This patent has a graph…
For any of you suffering from an oily scalp…topical soy isoflavones (you can buy gel caps and drain some of it in your shampoo—while its in your hand and mix it up, but not so much of it as to make your hair oily) really might help you have less sebum up there if its a problem for you. It also might help you with some acne if you leave it on overnight if thats a problem also.
Both genestein and daidzien soy isoflavones were also very potent at inhibiting alpha five reductase type TWO (the kind finasteride inhibits) in whole cell assays and genestein has been shown to downreg expression of androgen receptors in human prostate cancer cell lines…
A little more on soy from another article demonstrating its anti-androgenic topical efficay in a mammal:
Cut and pasted from another article:
Inhibition effect of genistein and soy isoflavone on sebum excretion in fuzzy rat
H.-W. PARK1, M.-S. Yang2, Y. C. Sim2, S. J. Lee2, and W. S. Park2. (1) Health products research team, Pharmaceutical & Health research institute, Amorepacific Corporation R&D Center, 314-1 Bora-ri, Kiheung-up, Yongin, 449-729, South Korea, (2) South Korea
Acne is a multifactorial disorder reflecting the role of infection, abnormal keratinization and immunologic reaction, as well as hormonal influences, on the pilosebaceous unit. For many clinical studies, acne had something to do with elevated levels of androgens, originating in both the andrenal glands and ovaries. The conversion of testosterone to dihydrotestosterone(DHT); 5a-reductase plays a crucial role in acne disorder. Isoflavone, flavonoids extracted from soy, is a estrogen-like compounds and genistein is one of the aglycone type of the soy flavonoids.
In order to search for effective plant extracts applied for androgenetic acne, we screened natural plant extracts having inhibitory activities of 5a-reductase type 2 and demonstrated its biological function in androgen-related animal models.
We evaluated the inhibition activities of isoflavone and genistein by contact cell based metabolic method using a stable HEK 293 cell line expressing human 5a-reductase(type 2). To elucidate the biological activity in vivo, the isoflavone and genistein were systemically applied to fuzzy rat(conc: 0mg, 50mg, 100mg, 200mg /body weight). The secreted sebum and the size of sebaceous glands of fuzzy rat were measured after 6 weeks.
Isoflavone showed higher inhibition activity of 5a-reductase type 2 ( IC50 value=2.4µ¶/µ¢) than that of isoflavone, but lower than that of finasteride. The amount of sebum and sebaceous gland size decreased remarkably in in-vivo test using fuzzy rat model
We have demonstrated the inhibitory activity of isoflavone and genistein for 5a-reductase type 2 and its biological action in fuzzy rat models, suggesting that genistein and isoflavone would be used as an effective agent for androgenetic acne and for the inhibition of secretion of sebum by modifying androgen conversion.
Session 114E, Nutraceuticals & Functional Foods: Bioactivity measurement and mechanism
8:30 AM - 12:00 PM, Friday AM Room Hall N-1
2004 IFT Annual Meeting, July 12-16 - Las Vegas, NV