Study of the Anti‐Proliferative Activity of 5‐Substituted 4,7‐Dimethoxy‐1,3‐Benzodioxole Derivatives of SY‐1 from Antrodia camphorata on Human COLO 205 Colon Cancer Cells

Abstract

A set of 10 4,7-dimethoxy-1,3-benzodioxole derivatives based on a lead compound previously discovered by our group, SY-1, which was isolated from Antrodia camphorata, were evaluated for their in vitro inhibitory activity on human colorectal carcinoma cells (COLO 205). Structure-activity relationship studies of the 10 compounds indicated the importance of the chain length of the alkyl group at the 5-position, and the 2-propenyl substituent named “apiole” exhibited the most potent inhibitory activity. In the present study, we demonstrate that the SY-1 analogue “apiole” decreased the proliferation of COLO 205 cells, but not that of normal human colonic epithelial cells (FHC). The G0/G1 cell cycle arrest induced by apiole (75–225 μM) was associated with significantly increased levels of p53, p21 and p27 and decreased levels of cyclin D1. Concerning COLO 205 cell apoptosis, apiole (>150 μM) treatment significantly increased the levels of cleaved caspases 3, 8, 9 and bax/bcl-2 ratio and induced ladder formation in DNA fragmentation assay and sub-G1 peak in flow cytometry analysis. These findings suggest that apiole can suppress COLO 205 cell growth; however, the detailed mechanisms of these processes require further investigation.

The in vivo antitumor effects on human COLO 205 cancer cells of the 4,7-dimethoxy-5-(2-propen-1-yl)-1,3-benzodioxole (apiole) derivative of 5-substituted 4,7-dimethoxy-5-methyl-l,3-benzodioxole (SY-1) isolated from the fruiting body of Antrodia camphorate

“…[7] In this study, p53 protein expression was significantly induced in the low-dose (> 1×) apiole-treated tumors. Our studies have suggested that p53-mediated signaling pathways play a role in apiole-induced antitumor effects.…”

“…Protein (50 g) from each sample was separated via 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to a nitrocellulose membrane, and analyzed using western blotting regulated in human cancer cells arrested at G0/G1 by apiole treatment. [7] In this study, the p21/Cip1 and p27/Kip1 proteins were significantly induced in tumors treated with low doses (> 1×) of apiole compared with those treated with the vehicle control [ Figure 4a]. The levels of cyclins D1 and D3 were down-regulated in the apiole-treated group compared with the vehicle-treated group, whereas CDK2 and CDK4 protein levels were unchanged [ Figure 4a].…”

“…Our previous study demonstrated that apiole has significant in vitro antitumor activity, inducing both cell growth arrest and apoptosis. [7] In this study, the average mouse body weight was 26 g. The mice were maintained on 5 g of Lab Diet per day [ Figure 2a]. No gross signs of toxicity (i.e., changes in body weight or general appearance or effects on individual organs) were observed in the mice receiving the treatment regimens.…”

“…Fast atom bombardment mass spectrometry (FAB-MS) ( [11] In a previous study, we demonstrated that apiole specifically induced cell cycle arrest and apoptosis in COLO 205 human colon cancer cells. [7] COLO 205 cells grown in RPMI 1640 supplemented with 10% fetal calf serum were harvested through two consecutive trypsinisations, centrifuged at ×300 g for 5 min, washed twice with PBS, and resuspended in sterile PBS. The cells (5 × 10 6 ) were resuspended in 0.1 mL of Roswell Park Memorial Institute (RPMI) 1640 and su`bcutaneously injected between the scapulae of BALB/c nu/ nu mice (4-week-old females, n = 5 per group) purchased from the National Science Council Animal Centre (Taipei, Taiwan).…”

“…Interestingly, we found that 4,7-dimethoxy-5-(2-propen-1-yl)-1,3-benzodioxole (referred to as apiole, apiol, or parsley apiol) led to potent G0/G1 phase cell growth arrest and apoptosis in human colon cancer cells through p53-mediated signaling. [7] Apiole has been reported to be a component of essential oils from different plant sources, such as the seeds of Petroselinum sativum [8] and Enterolobium contortisiliquum (Leguminosae) [9] and the leaves and fruits of Pituranthos chloranthus. [10] These results imply that the intake of healthy food ingredients (apiole), such as seed oil, may help to prevent colon cancer.…”