在雄性禿髮形成的原因中，5alpha-還原酶扮演著關鍵的角色。目前在治療雄性禿髮的方法主要以柔沛(finasteride)與落建(minoxidil)兩種藥物為主。研究顯示，柔沛可透過抑制第二型5alpha-還原酶的作用，促進男性雄性禿的毛髮生長；落建透過尚未清楚的作用機轉，促進毛髮生長。
某些種類的大豆異黃酮已經證明可以抑制第二型5alpha-還原酶，因此在本研究中，以動物實驗方式，評估含大豆異黃酮的大豆抽出物對於改善雄性禿髮的效果。研究分兩部分進行，第一部份以雄性禿老鼠(B6CBAF1 mouse)的動物模式，藉以探討活性型及非活性型大豆異黃酮素萃取物，對第二型5alpha-還原酶抑制能力的評估，及雄性禿老鼠抑制掉毛及促進毛髮生長情形。第二部分以C57BL/6 mouse alopecia model，評估非特異性掉髮的毛髮增生。第一部份研究結果顯示，活性型大豆異黃酮素萃取物在0.5%與1%的濃度，都有抑制雄性禿掉毛及促進毛髮生長情形，組織學切片檢查，也符合臨床及病理表現。而非活性型大豆異黃酮素萃取物，則無法抑制雄性禿掉毛。第二部分研究結果顯示活性型大豆異黃酮素萃取物也有促進非雄性禿脫毛的毛髮增生，但作用機轉是否與大豆異黃酮素多樣的藥理活性有關尚不清楚。這兩項研究結果提供了雄性禿髮往後相關的研究方向。 5alpha-reductase plays a crucial role in the pathogenesis of androgenetic alopecia. At present, there are two main drugs, finasteride and minoxidil, designed to treat androgenetic alopecia. Study showed that the inhibitor of 5alpha-reductase type 2, such as finasteride, promoted hair growth in male pattern alopecia. Also, minoxidil can promote hair growth by uncertain mechanism.
Some kinds of soy isoflavones have been proved to have abilities on the inhibition of 5alpha-reductase type 2. Therefore, we evaluate the effect of soy isoflavone extracts on the inhibition of androgenetic alopecia in animal model. There are two parts in our studies. The first part is androgenetic alopecia animal model (B6CBAF1 mouse) to evaluate the inhibition of 5alpha-reductase type 2 and promotion in hair growth when soy isoflavone extracts (aglycone type and glycone type) are used. The second part is C57BL/6 mouse alopecia model to evaluate hair growth in non-specific hair loss. The first part show that either 0.5% or 1% soy isoflavone extracts (aglycone type) can inhibit hair loss and promote hair regrowth in AGA mice. Histopathologic findings from skin of mice are compatible with clinical pictures. However, neither 0.5% nor 1% soy isoflavone extracts (glycone type) can inhibit hair loss of androgenetic alopecia of mice. The second show that soy isoflavone extracts (aglycone type) also promote hair growth on non-specific hair loss. It is not yet clear whether the mechanism of action is related to various pharmacological activities of soy isoflavone. The results of these two studies provide a direction in the future research of androgenetic alopecia.
