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WROBLEWSKA, K. B. Antioxidant and photoprotective activity of native Brazilian bamboo species. 2019. 172 p. PhD Thesis. Faculty of Pharmacy, University of Sao Paulo, Sao Paulo, Brazil, 2019. Differently of Asian species, the native Brazilian bamboo speciesare mostly used in the construction industry, with no pharmaceutical applications described, as their chemical composition and biological effects are unknown. In this project, we evaluated the chemical composition, antioxidant and photoprotective activity of ethanolic extracts from five bamboos from the South of Brazil: Aulonemia aristulata (Döll) McClure., Chusquea bambusoides Rupr. Ex Döll, Chusquea capituliflora Trin. var. pubescens McClure, Chusquea meyeriana Rupr. and Merostachys pluriflora Munro ex E.G. Camus. DPPH radical scavenging activity assay was used to estimate the antioxidant potencial of the plants, and the IC50 received varied between 137 and 260 μg/mL. Total phenolics and flavonoids contents were determined using FolinCiocalteau and AlCl3 reagents. The bamboo dry extracts showed between 43 87 μg gallic acid equivalents and up to 7 μg of quercetin equivalents per mg of the sample. Preliminary analysis of the chemical composition done by Thin Layer Chromatography in silica plates, indicated that the most common flavonoids found in Asian species were not present in the Brazilian bamboos. Photoprotective activity of the developed cosmetic formulations, containing commercial solar filters and 10% of the extracts, was evaluated by diffuse transmittance with an integrating sphere on PMMA plates. The samples presented Sun Protection Factor (SPF) from 34 – 86 before to 14 – 44 after the irradiation, and a broad spectrum of action. The most promising extract, M. pluriflora culms, was chosen for the second part of the project, which involved further studies on its composition and in vivo photoprotective activity. The selected extract had its cytotoxicity evaluated, to confirm its safety, against retinal pigmented epithelium (RPE) cells. The extract was fractioned, and the fractions were evaluated for their total phenolic and flavonoid contents. Fractions’ separation increased the quantity of the active compounds and, consequently, their antioxidant and photoprotective effect. Additionally, Gas Chromatography-Mass Spectrometry and High-Performance Liquid Chromatography analysis of the fractions showed the presence of fatty acids, phenolic acids and products of lignin decomposition as the main compounds. Due to its abundance, p-coumaric acid might be responsible for the antioxidant activity and photoprotection of the bamboo extract. The photoprotective formulation with 5% of the extract was sent to a clinical research center, IPClin, to have their SPF in vivo and photosensitivity effect estimated on healthy volunteers. The in vivo SPF was 23 for the extract formulation and 15 for the control with only commercial filters. These results indicated that native bamboo species can be a source of natural photoprotective substances, which would prevent the addition of high amount of synthetic solar filters, that can easily degrade and cause skin allergies and irritation.

Atividade antioxidante e fotoprotetora de bambus nativos do Sudeste brasileiro