SKIN PROTECTION 37
40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0
Control PM2.5 (1 µg/ml)
PM2.5 (1 µg/ml) +
Ougon Liquid
Figure 3: Down-regulation of PM2.5-induced expression of CYP1A1 by ougon in NHEK.
and transcription of many genes including the CYPs. There are several isoforms of CYPs, also known as xenobiotic metabolising enzymes, which are involved in the metabolism of different toxic substances in human. Although they are abundantly expressed throughout the body, their two isoforms, namely CYP1A1 and CYP1B1, are mainly found in skin keratinocytes and fibroblasts.
Solution to tobacco smoke-induced skin ageing There are many in vitro and in vivo evidences that tobacco smoke causes ageing of skin both in human and animals. It is reported that tobacco smoke not only causes degradation of collagen by inducing the expression of matrix metalloproteinases (MMPs), but also impairs collagen biosynthesis significantly in cultured normal human dermal fibroblast (NHDF). The induction of MMPs expression seems to be caused by the activation of AhR pathway because, in association with MMPs, the expression of CYP1B1 is also increased significantly.3,5
Epidemiological studies
indicate that tobacco smoke is an independent risk factor of facial wrinkle formation and other aspects of premature skin ageing.6
Clinical studies on mouse skin
also suggest a relationship between tobacco smoke and skin wrinkle formation.7 Additionally, tobacco smoke significantly increases the expression of MITF (melanogenesis associated transcription factor) in a dose-dependent manner, leading to more melanin production in melanocytes via AhR-mediated mechanisms.8 Therefore, it is necessary to develop a suitable product which may inhibit the AhR-CYP signalling pathway. We investigated many plant ingredients in our laboratory and found that one unique ingredient, ougon, was exclusively effective in protecting skin against environmental pollution. Briefly, we collected tobacco smoke in hexane and/or PBS solution. After
November 2017 30.0 25.0 20.0 15.0 10.0 5.0 0.0 Control PM2.5 (1 µg/ml) Ougon Liquid (0.5%)
PM2.5 (1 µg/ml) +
Figure 4: Inhibition of PM2.5-induced expression of CYP1B1 in NHEK by ougon.
the treatment of plant extracts with cultured NHDF for 3 hrs, the cells were exposed with tobacco smoke solution for 24 hrs. Then, total RNA was extracted for PCR analysis of CYP1B1 and MMP-1 gene expression using specific forward and reverse primers. It was found that the extract down-regulated the tobacco smoke-induced expression of CYP1B1 by almost 50% (Fig 1) in cultured fibroblasts. In the same experimental model, it also reduced MMP-1 expression level induced by tobacco smoke both at oil phase (70% reduction) (Fig 2a) and water phase (80% reduction) (Fig 2b). It is to be noted here that MMPs are a family of proteolytic enzymes that specifically degrade collagens, elastin, and other proteins in connective tissues. MMP-1 is specifically responsible for the breakdown of collagen-1 which is the most abundant protein in the skin providing firmness and elasticity to the skin. Thus, ougon could be the one which effectively prevents CYP1B1 mediated premature skin damage.
Solution to PM2.5-induced skin ageing According to the World Health Organization (WHO) one of the pollutants
5.0 4.0 3.0 2.0 1.0 0.0 Control PM2.5 (100 µg/ml) Ougon Liquid (0.02%)
PM2.5 (100 µg/ml) +
Figure 5: Suppression of mRNA expression of IL-1b induced by PM2.5 in human cultured keratinocytes by ougon.
PERSONAL CARE ASIA PACIFIC
to cause major public health concern is PM. It can have a significant impact on human health, not only for local populations, but also in regions far from its source of emission. It is reported that PAHs present on the surface of PM may penetrate into the intact skin and have direct effects on viable cells such as keratinocyte and melanocytes.4
But, into the barrier deficient
skin, PM themselves may penetrate and cause oxidative stress and skin inflammation.4
Among the PM particles,
PM2.5 is considered as the main cause of pollutant-induced skin ageing because most of the total mass of airborne PM is usually made up of PM2.5. One recent study carried out on normal human keratinocytes showed that PM2.5 inhibited cell proliferation, increased oxidative stress and induced DNA damage.9
So far, the
exact mode of action of PM2.5 is not clearly understood, but one of the possible mechanisms could be AhR signalling pathway because PM2.5 is reported to increase the expression and enzymatic activity of CYP1A1.9
PM particles contain
many constituents including some very high-affinity AhR ligands e.g. benzo[a]pyrine, dioxin etc. During the
Relative CYP1A1 Expression
Relative IL-1beta Expression
Relative CYP1B1 Expression
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