Interactive effect of carbendazim and imidacloprid on buffalo bone marrow derived mesenchymal stem cells: oxidative stress, cytotoxicity and genotoxicity.

The effect of a combination of two pesticides, carbendazim (CBZ) and imidacloprid (IMI), was investigated on mesenchymal stem cells derived from the bone marrow of buffalo (bMSCs). The bMSCs were exposed to the CBZ (2.25 µM, 4.49 µM, and 8.98 µM) and IMI (0.81 mM, 1.61 mM, and 3.22 mM) alone as well as in combinations. The bMSCs were found to be positive for the stem cell markers, AP, CD73, and OCT4. The bMSCs showed a significant reduction (p ≤ 0.05) in cell viability, and status of anti-oxidants while a significant increase (p ≤ 0.05) in the level of LDH, ALP, and CK-MB in CBZ and IMI-treated groups. A significant increase (p ≤ 0.05) was noticed in LPO, O2─ radical, total ROS, loss of ΔΨm, apoptotic index, and DNA damage in CBZ and IMI-treated groups. A low-dose combination group showed an elevated effect compared to the groups treated with the single pesticide. The interaction index was calculated for CBZ-IMI combined treatment groups on various parameters that showed the majority of antagonist effects. Present findings confirmed that CBZ and IMI-induced cytotoxicity in bMSCs was mediated via ROS production, altered ΔΨm and LPO along with depressed antioxidant status which was responsible for cell apoptosis and cell damage. This study suggested that CBZ and IMI had a dose-dependent toxic effect when the pesticides were used alone, while, co-exposure to both the pesticides simultaneously had an antagonist or non-additive effect on buffalo bMSCs at lower dose combinations and they induced a potentiating effect at high-dose combination.

Genotoxic effects of drospirenone and ethinylestradiol in human breast cells (in vitro) and bone marrow cells of female mice (in vivo).

Estrogen and progesterone congeners as found in various oral contraceptive formulations have been implicated as the cause of cancer in sex and tissue-specific targets. The mechanism of carcinogenesis by sex steroids is still debatable. In this study, we evaluated the genotoxicity induced by two components of one of the commonly used oral contraceptive formulation; drospirenone and ethinylestradiol in human breast cells (MCF-7) in vitro and in bone marrow cells of female mice in vivo. DNA damage was assessed by alkaline comet assay. Both of the drugs produced DNA damage in human breast cells at exposure concentrations which are about 100-fold and above than normally found in human blood after their lowest recommended doses. The DNA damage was produced only after metabolic activation by mice liver S-9 fraction in both cases. The co-exposure with both the compounds at median exposure levels resulted in potentiation of DNA damage. In bone marrow cells of adult female mice, both the compounds produced DNA damage at human equivalent doses after exposure was carried out repeatedly for approximately one estrus cycle (5 days). The co-administration with the compounds resulted in potentiation of DNA damage as indicated by percent tail DNA in comet assay. Thus it is concluded that drospirenone and ethinylestradiol cause DNA damage in certain target specific tissue (mammary epithelial cells) and in female bone marrow cells. The co-exposure with drospirenone and ethinylestradiol results in potentiation of genotoxicity which may pose a threat of cancer development in women taking these drugs for long periods.

Effect of quinestrol on body weight, vital organs, biochemicals and genotoxicity in adult male lesser bandicoot rat, Bandicota bengalensis.

The present study was aimed to evaluate the toxic effects of quinestrol (a synthetic estradiol) in male lesser bandicoot rat, Bandicota bengalensis. Effect was studied on body weight, weight of vital organs, changes in level of biochemical parameters and genotoxicity. Feeding of bait containing 0.01% quinestrol in bi-choice and 0.02 and 0.03% quinestrol in no-choice for a period of 10 days resulted in total ingestion of 19.50, 67.60 and 243.30 mg/kg bwt, respectively of the active ingredient. Autopsy of rats after 15 and 30 days of treatment withdrawal revealed no significant effect on body weight and weights of vital organs of rats. A significant decrease in the testicular levels of 17-beta hydroxysteroid dehydrogenase and increase in total soluble proteins was observed in rats treated with 0.02 and 0.03% quinestrol. The plasma levels of lipid peroxidation in the form of malondialdehyde concentration and lactate dehydrogenase increased significantly whereas the level of testosterone decreased significantly in treated rats. The plasma levels of acid and alkaline phosphatases, superoxide dismutase and total proteins differed non-significantly among rats of treated and untreated groups. The effect was found reversed partially in rats autopsied after 60 days of treatment withdrawal. No micronuclei in bone marrow cells, no aberrations in chromosomes and no DNA damage in blood cells during comet assay indicated no genotoxic effect of quinestrol on B. bengalensis at the test doses administered. The results thus revealed that quinestrol causes reversible toxic effects in the form of oxidative stress, increased lytic enzyme activity and decreased steroidogenesis which may further lead to testicular damage thereby inhibiting reproductive function. Also more effect was shown at higher doses ingested in no-choice test as compared to low doses ingested in bi-choice tests.

Rosuvastatin and retinoic acid may act as 'pleiotropic agents' against ß-adrenergic agonist-induced acute myocardial injury through modulation of multiple signalling pathways.

Cardiovascular disorders constitute the principal cause of deaths worldwide and will continue as the major disease-burden by the year 2060. A significant proportion of heart failures occur because of use and misuse of drugs and most of the investigational agents fail to achieve any clinical relevance. Here, we investigated rosuvastatin and retinoic acid for their "pharmacological pleiotropy" against high dose ß-adrenergic agonist (isoproterenol)-induced acute myocardial insult. Rats were pretreated with rosuvastatin and/or retinoic acid for seven days and the myocardial injury was induced by administering isoproterenol on the seventh and eighth day. After induction, rats were anaesthetized for electrocardiography, then sacrificed and different samples were collected/stored for various downstream assays. Myocardial injury with isoproterenol resulted in increased cardiac mass, decreased R-wave amplitude, increased QRS and QT durations; elevated levels of cardiac markers like cTnI, CK-MB, ALT and AST; increased lipid peroxidation, protein carbonylation and tissue nitric oxide levels; decreased endogenous antioxidants like SOD, CAT, GR, GST, GPx and total antioxidant activity; increased inflammatory markers like TNF-α and IL-6; decreased the mRNA expression of Nrf2 and Bcl-2; increased the mRNA expression of Bax, eNOS and iNOS genes. Pretreatment with rosuvastatin and/or retinoic acid mitigated many of the above biochemical and pathological alterations. Our results demonstrate that rosuvastatin and retinoic acid exert cardioprotective effects and may act as potential agents in the prevention of ß-adrenergic agonist-induced acute myocardial injury in rats. Cardioprotective potential of rosuvastatin and retinoic acid could be attributed to their influence on the redox pathways, immunomodulation, membrane stability, Nrf2 preservation, iNOS and Bax expression levels. Thus, they may act directly or indirectly at various steps, the breakpoints, in the pathophysiological cascade responsible for cardiac injury. Our study gives insights about the pharmacological pleiotropism of rosuvastatin and retinoic acid.

Evaluation of ameliorative effect of curcumin on imidacloprid-induced male reproductive toxicity in wistar rats.

This study was undertaken to investigate the toxic effects of imidacloprid (IM) on male reproductive system and ameliorative effect of curcumin (CMN) in male Wistar rats. For this purpose, IM (45 and 90 mg/kg, body weight) and CMN (100 mg/kg, body weight) were administered orally to the rats either alone or in combinations for a period of 28 days. At the end of experiment, male reproductive toxicity parameters (total sperm count and sperm abnormalities), testosterone level, steroidal enzymatic activity [3ß-hydroxysteroid dehydrogenase (3ß-HSD) and 17ß-HSD], and oxidative stress indicators were estimated in testis and plasma. IM treatments resulted in significant decrease (p < 0.05) in total epididymal sperm count, sperm motility, live sperm count, and increase (p < 0.05) in sperm abnormalities. Activities of gamma-glutamyl transpeptidase, lactate dehydrogenase-x, and sorbitol dehydrogenase were significantly increased (p < 0.05), while, 3ß-HSD and 17ß-HSD enzymatic activity along with testosterone concentration in testis and plasma were decreased significantly (p < 0.05) in IM-treated rats. IM exposure resulted in significant increase (p < 0.05) in LPO and decrease (p < 0.05) in GSH level along with decreased activities of CAT, SOD, GPx, and GST. IM-treated rats showed histopathological alterations in testis and epididymis. However, the reproductive toxicity parameters, oxidative stress indicators, and histopathological changes were minimized and functional restorations were noticed by co-administration of CMN in IM-treated rats. The results of this study suggest that IM-induced male reproductive toxic effects could be ameliorated by CMN supplementation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1250-1263, 2016.

Evaluation of imidacloprid-induced neurotoxicity in male rats: a protective effect of curcumin.

The present study was carried out to evaluate the neurotoxic effect and biochemical alteration as a result of imidacloprid (IMI) exposure and potential protective role of curcumin (Cur) against it in rats. Rats were administered with IMI (45 and 90 mg/kg body weight; orally) and Cur (100 mg/kg body weight; orally) alone and in combinations for the period of 28 days. Significant decrease in spontaneous locomotor activity (SLA) and pain threshold were observed in animals treated with the IMI, while the effect was attenuated by the Cur co-treatment. Acetylcholinestaerase, ATPase and serum biochemicals such as creatine kinase, lactate dehydrogenase, sorbitol dehydrogenase and alkaline phosphatase levels were significantly decreased (p < 0.05) as result of IMI exposure and these enzyme levels were reversed in groups treated with the Cur in IMI treatments. Also, IMI caused a significant decrease (p < 0.05) in antioxidant enzymes activity and non-enzymes level with increase in lipid peroxidation (LPO), while Cur administration in IMI treatments restored the altered activity of antioxidant system with decrease in LPO. The IMI induced brain damage was minimized as result of Cur co-administration in rats. In conclusion, Cur restores the altered functions of biochemical markers and neurotoxicity in IMI exposed rats.

Effect of S-methylisothiourea in acetaminophen-induced hepatotoxicity in rat.

Nitric oxide synthesized from inducible nitric oxide synthase (iNOS) plays role in acetaminophen (APAP)-induced liver damage. The present study was undertaken to evaluate the effect of iNOS inhibitor S-methylisothiourea (SMT) in APAP-induced hepatotoxicity in rats (1 g/kg, i.p.). SMT was (10, 30, and 100 mg/kg; i.p.) given 30 min before and 3 h after APAP administration. At 6 and 24 h, blood was collected to measure alanine transaminase (ALT), aspartate transaminase (AST), and nitrate plus nitrite (NOx) levels in serum. At 48 h, animals were sacrificed, and blood and liver tissues were collected for biochemical estimation. SMT reduced significantly the serum ALT, AST, and NOx levels at 24 and 48 h and liver NOx levels at 48 h as compared with APAP-treated control. The amount of peroxynitrite measured by rhodamine assay was significantly reduced by SMT, as compared with APAP-treated control group. SMT treatment (30 mg/kg) has significantly reduced the lipid peroxidation and protein carbonyl levels, increased SOD and catalase, and reduced glutathione and total thiol levels significantly as compared with APAP-treated control. SMT 30 mg/kg dose has protected animals from APAP-induced hypotension and reduced iNOS gene expression. Hepatocytes were isolated from animals, and effect of SMT on apoptosis, MTP, and ROS generation was studied, and their increased value in APAP intoxicated group was found to be significantly decreased by SMT (30 mg/kg) at 24 and 48 h. In conclusion, nitric oxide produced from iNOS plays important role in toxicity at late hours (24 to 48 h), and SMT inhibits iNOS and reduces oxidative and nitrosative stress.