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.

Supplementation with Herbal Extracts to Promote Behavioral and Neuroprotective Effects in Experimental Models of Parkinson's Disease: A Systematic Review.

Parkinson's disease (PD) consists of a neurodegenerative pathology that has received a considerable amount of attention because of its clinical manifestations. The most common treatment consists of administering the drugs levodopa and biperiden, which reduce the effectiveness of the disease and the progress of its symptoms. However, phytotherapy treatment of PD has shown great potential in retarding the loss of dopaminergic neurons and minimizing the behavioral abnormalities. The aim of this study is to systematically review the use of supplemental herbal plants with cellular protective effect and behavioral activity in in vivo and in vitro experimental models. A total of 20 studies were summarized, where the effectiveness of herbal extracts and their isolated bioactive compounds was observed in animal models for PD. The main neurochemical mechanisms found in these studies are schematically represented. The herbal extracts and their biocompounds have antioxidant, anti-apoptotic, and antiinflammatory properties, which contribute to avoiding neuronal loss. Reports show that besides acting on the biosynthesis of dopamine and its metabolites, these compounds prevent D2 receptors' hypersensitivity. It is suggested that further studies need be conducted to better understand the mechanisms of action of the bioactive compounds distributed in these plants. Copyright © 2017 John Wiley & Sons, Ltd.