• Applied Biological Chemistry
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• v.49 no.3
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• pp.227-232
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• 2006

Styela clava (also called as rough sea squirt or leathery tunicate) is regarded as native to the northwest Pacific region including Korea and widely distributed in parts of northwestern Europe, North America and Australia. To evaluate Styela clava as a potential bioactive agent, the antioxidant activity of aceton extracts from Styela clava (whole, substance and tunic) was tested by measuring inhibitory effect of $H_2O_2$ induced DNA damage using comet assay. Also, anticancer activity on human colon cancer cell (HT-29) was investigated by MTT reduction assay. The $200\;{\mu}M$ $H_2O_2$ induced DNA damage was inhibited with Styela clava aceton extract in dose dependent manner in human leukocytes. The maximum inhibition was by 62.8, 62.1 and 78.3% at the concentration of $50\;{\mu}g/ml$ of whole, substance and tunic extracts, respectively. The aceton extracts from S. clava were also found to inhibit the growth of human colon cancer cell. The cell proliferation rates decreased to 26.9, 30.6 and 12.0% at the concentration of $500\;{\mu}g/ml$ of whole, substance and tunic extracts, respectively. These results support that aceton extracts from S. clava may be a potential candidate as a possible antimutagenic and chemotherapeutic agent.

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.581-590
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• 1998

We developed a novel water-soluble camptothecin analobue, CKD602, and evaluated the inhibition of topoisomerase I and the antitumor activities against mammalian tumor cells and human tumor xenografts. CKD602 was a nanomolar inhibitor of the topoisomerase I enzyme in the cleavable complex assay. CKD602 was found to be 3 times and slightly more potent than topotecan and camptothecin as inhibitors of topoisomerase, respecitively. In tumor cell cytotoxicity, CKD602 was more potent than topotecan in 14 out of 26 human cancer cell lines tested, while it was comparable to camptothecin. CKD602 was tested for the in vivo antitumor activity against the human tumor xenograft models. CKD602 was able to imduce regression of established HT-29, WIDR and CX-1 colon tumors, LX-1 lung tumor, MX-1 breast tumor and SKOV-3 ovarian tumor as much as 80, 94, 76, 67, 87% and 88%, respectively, with comparable body weight changes to those of topotecan. Also the therapeutic margin (R/Emax: maximum tolerance dose/$ED-{58}$) of CKD602 was significantly higher than that of topotecan by 4 times. Efficacy was determined at the maximal tolerated dose levels using schedule dependent i.p. administration in mice bearing L1210 leukemia. On a Q4dx4 (every 4 day for 4 doses) schedule, the maximum tolerated dose (MTD) was 25 mg/kg per administration, which caused great weight loss and lethality in <5% tumor bearing mouse. this schedule brought significant increase in life span (ILS), 212%, with 33% of long-term survivals. The ex vivo antitumor activity of CKD602 was compared with that of topotecan and the mean antitumor index (ATI) values recorded for CKD602 were significantly higher than that noted for topotecan. From these results, CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.432-441
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• 2016

Machaerium cuspidatum, a canopy liana, is a species of genus legume in the Fabaceae family and contributes to the total species richness in the tropical rain forests. In the present study, we investigated the antioxidative and anti-cancer effects of M. cuspidatum and its mode of action. The methanol extract of M. cuspidatum (MEMC) exhibited anti-oxidative activity with an $IC_{50}$ value of $1.66{\mu}g/ml$, and this was attributable to its 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity. MEMC also exhibited a cytotoxic effect and induced morphological changes in a dose-dependent manner in several cancer cell lines including human lung adenocarcinoma A549 cells, human hepatocellular carcinoma HepG2 cells, and human colon carcinoma HT29 cells. Moreover, MEMC treatment induced the accumulation of subG1 population, which is indicative of apoptosis in A549 and HepG2 cells. MEMC-induced apoptosis was confirmed by the increase in Annexin V-positive apoptotic cells and apoptotic bodies using Annexin-V staining and DAPI staining, respectively. Further investigation showed that MEMC-induced apoptosis was associated with the increase in p53 and Bax expression, and the decrease in Bcl-2 expression. In addition, MEMC treatment led to proteolytic activation of caspase-3, 8, and 9 and degradation of poly-ADP ribose polymerase (PARP). Taken together, these results suggest that MEMC may exert a beneficial anti-cancer effect by inducing apoptosis via both the extrinsic and intrinsic pathways in A549 and HepG2 cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.937-941
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• 2005

The antioxidant and anticancer activities of Styela plicata extracts were evaluated. When extracts were prepared with fresh Styela plicata (FR), extraction yield was in the order of methanol > ethanol = acetone > water among treated solvents. However, the extraction order was methanol > water > ethanol > acetate in freeze dried Styela plicata (FD). Radical scavenging activity was the highest in acetone extracts $(37.39\%)$ from FR, while in ethanol extracts $(78.40\%)$ from FD. Reducing power of FR was the greatest in methanol extracts (1.076), and that of FD in ethanol extracts (1.360). The acetone extracts from FD showed significant anticancer activity when revealed with human colon cancer cell line HT-29. These results indicated that extraction yields and properties of extracts from Styela plicata were variable depending on solvent and/or physicochemical state, and appropriate extraction process could provide some valuable bioactive materials from Styela plicata.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.278-283
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• 2006

Styela clava was processed by four different kinds of method including FR (fresh S. clava), H1 (heat treated S. clava at $110^{\circ}C$ for 15 min) H2 (heat treated S. clava at $120^{\circ}C$ for 5 min), and FD (freeze dried S. clava). Each S. clava sample was treated with methanol, ethanol, acetone, and water, then antioxidant and anticancer activities of the extracts were evaluated. In extracts from non-dried S. clava (FR, H1, and H2), total extract yield decreased with increasing treated temperature. The extraction yield was in the order of ethanol>methanol>water>acetone among treated solvents. In case of dried S. clava (FR), the extraction yield was lower than non-dried samples, and was in the order of methanol>ethanol>water>acetone. The radical scavenging activity (RSA) of non-dried S. clava (FR, H1, and H2) was in the order of acetone>ethanol>methanol and heat treatment also decreased RSA. RSA of FD was the highest in ethanol extract, while acetone and water extracts did not show RSA. When antioxidant activity was determined by reducing power (RD), methanol extract of FR showed the highest values and heat treatment decreased RD, too. RD of FD was in the order of methanol>ethanol>water>acetone. The acetone extracts from FD showed significant anticancer activity against human colon cancer cell line HT-29. These results indicated that extraction yield and properties of extracts from S. clava were dependent on processing temperature, solvent and/or physicochemical state. The appropriate extraction process should provide some valuable bioactive materials from S. clava.