Oral administration of Nigella sativa oil and thymoquinone attenuates long term cisplatin treatment induced toxicity and oxidative damage in rat kidney.

Cisplatin (CP) is an effective anti-cancer drug which causes remarkable toxicity to the kidney, particularly to proximal tubules, by generating reactive oxygen species. Nigella sativa (NS), commonly known as "black cumin" reduces the progression of various kidney disorders. Thymoquinone (TQ), the major bioactive constituent of NS seeds, has been credited for various pharmacological effects of NS. Since, a typical clinical CP dosing regimen involves CP administration in multiple cycles over a long time duration, hence the present study aimed to evaluate the renoprotective efficacy of NS oil and TQ against multiple dose CP treatment induced deleterious biochemical and histological alterations in rat kidney. Adult male Wistar rats were divided into six groups viz. control, CP, CPNSO, CPTQ, NSO and TQ. Animals in CPNSO and CPTQ groups were pre-administered NSO (2ml/kg bwt, orally) and TQ (1.5mg/kg bwt, orally) respectively for 14 days and were then treated with CP (3mg/kg bwt, i.p), every fourth day for 20 days while still receiving NSO/TQ. NSO and TQ administration, prior to and along with CP treatment, attenuated CP induced renal functional impairment as evident by significantly restored serum creatinine and blood urea nitrogen levels. CP treatment alone led to significant decline in the specific activities of brush border membrane (BBM) marker enzymes viz. ALP (-46.64%), GGTase (-50.24%) and LAP (-42.15%), while NSO or TQ administration to CP treated rats significantly prevented the decline in the activities of these enzymes in isolated BBM vesicles (BBMVs) as well as in the homogenates of renal cortex and medulla. Furthermore, both NSO and TQ administration also mitigated the CP induced perturbations in renal metabolic and redox status. Histological studies supported these biochemical results showing significant attenuation of CP induced kidney damage in CPNSO and CPTQ cotreated groups. Thus, NSO and TQ have excellent scope for use as functional food or combinatorial nutraceuticals in CP chemotherapy to ameliorate the accompanying nephropathy in long term cancer chemotherapy.