Moringa oleifera, known as the “miracle tree”, grows in almost all tropical and subtropical regions (1). Moringa oleifera leaf infusion and powder are widely used by people due to their nutritional and medicinal potentials, however, data regarding the safety of use are still inconclusive, leading to the prohibition of this plant in some countries (2). Various experiments have been performed to evaluate the toxic potential of the plant. Most studies report that Moringa oleifera has almost no toxicity, it should be noted that very few studies on Moringa oleifera toxicity have been conducted to date (3). In 2020, a study on hot and cold extracts of leaves of Moringa oleifera revealed that ingestion of Moringa before, after, and during pregnancy may lead to adverse fetal developmental outcomes by causing rigorous contraction of the uterine wall (1). According to Liu et al’s review, acute toxic (5000 mg/kg) and subacute toxic (40-1000 mg/kg) did not show any adverse reactions in the study. Therefore, they concluded that consumption is safe, but to avoid cumulative toxicity, consumption should not exceed 70 grams per day (3). The leaf extract of Moringa oleifera at doses of 175 mg/kg has shown 100% abortifacient activity (3). According to Liu et al research, Moringa oleifera is an Indian traditional contraceptive medicine. The roots and bark extracts of Moringa oleifera at 200 and 400 mg/kg doses could prevent implantation when administered for 7 days (1–7) of pregnancy. Therefore, the usage of Moringa oleifera, especially at high doses such as 600 mg/kg, needs to be cautious for women who are trying to get pregnant. Experiments indicated that the stem bark extract did not cause any toxic effect up to 2000 mg/kg. Therefore, the researchers concluded that the stem bark of Moringa oleifera can be considered non-toxic when administered orally (3). Animal experiments revealed that the toxicity of Moringa oleifera was limited to the liver, kidney and blood and also indicated that an overdose may result in genetic toxicity. Therefore, determining the appropriate dosage of the chemical constituents of this plant is of great significance before use and provides a basis for future clinical toxicity research. In-vivo studies in a murine model revealed that Moringa oleifera seed extract was hepatotoxic and nephrotoxic as well as showed blood toxicity. The extract at a dose of 46 mg/kg can significantly alter serum aminotransferase and plasma cholesterol levels, while a dose of 70 mg/kg can alter the total bilirubin, non-protein nitrogen, blood urea, and plasma protein levels (3). In 2022, Barros et al conducted a 28-day repeated-dose toxicity test on male and female rats administered orally as an infusion or powder at doses of 250, 500, and 1000 mg/kg. The animals were evaluated in terms of body weight, water and feed consumption, biochemical and hematological parameters, and histology of the liver, spleen, and kidney. Based on the results, indiscriminate use of both infusion and leaf powder above 2000 mg/kg and powder with a dose of 500 and 1000 mg/kg were not recommended. Chronic toxicological studies and the establishment of preparation protocols to ensure safety in the use of Moringa oleifera leaves as food by the population were suggested (2). Moringa’s long history of use in herbal medicine and as food suggests that the plant is likely safe Moringa oleifera appears to have few or no side effects. Studies have reported no adverse effects in people who consumed 50 grams of leaf powder from the plant as a single dose or 7 grams daily for 90 days. However, anyone considering Moringa oleifera should discuss it with a doctor, as it may interact with other medications.
Reference
1. Attah, A.F., Moody, J.O., Sonibare, M.A., Salahdeen, H.H., Akindele, O.O., Nnamani, P.O., Diyaolu, O.A., Raji, Y. 2020. Aqueous extract of Moringa oleifera leaf used in Nigerian ethnomedicine alters conception and some pregnancy outcomes in Wistar rat. South African Journal of Botany.Vol 129, 255–262.
2. M. C. de Barros et al., “Evaluation of acute toxicity, 28-day repeated dose toxicity, and genotoxicity of Moringa oleifera leaves infusion and powder,” Journal of Ethnopharmacology, vol. 296, p. 115504, 2022/10/05/ 2022, doi: https://doi.org/10.1016/j.jep.2022.115504
3. Liu, R., Liu, J., Huang, Q., Liu, Sh., Jiang, Y. 2022. Moringa oleifera: a systematic review of its botany, traditional uses, photochemistry, pharmacology and toxicity. Journal of Pharmacy and Pharmacology. 2022, Vol 74, 296–320.
4. Pareek, A., Pant, M., Gupta, M.M., Kashania, P., 1, Ratan, Y., Jain, V., Pareek, A., Chuturgoon, A.A. 2023. Moringa oleifera: An Updated Comprehensive Review of Its Pharmacological Activities, Ethnomedicinal, Phytopharmaceutical Formulation, Clinical, Phytochemical, and Toxicological Aspects. International Journal of Molecular Sciences 2023, 24, 2098. https://doi.org/10.3390/ijms24032098.