Antiproliferative and Antifungal Activities of 1,3-diarylpropane-1,3-diones Commonly used as Sunscreen Agents

Parsol 1789 and eusolex 8021 are two 1,3-diarylpropane-1,3-diones widely used as UV-absorbing agents in sunscreen formulations. Their chemical structures are quite similar to that of curcumin, a natural compound known to present a wide range of relevant pharmacological activities, including antifungal and anticancer activities. Such structural similarity, together with their availability and low cost sparked our interest for investigating their potential as antiproliferative and antifungal agents. Parsol and eusolex presented antiproliferative activity against eight human cancer cell lines. Promisingly, parsol was almost as active against the human lung cancer cell line NCI-ADR/RES (GI50 1.1±0.8 μg mL) as the positive control doxorubicin (GI50 1.7±2.1 μg mL). When tested for antifungal activity, parsol and eusolex showed activity comparable to that of fluconazole, the reference drug, against Paracoccidioides brasiliensis and Cryptococcus neoformans. Sporothrix schenckii was significantly more sensitive to parsol and eusolex (MIC = 16 μg mL, for both compounds) than fluconazole (MIC = 64 μg mL).