Biochemical characterization and pharmacognostic evaluation of purified catechins in green tea (Camellia sinensis) cultivars of India

Green tea (GT) is derived from the leaves of Camellia sinensis implicated in a wide range of health attributes. In the present comprehensive study, methanolic, acetone and aqueous extract of leaves of C. sinensis var. sinensis [Kashmir (KW), Uttarakhand (IP & PN)] and C. sinensis var. assamica (Assam, AT) were explored for their phytoconstituents. Solvent extracts of GT cultivars showed rich presence of phytoconstituents in comparison with aqueous extracts. The methanolic extract of AT and acetone extract of KW showed highest total phenol content (18.32 ± 0.357 mg of GAE equivalent/g of sample) and total flavonoid content (29.25 ± 0.015 mg of catechin equivalent/g of sample), respectively. All the cultivars revealed higher free radical scavenging activity in the range of 73.80 ± 0.152 to 82.40 ± 0.004 % confirming antioxidant potentials. The HPLC analysis of purified residue procured from solvent partitioning depicted AT with highest concentration of epigallocatechin gallate (EGCg) i.e., 154.7 ± 4.949 mg/g followed by Kashmir and Uttarakhand GT cultivars. The present study revealed that Assam GT could be a potent herbal candidate with multiple nutraceutical applications. However, significant investigation of the cultivars is to be done to further explore the EGCg-dependent activity of GT for herbal drug development.