Antiteratogenic effect of the leaf crude extract of malunggay (Moringd oleifera) on ethanol-exposed zebrafish (Danio rerio) embryos

Abstract

Prenatal alcohol exposure causes a disruption of developmental processes in embryos and results in a wide range of alcohol-induced defects known as Fetal Alcohol Spectrum Disorder. The main mechanism through which alcohol induces its damage is oxidative stress, wherein reactive oxygen species overwhelm the functions of endogenous antioxidant defenses. Hence, administration of an exogenous antioxidant might be effective in preventing the development of abnormalities. Since methanol and ethanol extracts of Moringa oleifera leaves were reported to have high radical scavenging activity, they were tested for the prevention of teratogenesis in ethanol-exposed Danio rerio embryos. Results showed that there was a significant reduction in the occurrence of pericardial edema, yolk sac edema and a significant decline in mortality rate in D. rerio embryos exposed to ethanol with 2 mg/mL of the ethanol extract as compared to exposure to ethanol alone. However, there was no significant difference found in the same parameters between those exposed solely to ethanol and those exposed to ethanol with 2mg/mL of the methanol extract. Compared to methanolic extracts, the ethanolic extracts of M. oleifera leaves may contain more antioxidants such as polyphenols and vitamins C and E, which are effective in minimizing the effects of prenatal alcohol exposure. On the other hand, there may be some synergistic interactions between ethanol and compounds in the methanolic extract that resulted in increased toxicity to zebrafish embryos. Further experimental research is needed to characterize and identify the active phytoconstituents of M. oleifera exhibiting antioxidant property.