In Vivo Anti-Inflammatory, Analgesic, Sedative, Muscle Relaxant Activities and Molecular Docking Analysis of Phytochemicals from Euphorbia pulcherrima

Euphorbia pulcherrima is an important medicinal plant that is used in a traditional system for its curative properties such as analgesic potency, antipyretic, anti-inflammatory, sedation potential, and antidepressant and cure of diseases such as skin diseases. This study deals with the isolation of two flavonoids namely spinacetin (1) and patuletin (2) from chloroform fraction of Euphorbia pulcherrima. The isolated compound spinacetin (1) and patuletin (2) were screened for in vivo anti-inflammatory, analgesic, sedative, and muscle relaxant effects. Compounds 1 and 2 were assessed against hot plate-induced noxious stimuli at various doses which showed excellent (p < 0.05) analgesic effect in a dose-dependent manner. The muscle relaxant activity was determined by traction and inclined screening model, both compounds showed significant muscle relaxant activity with time. The sedative potential of isolated compounds 1 and 2 was determined by the open field model, both compounds showed good sedation (p < 0.05) at 20 mg/kg. The anti-inflammatory potential of compound 1 was recorded by histamine-induced paw edema and carrageen paw edema model, and in both models, compounds 1 and 2 showed strong effect at 20 mg/kg. Binding orientations, binding energy values, and computed inhibition constants (Ki) values revealed that the studied compounds have a good to excellent inhibition potential against μ-opioid receptors and COX-2.