Effect of Abelmoschus esculentus (okra)-based diet on streptozotocin-induced diabetes mellitus in adult Wistar rats

Abstract

Purpose: To evaluate the effects of an okra-based diet on streptozotocin-induced diabetes mellitus in adult Wistar rats and its mechanism of action.Methods: Wistar rats (6) were administered streptozotocin (50 mg/kg ip) after an overnight fast. Upon confirmation of diabetes mellitus, the animals were fed ad libitum for 21 days with formulated okrabased test diet in place of normal diet. The rats treated similarly with streptozotocin and fed ad libitum with the normal diet served as diabetic control while rats fed on normal diet and not treated with streptozotocin served as the negative control. Thereafter, the rats were sacrificed, fasting bloodcollected and analysed for glucose concentration and biochemical parameters. Pancreas was also excised for histopathological studies.Results: There was a significant increase in body weight, HDL-cholesterol (p< 0.05) but significant decrease in blood glucose (p < 0.05), serum total cholesterol, triglyceride, LDL-cholesterol and VLDLcholesterol concentrations in the okra-fed diabetic treated rats when compared to the diabetic control group. Furthermore, superoxide dismutase activity (SOD) was significantly higher in the diabetic control, and reduced significantly when fed with okra-based diet (p < 0.05). Catalase (CAT) activity was significantly (p < 0.05) decreased in diabetic control and treated group, whereas it was significantly (p < 0.05) increased in normal control rats. There was a significant (p < 0.05) decrease in reduced glutathione levels. The significant (p< 0.05) increase in malondialdehyde in the diabetic group was significantly decrease in the diabetic rats fed with okra-diet. Also serum insulin level was significantly (p < 0.05) increased and serum α amylase activity was significantly (p < 0.05) decrease in the diabetic treated rats. Histology results show that there was damage to the β cells of the pancreas in the diabetic control when compared to normal control, but rats fed okra diet was able to regenerate endocrine β cells.Conclusion: Okra-based diet lowers hyperglycaemia as well as regenerate/repair endocrine β-cells and exocrine tissues of the pancreas damage by streptozotocin
 Keywords: Abelmoschus esculentus, Diabetes mellitus, anti-diabetic, Insulin, α-amylase, Mechanism

Okra ameliorates hyperglycaemia in pre-diabetic and type 2 diabetic patients: A systematic review and meta-analysis of the clinical evidence

“…We found that okra treatment in pre-diabetic and T2D patients has beneficial effects on glycaemic control, as demonstrated by a significant reduction in the level of FBG. These findings are consistent with the results reported by previous researchers ( Khatun et al, 2011 ; Majd et al, 2018 ; Nguekouo et al, 2018 ; Husen et al, 2020 ; Uadia et al, 2020 ; Wu et al, 2020 ; Yan et al, 2020 ; Tyagita et al, 2021 ; Haque et al, 2022 ). One of the proposed mechanisms that okra targets in reducing FBG is the stimulation of hepatic glycogen synthesis and pancreatic islet regeneration, thus leading to increased insulin secretion and subsequent delay in the intestinal absorption of glucose.…”

Comprehensive Overview of the Effects of Amaranthus and Abelmoschus esculentus on Markers of Oxidative Stress in Diabetes Mellitus

“…Such an effect of okra may further lead to ameliorating secondary complications associated with oxidative stress. However, other studies showed a significant ( p < 0.05) decrease in SOD following the administration of Abelmoschus esculentus [ 91 , 102 , 115 , 116 ]. This suggests the limitation of Abelmoschus esculentus as an antioxidant; reduction of SOD in hyperglycemia or overproduction of ROS may subject the cells to damage and subsequently to apoptosis.…”

“…In contrast to the aforementioned encouraging discoveries, other researchers [ 91 , 95 , 105 , 106 , 115 , 116 , 123 ] have recently identified a notable decline in GSH levels after administering Abelmoschus esculentus treatment to rodent models with diabetes. This once again highlights a potential limitation of Abelmoschus esculentus as an antioxidant.…”

“…This suggests that Abelmoschus esculentus may ameliorate oxidative stress, further reduce complications of DM, or prevent DM in non-diabetics ( Figure 4 ). Although the potential benefits of Abelmoschus esculentus on CAT activity have been noted in DM rodent models, another group of researchers has reported contradictory findings, as shown by significantly reduced CAT activity [ 116 ]. This, disappointingly, suggests a limited beneficial impact of Abelmoschus esculentus in improving the activity of CAT enzymes in diabetic models and, thus, its limited efficacy in reducing oxidative stress.…”

Anti-diabetic effect of <i>Eucalyptus camaldulensis</i> (Red gum) leaf-supplemented diet in streptozotocin-induced diabetic rats

“…The approach reported by Uadia et al [9] was used to induce diabetic mellitus. Briefly, the rats were divided into three groups of six rats each.…”