Effects of White Rice, Brown Rice and Germinated Brown Rice on Antioxidant Status of Type 2 Diabetic Rats

Abstract

Oxidative stress is implicated in the pathogenesis of diabetic complications, and can be increased by diet like white rice (WR). Though brown rice (BR) and germinated brown rice (GBR) have high antioxidant potentials as a result of their bioactive compounds, reports of their effects on oxidative stress-related conditions such as type 2 diabetes are lacking. We hypothesized therefore that if BR and GBR were to improve antioxidant status, they would be better for rice consuming populations instead of the commonly consumed WR that is known to promote oxidative stress. This will then provide further reasons why less consumption of WR should be encouraged. We studied the effects of GBR on antioxidant status in type 2 diabetic rats, induced using a high-fat diet and streptozotocin injection, and also evaluated the effects of WR, BR and GBR on catalase and superoxide dismutase genes. As dietary components, BR and GBR improved glycemia and kidney hydroxyl radical scavenging activities, and prevented the deterioration of total antioxidant status in type 2 diabetic rats. Similarly, GBR preserved liver enzymes, as well as serum creatinine. There seem to be evidence that upregulation of superoxide dismutase gene may likely be an underlying mechanism for antioxidant effects of BR and GBR. Our results provide insight into the effects of different rice types on antioxidant status in type 2 diabetes. The results also suggest that WR consumption, contrary to BR and GBR, may worsen antioxidant status that may lead to more damage by free radicals. From the data so far, the antioxidant effects of BR and GBR are worth studying further especially on a long term to determine their effects on development of oxidative stress-related problems, which WR consumption predisposes to.

Antidiabetic Properties of Germinated Brown Rice: A Systematic Review

“…They showed that germinating BR in tap water at 25°C significantly improved total phenolic content of BR and antioxidant activities as determined by DPPH and ABTS radical scavenging activity and ferric reducing antioxidant power ( P < 0.05). Others have also reported similar findings [22, 23, 30, 35, 40]. Jiamyangyuen and Ooraikul [59] had reported also that GBR had lower amylose content consistent with reports in which activation of amylase enzyme was responsible for higher amounts of bioactives in GBR [60].…”

Lactoferrin and ovotransferrin contribute toward antioxidative effects of Edible Bird’s Nest against hydrogen peroxide-induced oxidative stress in human SH-SY5Y cells

“…1(B), EBN produced a hormetic effect on the viability of the cells in the presence of H 2 O 2 , with 1000 μg/ml EBN producing the best result. Although antioxidants are known to relieve oxidative stress and improve cell survival, it is also suggested that higher concentrations of antioxidants may in fact disrupt the natural hormetic capacity of cells 21) resulting in more damage. It is also likely that at higher concentrations, the oxidants simply became prooxidant.…”

Optimization of conditions to achieve high content of gamma amino butyric acid in germinated black rice, and changes in bioactivities

“…While, non-germinated rice showed 3.17 ± 1.68, 2.67 ± 0.24, and 6.82 ± 0.23 of total phenolic content, ABTS, and DPPH activity, respectively (Imam et al, 2012). The phenolic and flavonoid contents increased in germinated jasmine rice (KDML105) (Phattayakorn et al, 2016).…”