Polysaccharides and extracts from Agaricus brasiliensis Murill - A comprehensive review.

Edible mushrooms have been increasingly introduced into the human diet, which has driven research into their functional properties. Thus, Agaricus brasiliensis Murill or Agaricus blazei Murill (ABM) is a species native to the Brazilian biome, whose fruiting body has been used not only for dietary purposes, but also in the development of functional foods or as source of molecules of pharmacological interest. The bioactivity of ABM has been related to the presence of polysaccharides, although the contribution of other metabolites cannot be discharged. This work describes the polysaccharides isolation methodology and preparation of the extracts of ABM and their biological activities. Furthermore, it presents a general outline of its characterizations regarding composition, chemical structure and properties in solution. The ABM and its chemical constituents exhibit several biological activities that support their potential use for prevention or treatment of diseases with inflammatory background, such as cancer, diabetes and atherosclerosis. The mechanism of action of the extracts and polysaccharides from ABM is mainly related to a modulation of immune system response or reduction of inflammatory response. This review shows that the ABM has great potential in the pharmaceutical, biotechnological and food sectors that deserves additional research using standardized products.

Photoprotective potential of medicinal plants from Cerrado biome (Brazil) in relation to phenolic content and antioxidant activity.

Photooxidative damage affects cellular lipids, proteins and DNA in addition to being involved in the pathobiochemistry of erythema formation, premature skin aging, photodermatoses development and skin cancer. Phenolic compounds, flavonoids and hydroxycinnamic acid esters protect plant tissues against harmful UV-radiation. This study aimed to evaluate the sun protection factor of several Brazilian plant extracts in relation to UVB radiation absorption, which causes skin cancer, and to correlate the findings with their antioxidant activity, as well as with total phenol and flavonoid content. The antioxidant activity of the extracts were evaluated using the DPPH radical scavenging test. The photoprotective effect was evaluated using the methodology developed by Mansur. The antioxidant activity from the extracts showed IC50 values ranging from 4.91 to 132.24 µg/mL when compared to the standard quercetin with an IC50 of 5.01 µg/mL; the phenolic content varied from 3.77 to 57.14 mg GAE/g extract while flavonoid content varied from 1.80 to 5.89 mg EQ/g extract. Almost all extracts showed a potential for UVB radiation absorption in accordance with the ANVISA (Agência Nacional de Vigilância Sanitária) technical regulation for cosmetic sunscreens. The extracts with greater sun protection factors were those originating from Lippia microphylla (SPF = 26.82) and Dimorphandra gardneriana (SPF = 20.12). A sun protection factor of 15 or higher contributes to protect the skin, where the presence of sakuranetin flavonoids and quercetin glycosides contribute to this action.