It is a well-known fact that exposure to ultraviolet light, especially the UVA component, infects skin disorders such as melanoma and non-melanoma skin cancers. Superficial remedies like sunscreens are effective only up to a point. This discovery has led to the investigation of new methods to protect the skin from the damaging effects of solar UV radiation, or “photocarcinogenesis” as it is called. In recent years there has been considerable interest in the identification of botanicals of natural origin, such as silymarin, with antioxidant and anti-inflammatory properties, and which exhibit anticancer and antimutagenic functionality.
In this sense, the medicinal benefits of milk thistle have been the subject of intense research by scientists. Although its value as a medicine for a number of health conditions, including dermatological, has been known for more than 2,000 years, it is only now that science has begun to seriously examine the role that milk thistle and “silymarin” play, its active compound. in the treatment of skin damage.
In an experiment conducted at the University of Palacky in Czechoslovakia (1), researchers studied the impact of two components of Silybum marianum (technical name for milk thistle) as a preventive and treatment intervention for skin damage caused by exposure to lightning. GRAPE. Their findings were positive, as these two components, collectively known as “flavonolignans,” were found to perform a number of functions, such as increasing keratinocyte viability in irradiated cells, inhibiting ROS production, and stopping further reduction of ATP. and GSH which takes place at the intracellular level and stops the peroxidation of membrane lipids. In addition, the activation of the caspase-3 process that initiates exposure to UVA rays is stopped and reversed when the two components of Silybum marianum are applied. The general picture that emerges, therefore, is that Silybum marianum is a good candidate to be considered for inhibiting UV damage.
An interesting experiment carried out on mice at the University of Alabama at Birmingham (2) was reported in the March-April 2008 issue of the journal Photochem Photobiology (2). Two observations from this research are of special relevance to us here. One is CD11b + cells, which are the main source of oxidative stress in UV-irradiated skin, which were inhibited by Silymarin. The flavonoid also suppresses the leukocyte infiltration induced by UV exposure. The second important observation is that silymarin not only stops UV damage, but also acts as a preventative measure. Another researcher has taken a step forward with the identification of yet another investment that this chemical makes in the action of UV rays: it reduces the volume of cells that produce H2O2 and cells that produce interleukin-10 cytokines, whose generation is activated. by UV rays (6).
Researchers working in the Department of Pharmaceutical Sciences at the University of Colorado have reached almost the same conclusion (3). His research has shown a positive effect of silibinin in repairing UVB-induced DNA damage. Another experiment carried out at the Department of Dermatology at the University of Alabama has observed the inhibiting effect that the flavonoid has on tumor promoters such as 12-O-tetradecanoylphorbol-13-acetate, mezerein, benzoial peroxide and okadaic acid (4) .
Topical application of silibinin before or immediately after UV irradiation has been found to inhibit the generation of thymine dimer-positive cells that UV rays induce in the epidermis (5). This research has also shown that terminal sunburn cell formation that is again induced by UV rays is also inhibited when Silibinin is applied.
A strong case that silymarin is a highly effective agent for inhibiting and reversing cancers induced by carcinogens and tumor promoters is supported by two independent investigations. In both experiments (7), (8), silibinin has been reported to inhibit cancer cells (activation of ERK1 / 2) and promote benign cells (JNK1 / 2, p38), making it an effective anti-cancer agent. cancer intervention for Cancer.
An article published in the journal “Cancer Research” details other in-depth research carried out on the efficacy of silymarin as a possible interventional agent against stage I and stage II tumors (9). The article reports that milk thistle extract has been found to be especially helpful in suppressing stage I tumors and inhibiting the edema, hyperplasia, proliferation rate, and oxidative state that occur due to UV irradiation. This same result has been obtained by an independent group of researchers, who used a different chemical to induce skin edema in mice (10).
From previous research being conducted around the world, it can be safely concluded that silymarin is proving to be very effective in inhibiting UV-induced skin damage, and the day that thistle may not be far off. mariano become one of the main ingredients in sunscreen lotions. .
References
Svobodová A, Zdarilová A, Walterová D and Vostálová J. Flavonolignans from Silybum marianum moderate UVA-induced oxidative damage in HaCaT keratinocytes. J Dermatol Sci. 2007 Dec; 48 (3): 213-24. Electronic publication of August 3, 2007.
Katiyar SK, Meleth S and Sharma SD. Silymarin, a flavonoid from milk thistle (Silybum marianum L.) inhibits UV-induced oxidative stress by targeting CD11b + cells infiltrated in mouse skin. Photochem Photobiol. 2008 March-April; 84 (2): 266-71. Epub 2007 Nov 28.
Singh RP and Agarwal R. Mechanisms and preclinical efficacy of silibinin in the prevention of skin cancer. Eur J Cancer. September 2005; 41 (13): 1969-79.
Katiyar SK. Skin cancer prevention and silymarin: anti-inflammatory, antioxidant and immunomodulatory effects. Int J Oncol. January 2005; 26 (1): 169-76.
Dhanalakshmi S, Mallikarjuna GU, Singh RP and Agarwal R. Silibinin prevents skin damage caused by ultraviolet radiation in SKH-1 hairless mice by reducing thymine dimer positive cells and positive regulation of p53-p21 / Cip1 in the epidermis. Carcinogenesis. 2004 Aug; 25 (8): 1459-65. Epub 2004 Mar 19.
Katiyar SK. Treatment with silymarin, a plant flavonoid, prevents immunosuppression and oxidative stress induced by ultraviolet light in mouse skin. Int J Oncol. 2002 December; 21 (6): 1213-22.
Singh RP, Tyagi AK, Zhao J, and Agarwal R. Silymarin inhibits growth and causes regression of established skin tumors in SENCAR mice by modulating mitogen-activated protein kinases and inducing apoptosis. Carcinogenesis. 2002 March; 23 (3): 499-510.
Jifu Zhao, Moushumi Lahiri-Chatterjee, Yogesh Sharma, and Rajesh Agarwal. Inhibitory effect of a silymarin antioxidant flavonoid on benzoyl peroxide-induced tumor promotion, oxidative stress and inflammatory responses in SENCAR mouse skin. Carcinogenesis, vol. 21, No. 4, 811-816, April 2000.
Lahiri-Chatterjee M, Katiyar SK, Mohan RR, and Agarwal R. An antioxidant flavonoid, Silymarin, provides exceptionally high protection against tumor promotion in the SENCAR mouse skin tumorigenesis model. Cancer Res. 1999 Feb 1; 59 (3): 622-32.
Zhao J, Sharma Y and Agarwal R. Significant inhibition of the antioxidant flavonoid Silymarin against the modulation of antioxidant and inflammatory enzymes caused by 12-O-tetradecanoylphorbol 13-acetate, and the expression of cyclooxygenase-2 and interleukin-1-alpha in SENCAR epidermis mouse: implications in the prevention of the production of stage I tumors. Mol Carcinog. 1999 December; 26 (4): 321-33.