Plant-powered skincare: harnessing the benefits
Why do we use so many plant extracts in our products? Because plants, to survive in difficult environments and fight bacteria, fungi and viruses, evolved sophisticated chemical reactions capable of making complicated chemicals with very special abilities. And we don’t. Humans are complicated enough, but we can’t make stuff like apocynin, beta-glucans, or azelaic acid.
For example: if you plant sunflowers in your garden they will do a good job suppressing weeds. How? They produce a chemical called sesquiterpene lactones. These chemicals are a rich source of drugs (some have cytotoxic, anti-tumorgenic, anti-bacterial and anti-fungal properties). They can be toxic to grazing livestock, causing severe neurological problems in horses. Some corals make similar chemicals. We humans don’t and can’t. If we don’t like our neighbor, we can move! Plants can’t move.
Many plant chemicals have evolutionary significance; they have evolved as deterrents against herbivores, or are anti-fungal, anti-bacterial and/or anti-viral. Let’s clarify: there was no “intention” of making chemicals beneficial to humans, on the contrary! It just happens that some chemicals inhibit a human enzyme (or promote another) or bind to a receptor with a different intended ligand. For example, phytoestrogens may be beneficial to women going through menopause, but they evolved to provide advantage to the plants decreasing the birth rate of plant eaters!
The genetic machinery responsible for the evolution of chemical novelty on plants and major emergency events of plants and herbivore lineages
Many plant chemicals have antioxidant activity. Here, plants also use many of them as antioxidants because they have to control the redox state of their cells just as we humans do.
Pure chemicals vs. plant extracts
Not all plant extracts are the same. Some plant extracts are beneficial, and this is because there are some useful chemicals in the mix of hundreds present in the extract. As phytochemistry progresses, it is possible to identify the beneficial components and eventually determine how they work, i.e., their mechanism of action.
What are the advantages of identifying the active chemical? Once you know what works in that mix, it is possible to separate the useful chemical from the rest by using various purification methods. Step by step, you get the active chemical purer and purer. This process is costly but has advantages: the enriched extract is less likely to have adverse effects caused by other, non-beneficial chemicals that accompany the good one in the total extract. Besides, the pure chemical may be more pleasing and more compatible with the carrier cream or serum than the crude extract.
Sometimes, a plant contains so many beneficial chemicals that it does not make sense to purify one of them, like with our sea kelp extract ferment, which supplies a complete nutrient medium and moisturizes skin and scalp. The substrate for fermentation is kelp, a sea macroalga (Phaeophyta). Fermentation makes the cell contents of these algae readily available to our skin and scalp, maximizes its moisturizing properties, and makes nutrients available that are required by the skin. The ferment also has a calming, anti-itch activity. The ferment is rich in fucoidan, carrageenan, algin, minerals, and many active chemicals. It also provides minerals like iodine, copper, molybdate, magnesium, and others required as cofactors in enzymatic reactions of lipid metabolism and energy conversion. Fucoxanthin is a pigment present in Phaeophyta (brown algae) that may protect skin from photo-aging caused by UV. Fucoidans are sulfated polysaccharides with structures that depend on the plant source and growing conditions. When you apply fucoidan to the skin, it will increase the density of collagen bundles, decrease protease activity, increase scavenging of free radicals, and increase cell proliferation. These effects would be mediated through increased expression of ß1-integrin and may also help with wound healing. In addition to assisting in collagen synthesis, fucoidan inhibits the replication of many viruses, including herpes, human cytomegalovirus, HIV-1, and others.
In short, we use plants. When a plant extract is great as something, scientists work hard to identify the active chemicals. We then elucidate the mechanisms of action on humans, and purify the beneficial chemicals (leaving the less-good behind). When its possible (in chemistry, plants are better than human) we even synthesize the valuable plant chemical!
Hannah
References
Picman, AK (1986). Biological activities of sesquiterpene lactones, 14: 255–281. doi:10.1016/0305-1978(86)90101-8
Kariñho-Betancourt, E. (2019). Coevolution: Plant-herbivore interactions and secondary metabolites of plants. In: Merillon, JM., Ramawat, K. (eds) Co-Evolution of Secondary Metabolites. Reference Series in Phytochemistry. Springer, Cham. https://doi.org/10.1007/978-3-319-76887-8_41-1