Pheophorbide a from solanum diflorum interferes with NF-kappa B activation

Continuing our search for biogenic NF-kappaB inhibitors we investigated Sol anum diflorum, used by the Istmo Sierra Zapotec Indians of Mexico in the tr eatment of inflammatory skin conditions, it became obvious Very early that the active substance seems to be a degradation product of chlorophyll. Pheo phorbide A was identified as one of the key compounds responsible for the N F-kappaB inhibitory activity. The compound interferes with NF-kappaB activa tion, was cytotoxic if exposed to light, but devoid of any cytotoxic activi ty in the dark.