Researchers have suggested through a new study that the reason females itch less than males is the hormone estradiol.
Females have a significantly lower incidence of severe psoriasis and researchers have found that it is because the female hormone estradiol suppresses psoriasis, and the protective role of the hormone has provided a basis for its therapeutic potential. Researchers are quick to point out that their study has not only revealed the molecular mechanisms of sex differences in psoriasis but it has also managed to enhance their understanding of the physiological role of estradiol.
The team tested conditional knockout mice, or cko mice, with ovaries removed but supplemented with estradiol pellets or a placebo. In contrast to wild-type mice, the cko mice without the natural ovarian hormones estradiol showed symptoms of severe skin inflammation.
Once these mice were given estradiol, the production of IL-17A and IL-1β cytokines in neutrophil and macrophage immune cells was reversed, reducing the inflammation. This effect was also observed in human neutrophils in vitro.
What intrigued the researchers was how the lack of estrogen receptors in immune cells made estradiol ineffective against the cytokines.
“These results indicate that estradiol suppresses psoriatic inflammation by regulating neutrophil and macrophage cells,” concludes the author.