Enhancement of caudal fin regeneration in diabetic zebrafish: An insight into proangiogenic potential of bromelain

Objectives: Diabetes mellitus is a chronic metabolic disease that is characterised by hyperglycaemia, altered lipids, carbohydrates and protein metabolism, and in the long-term, with eye, kidney, cardiovascular and neurological complications. Poor wound healing is one of the major complications faced by diabetes mellitus patients. Angiogenesis is critical for tissue regeneration and wound healing. Impaired angiogenesis may lead to poor blood flow to the wound and hence delayed wound healing. Hence, it is important to find an antidote to speed up wound healing. Hence, this study focuses on the proangiogenic potential of bromelain in the caudal fin regeneration of diabetic zebrafish. Materials and Methods: Zebrafish were divided into control, Diabetic and Diabetic + Bromelain treated groups. Diabetes mellitus was induced using multiple doses of streptozotocin (350 mg/kg b.w./i.p.) on days 1, 3, 5, 12 and 19. Glucose levels were estimated on day 21 to confirm the induction of diabetes mellitus, and then, the caudal fin was amputated. After the amputation of the caudal fin, bromelain was administered orally at a dosage of 40 mg/kg b.w. on every alternate day for 15 days. Body weight, blood glucose level, total area and percentage of fin regeneration were observed on day 36. Images were compared and areas of regeneration were analysed with the help of Image J software. One-way analysis of variance followed by Tukey’s multiple comparison tests was used to analyse the data. Results: A significant increase in the blood glucose level was observed in the diabetic group compared with control. A significant decrease in the percentage of tail regeneration and area of regeneration was observed in diabetic fishes compared to the control. Bromelain treatment has significantly increased the percentage and area of regeneration and significantly decreased the blood glucose level in the treatment group compared with the control. Conclusion: The study confirms that bromelain can promote tissue regeneration; hence, it can be used to improve wound healing, which is one of the most common complications in diabetes mellitus.