Myricanol Induces Apoptotic Cell Death and Anti-Tumor Activity in Non-Small Cell Lung Carcinoma in Vivo

Abstract

This study explored the inhibiting effect and mechanism of myricanol on lung adenocarcinoma A549 xenografts in nude mice. Forty nude mice with subcutaneous A549 xenografts were randomly divided into five groups: high-dose myricanol (40 mg/kg body weight) group; middle-dose myricanol (20 mg/kg body weight) group; low-dose myricanol (10 mg/kg body weight) group; polyethylene glycol 400 vehicle group (1 mL/kg); and tumor model group. Nude mice were sacrificed after 14 days of treatment and the tumor inhibition rate (TIR, %) was then calculated. The relative mRNA expression levels of Bax, Bcl-2, VEGF, HIF-1α, and survivin in the tumor tissues were determined by real-time PCR. TUNEL assay was applied to determine cellular apoptosis, while IHC test was performed to detect the protein expression levels of Bax, Bcl-2, VEGF, HIF-1α, and survivin. The TIR of the three myricanol-treated groups ranged from 14.9% to 38.5%. The IHC results showed that the protein expression of Bcl-2, VEGF, HIF-1α, and survivin were consistently downregulated, whereas that of Bax was upregulated after myricanol treatment. Myricanol also significantly upregulated the mRNA expression of Bax and downregulated that of Bcl-2, VEGF, HIF-1α, and survivin in a dose-dependent manner (p < 0.05 to 0.001). These results are consistent with those of IHC. The TUNEL assay results indicated that apoptotic-positive cells significantly increased in the myricanol-treated tumor tissues compared with the cells of the vehicle control group (p < 0.01 to 0.001). These data suggest that myricanol could significantly decelerate tumor growth in vivo by inducing apoptosis.

The Mechanistic Antitumor Study of Myricanol 5-Fluorobenzyloxy Ether in Human Leukemic Cell Hl-60

“…Myricanol was extracted and detected as previously described [17]. Then, myricanol (50.0 mg) was added to 5.0 ml of acetone in a round-bottom flask, and was stirred until dissolved.…”

“…Cell apoptosis analysis by flow cytometry Briefly, HL-60 cells (1.5 × 10 5 /well) were incubated in IMDM + 10% FBS in six-well plates for 24 h. Then treated with different concentrations of 5FEM (1.25, 2.5 and 5.0 μg/ml), myricanol (5.0 μg/ml), DDP (5.0 μg/ml) or vehicle (0.1% DMSO) for 48 h. Then cell apoptosis was detected and quantified by flow cytometry (FCM) as previously described [17].…”

“…A total of 30-μg protein were separated using 12-15% SDS-PAGE. Then Western blot experiments were carried out as previously described [17]. The results of Western blot analysis were evaluated using the Quantity One software.…”

“…Myricanol significantly induced tumor growth inhibitory effects on the xenografts of lung adenocarcinoma A549 by upregulating the expression of Bax and downregulating that of survivin, Bcl-2, VEGF and HIF-1α. The experimentation has indicated that the possible antitumor effects of myricanol are via the mitochondrial apoptosis pathway [17].In order to improve anticancer effect of myricanol, and to further explore the structure-activity relationship of myricanol and discover novel myricanol derivatives as antitumor agents, some novel myricanol derivatives, such as 5-fluorobenzyloxy ether (5FEM), myricanol 5-chlorobenzyloxy ether and myricanol 5-bromobenzyloxy ether, were synthesized and evaluated against A549, HepG2 and HL-60 cancer cell lines. Among them, 5FEM was found to…”

“…Myricanol significantly induced tumor growth inhibitory effects on the xenografts of lung adenocarcinoma A549 by upregulating the expression of Bax and downregulating that of survivin, Bcl-2, VEGF and HIF-1α. The experimentation has indicated that the possible antitumor effects of myricanol are via the mitochondrial apoptosis pathway [17].…”