P. Dwivedi

Ochratoxin A and citrinin nephrotoxicity in New Zealand White rabbits: an ultrastructural assessment

In the present investigation, ochratoxin A (OTA) (0.75 mg/kg feed) and citrinin (CIT) (15 mg/kg feed) were fed alone and in combination to young growing New Zealand White rabbits for 60 days to evaluate renal ultrastructural alterations. The severity and intensity of renal ultrastructural changes varied with the type of the treatment, and predominant and consistent lesions were recorded in the proximal convoluted tubule (PCT) lining cells. The significant changes in mitochondria, the most affected cell organelle in all the treatment groups, included mitochondrial disintegration and distortion, pleomorphism, cluster formation and misshapen appearance such as signet ring, dumbbell, cup and U shapes. Intra-cisternal sequestrations of involuting mitochondria, and thickening of basal layer of PCT epithelial cells with partial detachment, were the characteristic features observed in OTA and combination treatments. CIT treatment revealed crenated nucleus, loss of nucleolus, depletion of cytoplasmic organelles, mitochondrial pleomorphism, nuclear fragmentation, uniform folding of cell membrane and cytoplasmic vacuolations in the PCTs. Focal thickening of the glomerular basement membrane and degeneration of endothelial cells were the prominent alterations in the glomeruli in OTA and combination treatments. Distal convoluted tubules were unaffected in CIT treatment, however, mild to moderate lesions were observed in OTA and combination treated rabbits. It may be concluded that on simultaneous exposure, CIT potentiated the toxic effects of OTA on renal ultrastructure.

Apoptosis and lipid peroxidation in ochratoxin A- and citrinin-induced nephrotoxicity in rabbits

Ochratoxin A (OTA) and citrinin (CIT) are nephrotoxic mycotoxins produced mainly by fungal species Aspergillus ochraceus and Penicillium citrinum, respectively, which have been found to occur together in various food and feed commodities. In the present study, both OTA and CIT were evaluated for their potential to induce oxidative damage by determining lipid peroxidation (LPO) through malondialdehyde (MDA) assay and apoptosis by flow cytometry, gel electrophoresis and renal ultrastructural morphology in rabbits fed with diets containing OTA (0.75 mg/kg feed), CIT (15 mg/kg feed) and OTA + CIT (0.75 and 15 mg/kg feed, respectively) up to 60 days. The concentration of MDA was found significantly higher in OTA and combination-treated groups. OTA and combination-treated groups revealed more apoptotic cells in flow cytometry when compared with the CIT-treated group. Characteristic DNA fragmentation, as evidenced by ladder pattern in electrophoresis appeared in the toxin-treated groups. Ultrastructurally, interstitial cells showed nuclear fragmentation and cytoplasmic blebbing in OTA- and CIT-treated groups; whereas, proximal convoluted tubular epithelial cells, besides interstitial cells, showed nuclear fragmentation in the combined treatment group. The results suggested that low concentrations of OTA and CIT either alone or in combination induced apoptosis in a time-dependent manner and LPO in the rabbit kidney, which appeared to play a major role in the pathogenesis of nephrotoxicity. Furthermore, the interaction of these two nephrotoxic mycotoxins was found to be additive.

Experimentally induced citrinin and endosulfan toxicity in pregnant Wistar rats: histopathological alterations in liver and kidneys of fetuses

In the present investigation, citrinin (CIT) (10 mg kg−1 feed) and endosulfan (1 mg kg−1 body weight) were administered orally alone and in combination to pregnant Wistar rats from gestational day 6 to 20 and their fetuses were collected to evaluate the histopathological alterations in hepatic and renal tissues. In CIT‐fed group fetal liver, the changes were less marked, showing only sinusoidal dilation and mild vacuolar degeneration, whereas the consistent changes in the fetal kidney included tubular degeneration, medullary tubular necrosis, cystic dilatation of tubules, distortion of glomerulur capillary tuft and interstitial fibroblastic proliferation which separated clusters of tubules. In the endosulfan group, the liver was predominantly affected, showing vacuolar degeneration, karyomegaly and severe sinusoidal dilation, whereas the renal changes were mainly confined to tubular degeneration and varying degree of interstitial fibrosis. In the combination group, the hepatic and renal histopathological alterations in the fetus, though of similar nature to those of the individual groups, were more severe. Copyright

Studies on apoptotic changes in combined toxicity of citrinin and endosulfan in pregnant Wistar rats and their fetuses

Background: Citrinin (mycotoxin) and endosulfan (pesticide) both environmental contaminants easily enter the food chain and are caoomon causes of various toxicities. Materials and Methods: In the present investigation, citrinin (CIT) (10 mg/kg feed) and endosulfan (1 mg/kg body weight) were administered orally alone and in combination to pregnant Wistar rats from gestational day 6 to 20 to study their effect to cause apoptosis in the pregnant Wistar rats and their fetuses. Apoptosis was assessed in dams by agarose gel electrophoresis, flow cytometry and electron microscopy, while in the fetuses it was assessed by flow cytometry only. Result: Citrinin and endosulfan in the combination group caused apoptosis in an additive manner as there was increased number of apoptotic cells as compared to the individual toxin and control groups. The fetuses also showed increased number of apoptotic cells in the combination groups, which also indicated that both the toxins crossed the placental barrier. Conclusion: So it was concluded that apoptosis played a significant role in the pathogenesis of endosulfan and citrinin toxicity.

Effect of feeding graded doses of citrinin on apoptosis and oxidative stress in male Wistar rats through the F1 generation

The objective of the present study was to study the effect of graded doses of citrinin (CIT) on apoptosis and oxidative stress in male Wistar rats till F1 generation. The animals were divided into four groups comprising 25 males and 25 females each, that is, group I: 1 ppm CIT; group II: 3 ppm CIT; group III: 5 ppm CIT; and group IV was kept as a control. The male and female animals of all the groups were kept separately and were fed basal rations containing the above-mentioned concentrations of CIT for 10 weeks. After 10 weeks, male and female animals of respective groups were kept for mating (one male/two females). After getting 10 pregnant females, the males were killed. These 10 pregnant females were allowed to give birth to young ones (F1 generation) naturally which were fed CIT in the above-mentioned doses till the age of 6 weeks and then were killed. Apoptosis was analysed in kidneys, liver and testes by DNA ladder pattern, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end-labelling assay and Bcl-2/Bax ratio. Besides, tissue oxidative stress was also analysed. It was concluded in the present study that CIT induces its toxic effects till F1 generation, and apoptosis and oxidative stress both play a very important role in toxicity. The effect of CIT was observed in a dose-dependent manner. However, in kidneys, both the mechanisms (apoptosis and oxidative stress) play their role in inflicting renal damage, while in liver only reactive oxygen species play a major role. Finally, the CIT toxicity did not lead to apoptosis and oxidative stress in male gonads till F1 generation.

Clinicohaemato-biochemical changes in F0 female Wistar rats fed with graded doses of citrinin

The objective of the present study was to study the clinicohaemato-biochemical changes in F0 female Wistar rats on fed with graded doses of citrinin (CIT). The animals were divided into four groups comprising 25 males and 25 females each, that is, group I: 1ppm CIT; group II: 3ppm CIT; group III: 5ppm CIT; and group IV was kept as a control. The male and female animals of all the groups were kept separately and were fed basal rations containing the above mentioned concentrations of CIT for 10 weeks. After 10 weeks, male and female animals of respective groups were kept for mating. After successful mating, 10 pregnant females (F0 females) were allowed to give birth to young ones (F1 generation) naturally and were killed after the weaning period of 21 days. Clinical signs, body weight and various haemato-biochemical parameters were estimated in these F0 females. It was concluded that the dietary exposure of CIT in female rats 10 weeks prior to mating, during mating and during lactation was found to cause anaemia, leucocytopenia due to lymphocytopenia and hepato-renal toxicity as evidenced by certain biochemical parameters.