In vitro photoprotection and antioxidant capacity of Sphagnum meridense extracts, a novel source of natural sunscreen from the mountains of Colombia

Abstract

Excessive ultraviolet radiation can cause skin cancer and related health problems in humans. Traditionally, organic and inorganic sunscreens have been used to minimize these effects. Besides, some phenolic compounds present in plants play an important role as photoprotectors. Sphagnum meridense (L), found in Colombia, is continuously exposed to sunlight on high mountain ecosystems. In this work, we evaluated the potential of S. meridense extracts to be applied as UVA-UVB filter in cosmetic formulations and its antioxidant capacity. The mixture acetone-37 % hydrochloric acid (1 %, v/v) showed the best polyphenol content and UVA-UVB absorption coefficient. These extracts also exhibited promissory UVAPF values, UVA/UVB ratio, critical wavelength (λ c ) and antioxidant capacity in vitro, comparable to that of conventional sunscreens.

Photoprotective Potential of Baccharis antioquensis (Asteraceae) as Natural Sunscreen

“…The total phenolic content (TPC) of the samples was measured using a modified colorimetric Folin‐Ciocalteu method . Briefly, 10 μL of extract solution and 615 μL of deionized water were added to a test tube.…”

Novel UV filters from Pentacalia pulchella extracts with photoprotective properties and antioxidant activity

“…However, TPC values decrease when activated carbon is added due to the low selectivity of activated carbon that not only adsorbs chlorophylls but may also be absorbing other types of compounds, such as polyphenols, as previously reported in B. antioquensis extracts, a plant of the same family Asteraceae [45]. In previous studies carried out by us and various publications have shown that the addition of acids, mainly HCl, increases the yield of polyphenol extraction [33,45,49,50], as observed in this study (Table 2 tests 1, 2, 3, and 4). The reason why we discarded the extracts where HCl was used was due to the poor sensory characteristics of these formulations, since the incorporation of these extracts was not adequate in the hydrogel, presenting brown colorations and large dispersed particles.…”

“…The antioxidant capacity was measured by the inhibition of lipid peroxidation in MeLo, through the production of conjugated diene hydroperoxide (CDH) and thiobarbituric acid reactive substances (TBARS), using the method described by Mejía-Giraldo et al [33]. Solutions of MeLo 10 mM (negative control), MeLo plus BHT 0.02% w/v (positive control), and MeLo plus 0.02% (w/v) of each extract were exposed to accelerated oxidation by heating at 40 ± 5 °C for 5 days in test tubes.…”

Selected Extracts from High Mountain Plants as Potential Sunscreens with Antioxidant Capacity

“…The antiradical ability of all extracts was determined using the DPPH• test as free radical (24,25). For each extract, different concentrations were evaluated and the radical scavenging activity was calculated, expressed as the number of mg of antioxidant substance (dry extract) necessary to reduce the initial concentration of the DPPH• radical by 50% and was expressed as the concentration effective (EC 50 ).…”

“…The antioxidant capacity was measured by the inhibition of lipid peroxidation in methyl linoleate (MeLo), through the production of conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS), using the method described by Mejía‐Giraldo et al . (26). Solutions of MeLo (10 mM), MeLo plus BHT 0.02% (w/v) and MeLo plus 0.02% (w/v) of each of the extracts were exposed to accelerated oxidation by heating at 40 ± 5°C for 5 days in test tubes.…”