Antioxidant and antimicrobial activities of native Rosa sp. from British Columbia, Canada.

Indigenous traditional knowledge and western science have revealed the potential for significant nutritional and therapeutic benefits among natural antioxidants. We investigated antioxidant and antimicrobial activity of rose hip extracts (Rosa nutkana, Rosa pisocarpa and Rosa woodsii) from wild British Columbia populations using liposome oxidation and disc diffusion assays. All extracts exhibited strong antioxidant activity. R. nutkana pericarp extracts contained high phenolic concentrations and showed greater antioxidant and antimicrobial activity than seed extracts. R. woodsii seed extracts had a higher phenolic concentration and greater antioxidant activity than pericarp extracts. Antioxidant activity was correlated with antimicrobial activity, and both extracts showed antimicrobial activity against yeast and Gram-positive bacteria. Our study is the first to demonstrate the antioxidant and antimicrobial properties of wild British Columbia roses. The effectiveness of selected species compared with standards demonstrates the significance of this natural resource to the continued health of human populations, and the need for conservation practices.