Investigation of proinflammatory genes expression in STZ-induced diabetic rats treated with extract of Hibiscus rosa-sinensis flower

Abstract

Abstract Background Diabetes mellitus, a metabolic disorder of carbohydrates and fat, which results from the deficiency of insulin secretion or varying degree of insulin resistance, is a major public health problem and has become a global menace. Aim This study is aimed to investigate the expression of proinflammatory genes in STZ-induced diabetic rat model, treated with Hibiscus rosa-sinensis flower extract. Methods Diabetes was induced by intraperitoneal injection of streptozotocin (65 mg/kg). Thirty-six diabetic rats were divided into 6 groups which includes the diabetic control, another group treated with 100 mg/kg of sildenafil citrate and the 4 other groups treated with varying concentrations of aqueous extract of Hibiscus rosa-sinensis flower (50 mg/kg, 100 mg/kg, 200 mg/kg and 1000 mg/kg). Six animals were given only distilled water throughout the experiment as the normal control. The treatment was administered for 21 days. The mRNA expression of the pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) in the pancreas, kidney, liver and brain of the experimental animals were investigated using reverse-transcriptase polymerase chain reaction (RT-PCR). The fasting blood sugar and body weight of the experimental animals was also monitored throughout the experiment. Results Oral administration of Hibiscus rosa-sinensis flower extract (100, 200 and 1000 mg/kg) to STZ-induced diabetic rats significantly (p < 0.05) down-regulated the pancreatic mRNA expression of IL-6, IL-1β and TNF-α when compared with the diabetic control group. 200 and 1000 mg/kg of the extract down-regulated (p < 0.05) the mRNA expression of TNF-α and IL-6 in the kidney when compared with the diabetic and normal control group. 100, 200 and 1000 mg/kg of the extract significantly up-regulated (p < 0.05) the mRNA expression of IL-6 in the liver when compared with the diabetic and normal control group. 200 and 1000 mg/kg of extract significantly down-regulated the mRNA expression of TNF-α in the brain of diabetic rats. In addition, the oral administration of Hibiscus rosa-sinensis flower extract (50, 100, 200 and 1000 mg/kg) significantly (P < 0.05) reduces the fasting blood sugar and increases the body weight of experimental animals. Conclusion Observation drawn from this study suggests that Hibiscus rosa-sinensis flower extract possess antidiabetic potential and can suppress the JAK/STAT pathway thereby regulating the mRNA expression of the proinflammatory cytokines.