Table 2: Summary of findings on mechanisms for antidiabetic properties of germinated brown rice.

ReferenceStudy type/commentsSummary of main changes in metabolic indices

Noriega et al. (1993) [44]Assessed glycemic and insulin indices in healthy subjects using 50 g available carbohydrate portionsBlood glucose, insulin response

Hagiwara et al. (2004) [45]Assessed changes in various metabolic indices in diabetic rats (fasting blood glucose of >300 mg/dL) induced through i.p. injection of 65 mg/kg body weight of STZ dissolved in 100 mmol/L sodium citrate buffer, pH 4.5Blood glucose, PAI-1, and lipid peroxidation

Morita et al. (2004) [46]Assessed effects of WR and GBR + WR (1 : 1, w/w) in 67 healthy volunteers (aged 71 ± 8) over 11–13 monthsHbA1c, BMI, blood pressure, lipid profile, kidney and liver functions, blood glucose, and insulin response

Ito et al. (2005) [47]Assessed glycemic and insulin responses over 120 min in 2 studies using 19 (12 male, 7 females, age 23–41 years, body mass index 15.4–28.8 kg/m2) and 13 (5 males, 8 females, age 25–32, body mass index 15.4–25.6 kg/m2) healthy subjects. Intervention compared 50 g available carbohydrate portion of GBR, BR, and WRBlood glucose, insulin response

Seki et al. (2005) [48]Assessed glycemic and insulin indices of WR and GBR in normal Wistar rats over 120 minBlood glucose, insulin response

Miura et al. (2006) [49]Assessed effect of GBR on hypercholesterolemia in hepatoma bearing rats for 19 dTotal cholesterol

Usuki et al. (2007) [50]Assessed effect of GBR on diabetic rats (fasting blood glucose of >400 mg/dL) induced through i.p. injection of 65 mg/kg body weight of STZ dissolved in 100 mmol/L sodium citrate buffer, pH 4.5, and effect of acylated steryl glycoside on in vitro cultures of rat cells Glucose, ↑nerve conduction velocity, and ↑HTase

Hsu et al. (2008) [51]11 diabetic subjects (6 males, 5 females, age 27–72, body mass index 18.9–31.2 ± 3.4 kg/m2, fasting blood glucose > 110 mg/dL) in a crossover design for 14 weeks (6 weeks of feeding with either GBR or WR and a 2-week washout period in between) were used to assess effects of 180 g test diets 3 times daily; subjects were maintained on their medications (1 on insulin, 10 on oral hypoglycemics)Blood glucose, fructosamine, total cholesterol, and triglycerides

Hayakawa et al. (2009) [52]Assessed various metabolic indices in 24 diabetic subjects on WR or GBR over 3 monthsHbA1c, insulin response, HOMA-IR, LDL cholesterol, ↑HDL cholesterol, and blood glucose

Ebizuka et al. (2010) [53]Assessed serum lipids and blood pressure on spontaneously hypertensive rats on control or 40% GBR diet for 8 weeksTotal cholesterol, blood pressure

Roohinejad et al. (2010) [54]Assessed serum lipids in diet-induced hypercholesterolemic rats on control diet, 24 h germinated BR diet, or 48 h germinated BR diet for 6 weeksTotal cholesterol, LDL cholesterol

Shallan et a. (2010) [55]Assessed changes in metabolic indices in diabetic albino rats on control or GBR diets for 5 weeksWeight, glucose, and cholesterol

Torimitsu et al. (2010) [56]OLEFT rats (model of type 2 diabetes) were used as diabetic animals and LETO rats as nondiabetic controls to assess effects of GBR and control diet on various metabolic indices for 30 weeksBlood glucose, TNF, PAI-1, and ↑adiponectin

Mohd et al. (2011) [57]Assessed various metablic indices in diet-induced hypercholesterolemic rabbits on GBR, BR, or WR diets for 10 weeksTotal cholesterol, LDL cholesterol, atherogenic index, MDA, and ↑HDL cholesterol

Usuki et al. (2011) [58]Assessed effects of GBR on metabolic indices of diabetic rats (fasting blood glucose of >400 mg/dL) induced through i.p. injection of 65 mg/kg body weight of STZ dissolved in 100 mmol/L sodium citrate buffer, pH 4.5 and effect of ASG on in vitro cultures using INS-1 cellsGlucose, LDL cholesterol, ↑nerve conduction velocity, ↑HTase, ↑IGF-1 (oxidative stress), and ↑insulin secretion

Imam et al. (2012) [40]Assessed effects of WR, BR, and GBR on glycemia and antioxidant status of diabetic rats (fasting blood glucose of >250 mg/dL) induced through i.p. injection of 35 mg/kg body weight of STZ dissolved in 100 mmol/L sodium citrate buffer, pH 4.5, in high-fat diet-induced obese ratsGlucose, ↑total antioxidant status, ↑hydroxyl radical scavenging capacities of liver and kidneys, and ↑expression of superoxide dismutase gene

↑: increased, : decreased, and : not changed. BMI: body mass index; HDL: high-density lipoprotein; HTase: homocysteine thiolactonase; HOMA-IR: homeostasis model assessment-estimated insulin-resistance; IGF: insulin-like growth factor; INS-1: insulin-secreting cell lines; i.p.: intraperitoneal; LDL: low-density lipoprotein; LETO: Long-Evans Tokushima Otsuka; MDA: malondialdehyde; OLEFT: Otsuka Long-Evans Tokushima Fatty; PAI-1: type 1 tissue plasminogen activator inhibitor; STZ: streptozotocin; TNF: tumor necrosis factor.