The invention relates to a cosmetic composition comprising at least one extract from the orchid Dendrobium chrysotoxum as an active agent and at least one cosmetically acceptable excipient. The invention relates to the use in a cosmetic composition of an extract from the orchid Dendrobium chrysotoxum as an active agent for preventing or delaying the appearance of the signs of skin ageing or for slowing or attenuating the effects thereof, or else also for promoting cell or tissue longevity. The invention in particular relates to an orchid extract inhibiting the expression and/or the activity of the mitochondrial protein Smac/DIABLO.
