fruits were also potential inhibitors of lipid peroxidation (LPO) and nitroblue tetrazolium chloride (NBT) reduction caused by superoxide anions. Specific phenolic composition performed through LC-PDA-MS-MS showed that the plant parts, especially fruits were rich in gallic acid, ellagic acid, and quercetin. The fruit extract of all species showed significant protection of DNA damage caused by free radicals.