Insecticidal, Antimalarial, and Antileishmanial Effects of Royal Jelly and Its Three Main Fatty Acids, trans-10-Hydroxy-2-decenoic Acid, 10-Hydroxydecanoic Acid, and Sebacic Acid

Natural Products and their derivatives as an inexpensive, accessible, and useful alternative medicine are broadly applied for the treatment of a wide range of diseases and infectious ones. The present study was designed to evaluate the insecticidal, antimalarial, antileishmanial, and cytotoxic effects of royal jelly and its three main fatty acids (trans-10-hydroxy-2-decenoic acid (10-H2DA), 10-hydroxydecanoic acid (10-HDAA), sebacic acid (1,10-decanedioic acid)). Insecticidal activity of RJ and 10-H2DA, 10-HDAA, and sebacic acid was performed against healthy 4th instar larvae at 25 ± 2°C. Antiplasmodial and antileishmanial effects of RJ and 10-H2DA, 10-HDAA, and sebacic acid were also performed against chloroquine-resistant Plasmodium falciparum K1-strain and Leishmania major amastigotes according to the Malstat method and macrophage model, respectively. In addition, the level of nitric oxide (NO) production in J774-A1 macrophages cells, plasma membrane permeability, and caspase-3-like activity and cytotoxicity effects of RJ and 10-H2DA, 10-HDAA, and sebacic acid against human embryonic kidney 293 (HEK239T cells) were evaluated. Considering the insecticidal activity, the results showed that the lethal concentration 50% value for RJ, 10-H2DA, 10-HDAA, and sebacic acid was 24.6, 31.4, 37.8, and 44.7 μg/mL μg/mL, respectively. RJ, 10-H2DA, 10-HDAA, and sebacic acid showed potent (P < 0.0001) antileishmanial effects with IC₅₀ values ranging from 2.4 to 8.4 μg/mL. Various concentrations of RJ, 10-H2DA, 10-HDAA, and sebacic acid significantly (P < 0.05) increased the production of NO, plasma membrane permeability, and caspase-3-like activity level as a dose-dependent response. Considering the cytotoxicity, SIs > 10 of these compounds exhibited their specificity to parasites and safety against human HEK239T normal cells. The results of the present investigation revealed the promising insecticidal, antimalarial, and antileishmanial effects of RJ and its three main fatty acids (10-H2DA, 10-HDAA, and sebacic acid). However, more studies are required to confirm the mechanisms of action mode of these compounds as well as their efficacy in animal models and clinical settings.