Abstract
INTRODUCTION: Phenolic compounds isolated from medicinal plants are used against several physiological disorders. METHODS: In this investigation, microwave-assisted extraction parameters were optimized using response surface methodology (RSM) to determine the optimal extraction conditions for phenolic compounds from Periploca angustifolia extract (PAPE). The phenolic extract was characterized by nuclear magnetic resonance (NMR) spectroscopy. The antioxidant activity of the extract was evaluated using standard antioxidant assays. In addition, the protective effect of the phenolic extract was evaluated against cadmium toxicity. RESULTS AND DISCUSSION: Our analysis showed that the optimum extraction conditions were an irradiation time of 10 min, an extraction temperature of 100 °C, and a water-to-raw-material ratio of 30 mL/g. HPLC analysis indicated that PAPE contained quercetin, catechin, and caffeic acid. NMR (1D and 2D) spectra confirmed the compounds identified by HPLC. Antioxidant assays showed that PAPE exhibited a strong free-radical scavenging ability. In vivo analysis showed that PAPE produced a significant (p < 0.01) protective effect against oxidative damage induced by cadmium exposure in rat testicles. In conclusion, PAPE demonstrated strong antioxidant potential that is likely attributable to the active compounds present in the extract.