ANTI-HIV ACTIVITY OF EXTRACTS FROM CALENDULA-OFFICINALIS FLOWERS

Extracts of dried flowers from Calendula officinalis were examined for their ability to inhibit the human immunodeficiency virus type 1 (HIV -1) replication. Both organic and aqueous extracts were relatively non toxic to human lymphocytic Molt-4 cells, but only the organic one exhi bited potent anti-HIV activity in an in vitro MTT/tetrazolium-based as say. In addition, in the presence of the organic extract (500 mu g/mL) , the uninfected Molt-4 cells were completely protected for up to 24 h from fusion and subsequent death, caused by cocultivation with persis tently infected U-937/HIV-1 cells. It was also found that the organic extract from Calendula officinalis flowers caused a significant dose- and time-dependent reduction of HIV-1 reverse transcription (RT) activ ity. An 85% RT inhibition was achieved after a 30 min treatment of par tially purified enzyme in a cell-free system. These results suggested that organic extract of flowers from Calendula officinalis possesses a nti-HIV properties of therapeutic interest.