In vivo assessment of antidiabetic and antioxidant activities of rosemary (Rosmarinus officinalis) in alloxan-diabetic rabbits.

Rosemary (Rosmarinus officinalis), used in traditional Turkish folk medicine for the treatment of hyperglycaemia, is widely accepted as one of the medicinal herb with the highest antioxidant activity. Accordingly, the present study was designed to investigate the possible actions of ethanolic extract of the leaves of Rosmarinus officinalis on glucose homeostasis and antioxidant defense in rabbits. In the first set of experiments, hypoglycaemic effects of oral administration of various doses (50, 100 and 200 mg/kg) of the extract were examined in normoglycaemic and glucose-hyperglycaemic rabbits. Optimal effect was observed in both of the animal groups with a dose of 200 mg/kg of the extract and this activity was independent from the effects of insulin. In another part of experiments, acute effect of various doses of the Rosmarinus officinalis extract on blood glucose and serum insulin levels was studied in alloxan-induced diabetic rabbits. Of the three doses of extract, the highest dose (200 mg/kg) significantly lowered blood glucose level and increased serum insulin concentration in alloxan-diabetic rabbits. The last set of experiments designed to investigate the subacute effect of the Rosmarinus officinalis extract on repeated administration in alloxan-diabetic rabbits. At the doses of 100 and 200 mg/kg, antihyperglycaemic effect of extract was accompanied by a significant increase in serum insulin levels in diabetic rabbits. Furthermore, during 1 week of treatment of diabetic rabbits with a dose of 200 mg/kg of the extract showed that the extract possessed a capability to inhibit the lipid peroxidation and activate the antioxidant enzymes. It was concluded that probably, due to its potent antioxidant properties, the Rosmarinus officinalis extract exerts remarkable antidiabetogenic effect.

Effect of linear alkylbenzene sulphonate (LAS) on non-specific defence mechanisms in rainbow trout (Oncorhynchus mykiss).

Linear alkylbenzene sulphonate (LAS) is among the most widely disseminated xenobiotics to enter waste streams and the aquatic environment. In the present investigation, we present a novel approach to evaluate in toxicity of LAS. The effects of sublethal levels (0.2 and 0.4 mg/l) of LAS on non-specific immune system, phagocytosis, respiratory burst and lyzosyme activity, and specific growth rate in the rainbow trout, Oncorhynchus mykiss, during a 54-day exposure were examined by a static bioassay test procedure. The phagocytic activity of leukocytes from fish exposed to 0.4 mg/l LAS statistically decreased compared with the control fish values. No significant reductions were observed in the extra-intracellular respiratory burst and lysozyme activities after exposure to LAS at any of the concentrations tested. The final body weight in fish groups exposed to the LAS were found to be significantly lower than in the control. The specific growth rate results also supported the result above. The results of this study showed sublethal doses (0.2-0.4 mg/l) of LAS caused to statistically insignificant suppression of non-specific immune system mechanisms excluding phagocytosis in fish at laboratory conditions. These doses of LAS may produce potential synergism on immune system when presented with other environmental pollutants.