Chronopharmacology of the alpha-lipoic acid/nifedipine/glimepiride combination in the amelioration of retinopathy in rats.

Time of drug administration affects both the kinetics and dynamics of medications. This study investigated diurnal efficacy of alpha-lipoic acid (ALA), nifedipine, and glimepiride combination in the treatment of diabetic retinopathy. The study design comprised seven groups of rats, with groups 1 and 2 serving as non-diabetic and diabetic controls, respectively, receiving 1 ml/kg distilled water. All other groups were diabetic, and received 10 mg/kg glimepiride at 20:00 h. Groups 4-7 also received 20 mg/kg nifedipine at 08:00 h. In addition, groups 5-7 received 100 mg/kg ALA at 08:00 h, 14:00 h, and 20:00 h, respectively. Oral drug administration was for 28 days during which fasting and random blood glucose sampling were done weekly at 07:30 h and 13:30 h, respectively. On the 29th day, rats were euthanized; blood was collected via the jugular veins for determination of serum ocular markers like magnesium, cholesterol, and triglyceride. Furthermore, the eyes were excised and their relative organ/body weight ratios determined. The right eyes were persevered in phosphate buffer for homogenization and determination of retina antioxidant profile (MDA, SOD, CAT, GSH), while the left eyes were preserved in formalin for histological examination. Results showed that treatment with ALA and glimepiride at 20:00 h along with nifedipine at 08:00 h resulted in better prognosis than other treatment groups and with improved glycemic control. Also, all their serum markers for retinopathy, organ weight, and histology did not differ significantly from that of the non-diabetic rats. Findings imply that diurnal efficacy in alpha-lipoic acid, nifedipine and glimepiride combination ameliorates diabetic retinopathy in rats and may be beneficial in the treatment of diabetic retinopathy.

Effects of melatonin on changes in cognitive performances and brain malondialdehyde concentration induced by sub-chronic co-administration of chlorpyrifos and cypermethrin in male Wister rats

<p><b>OBJECTIVE</b>To evaluate the ameliorative effect of melatonin on sub-chronic chlorpyrifos (CPF) and cypermethrin (CYP)-evoked cognitive changes in male Wistar rats.</p><p><b>METHODS</b>Fifty adult male Wistar rats, divided into five groups of ten rats each, were used for the study. Groups 1 and II were given distilled water and soya oil (2 mL/kg) respectively. Group III was administered with melatonin at 0.5 mg/kg only. Group IV was administered with CPF [7.96 mg/kg (1/10th LD50)] and CYP [29.6 mg/kg (1/10th LD50)], and Group V was administered with CPF [7.96 mg/kg (1/10th LD50)] and CYP [29.6 mg/kg (1/10th LD50)] 30 min after melatonin (0.5 mg/kg). The regimens were administered by gavage once daily for 12 weeks. Thereafter, cognitive performances were determined and the brain was evaluated for malonaldehyde concentration.</p><p><b>RESULTS</b>CPF and CYP induced cognitive deficits and increased brain malonaldehyde concentration, which were all ameliorated by melatonin.</p><p><b>CONCLUSION</b>Cognitive deficits elicited by CPF and CYP was mitigated by melatonin due to its antioxidant property.</p>

Histopathological effects of sub-chronic lamivudine-artesunate co-administration on the liver of diseased adult Wistar rats.

BACKGROUND: Lamivudine and artesunate are sometimes co administered in HIV-malaria co morbidity. Both drugs are used concurrently in presumptive malaria treatment and simultaneous HIV post exposure prophylaxis. AIM: The aim of this study was to investigate the effect of lamivudine-artesunate co administration on the histology of the liver of diseased adult Wistar rats. MATERIALS AND METHODS: Five groups of rats of both sexes were used for the study and placed on feed and water ad libitum. Disease state consisted of immunosuppression with cyclophosphamide, and infection with Plasmodium berghei. Group 1 animals served as vehicle control, while group 2 were the diseased controls. Group 3 animals received 20 mg/kg lamivudine for three weeks, while group 4 similarly received 20 mg/kg Lamivudine but also received 10 mg/kg artesunate from day 12. Animals in group 5 received 10 mg/kg artesunate from day 12. All drugs were administered intraperitoneally. The animals were treated for twenty-one days, at the end of which they were sacrificed and their livers fixed in 10% formalin for histological studies. RESULT: Results from the study show the presence of regions of focal necrosis and perivascular cuffing with animals that received artesunate. Hemosiderosis was a common feature in all the parasitized groups, while fatty degeneration was observed in the group that received artesunate alone. CONCLUSION: Concurrent lamivudine-artesunate administration resulted in some histopathological changes in the liver. This study suggests there may be considerable histological changes with repeated occurrence of malaria and immunosuppression that may warrant intermittent lamivudine-artesunate administration, and may require evaluation as well as monitoring of liver function during such therapeutic interventions.