Botanical Skin Science

Once you have treated an acne infection, how do you prevent acne from re-occurring? This post describes a research paper that shows how topical application of Nobiletin, an ingredient found in citrus fruits, can prevent acne by reducing the size of the sebaceous glands, by reducing the amount of oil at the skin surface, and by reducing the rate of cell division by sebocytes (the cells that produce oil). Check out the ”The Skinny on Acne” article for more information on the causes of acne.

Overproduction of sebum increases acne

Overproduction of sebum increases the likelihood of infections and acne out-breaks. Over-active sebaceous glands also cause an excessively oily facial skin. This feels unpleasant and is shiny and feels greasy. The pores are large and the whole situation feels unpleasant and ofcourse can result in inreased occurence of acne.

Retinoic acid reduces oil production but has side effects

Since an overproduction of sebum (oil) increases your chances for infections and acne, it makes sense that if you could reduce the amount of oil that is produced by the sebaceous glands, this should result in a reduction of infections and acne. Dermatologists have been looking for ways to reduce sebum production, but there are only a few known medications that are known to be effective for this. The best known are the retinoic acids such as Retin-A. Unfortunately these medications can have nasty side-effects such as severe skin dryness , flaking and blistering, as has been shown to cause birth defects and certain cancers in mice and rats. For more on Retin-A check out The Skinny on Retin-A. Obviously such medications are only available on prescription.

Mother nature to the rescue

While it is desireable to reduce sebum production to improve and prevent acne and oily skin, retinoic acid based medications have many side effects and are only available by presrciption. Fortunately, mother nature comes to the rescue. In the recent scientific literature there are a number of papers that discuss botanicals that have been shown to also reduce sebum production. One of these papers is discussed below. Be on the look-out for another post on this topic soon!

Nobiletin prevents acne and reduces oily skin

In an elegant paper by Takashi Sato and co-workers (1), we can read about the beneficial effects of Nobiletin on sebum reduction. Nobiletin is a flavonoid that is present in the peel of many citrus fruits. It is especially prevalent in mandarines (Citrus nobilis). Medicinal flavonoids have been shown to have a variety of beneficial effects when taken internally or used topically. These include antioxidant, free radical scavenging and anti-inflammatory activities, as well as antitumorigenic and antitumor metastatic activities (1).

The researchers applied a mixture of 2% nobiletin in 95% ethanol and 5% glycerol to the ears of hamsters once a day for 14 days and then measured the amount of triacylglycerol on the skin surface. Triacylglycerol is the main constituent of mammalian fat and is a major component of sebum. They also made microscope sections of the skin and analyzed the size of the sebaceous glands. The treatment decreased the amount of triacylglycerol on the skin surface by 34% and also reduced the size of the sebaceous glands. The researchers were even able to show that nobiletin reduced the rate of cell divisions by sebocytes, the cells in the sebaceous glands that secrete sebum.

Adapted from Sato et al. J Invest Dermatol 127 (2007) 2740

In another study, the researchers treated cultured hamster sebocytes with nobiletin. When these cells are treated with insulin, they respond by producing high levels of oil (triacylglycerol – compare the left two bars in the graph: “control” and “10 nM insulin”). By simultaneously treating the cells every 3 days with increasing concentrations of nobiletin, the researchers were able to force the cells to reduce the secretion of triacylglycerol almost back down to the low levels secreted in the absence of insulin (these are the three right bars in the graph).

In summary, this paper shows that nobiletin can effectively reduce the amount of oil produced by the sebaceous glands. Since less oil production means less predisposition to acne out-breaks, nobiletin should be a valuable addition to your acne treatment war chest!

Inspired by the scientific data above, Sana Fela is currently working on a new formulation of a Sebum Control cream based on Extracts of Tangerine. We will introduce this product soon. We are actively working on a complete line of botanical skin care products. If you would like to be notified about updates on our products or web site, please leave your contact information on our contact form

*** UPDATE***  November 2009 – Product development for Tangerine Anti-Shine Cream is now complete!  For details, see How to reduce oily skin and prevent acne part (3). Or visit our store to get your own!

References

(1) Takashi Sato, Aiko Takahashi, Mika Kojima, Noriko Akimoto, Masamichi Yano and Akira Ito (2007). A Citrus Polymethoxy Flavonoid, Nobiletin Inhibits Sebum Production and Sebocyte Proliferation, and Augments Sebum Excretion in Hamsters. Journal of Investigative Dermatology 127: 2740-2748

For further reading

How to reduce oily skin and prevent acne. Part (2)
How to reduce oily skin and prevent acne. Part (3)