Evaluation of the therapeutic efficacy and safety of topical application derived from tocotrienol rich fractions

Abstract

The therapeutic effects and safety of topical Tocotrienols Rich Fractions (TRF) in high concentration were studied using animal and human skin. Non-invasive methods were applied on human subjects using various skin bioengineering instruments. Undiluted TRF causes slight inflammation to the skin relative to sodium lauryl sulphate, which causes severe inflammation. Although the undiluted TRF is indicative of weak irritant, diluted TRF of 5% and below did not invoke any cutaneous reactions on human skin and 21 days of repeated exposure did not show any significant skin irritations. The 5% TRF preparation was found to be the maximum concentration with no cutaneous reactions. At 5% concentration it significantly increased 43% of skin hydration after single application and the skin hydration level was maintained for 90 minutes. No significant difference in transepidermal water loss was observed between SLS-damaged skin treated with 5% TRF and untreated area. The 5% TRF application did not significantly improve the recovery of a damaged-skin barrier. However, it significantly reduced the UVB-induced skin erythema of 1 Minimal Erythema Dose on area pre-treated with TRF. The protective effect percentage of 5% TRF was 36% against the SPF 15 sunscreen which had protective percentage of 44%. Combination of 5% TRF with 1% Ascorbic Acid significantly reduce 43% of the skin erythema. The TRF preparation was also effective in recovering UVB-induced skin erythema. An immediate post-treated of 5% TRF on test area pre-exposed to UVB, may inhibit 28% of the skin erythema compared to positive control of 1% Indomethacin which inhibit 17% of the skin erythema. However, combination of 1% Ascorbic Acid and 5% TRF inhibited 31% of the erythema which is indicative of synergistic effects of the antioxidants. These findings showed that topical application of TRF at 5% did not induce adverse skin reactions but significantly increase the skin hydration and protects the skin against UVB induce skin damage. The TRF efficacies are much enhanced with the addition of other antioxidant.