Taiwanofungus camphoratus (Syn Antrodia camphorata) Extract and Amphotericin B Exert Adjuvant Effects via Mitochondrial Apoptotic Pathway

Abstract

The use of multiple drugs in cancer therapy increases the efficacy of the potential therapeutic effects. In this study, the authors investigated the adjuvant effects of an ethanol extract of solid-state cultivated Taiwanofungus camphoratus (TCEE) and amphotericin B (AmB) in the human cancer cell lines RPMI7951 and MG63. Taiwanofungus camphoratus is a well-known Chinese medicine in Taiwan, and AmB is a widely used antifungal agent. The authors demonstrated that TCEE pretreatment followed by AmB treatment effectively inhibited cell growth. The combination of sublethal doses of TCEE and AmB revealed a significant growth inhibitory effect in both cell lines. The combination of TCEE and AmB but not AmB alone induced phosphatidylserine externalization and loss of mitochondrial membrane potential. Cell cycle analyses revealed that combination of TCEE and AmB triggered G2/M arrest and significant apoptosis after 48 hours. These effects were greater than those achieved using TCEE or AmB alone. Furthermore, the authors demonstrated that the drugs increased the levels of p21(Cip1/Waf1) and pro-apoptotic protein Bax and reduced the level of anti-apoptotic protein Bcl-2. Taken together, the results showed that the combination treatment of TCEE and AmB displays strong adjuvant effects, which are indicated by the inhibition of cell proliferation in 2 human cancer cell lines, RPMI7951 and MG63. These findings suggest possible therapeutic applications and alternative medicines using this drug combination.