The effects of non-bitter Cucumis metuliferus fruit extract on blood sugar of high-fat/fructose diet and streptozotocin-induced type II diabetic Wistar Albino rats

Abstract

Globally, diabetes mellitus (DM) remains one of the leading debilitating non-communicable diseases, with its prevalence projected to increase from 8.8% in 2015 to 10.0% in 2030. The management of diabetes mellitus remains a major challenge, and the number of diabetes-related deaths is projected to rise from 3.1 million in 2015 to 4.2 million in 2030. This continues to be a public health concern, particularly in developing countries where the majority of people are poor and predominantly live in rural areas, facing challenges in accessing healthcare services. However, the non-bitter Cucumis metuliferus fruit is being used for managing type 2 diabetes mellitus by some communities in Kenya, although its therapeutic benefits have not been adequately studied and proven. The study aimed to determine the effects of non-bitter Cucumis metuliferus fruit extract on blood sugar in high-fat/fructose diet and streptozotocin- induced type II diabetic Wistar albino rats. This study adopted an experimental laboratory-based design. A sample size of 64 male Wistar albino rats, aged 5 weeks and weighing between 90 and 130 grams, was randomly assigned to two major study groups: the control group and the experimental group. The experimental group received a high-fat/fructose diet plus streptozotocin (STZ) injection to induce diabetes mellitus, whereas the control group received a standard rodent pellet diet plus 0.9% normal saline injection. The experimental group was further divided into a positive control group treated with pioglitazone (the standard drug) at a dose of 20 mg/kg body weight, a low-dose CMFE group at 200 mg/kg body weight, and a high-dose CMFE group at 400 mg/kg body weight. Fasting blood sugar (FBS), oral glucose tolerance test (OGTT), and haemoglobin A1c (Hb A1c) tests were used as indicators, and the results were compared between the groups. The study findings revealed a significant statistical rise (P<0.001) of FBS in the treatment group after induction of type II DM, followed by a decline to pre-induction levels after treatment. Similarly, there was a statistically significant increase (P<0.001) of the OGTT after induction of type II DM, with the OGTT declining to pre-induction levels following treatment (P =0.106). The findings on both the FBS and OGTT tests indicate that treatment with CMFE controlled the blood sugar. Consequently, there was no significant difference (P =0.712) in Hb A1c test results between the control group and the treatment group at the end of the experiment, indicating that treatment with CMFE had a long-term control effect on blood sugar. This study concludes that the non-bitter CMFE possesses both short-term and long-term hypoglycemic properties in type II diabetes mellitus. Key Word: Streptozotocin; Cucumis metuliferus; herbal remedy; fasting blood sugar; oral glucose tolerance test; haemoglobin A1c.