Chronic Oral Exposure to Dichlorvos and its Impact on Cardioprotective and Atherogenic Indices in New Zealand White Rabbits

Background: The toxicity of dichlorvos on the heart is based on its ability to inhibit acetylcholinesterase enzyme leading to the accumulation of acetylcholine in the presynaptic space. This can be associated with various health issues such as muscle incoordination, tremors, myosis, chest discomfort, decreased heart irregularities, loss of reflexes, muscular paralysis, autonomic overstimulation and cardiorespiratory failure.

Aim: The present study assesses the Effects of Dichlorvos Oral Exposure on Cardio protective and Atherogenic Indices of New Zealand White Rabbits.

Methodology: A total of twenty-four male News Zealand white rabbits, two months old weighing between 1.0 and 1.2 kg, were used for the study. They were divided into three (3) groups, each consisting of four (4) rabbits and a corresponding number of matched controls, for long-term toxicological effects of dichlorvos on the rabbits (30 days, 60 days and 90 days).The rabbits received ten (10%) of the LD50 dose . The LD50 dose was 0.05 mg/m3, while 10% of the median lethal dose of dichlorvos which was 0.005 mg/dl was diluted with 1.0 milliliter of distilled water. It was administered by oral route daily for the stipulated periods of thirty, sixty, and ninety days. At the end of each month, a set of rabbits in the experimental group with their matched control were sacrificed using chloroform. Five milliliters (5 mls) of blood was collected from each rabbit at the stipulated period of thirty, sixty, and ninety days. The analysis of Lipid profile was carried out using autolab chemistry analyser, while Cardioprotective and Atherogenic Indices were calculated. Data generated were expressed as mean ± SD. ANOVA and Tukey’s multiple comparison tests was used for result analysis. Variation in mean of parameters were considered statistically significant at P<0.05.

Results: At day 30 oral exposure to dichlorvos cardio protective parameter AAI (anti Atherogenic index) showed significant decrease while TG/HDL-C, CRI-I, CRI-II, AIP, AC showed no significant differences when compared with the control. Between day 60 and 90 days of exposure, significant elevations were observed on CRI-I, CRI-II with significant decrease in AAI level as shown: AAI control-(39.16±5.79), day 30-(21.70±3.59), day 60-(20.09±5.19), day 90-(11.93±1.69); CRI-I control-(6.44±1.18), day 30-(6.85±1.56), day 60-(7.16±1.31), day 90-(11.38±0.77); CRI-II control-(4.46±0.85), day 30-(5.25±1.52), day 60-(5.83±1.18), day 90-(9.83±0.74).

Conclusion: Dichlorvos oral exposure significantly reduced the cardioprotective index (AAI) and increased atherogenic indices, with the most pronounced changes observed at 90 days (p < 0.05).