amylose

The scientific name of rice is Oryza sativa. It is one of the important staple human foods. There are more than 110,000 cultivated varieties of rice, most widely known and grown. Nutrient concentration may vary depending on production, environment, pre- and post-harvesting treatment, and processing. Cooked rice with high amylose content effectively controls metabolic disorders, serum blood glucose levels, and lipid profile and is also effective in weight loss.

This study aimed to determine the comparative effect of amylose concentration in brown and white rice on hepatocellular insufficiency in healthy rat models.

We divided 25 rats into 5 groups (G0, G1, G2, G3, and G4). There were 5 rats in each group. Group 0 was the control group on a normal diet. Group 1 was fed white rice flour, G2 was fed cooked white rice, G3 was fed brown rice flour, and G4 was fed cooked brown rice. Free access to food and water was secured. Weight changes, blood glucose, and lipid profiles were analyzed pre and post-treatment.

Rats on white rice feed showed weight gain, increased blood glucose, cholesterol, triglycerides, and low HDL levels. However, rats on brown rice feed showed less weight gain (P < 0.05), a lower increase in blood glucose (P < 0.05), high HDL, lower LDL cholesterol, and triglycerides. The pancreas and liver histopathology showed no major changes due to the short trial duration.

Rats fed white rice showed ineffective results disturbing biological parameters as compared to those rats which were fed brown rice. Due to low amylose content and the presence of antioxidants, flavonoids, and high fiber content, brown rice shows beneficial effects in controlling and maintaining relevant biological parameters.

One disadvantage of expressing heterologous proteins in Escherichia coli is that the proteins are frequently expressed as insoluble inclusion bodies. To avoid this problem, heterologous proteins are typically expressed as a fusion protein. Maltose binding protein (MBP) is one of the widely used partners for production of recombinant fusion proteins in E. coli. MBP is among the most effective solubility enhancers. In addition, MBP can be used as an affinity tag for purification of recombinant proteins on a column of amylose resin. The purpose of this study was to investigate the use of rice flour, a natural source of amylose, for purification of MBP fusion proteins. MBP and a fusion protein of MBP and avian influenza virus nucleoprotein (MBP-NP) were expressed in E. coli and subjected to purification by rice flour and a commercial amylose resin. The purified proteins were analyzed by SDS-PAGE. The results indicated that MBP and MBP NP, both were successfully purified by rice flour. Rice flour can be used for purification of MBP fusion proteins. Although the efficiency of purification by rice flour is less than amylose resin, however, the yield is sufficient to obtain a quantity of protein required for research purposes.