Bioactive Compounds From Swertia kingie Hook. f.: A Promising Resource for Innovative Crop Disease Management Under Changing Environmental Conditions

Swertia is the diverse genus of herbs, belonging to family Gentianaceae. Round about 170 species are distributed cosmopolitanly and widely in subtropical and temperate regions. Some Swertia species are traditionally used in the treatment of diabetes, inflammation, malaria, fever, hepatitis, gastric, liver and other ailments. The aim of the study was to evaluate the phytochemical and pharmacological uses of Swertia species with special emphasis on Swertia kingie Hook. f. (SK). S. kingie is the ethno-medicinally important herb as previously no literature regarding the therapeutic potential was recorded. Extraction was carried out using five different solvents. Phytochemical and antioxidant activities were determined calorimetrically. The antidiabetic potential was evaluated using the α-amylase inhibition assay, cytotoxicity was assessed through the brine shrimp lethality assay, and anti-leishmanial activity was determined via the MTT assay. A considerable amount of phenolic and flavonoid contents was identified in methanol extract (SKM) 95.76 mg GAE/mg and 86.69 mg QE/mg respectively. All the extracts show substantial antioxidant potential while the maximum DPPH (IC₅₀ 19.6 μg/mL), total antioxidant capacity (90.60%) and total reducing power (94.44%) activity were noticed in SKM. Potential antibacterial and antifungal activities are reported for S. kingie extracts. Significant protein kinase, alpha amylase inhibition, and cytotoxic activity using brine shrimps (LC₅₀ 3.35 μg/mL) were revealed. Dose-dependent cytotoxic activity was exposed against Leishmania tropica (88.65%) using different concentrations (6–250 μg/mL) were calculated. The bioactive compounds extracted from Swertia kingie exhibit significant antimicrobial and cytotoxic properties, making them potential candidates for developing eco-friendly biopesticides against phytopathogenic fungi and bacteria. Their antioxidant and protein kinase inhibition activities suggest a role in enhancing plant defence mechanisms, offering a sustainable approach to disease management in crops.