Ameliorative Effects of Cymbopogon citratus Aqueous Leaf Extract on Dichlorvos–induced Hypersensitivity Pneumonitis in Wistar Rats

Occupational dichlorvos exposure can cause organophosphate poisoning, which can be fatal if left untreated. This study aimed to investigate the effects of aqueous leaf extract of Cymbopogon citratus on dichlorvos-induced hypersensitivity pneumonitis in Wistar rats. Thirty Wistar rats weighing between 236 and 256 g were divided into five groups of six rats each. Group A rats were administered feed and water only. Group B rats were exposed to 2 puffs of dichlorvos. Group C rats received 500 mg/kg body weight per day (BWT/D) of Cymbopogon citratus only. Groups D and E rats were exposed to 2 puffs of dichlorvos and received 250 mg/kg BWT/D and 500 mg/kg BWT/D of Cymbopogon citratus respectively. The dosages of the extract were given for 30 days via an orogastric tube. At the end of the 30th day of exposure, the animals were euthanized under chloroform anaesthesia and the lungs were harvested and processed for histological examination. The histological sections of the lungs of rats in Groups A, C, D and E showed normal histoarchitecture of the lungs. There were observable histological variations in the lung histoarchitecture of the rats exposed to dichlorvos (Group B) which include alveolar hemorrhage, bronchiolar hemorrhage, and interstitial infiltrates of inflammatory cells (evidence of hypersensitivity pneumonitis) This study demonstrates that Cymbopogon citratus has a protective role in combating dichlorvos-induced hypersensitivity pneumonitis, characterized by reduced severity of bronchiolar and alveolar hemorrhage and interstitial inflammation, in Wistar rats.

Key Words: Cymbopogon citratus; Dichlorvos; Histoarchitecture; Hypersensitivity pneumonitis; Exterminators