Sunday 21st January is the USA’s National Hyaluronic Acid(HA) Day, (https://lnkd.in/dpqzSMZy), created to promote HA use in skincare products. HA is a polysaccharide that occurs naturally in the skin, joints and connective tissues, providing contributing lubrication and flexibility. The average person has around 15 grammes of HA. A third of our HA is replaced every day, which becomes a problem as we age. HA supplementation can help offset natural decline, and HA is increasing popular as an ingredientin cosmetics.
Most commercial HA is extracted from animal tissues such as cockscomb or bovine eyes. It may also be obtained from certain pathogenic bacteria, from which it needs to be purified away from the toxins. There is interest in HA from “greener” sources, but plants, unfortunately, don’t have it.
HA is a polymer whose structure is depicted in the cover picture; it consists of long chains of alternating D-glucuronic acid (red) and N-acetyl-D-glucosamine (blue) units. Plants can make both of these monomericunits but lack the enzyme that strings them together as HA. Nazeri et al (2021)succeeded in introducing human HA synthase gene into tobacco plants. The resultinggenetically engineered plants were then able to synthesise HA. This approaches been used to produce other human proteins in plants.
For those who are averse to genetically modified organisms, plants make other polysaccharides that could serve as HA alternatives in skincare products. These include glucans, fructans, mannans and compound polysaccharides, some mentioned in previous instalments of The Weekly Leaf (https://www.greenmbio.com/gmb/weekly-leaf). Particularly interestingare vegetable gums from plants of the Fabaceae family, notably from liquorice and from trees such as Cassia, Senna, Delonix, Ceratonia (carob). You can do yourown internet search to find products using extracts of these plants, and alsostunning pictures of the colourful trees.
Further reading
🧬Wikipedia(2024) Hyaluronic acid, https://en.wikipedia.org/w/index.php?title=Hyaluronic_acid&oldid=1195174187
🧬Sze JH et al(2016). Biotechnological production of hyaluronic acid: a mini review. 3Biotech, 6(1), 67. https://doi.org/10.1007/s13205-016-0379-9
🧬Nazeri A et al(2021). Heterologous production of hyaluronic acid in Nicotiana tabacum hairyroots expressing a human hyaluronan synthase 2. Scientific reports,11(1), 17966. https://doi.org/10.1038/s41598-021-97139-0
🧬Niyigaba T et al(2021). The Extraction, Functionalities and Applications of Plant Polysaccharides in Fermented Foods: A Review. Foods (Basel), 10(12),3004. https://doi.org/10.3390/foods10123004
