Body clock linked to how drugs work, study finds

A team of scientists at the University of Pennsylvania have provided important clues about how the role of timing may influence the way drugs work in the body.

By monitoring the function of cells in 12 tissues in mice, they found vast shifts in activity throughout the day and used these to work out the time of day that genes in individual organs of the body were most active.

Their study discovered that the liver and the kidneys are at peak activity after 6pm. The genes linked to the lungs were shown to peak at around lunchtime, while the heart is most active in the morning.

The researchers found that 56 of the top 100 selling drugs and nearly half of the World Health Organization’s list of essential medicines acted on genes with circadian rhythms (body clocks).

Taking medication at the wrong time of the day – when the genes are not active – could render it useless or potentially cause side-effects.

Dr John Hogenesch told the BBC News website: “I’m hopeful that we can use this information to design better therapies with existing drugs, and that’s huge because it’s not going to cost any more money. Now we know which drug targets are under clock control and where and when they cycle in the body. This provides an opportunity for prospective chronotherapy.”

Chronotherapy – aligning medical treatment to our circadian rhythms – is of increasing interest to doctors, with cancer and rheumatoid arthritis, two areas showing particular benefits with the treatment.

Dr Simon Archer, a body clock scientist from the University of Surrey, told the BBC: “Thousands, millions of people potentially, could benefit from taking their medication at a different time of day and raising this kind of awareness is important.”

                                                                                                                                                                Mel Green