---

Background and Objective: Chronic diabetes mellitus is accompanied with enhanced oxidative stress and reduce the activity of antioxidant defense system. Due to significant role of enhanced oxidative stress in development of renal damage in diabetices, this study was conducted to evaluate the effect of chronic administration of Silymarin on oxidative stress markers in renal tissue of diabetic rats. Materials and Methods: In this experimental study, 40 male Wistar rats were divided into 5 groups: control, silymarin-treated control (100 mg/kg bw), diabetic, and silymarin -treated diabetic groups (50 and 100 mg/kg bw). Silymarin was administered (daily and intraperitonealy) ten days after Streptozotocin injection for 4 weeks. Tissue level of malondialdehyde and nitrite and nitrate and activity of superoxide dismutase in kidney tissue were measured. Data were analyzed using ANOVA and Tukey tests. Results: A significant increase in tissue level of malondialdehyde, nitrite and nitrate in diabetic rats were observed (P<0.05). Silymarin treatment (100 mg/kg/bw) significantly reduced the tissue level of Malondialdehyde, nitrate and nitrate (P<0.05). Non-significant recduction of activity of superoxide dismutase was oberved in diabetic rats and Silymarin treatment (50 and 100 mg/kg bw) did not significantly altered enzyme activity. Conclusion: Four weeks treatment of Silymarin (100 mg/kg bw) reduce oxidative stress indexes in renal tissue of diabetic rats.

---

Background and Objective: Diabetes mellitus cause learning, memory and cognitive skills disorders in the long term. This study was conducted to determine the protective effect of silymarin on the learning and memory deficiency in streptozotocin-diabetic rats. Materials and Methods: This experimental study was conducted on 40 male Wistar rats weighing 240-300 grams. The rats were randomly allocated into 5 groups: control, silymarin -treated control (100 mg/kg), diabetic, and two silymarin -treated diabetic groups (50 and 100 mg/kg). Silymarin was daily administered (i.p. and daily) ten days after streptozotocin injection for 4 weeks. Finally, initial (acquisition index) and step-through latencies (retention and recall index) were measured using passive avoidance test and alternation behavior percentage as an index of spatial memory was determined using Y maze. The level of malondialdehyde in the homogenate hippocampal tissue of the animals brains was measured. Data were analyzed using Sigma Stat-3.5, one-way and two-way ANOVA, Tukey, and Kruskall-Wallis tests. Results: A significant reduction of STL was observed in diabetic (P<0.01) and silymarin-treated (50mg/kg) diabetic (P<0.05) groups and this parameter was significantly higher in diabetic group receiving a high dose of silymarin compared to diabetic group (P<0.05). Meanwhile, alternation percentage in diabetic animals was significantly lower than control group (P<0.05) and this index did not show a significant difference in silymarin-treated diabetic groups in comparison with diabetic group. In diabetic rats, there was a significant increase in the tissue level of malondialdehyde (P<0.05) and silymarin treatment with dosage of (100 mg/kg) significantly reduced the level of MDA (P<0.05). Conclusion: This study showed that although long-term administration of silymarin at a high dose (100 mg/kg) affects the ability to store data in memory and to recall it in diabetic animals in passive avoidance test, it does not improve short-term spatial memory in diabetic animals. The beneficial effects of silymarin may be via attenuation of lipid peroxidation in hippocampus tissue.

---

Background and Objective: Temporal lobe epilepsy is the most common type of epilepsy in human. Patients suffer from spontaneous seizures and memory deficiency. This study was done to assess the effect of Co-enzyme Q10 (CoQ10) administration on seizure, short-term spatial memory and stress oxidative indices in hippocampus of kainic acid-induced epilepsy. Methods: In this experimental study, 48 male rats were randomly allocated into six groups: sham-operated CoQ10 (10 mg/kg/bw)-treated SH kainate CoQ10 (2, 5 and 10 mg/kg/bw) treated kainic acid. CoQ10 was intraperitoneally administered daily for one week before intra-hippocampal injection of kainic acid (4µg/kg/bw) in animals. Results: Kainic acid induced chronic and acute spontaneous seizures in animals. Also, kainic acid administration caused a reduction in alternational behavior rate (consecutive or serially entrance into all of arms in triplet set), increasing of malondialdehide, nitrite level and decreasing of superoxide dismutase activity compared to sham group (P<0.05). Pre-treatment of kainate rats with CoQ10 decreased rate of spontaneous seizures (P<0.05). CoQ10 increased alternational behavior rate, decreased malondialdehide and nitrite serum level (P<0.05). But it had no significant effect on superoxide dismutase activity. Conclusion: Pre-treatment of kainic acid exposed rats with CoQ10 reduced rate of seizures and improved short-term spatial memory and oxidative stress indices in rats.