The invention relates to a preparation containing an extract of a plant of the family Euphorbiaceae genus Plukenetia and cosmetic and pharmaceutical preparations containing the extract. The extract contains proteins which when applied to the skin can provide an anti-inflammatory effect, a skin tightening effect, an antiaging effect and a substantivity effect. The preparations can also contain an oil of the plant. The preferred plant is Plukenetia volubilis. The extract, protein or mixture of proteins in the extract can be modified by hydrolysing, grafting or crosslinking.