Standardized flavonoid-enriched extract from kenaf (Hibiscus cannabinus L.) promotes cutaneous wound healing in non-diabetic and diabetic model of adult zebrafish (Danio rerio) using non-invasive technique

Abstract

The present study investigates the wound healing potential of a standardized flavonoid-enriched extract from kenaf (Hibiscus cannabinus L.) in both non-diabetic and diabetic adult zebrafish (Danio rerio). Flavonoids were extracted from kenaf wastes including leaves, flowers, and bulbs using ultrasonic-assisted extraction coupled with a natural deep eutectic solvent (NaDES), followed by flavonoid enrichment via macroporous adsorption resin chromatography to obtain the kenaf flavonoid-enriched extract (KFEE). LC/Q-TOF-MS analysis identified 18 compounds, including flavonoid glycosides (kaempferol, apigenin, quercetin, and rutin), phenolic acids and fatty acids. KFEE demonstrated strong radical scavenging capacity and significantly enhanced anti-inflammatory activity, outperforming both the crude extract (p < 0.05) and the reference anti-inflammatory drug, diclofenac sodium (p < 0.01). Acute toxicity testing revealed that KFEE exhibited greater dose-dependent toxicity, with an LC₅₀ of 71.04 mg/L compared to 267.20 mg/L for the crude extract. Wound healing efficacy assessed over 30 days showed that KFEE at 25 and 6.25 mg/L significantly accelerated wound closure in both non-diabetic and diabetic zebrafish followed by positive control, allantoin. At 25 mg/L, KFEE achieved up to 95 % closure in non-diabetic and 80 % in diabetic groups by day 30, improving healing rates by 1.18-fold and 1.34-fold over negative controls, respectively. This enhanced efficacy under diabetic conditions suggests that KFEE may target impaired healing mechanisms such as oxidative stress and inflammation. Overall, these findings highlight KFEE's therapeutic potential in promoting cutaneous wound repair, especially in diabetes-impaired healing.