Phytochemical Profiling and Pharmacological Evaluation of Methanolic Leaf Extract of C. digyna for Cytotoxic, Anti‐inflammatory, Antioxidant, Antiarthritic, and Analgesic Activities

Abstract

ABSTRACTCaesalpinia digyna (Family: Fabaceae) is traditionally used in Ayurvedic medicine for various medicinal purposes, including as a treatment for wounds, leprosy, skin diseases, fever, diabetes, etc. Although the root and stem of this plant have a significant medicinal value, there was little research on the leaves of this plant. This study aimed to investigate the qualitative phytochemical profile and evaluate the in vitro cytotoxic, anti‐inflammatory, antioxidant, and antiarthritic activities, as well as the in vivo anti‐inflammatory and analgesic activities, of C. digyna leaf extract. The methanolic extract of C. digyna leaves was prepared using an ultrasonic‐assisted extraction process. In vitro and in vivo anti‐inflammatory activities were evaluated using the hypotonicity‐induced hemolysis and carrageenan‐induced paw edema methods, respectively. Additionally, the extract was assessed for in vitro DPPH (1, 1‐diphenyl‐2‐picrylhydrazyl) free radical scavenging, antiarthritic (protein denaturation), and in vivo analgesic (acetic acid‐induced writhing and tail immersion) activities. Brine shrimp lethality bioassay (BSLB) showed moderate cytotoxic activity (LC50 = 2.25 μg/mL) compared with the standard vincristine sulfate (LC50 = 1.61 μg/mL). In vitro, anti‐inflammatory activity exhibited 85.13% (IC50 value = 2.51 μg/mL) inhibition of Human Red Blood Cell (HRBC) membrane lysis at a concentration of 2000 μg/mL whereas in vivo anti‐inflammatory study exerted its maximum effect (p < 0.05) at 400 mg/kg bw dose. This extract also showed significant antioxidant (IC50 = 0.218 μg/mL), antiarthritic (83.61% inhibition) activity, and moderate analgesic effect (p < 0.05) in both methods. These research findings indicated that C. digyna leaves extract has potent antioxidant, analgesic, and anti‐inflammatory effects which can be used as a supplementary medication for inflammatory pain‐relieving factors. In future, finding the mechanism involved in these effects could have significant impact on clinical science.