Antioxidant-mediated Anti-inflammatory Activity of Bougainvillea spectabilis Leaf Extracts: In vitro and In vivo Evaluation

Abstract

Background: Oxidative stress plays a major role in the development of inflammatory disorders, and plant-derived antioxidants are being explored for their ability to modulate oxidative stress-induced inflammation. Bougainvillea spectabilis is traditionally used in herbal medicine, but the impact of different extraction solvents on its phytochemical composition and antioxidant-mediated anti-inflammatory activity has not been systematically investigated. Objectives: This study aimed to examine the effect of extraction solvents on the phytochemical content of Bougainvillea spectabilis leaf extracts and to evaluate their antioxidant-mediated anti-inflammatory activity using both In vitro and In vivo approaches. Materials and Methods: Leaves of Bougainvillea spectabilis were extracted with ethanol, petroleum ether, and water. Phytochemical screening and quantification of total phenolic and flavonoid content were performed. The In vitro antioxidant potential of the extracts was assessed using standard assays, including the ferric reducing antioxidant power (FRAP) method. The In vivo anti-inflammatory activity of the most potent extract was evaluated in rats using the carrageenan-induced paw edema model. Paw edema volume was measured, and histopathological analysis of tissue was conducted. Statistical analysis was performed using ANOVA, with P < 0.05 considered significant. Results: The ethanol extract exhibited the highest phenolic and flavonoid content and showed significant In vitro antioxidant activity in the FRAP assay. Administration of this extract in rats significantly reduced paw edema compared to the control group, indicating notable anti-inflammatory activity. Histopathological evaluation revealed decreased inflammatory cell infiltration in treated animals. Conclusion: The anti-inflammatory effects of Bougainvillea spectabilis leaf extracts appear to be mediated, at least in part, by their antioxidant potential. Solvent selection significantly affects the phytochemical composition and biological activity, highlighting ethanol-extracted leaves as a promising source of antioxidant-mediated anti-inflammatory agents.