Vitamins E and A increase the passing of the P-gp substrate ivermectin into the brain in mice.

This study aimed to determine the effect of administration of oral vitamins A and E at different doses on plasma and brain concentrations of ivermectin in mice. The study was carried out on 174 Swiss Albino male mice aged 8-10 weeks. After leaving six mice for method validation, the remaining mice were randomly divided into seven groups with equal numbers of animals. Mice received ivermectin (0.2 mg/kg, subcutaneous) alone and in combination with low (vitamin A: 4000 IU/kg; vitamin E: 35 mg/kg) and high (vitamin A: 30 000 IU/kg; vitamin E: 500 mg/kg) oral doses of vitamins A and E. The plasma and brain concentrations of ivermectin were measured using high-performance liquid chromatography-fluorescence detector. We determined that high doses of vitamins A and E and their combinations increased the passing ratio of ivermectin into the brain significantly. The high-dose vitamin E and the combination of high-concentration vitamins E and A significantly increased the plasma concentration of ivermectin (P < 0.05). The high-dose vitamins E and A and their high-dose combination increased the brain concentration of ivermectin by 3, 2, and 2.7 times, respectively. This research is the first in vivo study to determine the interaction between P-gp substrates and vitamins E and A.

Effects of enrofloxacin, flunixin meglumine and dexamethasone on disseminated intravascular coagulation, cytokine levels and adenosine deaminase activity in endotoxaemia in rats.

The aim of this study was to determine the effects of drugs used in the treatment of endotoxaemia on disseminated intravascular coagulation, cytokine levels and adenosine deaminase activities in endotoxaemic rats. Rats were divided into seven groups. Lipopolysaccharide (LPS) was injected into all groups, including the positive control group. The other six groups received the following drugs: enrofloxacin (ENR), flunixin meglumine (FM), low-dose dexamethasone (DEX), high-dose DEX, ENR + FM + low-dose DEX, and ENR + FM + high-dose DEX. After the treatments, serum and plasma samples were collected at 0, 1, 2, 4, 6, 8, 12, 24 and 48 hours (h). A coagulometer was used to determine the levels of coagulation values, while ELISA was used to assay serum cytokines and adenosine deaminase (ADA). Low-dose DEX alone and combined treatments depressed the levels of cytokines and ADA (from 371 to 70 IU/L at 6 h) significantly and inhibited the decrease of coagulation values (antithrombin from 67 to 140% at 6 h, fibrinogen from 54 to 252 mg/dL at 6 h). In summary, FM + high-dose DEX may be the preferred treatment of endotoxaemia because of its highest effectiveness. FM plus high-dose DEX may be a new therapy for endotoxaemic domestic animals.

Effects of drugs used in endotoxic shock on oxidative stress and organ damage markers.

The aim of this study was to determine the effects of enrofloxacin (ENR), flunixin meglumine (FM) and dexamethasone (DEX) on antioxidant status and organ damage markers in experimentally-induced endotoxemia. Rats were divided into three groups. To induce endotoxemia, lipopolysaccharide (LPS) was injected into all groups, including the positive control. The two other groups received the following drugs (simultaneously with LPS): ENR + FM + low-dose DEX and ENR + FM + high-dose DEX. After the treatments, blood samples were collected at 0, 1, 2, 4, 6, 8, 12, 24 and 48 h. Oxidative stress parameters were determined by ELISA, while serum organ damage markers were measured by autoanalyser. LSP increased (p < 0.05) malondialdehyde, 13,14-dihydro-15-keto-prostaglandin F(2 alpha) and nitric oxide, while LPS reduced vitamin C. These changes were especially inhibited (p < 0.05) by ENR + FM + high-dose DEX. LPS increased organ damages markers. Cardiac and hepatic damage was not completely inhibited by any treatment, whereas renal damage was inhibited by two treatments. This study suggested that ENR + FM + high-dose DEX is most effective in the LPS-caused oxidative stress and organ damages.