Anti-inflammatory and nephroprotective influence of virgin coconut oil on gentamicin‐induced nephrotoxicity in non-diabetic and streptozotocin-induced diabetic rats

Abstract

Gentamicin is an effective antibiotic against severe infections, but a major downside is its nephrotoxic effects. Virgin coconut oil has potential antidiabetic effects, but there has been no study on its potential role in gentamicin‐induced nephrotoxicity in streptozotocin -induced diabetic rats. Thus, the aim of the current study is to explore the anti‐inflammatory and nephroprotective effects of virgin coconut oil on non-diabetic and streptozotocin-induced diabetic rats. A total of 48 adult male Sprague-Dawley rats were randomly divided into eight groups (n=6), including non-diabetic groups (groups 1-4) and streptozotocin-induced diabetic groups (groups 5-8). Groups 1 and 5 received a normal diet, groups 2 and 6 were fed a normal diet + gentamicin at 100 mg/kg/day for the last 10 days of the study period, groups 3 and 7 were treated with 10 ml/kg/day of virgin coconut oil for four weeks, and groups 4 and 8 were given gentamicin for the last 10 days of the study period plus virgin coconut oil for four weeks at the same doses mentioned. Gentamicin adminstaration caused oxidative stress, and led to antioxidant defense depression which was confirmed by elevated kidney Malondialdehyde (MDA) (4.53, 5.62) and reduced renal antioxidant enzymes including renal superoxide dismutase (59.82, 45.58), catalase (53.11, 37.3) and glutathione peroxidase (51.41.36.34) in non-diabetic (ND) and diabetic (D) rats, respectively. It also resulted in a significant increase of serum urea (31.72, 50.78), creatinine (2.88, 4.16), cystatin-C (13.75, 17.69), and inflammatory biomarkers interleukin-6 (IL-6) (84.01, 102.73) and tumor necrosis factor-α (TNF-α) (667.05, 853.05) in ND and D rats, respectively. Virgin coconut oil showed protective effects and significantly improved renal function parameters, including serum urea (17.35, 38.9), creatinine (1.69, 2.96) and cystatin-C (14.26, 15.94) for ND and D groups, respectively. Pre- and co-administration of virgin coconut oil exerted a remarkable protective effect against oxidative stress induced by gentamicin in normal and diabetic rats. Pro-inflammatory biomarkers were also improved in groups treated with virgin coconut oil. The results are promising in terms of the use of virgin coconut oil as a dietary agent in attenuating the progression of chronic renal disease, especially in the context of diabetes. Key words: anti‐inflammatory, nephroprotective, virgin coconut oil, gentamicin, streptozotocin, flavonoid, phenol, oxidative stress