Dietary supplementation with thymoquinone inhibits rotenone induced developmental toxicity in Drosophila melanogaster: Focus on ovary and larval development.

Pesticide exposure has been associated with various health conditions like asthma, Parkinson’s disease, Alzheimer’s
disease, genetic disorders, epigenetic changes, oxidative stress, and hormonal disruption. Recent evidence
suggests that infants are more vulnerable to pesticides (such as rotenone) than adults. Although the disease
has already been clinically characterized, no treatment has yet been developed to improve pathology or prevent
developmental toxicity. Therefore, the purpose of this study was to investigate whether thymoquinone (TQ) from
Nigella sativa seeds could ameliorate rotenone (ROT)-induced developmental damage in both Drosophila melanogaster
ovary and third instar larvae. Female adult wild-type flies and third instar larvae (72 ± 2 h after egg
laying) were exposed to ROT and/or TQ through food for 48 and 24 h respectively. Results indicate that coexposure
of TQ inhibits ROT-induced increased oxidative stress and alleviates abnormal antioxidant enzyme
activities. Further, TQ alters developmental gene expression (Bacoid, Oscar, Nanos, and Gurken), impedes
mitochondrial dysfunction, and reduces apoptosis in ROT induced ovary. In addition, TQ changes ROT induced
abnormal crawling behaviour, cholinergic dysfunction, and dopamine depletion to normal levels in third instar
larvae. Also, TQ reduces pupation and emergence time in ROT induced third instar larvae. The above findings
demonstrate that ROT exposure during early developmental stages is inevitable, and TQ supplementation prevents
developmental toxicity in the Drosophila ovary and third instar larvae. A diet enriched TQ provides a ray of
hope in preventing ROT induced developmental toxicity.