Nine tannins, including gallo- and ellagitannins, were evaluated as potential inhibitors of HIV replication. 1,3,4-Tri-O-galloylquinic acid 1, 3,5-di-O-galloyl-shikimic acid 2, 3,4,5-tri-O-galloylshikimic acid 3, punicalin 6, and punicalagin 7 inhibited HIV replication in infected H9 lymphocytes with little cytotoxicity. Two compounds, punicalin and punicacortein C 8, inhibited purified HIV reverse transcriptase with ID50 of 8 and 5 microM, respectively. Further studies with H9 lymphocytes indicated that chebulagic acid 5 and punicalin did not inactivate virus directly. However, 1,3,4-tri-O-galloylquinic acid and 3,5-di-O-galloylshikimic acid were more effective inhibitors under those conditions. All tannins appear to inhibit virus-cell interactions. Thus, inspite of their anti-RT activity, the mechanism by which tannins inhibit HIV may not be associated with this enzyme.
Nonaka et al. (Tue,) studied this question.