Background: Leishmaniasis is a vector-borne parasitic disease caused by an obligate intracellular protozoan. Despite the significant frequency of cutaneous leishmaniasis, there is still no appropriate prevention, control and treatment. In recent years, a few studies have been performed on the effects of garlic extract for the treatment of cutaneous leishmaniasis. Current drugs, such as glucantime, have several side effects and lead to direct cellular damage. If an herbal-based drug reduces Leishmania by augmenting the immune system, it has the potential to possess a wider margin of safety. This study aimed to investigate the effects of in vitro systematic review of the effects of garlic (Allium sativum) and its compounds on Leishmania major.
Methods: Five English databases (PubMed, Google Scholar, Embase, Scopus, and Web of Science) were searched until the end of December 2022. The syntax and specific tags have been used for each database. The studies with poor methodology, inadequate information, inappropriate analysis, and confusing presentation were excluded from the current study. The quality of articles was assessed by eleven questions developed by the authors and the data were extracted from the selected articles and discussed.
Results: In this study, 198 articles were selected in the search step, of which five eligible articles were included for examination. The most commonly used solvent for the preparation of garlic extract was distilled water (60%), followed by methanol (40%). In these studies, the bulb of garlic is mostly used (80%). Cell type of J774 was used in only one study (20%), and murine peritoneal macrophages were used in the other studies (80%). The effect of garlic on Leishmania major was strong (80%). Studies have shown that garlic extract or its active compounds can increase cellular immune responses, which play an important role in inhibiting the Leishmania parasite. This is associated with the activation of macrophages and increased IFN-γ levels and NO production.
Conclusion: According to the studies, the effect of different combinations of garlic on the Leishmania parasite has been shown. However, the exact mechanism of the anti-Leishmanial effect of garlic has not been determined. Thus, this issue needs further investigation.
