Red algae delays chronological ageing

The unicellular red alga belongs to the extremophilic microorganisms, which are able to survive under extreme conditions. During its evolution Cyanidium caldarium has adapted to extreme habitats and grows between pH 0.05 and 5 and up to 60°C. Growth under such hostile conditions requires biosynthesis of special substances, and one of these bioactive substances produced by Cyanidium caldarium is gamma aminobutyric acid (GABA). GABA is a non-proteinogenic amino acid and functions in the central nervous system as a neurotransmitter. It is found in animals and many plant forms. The production of GABA by an alga has not been reported previously and is rather surprising. It is assumed that GABA influences internal proton pumps and thereby maintains the essential intracellular pH value of 6.6 to protect cellular components from the acidic stress of the environment. In addition, GABA is said to stimulate hyaluronic acid and collagen synthesis in fibroblasts and enhances the survival rate of dermal fibroblasts when exposed to oxidative stress.1 GABA is also known as a functional food ingredient and as an active ingredient in the cosmetic industry. It is applied in the context of anti-wrinkle and skin smoothing products. GABA is described as possessing antiinflammatory activity.2 Inflammatory processes are also known in the context of chronological ageing, which is referred to as ‘inflammaging’ (inflammation-induced ageing). Recently, it was described that age-associated inflammation inhibits epidermal stem cell function.3 Another stress response mechanism relates to the production of osmoprotectants or compatible solutes. These are low molecular weight organic compounds from different natural product classes like sugars, amino acids and their derivatives. These molecules accumulate in cells and balance the osmotic gradient between the cell’s surrounding and the cytosol. Due to their protective properties against extreme environmental stress they are also referred to as extremolytes. Such substances often show high protective potential with respect to cellular macromolecules, for instance DNA. Cyanidium caldarium synthesises extremolytes like prolin, lysine and ornithin and their derivatives to survive under extreme temperatures and very low pH levels. Besides the above mentioned properties, Cyanidium algae contain dermatologically valuable proteins and polyphenols, which were shown to delay the natural ageing process. The micro alga Cyanidium caldarium was found in a broad screening process of numerous micro algae. The most promising candidates out of this research were selected and cultivated. Depending on their growth properties, some of these micro algae were further explored for potential cosmetic activity. Finally, Cyanidium caldarium was the most promising alga that was extensively further examined regarding biological and physiological properties on the skin. The strain that is used for the production of the Cyanidium caldarium extract was isolated on the Sunda Islands in Southeast Asia from Mount Lawu fumaroles on the island of Java. Production of the bioactive algae extract is a natural and eco-friendly process from biorenewables. After cultivation, the algae cells are processed by a proprietary mild extraction method followed by a filtration step enriching the bioactive compounds. Cyanidium caldarium extract was found to protect and maintain epidermal stem cell capacity for a rejuvenated skin activity. On a molecular level, it boosts elastic fibres leading to highly supple skin and a reduction of skin elasticity fatigue (Fig. 1).

In vitro studies

Different in vitro studies were carried out to analyse the effects of Cyanidium caldarium extract on a biological level. Commercially available epidermal keratinocyte progenitor cells were used as cell culture model to study the effects on epidermal stem cells. Dermal fibroblasts were used to evaluate dermal effects.