Stimulatory effect of Brazilian propolis on hair growth through proliferation of keratinocytes in mice.

Propolis is a natural honeybee hive product with the potential for use in the treatment of dermatological conditions, such as cutaneous abrasions, burns, and acne. In this study, we investigated whether propolis stimulates hair growth in mice. Ethanol-extracted propolis, which contains various physiologically active substances such as caffeic acid and kaempferol, stimulated anagen induction in shaved back skin. Anagen induction occurred without any detectable abnormalities in the shape of the hair follicles (HFs), hair stem cells in the bulge, proliferating hair matrix keratinocytes in the hair bulb, or localization of versican in the dermal papilla. Propolis treatment also stimulated migration of hair matrix keratinocytes into the hair shaft in HFs during late anagen in the depilated back skin. Organotypic culture of skin containing anagen stage HFs revealed significant stimulation of hair matrix keratinocyte proliferation by propolis. Furthermore, propolis facilitated the proliferation of epidermal keratinocytes. These results indicate that propolis stimulates hair growth by inducing hair keratinocyte proliferation.

A flow microreactor system enables organolithium reactions without protecting alkoxycarbonyl groups.

A flow microreactor system consisting of micromixers and microtube reactors provides an effective tool for the generation and reactions of aryllithiums bearing an alkoxycarbonyl group at para-, meta-, and ortho-positions. Alkyl p- and m-lithiobenzoates were generated by the I/Li exchange reaction with PhLi. The Br/Li exchange reactions with sBuLi were unsuccessful. Subsequent reactions of the resulting aryllithiums with electrophiles gave the desired products in good yields. On the other hand, alkyl o-lithiobenzoates were successfully generated by the Br/Li exchange reaction with sBuLi. Subsequent reactions with electrophiles gave the desired products in good yields.

Generation and reaction of cyano-substituted aryllithium compounds using microreactors.

We developed a microflow method for the generation and reactions of aryllithiums bearing a cyano group, including o-lithiobenzonitrile, m-lithiobenzonitrile and p-lithiobenzonitrile. The method was effective at much higher temperatures than are required for conventional macrobatch reactions, by virtue of rapid mixing, short residence time, and efficient temperature control. In addition, reactions of o-lithiobenzonitrile with carbonyl compounds followed by trapping of the resulting lithium alkoxides with electrophiles were achieved in an integrated microflow system.