Formulation of bio-cellulose containing aloe gel extract for anti-aging

Abstract

Photoaging of the skin is caused by ultraviolet exposure that promotes the expression of cytokines such as interleukin 1, epidermal growth factor, and tumor necrosis factor-alpha (TNF-α). Aloe vera has been reported as suppressing the level of TNF-α but aloe vera degrades easily so becomes ineffective against inflammation very quickly. However, applying the dry formulation as a skin patch helps to maintain the stability of the active compound. Bio-cellulose (BC) is a natural material that has a highly porous nanofibril structure that incorporates and releases compounds very quickly. For these reasons, we have an idea to prepare BC containing aloe gel extract and study its anti-inflammatory effect of the extract. An extraction showed that aloe gel extract provided approximately 0.6% of yield. Using high-performance liquid chromatography calculated the aloe-emodin content in the aloe gel extract to be 17.0 ± 3.1 µg/g of lyophilized extract. The cell viability when applying the aloe gel extract to Raw 264.7 cells was studied by colorimetric assay, which showed no cytotoxicity up to 200 µg/mL concentration of aloe gel extract. The anti-inflammatory activity of the aloe gel extract was then evaluated by an enzyme-linked immunosorbent assay at a concentration of 50-200 µg/mL which demonstrated anti-inflammatory activity through the inhibition of TNF-α in LPS-induced Raw 264.7 cells. The BC that was prepared from cultured bacteria Gluconacetobacter xylinus was then lyophilized. Dried BC samples were soaked in a solution of formulation that contained the aloe gel extract as well as 0.2% carboxymethyl chitosan and propylene glycol. This formulation was found to be the most efficient in changing the tensile properties and the appearance of the formulation and increasing the flexibility of the BC. This formulation, designated as Formulation 5, was chosen for stability testing. The results from the stability testing showed that Formulation 5 consisting of aloe gel extract as well as 0.2% carboxymethyl chitosan and propylene glycol provided good stability on physical and mechanical properties during storage. The release study of the aloe gel extract indicated that the release of the aloe-emodin from the BC was time-dependent. These results suggest that the BC containing aloe gel extract has good potential for use in anti-photoaging cosmetic products.

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