Autism Spectrum Disorder (ASD) affects 1 in 100 children in India. But the exact set of causes of autism remains unknown, and there is no cure for this disorder. However, the study by researchers at the Central University of Kerala, found males can be more susceptible to Autism-like behaviour than females when exposed to heavy metals like Lead.
The study, published in the journal Molecular Neurobiology, also proposed that autism in children could be ameliorated by antioxidant therapy.
Dr. H.P. Gurushankara, who led the team of researchers, including Shilpa Olakkaran, Anupama K.P., and Anet Antony, from the Department of Zoology, said that several studies had shown a link between genetics and environmental pollution for ASD.
However, their research was to understand the involvement of Lead-induced oxidative stress in developing ASD behaviour.
He said Lead, a naturally occurring heavy metal, was extensively used in many things, including medicines, batteries, and other objects, making human exposure inevitable.
He said that the Centre for Disease Control and Prevention had established that even a low level of blood Lead concentration would correlate with intelligence quotient deficit, social behavioural disabilities, Autism, and attention deficit hyperactivity disorder.
To establish their research, they used the common fruit fly ‘Drosophila melanogaster’, which showed that the core diagnostic features of human autistic behavioural phenotypes, he said.
“We found that early developmental exposure of Lead (Pb) in the Drosophila leads to accumulation in the brain, induces oxidative stress, and causes sex-specific human autistic-like behaviour, such as reduced climbing, increased grooming, increased social spacing, and decreased learning and memory,” said Dr. Gurushankara.
On the contrary, overexpression of antioxidant genes like Superoxide dismutase (Sod) and Catalase (Cat), attenuated the ASD-like behaviour, strengthening the role of antioxidants in alleviating ASD, said Ms. Shilpa.
These results were significant, and it proved that ASD in children could be ameliorated by antioxidant therapy.
She further said that the present study also revealed that Lead treatment during the Drosophila developmental period significantly affected the biochemical and behavioural parameters, demonstrating sex-dimorphism. Pb-exposed males were more prone to these behavioural deficits than females.
She said the epidemiological studies of humans had presented the susceptibility of males over females to ASD. Interestingly, their study observed the same phenomenon, when, both human and Drosophila data were correlated, she added.
Ms. Shilpa said that they were successfully able to carry the study in Drosophila, a widely used model to mimic genetic and pathological aspects of the human disorder.
Understanding the complex aetiology of autism was primarily hampered due to the unavailability of a suitable animal model.
However, the research also proven that Drosophila was a model to analyse the effects of environmental pollutants on the onset of neurodevelopmental disorders, she added.
