Evaluation of Vinca Rosea's Protective Effects on Hepatic Function in Streptozotocin-Induced Diabetic Wistar Albino Rats

Abstract

Background Diabetes mellitus, characterized by chronic hyperglycemia, often leads to severe hepatic dysfunction, including increased liver enzyme levels and histopathological changes in the liver. Streptozotocin (STZ)-induced diabetic rat models provide a valuable method for evaluating potential therapeutic agents that target hepatic complications. Vinca rosea, a medicinal plant with known anti-diabetic properties, has been used traditionally for its hepatoprotective effects, although scientific evidence is limited. Objective This study aimed to evaluate the protective effects of Vinca rosea leaf extract on hepatic function, including biochemical and histopathological changes, in STZ-induced diabetic Wistar albino rats. Methods Thirty male Wistar albino rats were randomly divided into five groups: Normal control (NC), diabetic control (DC), low-dose Vinca rosea (LD, 200 mg/kg), high-dose Vinca rosea (HD, 400 mg/kg), and positive control (PC, metformin 100 mg/kg). Diabetes was induced by a single intraperitoneal injection of STZ (100 mg/kg). Vinca rosea treatment was administered daily for 30 days. Blood samples were collected at 15 and 30 days to assess blood glucose and liver function, including serum bilirubin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels. Liver tissue was collected for histopathological examination. Data were analyzed using analysis of variance (ANOVA), with p < 0.05 considered statistically significant. Results The DC group showed significantly elevated blood glucose levels (256 ± 19.8 mg/dL at 15 days and 308.5 ± 13.1 mg/dL at 30 days). Vinca rosea treatment significantly reduced blood glucose in a dose-dependent manner, with the HD group showing the greatest improvement (143 ± 12.7 mg/dL at 15 days and 158.5 ± 10.7 mg/dL at 30 days). Liver function markers, including total and direct bilirubin, AST, and ALT, were significantly elevated in the DC group, indicating hepatic damage. Vinca rosea-treated groups showed significant improvements in all liver function parameters, with the HD group displaying the most substantial reductions in bilirubin, AST, and ALT levels. Histopathological analysis revealed marked hepatocellular damage in the DC group, including necrosis and ballooning degeneration. In contrast, Vinca rosea-treated groups, particularly the HD group, exhibited near-normal liver architecture with minimal damage. Conclusion Vinca rosea demonstrated significant hepatoprotective effects in STZ-induced diabetic rats by reducing blood glucose levels and improving liver function. These results suggest that Vinca rosea could be a promising therapeutic agent for managing diabetes-related hepatic dysfunction.

Keywords: alt; ast; diabetes; hepatic function; liver enzymes; serum bilirubin; stz; vinca rosea; wistar rats.

Figure 1. Normal control rat liver showing central vein with radiating hepatic cords.

H&E staining of the tissue section, viewed under 10x magnification. Yellow arrows indicate areas of interest, highlighting specific morphological features within the tissue.

Figure 2. Diabetic control: After administration of streptozotocin (30 days), liver showing degenerative changes and necrosis with mild periportal infiltration.

Tissue section stained with H&E, observed at 10x magnification.

Figure 3. Liver tissue from a low-dose (200 mg/kg) Vinca rosea-treated group, showing slight resemblance to normal liver morphology.

Tissue section stained with H&E, observed at 10x magnification.

Figure 4. Liver tissue from a high-dose (400 mg/kg) Vinca rosea-treated group after 30 days of administration, showing notable resemblance to normal liver morphology.

Tissue section stained with H&E, observed at 10x magnification.

Figure 5. Liver tissue from the metformin-treated group (100 mg/kg) after 30 days of administration, showing resemblance to normal liver morphology.

H&E staining of tissue section, viewed under 10x magnification.