RESUMO
It was found that Argentatins A and B triterpenoids make up approximately 20-30 % of the waste resin produced from the industrial processes to isolate rubber from P. argentatum. We have developed an efficient protocol for synthesizing cycloartane-16ß-ol derivatives by opening the oxepane ring of argentatin B acetate (2) with BF3-OEt2. Although three new cycloartenol derivatives showed high cytotoxicity against PC-3 and HCT-15 cancer cell lines, nevertheless, the best results were obtained for (16ß,24R) -(16,24-epoxy-cycloartan-2(1H)-ylidene) acetate (14), compound with intact oxepane ring. These results indicate that the substituents in the argentatin nucleus and a side chain account for the cytotoxic activity. However, according to the selectivity index (SI), 14 did not show selectivity activity to cancer cell lines over the HaCat noncancerous cell line. The compound 3ß,16ß-Dihydroxy-cycloartan-24-one (5), synthesized by oxepane opening, demonstrated high cytotoxic activity to cancer cell lines and showed a remarkable selectivity to cancer cell lines over the noncancerous ones. These results suggest that 5 could lead to the development of new anticancer compounds.
Assuntos
Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Relação Estrutura-Atividade , Proliferação de Células/efeitos dos fármacos , Triterpenos/farmacologia , Triterpenos/química , Triterpenos/síntese química , Tetrazóis/farmacologia , Tetrazóis/síntese química , Tetrazóis/química , Estrutura Molecular , Relação Dose-Resposta a Droga , Sobrevivência Celular/efeitos dos fármacosRESUMO
The cytotoxic activity of combinations of masticadienonic (AMD) or 3αOH-hydroxy-masticadienonic (3αOH-AMD) acids with cisplatin (CDDP) was evaluated against PC3 prostate and HCT116 colon cancer cell lines. Combinations A (half the IC50 value), B (IC50 value), and C (twice the IC50 value) were tested at a 1 : 1 ratio. All AMD plus CDDP combinations demonstrated increased cytotoxic effect, as determined by the sulforhodamine B test, in both cell types. The best combination was B, which showed 93 % and 91 % inhibition of the proliferation of PC3 and HCT116 cells, respectively. It also increased apoptosis in the PC3â cell lines, as evaluated by flow cytometry. However, inâ vivo tests showed no additional activity from the AMD plus CDDP combinations. These results showed that the increased cytotoxic activity of the combinations inâ vitro did not reflect inâ vivo tests. All combinations of 3αOH-AMD plus CDDP exerted antagonistic effects in both cell types.