research. Free radicals may not be all bad, say scientists

Free radicals are hyper reactive molecules that are implicated in a range of diseases ranging from cancers to neurodegenerative disorders to cardiovascular complications. But, these biological molecules, which are perceived to be villains and are destroyed using antioxidants, may have a positive role to play too, according to a team of Indian scientists.

In a finding that may alter our fundamental understanding about free radicals, or reactive oxygen species (ROS) as they are called in scientific parlance, a team of researchers from the Indian Institute of Science Education and Research (IISER), Mohali, has found that these unstable and highly reactive molecules may be vital in regulating growth and the size of organisms.

“ROS is generally considered a highly reactive and damaging agent for cells. At the same time there is some evidence that they regulate a number of biological processes inside the cells. But now, for the first time, we have shown that it was also used by an organism to modulate its systemic growth,” said Sudip Mandal, Associate Professor off biological sciences at IISER and the main author of a study that appeared in the journal Developmental Cell on Monday.

Antagonistic relationship

The study is significant because it throws light on the interplay between certain vital biological processes during the early stages of life. To unearth the spectacular role of free radicals, the scientists used fruit flies as model organism.

Insulin, a hormone, plays a key role in promoting growth at the cellular level. Another hormone, ecdysone, does the opposite — applying the brakes on growth. “The spree of growth that an animal undergoes during larval stages is brought about by insulin. But the continuous spell of growth needs to be controlled and this is done by ecdysone. In other words, there is an antagonistic relationship between these two hormones, which needs to be stabilised. Our study has shown that reactive oxygen species do this job wonderfully,” said Lolitika Mandal, another senior author of the study and IISER scientist.

“The stabilising of the hostile relationship between insulin and ecdysone is a must for progression of development,” said Lolitika, who along with her husband Sudip moved back to India from the US to take up positions in the fledgling IISER Mohali years ago.

Among others who contributed to the study are Ashish Toshniwal and Sakshi Gupta, researchers from Sudip Mandal’s lab.