本发明涉及一种用于增加胶原蛋白基因和/或蛋白质表达的美容方法，包括将有效量的植物Quassia amara的提取物局部施用于皮肤和/或粘膜上。 本发明还涉及一种美容方法，其包括局部施用有效量的这种提取物，以增加有需要的个体的皮肤和/或粘膜的硬度。 本发明还涉及一种化妆品护理方法，其包括将包含有效量的Q.Aamara提取物的组合物局部施用于皮肤和/或粘膜上，以增加胶原基因和/或蛋白质表达。

The present invention relates to cosmetic and / or dermatological an extract of the tropical plant Quassia amara to increase gene expression and / or protein collagen. The invention also relates to the cosmetic and / or dermatological such an extract to increase the firmness of the skin and / or mucous membranes. The invention further relates to a cosmetic care method comprising topically applying a composition containing the extract of Q. amara, on at least a portion of the skin, to increase the gene expression and / or protein collagen.