Researchers at the ORGANIZATION@1 -LRB- NUMBER@1 -RRB- found yerba mate to be `` rich in phenolic constituents '' and to `` inhibit oral cancer cell proliferation '' while it promoted proliferation of oral cancer cell lines at certain concentrations .

Researchers at the ORGANIZATION@1 -LRB- NUMBER@1 -RRB- found yerba mate to be `` rich in phenolic constituents '' and to `` inhibit oral cancer cell proliferation '' .
