Exploration of hypoglycemic effect of an extract from leaves of a plant from Tunisian pharmacopeia: Artemisia campestris (Asteraceae).

BACKGROUND AND OBJECTIVES: A lot of research has been directed towards medicinal plants which are considered as a source of multiple phytotherapic substances endowed with hypoglycemic activities that could be used to treat diabetes and its complications. Our study was carried out in Wistar rats to investigate the hypoglycemic effect of n-Butanol Fraction from Artemisia campestris leaf Methanolic Extract (BFACME). METHODS: Two experimental models were used in rats: orally induced hyperglycemia (OGTT) and isolated perfused liver (IPRL). RESULTS: BFACME at 550 mg/kg BW dose significantly reduced fasting glucose level in normal rats as compared to controls. The decrease of glycaemia was 12.6% more significant than that obtained with the standard drug glibenclamide (10 mg/kg BW), an oral antidiabetic preparation belonging to sulfonylurea class. In OGTT model, BFACME at the highest doses of 550 and 400 mg/kg BW significantly reduced the postprandial hyperglycemic peak compared to controls. In the IPRL model, treatment with BFACME significantly decreased glucose concentrations after 30 min of perfusion with 30 mM glucose solely when insulin was present. The higher doses of BFACME lead to glucose concentration at basal level as early as 90 min, while the lowest dose does not restore this concentration even to t = 120min. The best initial glucose concentration retrieval was obtained with 0.7 mg BFACME/mL/g liver. At this dose, BFACME improves the decrease of glucose level caused by only insulin by about 18%. CONCLUSION: The BFACME appears to exert a hypoglycemic activity by potentiating the insulin action.

Protective effects of phycocyanin on ischemia/reperfusion liver injuries.

In this study, phycocyanin (Pc) extracted from Spirulina platensis was used to evaluate its antioxidants effects after ischemia/reperfusion injury (IRI) using the ex-vivo model of isolated perfused rat liver. The rats were divided into eight groups : Control group, where livers were directly perfused after their removal; Cold Ischemia group (CI), livers were treated in the same way as the control group, except that after their collection, they were stored for 12 h and 24 h in the Krebs Henseleit (KH) preservation solution at 4 °C and Treated group (PHY), livers were preserved in the same way as the preceding group except that the KH solution was enriched with phycocyanin at two different concentrations. Pc, a powerful antioxidant, significantly reduced ischemia/reperfusion injury in the liver. In fact, the addition of phycocyanin to the preservation solution significantly decreased the activity of liver transaminases (AST) and (ALT), alkaline phosphatase (ALP), the rate of lipid peroxidation (MDA) and the activity of certain antioxidant enzymes, essentially glutathione-S-transferase (GST) and glutathione peroxidase (GPx). On the other hand, Pc increases the level of thiol groups in hepatic tissues. In conclusion, the results show the Pc-enriched KH conservation solution is effective in preserving the hepatic graft and protecting it against IRI by acting as a potent antioxidant against the products of oxidative stress.