Protein hydrolysate derived from Pistachio vera regulates blood glucose level in streptozotocin-diabetic and high-sugar diet-fed rats

Diabetes is one of the most common metabolic disorders that is increasing at an alarming rate, for the prevention, control, and treatment of which an appropriate diet is needed. This study aims to examine effects of pistachio hydrolysates on blood glucose in streptozotocin-diabetic and high-sugar diet-fed rats.

The prepared pistachio hydrolysates were administered to 96 rats that were divided into 12 groups, including 9 target groups and 3 control groups. The target groups were divided into three groups of rats with a normal diet, rats with a high-sugar diet, and streptozotocin-diabetic rats with a normal diet, which were fed on different doses of pistachio hydrolysates (5, 50, and 500 mg/kg) for 8 weeks. After 8 weeks, the levels of fasting blood glucose, two-hour postprandial glucose, fourhour postprandial glucose, HbA1c, and insulin were measured.

The results showed that pistachio hydrolysates could significantly reduce the level of blood sugar in type 1 diabetic and high-sugar diet-fed rats compared to the control groups (P˂ 0.05). This research is the first one to have demonstrated that pistachio protein lysates have a strong effect on blood glucose in type 1 diabetic rats and the ones received a high-sugar diet. This treatment decreased the blood glucose level in the former but controlled glucose concentration in the latter. Besides, the results showed that HbA1c, FBG, two-hour postprandial glucose, and four-hour postprandial glucose decreased significantly, while the insulin level increased in rats having consumed pistachio hydrolysates (P˂ 0.05).

It is concluded that pistachio proteins could play a positive role in type 1 diabetic people and those having a high-sugar diet.