The cloud ear mushroom (A. polytricha), widely cultivated in East Asia, is renowned for its bio-active compounds, giving rise to hypoglycaemic, anti-tumour, and antioxidant effects.
Beyond its medicinal properties, A. polytricha is highly nutritious. Hence, there is a growing interest in harnessing its potential to create transparent thin films for various therapeutic applications on human skin, such as improving skin hydration and maintaining optimal water balance.
In this latest study, researchers formulated a spray (BE-FFS) using 0.74% brown cloud ear mushroom water extract, 1.38% sodium polystyrene sulfonate (SPS), and 0.87% glycerin which gave the best drying time of 2.21 minutes and occlusive factor of 17.67.
The formulation was subsequently evaluated for its physical appearance, spray angle, spray pattern, and in vitro skin permeation on synthetic membranes that acted as human skin.
Effectiveness of the new spray
At pH 5, which aligns with the human skin pH range, researchers found that BE-FFS adhered to the synthetic membranes without dripping and exhibited a consistent spray pattern at an angle of 82.46°.
This suggests that the blend of polymers can envelop the skin effectively, enrich hydration and prevent water loss.
To assess the skin permeation of BE-FFS, two active compounds from the brown cloud ear mushroom water extract - ergothioneine (ERT) and gallic acid (GA), were selected as markers. Results showed that BE-FFS steadily penetrated the skin over 12 hours, leaving a moderate amount of ERT and GA in the receptor medium.
Moreover, the unique characteristics of BE-FFS derived from natural polysaccharide and synthetic polymer also facilitated the build-up of active compounds on the skin, fostering hydration and shielding against water loss.
Skin irritation tests were performed using Finn chamber® allergy patch after 48 hours of BE-FFS application. BE-FFS demonstrated a non-irritating profile, with a low Primary Dermal Irritation Index that’s less than 0.5.
This outcome suggests the skin-friendly nature of BE-FFS, warranting its safety for skin use and consideration for further trials involving human volunteers.
The moisturising properties of BE-FFS were also evaluated over a period of four weeks. The results revealed a consistent increase in skin hydration from week 0 to week 4, indicating a noteworthy improvement in hydration levels.
The significant reduction in transepidermal water loss after four weeks also suggests that BE-FFS can protect against water loss and hydrate the skin.
Brown cloud ear mushroom water extract in skin protection
Prior to the formulation and testing of BE-FFS, researchers also examined the anti-inflammation and skin-protective properties of brown cloud ear mushroom water extract (CW) using HaCaT cells as a human skin model.
The CW used had a percentage yield of 20.99 ± 1.65%, with a total polysaccharides content of 748.2 ± 0.02 mg glucose/g extract. Testing CW at concentrations ranging from 37.5 to 300 µg/mL on HaCaT cells revealed a non-toxic concentration of 300 µg/mL (IC20).
This concentration was chosen to further investigate the anti-inflammatory activity and expression assessments of filaggrin (FLG) and Aquaporin-3 (AQP3) – two proteins related to skin hydration and enhance skin barrier function.
For hydration, the HaCaT cells were treated with CW at a concentration of 300 µg/mL for 96 hours. This significantly increased the expression of AQP3 and FLG. This suggests that CW has the power to strengthen the skin barrier and make the skin more hydrated by increasing these crucial proteins.
For inflammatory response, when HaCaT cells were exposed to Lipopolysaccharide (LPS) and incubated for 24 hours, researchers found that a mixture of CW and LPS shielded the cells from the secretion of IL-6, a pro-inflammatory cytokine. This is a protective effect that is also observed in CW alone.
Similarly, the CW and LAP mixture slightly reduced the production of a separate anti-inflammatory cytokine, TNF-α, compared to just using CW alone. All these mean that CW can alleviate inflammation caused by LPS and reduce the production of pro-inflammatory cytokines in HaCaT cells.
This hints that CW could be useful to fight against inflammation and protect the skin by improving its barrier function.
BE-FFS as an alternative skin hydration product
Overall, researchers of the current study are confident about the potential of A. polytricha for making skin healthier in cosmetic products. The BE-FFS formulation they have derived showed effective skin penetration and helped improve skin hydration. This makes it a promising candidate for further clinical studies to validate its effects while ensuring it remains gentle and non-irritating.
“The BE-FFS demonstrated an excellent potential effect on hydrating skin and preventing skin water loss. The likely explanation is that the mixed CW and synthetic polymer as a thin film polymer produced an occlusive effect.” The researchers wrote.
“In addition, CW is composed of many polysaccharides according to the results of total polysaccharides content. Natural polysaccharides function as a moisturising agent and natural film formers that could retain prolonged skin hydration and protect the skin barrier.”
Multifunctional Biological Properties and Topical Film Forming Spray Base on Auricularia polytricha as a Natural Polysaccharide Containing Brown Agaricus bisporus Extract for Skin Hydration
Authors: Nichcha Nitthikan et al.