BACKGROUND AND OBJECTIVE: Considering the possibility of increased renal toxicity induced by streptomycin in tea and coffee, which contain methylxanthines such as caffeine, we aimed to investigate the histopathological changes in the kidney and liver of rats. We also evaluated some serum parameters after the concurrent use of streptomycin and caffeine.

METHODS: This experimental study was performed on 25 female Wistar rats, with the average weight of 200 g the rats were divided in five groups. Group I was regarded as the control group, group II received streptomycin (25 mg/kg), group III was administered streptomycin+caffeine (5 mg/kg), group IV received caffeine (5 mg/kg) and group V received streptomycin + vitamin C (100 mg/kg) for a period of 21 days. Afterwards, the rats were anesthetized with ether and blood samples were obtained from the heart. Serum creatinine, blood urea nitrogen, sodium and potassium levels were measured in rats. After preparing and sectioning renal and hepatic tissues for pathological examinations, they were stained by hematoxylin and eosin (H&E) the samples were examined, using a light microscope.

FINDINGS: Serum creatinine and potassium levels were not significantly different between the groups, while urea nitrogen level in group V (15±07 mg/dL) was significantly lower than the values reproted in groups I and IV (p<0.05). Sodium level increased in group II (139. 8±0.2 mEq/L) and group IV (140±0.447 mEq/L), while a significant reduction was reported in group V (137.25±0.75 mEq/L) (p<0.05). According to the findings, hepatic and renal damages were severe after the concomitant use of streptomycin and caffeine. However, vitamin C reduced the induced damages.

CONCLUSION: As the results indicated, caffeine could aggravate renal injuries, induced by streptomycin, while vitamin C had an alleviating effect.