Ameliorating activity of polyphenolic-rich extracts of Basella rubra L. leaves on pancreatic β-cell dysfunction in streptozotocin-induced diabetic rats

OBJECTIVES

To assess the ameliorative activity of polyphenolic-rich extracts of Basella rubra leaves on β-cell dysfunction in type-II diabetes (T2DM).

METHODS

Total phenolic and flavonoid contents; α-amylase and α-glucosidase inhibitory actions and qualitative analysis of the bioactive compounds of the polyphenolic-rich extract of B. rubra leaves were investigated using gas chromatography-mass spectroscopy (GC-MS). Diabetes mellitus (DM) was induced by single intraperitoneal injection of streptozotocin (60 mg/kg body weight) and the rats were orally given bound phenolic (BPE) and free phenolic extracts (FPE) of B. rubra (B.R) leaves at 200 and 400 mg/kg b.w once daily for 14 days. Biochemical analyses were executed for evaluation of serum insulin, serum lipid profile concentrations, liver enzymes activities.

RESULTS

The extracts demonstrated antioxidant potentials and enzymes inhibitory activities in dose dependent manner; and several bioactive compounds as revealed by GC-MS. BPE and FPE considerably (p<0.05) reduced hyperglycemia, improved serum insulin levels, ameliorated the concentration of serum lipid profiles and improved liver antioxidant activities. Additionally, BPE and FPE expressively decreased alanine aminotransferases (ALT), aspartate aminotransferases (AST), gamma-glutamyl transferase (GGT) activities along with levels of bilirubin and urea when compare to diabetic control rats.

CONCLUSIONS

Data acquired exhibited the ability of BPE and FPE to improve pancreatic beta-cell in streptozotocin-induced rats.

Essential amino acid composition and biological quality of yambean, Sphenostylis stenocarpa (Hochst ex A. Rich) harms

The essential amino acids and protein bioavailability of raw, roasted and pre-soaked, pressure cooked yambean were evaluated. Roasting caused decrease of 8% while soaking with pressure cooking caused decrease of 15-39% in the lysine composition of yambean. Rats fed raw, unprocessed bean diet showed overt signs of diarrhoea, poor protein utilization and hence poor growth. Processing considerably improved all growth indices--food conversion efficiency, protein efficiency ratio, digestibility, biological value, net protein utilization, protein retention efficiency and net protein ratio.

African yam bean hull chemical composition and its effects on rat's mineral retention, serum biochemical components and enzymatic activities

The influence of yam bean hull on rat's mineral metabolism, serum composition and enzymatic activities was investigated. The chemical composition of the bean's hull shows a reasonably high crude protein (11.4%) but very low contents of crude fat (2.6%), phytic acid (82 mg/100 g) and phytin-phosphorus (23 mg/100 g). K and Ca are the major minerals present in yam bean hull. The hull, rich in cell wall polysaccharides, is composed of cellulose (35.4%), non-cellulose fractions made of pectin and hemicellulose put together (41.9%) and lignin (3.6%). The growth and feed conversion efficiency of rats fed yam bean hull diet were significantly better than rats fed pure cellulose and cellulose-free diets. Conversely, the metabolizable energy of yam bean hull diet (16.4 MJ/kg) was significantly (p < 0.05) lower than that of either cellulose-free (17.8 MJ/kg) or pure cellulose diet (17 MJ/kg). The retention of the minerals examined, except for Ca, was lower when the hull was included in diet as compared to the control (fibre-free) diet. The fibre containing diets decreased serum cholesterol, glutamic oxaloacetate transaminase (SGOT) and glutamic pyruvate transaminase (SGPT). Yam bean hull had no effect on packed cell volume and serum total protein.