Hepatoprotective potential of flavonoid-rich extracts from Gongronema latifolium benth leaf in type 2 diabetic rats via fetuin-A and tumor necrosis factor-alpha

Background

This study assessed the hepatoprotective potential of flavonoid-rich extracts from Gongronema latifolium Benth on diabetes-induced type 2 rats via Fetuin-A and tumor necrosis factor-alpha (TnF-α).

Methods

In a standard procedure, the flavonoid-rich extract was prepared. For experimental rats, streptozotocin was injected intraperitoneally (45 mg/kg body weight) to induce diabetes mellitus. Following this, rats were given 5% of glucose water for 24 h. Hence, the animals were randomly divided into five groups of ten rats each, consisting of non-diabetic rats, diabetic controls, diabetic rats treated with low and high doses of flavonoid rich-extracts from Gongronema latifolium leaf (FREGL) (13 and 26 mg/kg, respectively), and diabetic rats treated with 200 mg/kg of metformin glibenclamide orally for 3 weeks. Afterwards, the animals were sacrificed, blood and liver were harvested to evaluate different biochemical parameters, hepatic gene expressions and histological examinations.

Results

The results revealed that FREGL (especially at the low dose) significantly (p?<?0.05) reduced alanine transaminase (ALT), aspartate aminotransferase (AST) and alkaline phosphate (ALP) activities, lipid peroxidation level, as well as relative gene expressions of fetuin-A and TNF-α in diabetic rats. Furthermore, diabetic rats given various doses of FREGL showed an increase in antioxidant enzymes and hexokinase activity, as well as glucose transporters (GLUT 2 and GLUT 4), and glycogen levels. In addition, histoarchitecture of the liver of diabetic rats administered FREGL (especially at the low dose) was also ameliorated.

Conclusion

Hence, FREGL (particularly at a low dose) may play a substantial role in mitigating the hepatopathy complication associated with diabetes mellitus.

     

A new variant activator involved in the degradation of phenolic compounds from a strain of Pseudomonas putida

A new variant type of regulatory activator and relevant promoters (designated capR, Pr and Po) involved in the metabolism of phenolic compounds were cloned from Pseudomonas putida KCTC1452 by using PCR. The deduced amino acid sequence of CapR revealed a difference in nine amino acids from the effector binding domain of DmpR. To measure effector specificity, plasmids were constructed in such a way that the expression of luc gene for firefly luciferase or lacZ for beta-galactosidase as a reporter was under the control of capR. When Escherichia coli transformed with the plasmids was exposed to phenol, dramatic increases in the activity of luciferase or beta-galactosidase were observed in a range of 0.01-1 mM. Among various phenolic compounds tested, other effective compounds included catechol, 2-methylphenol, 3-methylphenol, 4-methylphenol, 2-chlorophenol, 4-chlorophenol, 2-nitrophenol, resorcinol, and 2, 5-dimethylphenol. The results indicate that CapR has effector specificity different from other related activators, CatR and DmpR. Waste water and soil potentially containing phenolic compounds were also tested by this system and the results were compared with chemical and GC data. The present results indicate that the biosensor consisting of capR and the promoters may be utilized for the development of a phenolic compounds-specific biosensor in monitoring the environmental pollutant.