Came across this article doing research on different ways to remove hair…any thoughts?
Soymilk reduces hair growth and hair follicle dimensions
M. Seiberg, J.-C. Liu, L. Babiarz, E. Sharlow and S. Shapiro
Abstract: We have recently shown that soybean-derived serine protease inhibitors and soybean extracts alter skin pigmentation, suggesting that soymilk could be used as a natural alternative to skin lightening. The present studies were initiated to examine the possible effect of STI, BBI and soymilk on hair pigmentation. Interestingly, these agents were found to affect not only hair pigmentation, but also the rate of hair growth, the dimensions of the hair follicle and hair shaft, and the appearance of the hair. The studies presented here provide first evidence, at the morphological and histological level, that soymilk and the soybean-derived serine protease inhibitors could be used as effective agents for hair care and management. These agents could reduce the rate of hair growth, decrease hair shaft dimensions and alter the pattern of melanogenic gene expression.
The hair follicle is an epithelial structure that undergoes cycles of active growth (anagen), regression (catagen) and rest (telogen) (1). During anagen the hair follicle grows down into the dermis, forming a complex layered structure with a pigmented shaft. During catagen the hair follicle shortens, and in telogen the epithelial cells are resting while the hair shaft remains inside the short follicle. The morphological changes throughout the hair cycle are well-documented (2), but the regulation of the different phases of this cycle is not completely understood. The synchronized hair growth mouse model (3, 4) has been extensively utilized to better understand the regulation of hair growth and cycling.
One main function of mammalian hair is to provide environmental protection. However, that function has been lost in humans, in whom hair is kept or removed for social and cosmetic purposes. Many procedures are used to remove unwanted hair, from simple inexpensive home treatments like shaving, plucking and waxing, to expensive and potentially time-consuming methods like electrolysis, laser, light therapies and therapeutic antiandrogens. These methods differ not only in the duration of hair removal, their price range and their pain and discomfort levels, but also in their possible undesired effects (reviewed in (5)). Shaving may result in nicks and cuts in the skins surface, may increase the risk of infection, may leave a perception of an increase in the rate of hair growth, and may also leave undesirable stubble. Plucking causes pain and discomfort, and often results in poor removal of short hair. While electrolysis may keep an area free of unwanted hair for a prolonged period of time, the process is expensive and painful and may further result in scarring. Promising clinical results have been obtained with laser treatments, but not without changes in skin texture and pigmentation. Several unwanted side effects, such as liver toxicity or effects on muscularity often accompany the use of antiandrogens. Alternatives to hair removal are popular hair cosmetic treatments like hair dying or bleaching, used to reduce hair visibility in desired body parts. These treatments, which are sometimes irritating, are not always satisfying, as the emerging portions of the hair shafts are always darker than the already treated parts.
The Kunitz-type trypsin inhibitor (soybean trypsin inhibitor, STI), and the Bowman-Birk protease inhibitor (BBI) are two serine protease inhibitors isolated from soybeans (reviewed in (6, 7)). STI inhibits the proteolytic activity of trypsin (6), and BBI inhibits trypsin and chymotrypsin (7, 8). Recently we demonstrated that soymilk, STI and BBI inhibit PAR-2 activation and thus induce skin depigmentation (9). The studies described here were designed to explore the potential use of these agents in the inhibition of hair pigmentation. Our data demonstrate that STI, BBI and soymilk reduce not only hair pigmentation, but also the rate of hair growth and the final dimensions of the hair shaft. These data suggest that such agents may serve as an inexpensive, natural alternative treatment for undesired hair growth.
The inhibition of PAR-2 activation by synthetic serine protease inhibitors (15, 17) results in skin lightening, suggesting a new class of depigmenting agents. Similarly, inhibition of the PAR-2 pathway by soymilk leads to skin depigmentation, suggesting that soymilk could be used as a natural alternative to skin lightening (9). The present studies were initiated to examine the possible effect of STI, BBI and soymilk on hair pigmentation. Interestingly, these agents were found to affect not only hair pigmentation, but also the rate of hair growth, the dimensions of the hair follicle and hair shaft, and the appearance of the hair.
Soybeans were not utilized as food until precipitation and fermentation techniques were developed, because they produced serious gastric distress. These are due to the inhibitory activity of STI and BBI, which block the action of trypsin and other proteases needed for protein digestion (18). It is the heat inactivation of STI and BBI during soybean processing (reviewed in (19, 20)) that renders the soybean edible. It is important to note that fresh soymilk, but not heat-denatured or pasteurized soymilk, was the active inhibitor in our hair growth studies. Since STI is heat labile, but BBI is less affected by heat (6, 21), it is more likely that STI is the major protein agent in soymilk that affects hair growth, size and pigmentation.
Topical treatments with 17-beta-estradiol inhibited hair growth in mice, while an estrogen receptor antagonist initiated hair growth in this system (22, 23). This treatment was more effective at the site of application than at distant sites, indicating a direct rather than systemic effect. These studies implicate a skin-specific estrogen receptor pathway in the regulation of the hair cycle (23). The weak estrogenic effects of isoflavones are heavily documented. Interestingly, the soy derived phytoestrogen genistein was shown to decrease hair growth by 60%-80%, when hair follicles isolated from scalp biopsies were treated in culture (16). Our data clearly demonstrate a role for soy isoflavones in the regulation of hair growth. However, we also show that the soy-derived serine protease inhibitors, STI and BBI, alone, affect hair growth. Since these agents are not known to act via the estrogen receptor, we suggest that they affect hair growth via a different pathway. Moreover, the combinations of soy and isoflavones tested show an additive effect, until saturation is observed.
A serine protease inhibitor treatment of keratinocyte-melanocyte co-cultures results in a decrease in TRP-1 gene expression, but in no changes in tyrosinase gene expression (15). As TRP-1 is a regulator of tyrosinase by stabilizing the protein (24, 25), we suggested that the down regulation of TRP-1 expression led to reduced tyrosinase half life and activity, and reduced pigment production (15). This suggests that while tyrosinase mRNA levels were not affected by the serine protease inhibitor, its steady state protein level should be reduced. Our current hair studies support this suggestion, demonstrating reduced tyrosinase and TRP-1 protein levels following soymilk treatment. These data could also imply that soymilk reduces pigment deposition within the hair follicle via the PAR-2 pathway. However, studies that induce PAR-2 activation and enhance pigment deposition are required to substantiate this hypothesis.
Using the synchronized hair growth mouse model (3, 4) we showed that topical trypsin treatment, immediately after depilation, induced cell death at the follicular papilla. This death signal, which is independent of the proteolytic activity of the protease, resulted in delaying hair growth and pigmentation (26). Here we show that the trypsin inhibitors STI and BBI also lead to delayed hair growth, as well as to reduced follicle dimensions and reduced pigment deposition within the hair shaft. Since we could not detect apoptotic cells in the papillae of soymilk, STI or BBI treated mice (not shown), we suggest that STI and BBI do not affect papillae cell death, but exert their effect on hair growth and size via a different mechanism.
Humans keep or remove hair from different body parts for social and cosmetic purposes. Unwanted hair is removed using home treatments or professional services, or is bleached to reduce its visibility. A safe and effective agent that could reduce hair growth, hair size and hair pigmentation would add to the available home treatments, which are not always satisfying. The finding that soymilk and soymilk-derived serine protease inhibitors delay hair growth and reduce hair shaft dimensions and pigmentation provides a new concept in hair growth and management, and could serve as an effective natural way to manage unwanted hair growth. The human studies presented here represent a positive proof-of-concept pilot study, which led us to perform larger double blind studies. Preliminary data of these studies (J.-C. Liu, in preparation) indicate that treatment with soymilk-containing formulations reduced the rate of hair growth of womens legs, affected the direction of hair growth to look more homogeneous, and made the hair softer, finer and less noticeable.
Hirsutism is a relatively frequent condition affecting about 4% of women. Facial hirsutism often interferes with personal and work activities, and temporary hair removal is a major component in the management of hirsute patients. Shaving is the most frequently used temporary method for facial hair, as plucking, waxing and depilatories are more difficult to tolerate and care must be taken to avoid folliculitis, pigmentary changes, and scarring. Cosmetic cover-ups are usually used to hide cuts and stubble (27, 28), and electrolysis and thermolysis are used for permanent hair removal when affordable (29). Daily treatment with soybean-derived protease inhibitors or soymilk products would be painless and of modest cost and could serve to reduce hair growth and visibility in these patients, enhancing their quality of life. Preliminary clinical data (J.-C. Liu, in preparation) indicate that treatment with STI and soymilk-containing formulations significantly reduced womens facial hair growth rate and visibility.
African-type hair is unique in its morphology - a kinky hair shaft with variations in diameter. This complex shaft structure creates the need for specialized grooming products and procedures to ensure that the African-type hair maintains cosmetic desired properties. The addition of STI, BBI or soymilk into hair care products could reduce this complexity and make the African-type hair more manageable, improving its appearance.
The studies presented here establish soymilk and the soybean-derived serine protease inhibitors as effective and inexpensive cosmetic agents for hair care and management. These agents could reduce the rate of hair growth, decrease hair shaft dimensions and reduce hair pigmentation, resulting in slower hair growth, softer and lighter hair shafts, and more manageable hair care.
Interesting article and hopeful results but so is every other hair removal method out there. Just novel to see Soy as the actual product used to yield results - go figure.