Efficacy and safety of two analogs of L-carnitine on rats made insulin resistant by a high-fructose diet.

AIM: To evaluate the efficacy and safety of 2 analogs of L-carnitine on rats made insulin resistant by a high-fructose diet. METHODS: Using rats made insulin resistant by a high-fructose diet, we investigated the impact of 2 analogs of L-carnitine (25 mg/kg) and L-carnitine (250 mg/kg) on glucose, triglycerides and cholesterol blood levels, and liver glycogen. We also evaluated the safety of both analogs by the assessment of some biochemical and hematological parameters, a histological analysis and a study of embryotoxicity. RESULTS: Both analogs reduced the levels of triglycerides in the liver and plasma, but only analog 2 reduced the cholesterol levels in insulin-resistant rats. No changes were observed in glycogen content. Safety evaluations revealed alterations in blood lymphocytes and embryotoxicity data. CONCLUSION: This study demonstrated that the 2 analogs maintain the pharmacological properties of L-carnitine but have a different efficacy, potency and toxicity.

Preclinical safety evaluation of amphotericin A21: A novel antifungal.

Safety studies are essential in drug development. This study evaluates the safety of Amphotericin A21 (AmB-A21), a derivative of amphotericin B with antifungal therapeutic potential. We performed a chronic toxicity study, a targeted organ study and a dermal irritation test. To evaluate chronic toxicity, 18 male adult rats were treated orally with AmB-21 (2 mg/kg) for 26 weeks. The effects on body-weight and animal health were measured, and haematological, clinical chemistry and histopathological tests were conducted on various organs. In the target organ toxicity study, male adult rats received a daily oral dose of AmB-21 (2 mg/kg) for 6 and 17 weeks; testicle histology and testosterone levels were then evaluated. For the dermal irritation study, AmB-21 (200 and 1000 mg/kg) was placed on the skin of adult male rabbits; macroscopic and microscopic studies, as well as haematological and clinical chemistry tests were then conducted. The chronic toxicity study revealed that AmB-21 caused testicle damage, and the testicle-targeted study showed structural alterations and changes in testosterone levels at 17 weeks. However, these alterations were no longer observed 8 weeks after discontinuation of treatment, and the testes showed very similar characteristics to those in the control group. The dermal irritation study showed skin thickening and reddening in rabbits treated with 2000 mg of AmB-A21 after 14 days of exposure. This same group also showed changes in liver enzymes, renal parameters and platelet levels. Based on our results, we consider AmB-21 to be a potential candidate for safe, long-term antifungal treatment given its reduced side effects.

Immuno-modulator metallo-Peptide reduces inflammatory state in obese zucker fa/fa rats.

Metabolic syndrome is a prothrombotic and proinflammatory chronic state. In obesity, the adipose tissue secretes various adipokines that take part in a variety of physiological and pathophysiological processes, including immunity and inflammation. Previous studies using a liver damage model treated with the immune-modulator metallo-peptide (IMMP) showed lessening in the degree of inflammation. Therefore, this study was set up to evaluate the anti-inflammatory effect of IMMP in obese Zucker fa/fa rats. We used Zucker-Lepr fa/fa and Zucker-Lean in this protocol. The groups received IMMP 50 ng/kg by i.p., three times per week for 8 weeks. Blood samples were collected by cardiac puncture and the serum was preserved at -80°C until analysis; the liver was excised and preserved in formaldehyde 4%. Analyses were performed to determine cytokine, insulin, glucose, triglyceride and cholesterol levels in serum, and histological analysis was also performed. IMMP treatment of obese rats resulted in decreased levels of proinflammatory cytokines (leptin, lL-6, IL-1betha, INF-gamma) and a chemokine (MCP-1), and increased levels of anti-inflammatory adipokine (adiponectin). In addition, treatment decreased the damage and hepatic steatosis generated in the tissue of obese rats. The IMMP exerted an anti-inflammatory effect in obese rats and therefore may be an effective and safe therapeutic alternative in the treatment of metabolic syndrome.