The prostamide-related glaucoma therapy, bimatoprost, offers a novel approach for treating scalp alopecias
Karzan G. Khidhir,* David F. Woodward,† Nilofer P. Farjo,‡ Bessam K. Farjo,‡, Elaine S. Tang,† Jenny W. Wang,† Steven M. Picksley,* and Valerie A. Randall*,1
*Centre for Skin Sciences, University of Bradford, Bradford, UK; †Allergan, Irvine, California, USA;
and ‡Farjo Medical Centre, Manchester, UK
Published in FASEB Journal in February 2013:
The commonest hair loss treatment, minoxidil, was originally an antihypertensive drug that promoted unwanted hair. We hypothesized that another serendipitous discovery, increased eyelash growth side-effects of prostamide F2-related eyedrops for glaucoma, may be relevant for scalp alopecias.
Eyelash hairs and follicles are highly specialized and remain unaffected by androgens that inhibit scalp follicles and stimulate many others. Therefore, we investigated whether non-eyelash follicles could respond to bimatoprost, a prostamide F2 analog recently licensed for eyelash growth.
Bimatoprost, at pharmacologically selective concentrations, increased hair generation in scalp follicle organ culture and advanced mouse pelage hair regrowth in vivo compared to control alone.
A prostamide receptor antagonist blocked isolated follicle growth, confirming a direct, receptor mediated mechanism within follicles; RT-PCR analysis identified 3 relevant receptor genes in scalp follicles in vivo. Receptors were located in the key follicle regulator, the dermal papilla, by analyzing individual follicular structures and immunohistochemistry.
Thus, bimatoprost stimulates human scalp follicles in culture and rodent pelage follicles in vivo, mirroring eyelash behavior, and scalp follicles contain bimatoprost-sensitive prostamide receptors in vivo. This highlights a new follicular signaling system and confirms that bimatoprost offers a novel, low-risk therapeutic approach for scalp alopecias
The above work was a collaboration between University of Bradford, Allergan Inc and Farjo Hair Instiute. Currently, Allergan (makers of Bimatoprost), are running multi centred clinical trials on humans.