Effects of <i>Turnera diffusa</i> Will. over blood glucose and oxidative stress in kidney mitochondria diabetic‐STZ rats

Abstract

Turnera diffusa Will (damiana) is used in Mexican traditional medicine for treatment of various disorders including diabetes mellitus (DM). Not with standing, there is not a study that proves this effect on DM‐STZ for a long period. Also, there are not reports about the effects of damiana over the oxidative stress; a marker of damage in DM, in kidney mitochondria. By this reason, we set a main aim in this work for evaluate the antioxidant ability of this important medicinal plant in a worldwide pathology DM. To achieve this purpose we use STZ‐DM rats (65mg/kg body weight). We administered aqueous extract (150mg/kg body weight) from aerial parts of damiana. The blood glucose and animal weight was recorded every five days during 3 and 5 weeks of treatment. At the end of the treatments rats were sacrificed and kidney removed for mitochondria isolation by differential centrifugation. Lipid peroxidation, nitric oxide (NO) and nitrosylation profile in mitochondrial proteins were evaluated. Our results shown that T. diffusa in this investigation has no capacity to reduce the blood glucose at any time after 3 or 5 weeks of treatment, but induce to DM‐STZ animals to maintain the body weight, an important sign in DM. Our investigation also reveals the protection versus lipid peroxidation at the end of 5 weeks of treatment in control and DM groups (from 7.60 ± 0.38 to 6.48 ± 0.87 and 7.802 ± 0.70 to 3.358 ± 0.04 nmoles/mg prot, respectively), decreases the NO levels in both 3 and 5 weeks of treatment (from 0.703 ± 0.03 to 0.248 ± 0.05 and 0.754 ± 0.07 to 0.433 ± 0.02 μMole/mg prot, respectively). Nonetheless, nitrosylation of mitochondrial proteins remains unchanged compared with the control groups in all treatments. Finally, either control groups with or without treatments do not modifies the parameters measured in any case. In conclusion, aqueous extract from aerial parts of damiana has the capacity to mitigate the oxidative stress present in rat kidney mitochondria in DM‐STZ rats and the protector effects in this pathology is due to antioxidant properties more than lower the blood glucose. Support or Funding Information EREG is Postdoctoral Fellow CONACYT.