Determination of polyphenolic content and antioxidant potential of callus extract obtained from Celastrus paniculatus Willd. and their free radical estimation by electron spin resonance spectroscopy

Abstract

Celastrus paniculatus Willd. belongs to the family Celastraceae is an important medicinal plant distributed all over India. Since the anti-oxidative polyphenols in C. paniculatus have received an increase in attention for health-promoting properties by scavenging the free radicals, the objective of the present study is aimed to understand the antioxidant potential of calli cultures generated from C. paniculatus. To establish the calli cultures, leaf explants of C. paniculatus were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of 6 -BAP (0.5 mg. L-1) along with 2,4-D and NAA (0.1 to 0.7 mg. L-1). MS medium supplemented with 0.5 mg. L-1 (BAP + NAA) and 0.5 mg. L-1 of BAP + 0.3 mg. L-1 2,4-D showed to be the best medium for the formation of calli. The calli cultures were harvested and lyophilized for methanolic extraction and estimate the total phenolic and flavonoid content in the calli cultures by using the spectroscopic method and also analyzed by HPTLC profiling and HPLC to assess their antioxidant potential. Histological findings supported the result of HPTLC and HPLC by displaying a clear deposition of polyphenols in the vacuoles. Additionally, free radical generated from biological system detected and ‘g’ value identified by the electron spin resonance spectrum and understood their radical scavenging activity by several non-enzymatic methods which includes DPPH assay, reducing power activity, ABTS radical scavenging assay and ferric reducing antioxidant power assay. Based on the present investigation it was concluded that 0.5 mg. L-1 of BAP alongwith NAA is optimal hormone concentration for developing friable calli which inturn yielded higher phenolic and flavonoid content.