Long-haul flights are a real ordeal for the body. Not only because of the increasingly small seats on airplanes, but especially because of jet lag, which disrupts our internal clock. This clock synchronizes our body's physiology with the natural rhythms of our environment, particularly the day/night cycle. But when this cycle changes abruptly, for example, by crossing several time zones in a few hours, our body becomes disoriented. This causes fatigue and other common symptoms of jet lag. time differencewhich last about as many days as there are hours of difference (so about six days of adjustment for six hours of difference, for example).
And this discrepancy is all the more significant. while travelling eastBecause the days are getting shorter, disrupting our circadian rhythms. Fortunately, researchers from the Japanese universities of Osaka, Toyohashi, Kanazawa, and the Tokyo Institute of Science seem to have found a solution: a molecule that advances our internal clock so that it adjusts more quickly to the new day/night cycle. Their discovery, presented on January 23, 2026, in the journal PNASIt could also be useful for people who work nights, who may encounter problems similar to those associated with air travel.
A molecule that artificially advances the internal clock
The molecule, named Mic-628, acts on the Period1 (or Per1) protein, which is key in regulating circadian rhythms throughout the body. This protein is expressed particularly in the brain, at the level of the suprachiasmatic nucleus in the hypothalamus, the structure that manages sleep, body temperature, alertness, and other cyclical functions of the body. Its role is, basically, to tell the body that the day is progressing, so that the internal clock also progresses. The Per1 cycle is self-regulated: the expression of this gene is activated by light, which leads to the production of the protein, but when it begins to accumulate, it inhibits gene expression, causing a decrease in production. there protein. The expression of this gene is also regulated by the protein cryptochrome1, which blocks this process.
Mic-628 alters this cycle, forcing Per1 expression at two levels. First, it interacts with the cryptochrome1 protein, preventing it from blocking Per1 expression. Furthermore, this interaction between the two molecules facilitates the assembly of another protein complex (formed by the Clock and Bmal1 proteins) that enhances Per1 gene expression. Even better, the activation becomes more resistant to the inhibitory effect of Period1 protein accumulation. It can therefore accumulate more, advancing the internal clock even further. Thus, Mic-628 activates Period1, causing the body to perceive more hours of daylight than actually occurred, thereby reducing the jet lag caused by the shortening days of eastward travel.
The adaptation time is almost halved
The anti-jet lag effect of Mic-628 has been confirmed in mice exposed to changes in their day-night cycle. Their light cycle now began six hours earlier than usual, causing jet lag that required seven days of adjustment in untreated mice. This is equivalent to the jet lag caused by flying from Mexico to France. The molecule allowed the mice to resume their normal physical activities in just four days, thus reducing the adjustment time by almost half. This makes life a little easier on a long-haul flight.
The authors hope that Mic-628 could become a "smart drug" to mitigate the effects of jet lag, and plan further animal studies before testing it on humans. However, this trick would only work to advance the internal clock, not to set it back. In other words, it would only be useful for eastbound travel, which shortens the day, and not westbound travel. For the return trip, but not the outbound one. At the same time, the most difficult journey to manage is precisely the one that marks… the end of the vacation!
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