Assessment of the efficacy of thymol against Toxocara vitulorum in experimentally infected rats.

The effect of thymol and ivermectin on the development and embryonation of Toxocara vitulorum (T. vitulorum) eggs, as well as their migration in albino rats was investigated both in vitro and in vivo. A total of forty male albino rats were divided into four groups for an in vivo experiment. The first group was uninfected; the second group was infected but left untreated; the third group was infected and received thymol at a dose of 40 mg/kg; and the fourth group was infected and received ivermectin (0.2 mg/kg). In vitro, thymol inhibited the development of Toxocara larvae within the eggs. However, ivermectin, produced inconsistent results. The in vivo results indicated that the recovery rates of Toxocara larvae from the liver and lungs on day 7 post-infection were significantly lower in the thymol or ivermectin-treated groups than in the infected untreated control. Albumin levels were significantly increased in the thymol-treated group as compared to the positive control and ivermectin groups. Nitric oxide, IL-4, and IFN- levels in the serum of the thymol or ivermectin-treated groups were significantly lower than that of the positive control group. Histopathological examination demonstrated that thymol and ivermectin were effective in reducing larval load, reducing the number and size of granulomas in the absence of larvae, and improving tissue architecture. The current study concluded that thymol possessed anti-Toxocara activity in a rat model. Additionally, thymol possessed ovicidal properties and may be used as a disinfectant. © Indian Society for Parasitology 2022.