- Plant-derived natural product chemicals could offer protection to the skin from the harmful effects of gamma radiation during cancer radiotherapy, suggests research.
Writing in the International Journal of Low Radiation, Faruck Lukmanul Hakkim of the University of Nizwa, Oman and Nagasaki University, Nagasaki, Japan, and colleagues there and at Macquarie University, New South Wales, Australia, Bharathiar University, India and Konkuk University, South Korea, explain how three ubiquitous and well-studied natural products derived from plants can protect the skin against gamma radiation during radiotherapy.
Hakkim and colleagues discuss the benefits of the organic, antioxidant compounds caffeic acid (CA), rosmarinic acid (RA) and trans-cinnamic acid (TCA) used at non-toxic concentrations.
They tested the radio protective effect of these compounds against gamma-radiation in terms of reducing levels of reactive oxygen species generated in skin cells by clinical relevance dose of gamma ray in the laboratory and in terms of the damage to the genetic material DNA, specifically double strand breaks in laboratory samples of human skin cells (keratinocytes).
They found that treating the human skin cells with CA, RA and TCA can protected the cells by 40, 20 and 15 percent respectively from gamma ray toxicity.
They suggest that the protective effect arises because the compounds mop up the reactive oxygen species and chemically deactivate them as well as enhancing the body’s natural DNA repair mechanisms.
The team suggests that these compounds might best be used as skin protectants during combination chemo- and radio-therapy. Further work is under way to investigate the clinical potential of mixtures of the three natural products.
It is found most notably in many Lamiaceae (dicotyledons in the order Lamiales), especially in the subfamily Nepetoideae. It is found in species used commonly as culinary herbs such as Ocimum basilicum (basil), Ocimum tenuiflorum (holy basil), Melissa officinalis (lemon balm), Rosmarinus officinalis(rosemary), Origanum majorana (marjoram), Salvia officinalis (sage), thymeand peppermint or in plants with medicinal properties such as common self-heal (Prunella vulgaris) or species in the genus Stachys.
It is also found in other Lamiales such as Heliotropium foertherianum, a plant in the family Boraginaceae.
It is also found in plants in the family Marantaceae (monocotyledons in the order Zingiberales) such as species in the genera Maranta (Maranta leuconeura, Maranta depressa) and Thalia (Thalia geniculata).
Cinnamic acid is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter. Cinnamic acid has a honey-like odor; it and its more volatile ethyl ester (ethyl cinnamate) are flavor components in the essential oil of cinnamon, in which related cinnamaldehyde is the major constituent. Cinnamic acid is also part of the biosynthetic shikimate and phenylpropanoidpathways. Its biosynthesis is performed by action of the enzyme phenylalanine ammonia-lyase (PAL) on phenylalanine.