Blackberry leaf extract: a multifunctional anti‐aging active

Abstract

Matrix metalloproteinases (MMPs) play a major role in wrinkle formation. Their expression increases with aging and is further enhanced by UV irradiation. Blackberry (Rubus fruticosus) leaf extract has been shown to suppress MMP‐1, ‐2 and ‐9 in cell‐free assays. We have now further explored the activity of this extract. The effect on MMP‐1 expression at the protein and the mRNA level was investigated using non‐irradiated and UVA‐irradiated human dermal fibroblasts. The extract showed a dose‐dependent reduction of the MMP‐1 protein level of both irradiated and non‐irradiated cells with an almost complete inhibition at a dosage of 0.1%. MMP‐1 mRNA expression of UVA‐irradiated cells was decreased after pre‐incubation as well as after post‐incubation with the extract. Best results were obtained with combined pre‐ and post‐treatment (0.1% extract led to 59% reduction in comparison with the respective control). Moreover, we found that blackberry leaf extract inhibits IL‐1α, a cytokine known to induce MMP expression. At a dosage of 0.2% the inhibition was 40% compared with that of the stimulated control. The extract also exhibited a potent radical scavenging activity comparable to that of α‐tocopherol as was shown by the ABTS assay. Taken together, these biological activities make blackberry leaf extract a highly efficient multifunctional anti‐aging active.