Investigation of Histopathological Changes Caused by Leishmania major in BALB/c Mice Treated with Aqueous Extract of Allium sativum (Garlic)

Cutaneous leishmaniasis is a tropical and treatment-resistant disease which the range of treatment strategies based on effective plant substances has been expanded due to the side effects of standard druge. Therefore, the aim of the present study was to determine and investigate the histopathological changes caused by Leishmania major in BALB/c mice treated with aqueous extract of garlic.

Methods:

 In this experimental study, which was conducted in 2018 at the Faculty of Veterinary Medicine of Bou Ali Sina University,, 36 female BALB/c mice with an average weight of 30g were equally divided into 6 groups and the standard strain of Leishmania major parasite was injected into 5 groups. Three groups were treated with aqueous garlic extract orally and topically, and three groups were treated as control, without treatment and received Glucantim as drug. The size of the wound in five groups were evaluated weekly, and after the 90-day of treatment, skin tissue around the wound, lymph nodes, spleen, and liver were taken for histopathologic evaluation. The collected data were analyzed using statistical tests of two-way analysis of variance (pvalue ≤ 0.05).

A significant reduction in wound size was observed in the groups receiving the garlic extract orally (p≤0.0001). The structures of the lymphoid organs differed in these two groups in inflammation, granuloma, and lymphocyte populations compared to the control groups and even to the group receiving garlic topical ointment, and the healing process was observed in them, also, wound healing was significantly accelerated in the group receiving oral garlic extract before parasite injection (p≤0.05). Histopathological changes in the group receiving garlic ointment also showed evidence of wound healing, but at the end of the treatment period, it was less effective than the group receiving oral garlic (p≤0.05).

The oral extract of garlic changes the inflammatory reactions in the wound site of cutaneous leishmaniasis towards repair and accelerates the healing process of the wound. Garlic extract compounds can be considered as a natural treatment option in treatment-resistant Leishmania infection.