The prostamide‐related glaucoma therapy, bimatoprost, offers a novel approach for treating scalp alopecias

Abstract

Balding causes widespread psychological distress but is poorly controlled. The commonest treatment, minoxidil, was originally an antihypertensive drug that promoted unwanted hair. We hypothesized that another serendipitous discovery, increased eyelash growth side-effects of prostamide F2α-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 F2α analog recently licensed for eyelash hypotrichosis. Bimatoprost, at pharmacologically selective concentrations, increased hair synthesis in scalp follicle organ culture and advanced mouse pelage hair regrowth in vivo compared to vehicle 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.—Khidhir, K. G., Woodward, D. F., Farjo, N. P., Farjo, B. K., Tang, E. S., Wang, J. W., Picksley, S. M., and Randall, V. A. The prostamide-related glaucoma therapy, bimatoprost, offers a novel approach for treating scalp alopecias.

Bimatoprost versus Mometasone Furoate in the Treatment of Scalp Alopecia Areata: A Pilot Study

“…Recently, Khidhir et al [16] demonstrated that the PG-related glaucoma drug bimatoprost can stimulate growth in non-eyelash hair follicles in mice in vivo and in human scalp hair follicles in dynamic organ culture, mirroring the stimulation of eyelashes known to occur in vivo. These strong similarities in responses by eyelash and scalp follicles contrast with their differing physiology [17], biological responses to androgens [18] and aging pigmentary changes [17].…”

“…These strong similarities in responses by eyelash and scalp follicles contrast with their differing physiology [17], biological responses to androgens [18] and aging pigmentary changes [17]. However, through studying the effects of bimatoprost and its antagonist in hair follicle organ culture, Khidhir et al [16] explained this dilemma by suggesting that the in vivo action of bimatoprost might be via direct effects on prostanoid receptors within the follicles themselves rather than indirect effects involving the vasculature or other surrounding tissues.…”

FGF5 is a crucial regulator of hair length in humans

“…(D) Macroscopic images of hair follicles, either in control medium or FGF5 medium on days 0 through 8. In cultures containing FGF5, catagen entry, as determined by the shape of the end bulb (43), was earlier than in control cultures, explaining the observed reduction in growth rate.…”

Recent Progress in Prostaglandin F2αEthanolamide (Prostamide F2α) Research and Therapeutics

“…A significant increase in the percentages of follicles in anagen phase was apparent, with a significant decrease in follicles in the telogen and late catagen phases (Tauchi et al, 2010). In recent studies, bimatoprost dose dependently prolonged anagen in human scalp follicles in vitro and stimulated the initiation of anagen of rodent pelage follicles in vivo Khidhir et al, 2013). As a pharmacological correlation, the prostamide receptor for bimatoprost was detected in the dermal papilla of human scalp follicles (Khidhir et al, 2013).…”

“…In recent studies, bimatoprost dose dependently prolonged anagen in human scalp follicles in vitro and stimulated the initiation of anagen of rodent pelage follicles in vivo Khidhir et al, 2013). As a pharmacological correlation, the prostamide receptor for bimatoprost was detected in the dermal papilla of human scalp follicles (Khidhir et al, 2013). In mouse skin and blood, bimatoprost was found as an intact molecule not metabolized to the free acid 17-phenyl PGF 2a , indicating its stimulatory effect on hair growth is through interaction with prostamide receptors.…”