• 약학회지
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• 제44권6호
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• pp.601-606
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• 2000

Recently, studies on missile antitumor drugs, which selectively act on tumor cell and display drug effects, have been performed. These missile antitumor drugs which can increase drug effects and decrease side effects, are ideal medication method. Lectin has been reported as tumor cell specific binding protein and tannin as antitumor substance. In this study, we studied inhibition of melanoma metastasis by lectin-conjugated ellagitannin and used praecoxin A as ellagitannin source. Mouse melanoma cell, B16-F10, was injected into the sole of forefoot of C57BL/6 mouse, and after administration with drug, the number of pulmonary tumor colony was counted. The administration of praecoxin A, lectin-praecoxin A mixiture, and lectin-conjugated praecoxin A was started after amputation of established tumor foci at right forefoot of mice and continued for 3 weeks with i.p. injection of one of those drugs A every 24 hours. Lectin-praecoxin A mixture, and lectin-conjugated praecoxin A significantly reduced the number of spontaneous pulmonary metastasis. Exposure to 5 mg/kg of lectin-praecoxin A mixiture and lectin-conjugated praecoxin A produced a statistically significant 38.3%, 41.8% reduction in the number of remaining pulmonary metastasis. These results suggest that metastasis inhibition by lectin-praecoxin A mixiture and lectin-conjugated praecoxin A are better than that of praecoxin A.

• 약학회지
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• 제44권6호
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• pp.607-612
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• 2000

Generally, antitumor drugs have strong toxicity and result in damage in normal cells. Previously, lectin has been reported as a tumor cell specific binding protein and tannin as an antitumor substance. In this study, we investigated antitumor activity of lectin-conjugated ellagitannin and used praecoxin A as an ellagitannin source. We injected mouse melanoma cell, B16-F10, on right the femoral region of C57BL/6 mouse. After 10 hours later, first treatment with praecoxin A, lectin-praecoxin A mixiture and lectin-conjugated praecoxin A was carried and followed by injection i.m. every 48 hours. Praecoxin A extended the life of mice up to 14.8% in comparison with the negative control group at 5 mg/kg dose. The life extending ratio of Lectin-praecoxin A mixture was 26.1% at 5 mg/kg dose, and the life extending ratio of lectin-conjugated praecoxin A was 28.7% at 5 mg/kg dose. On the basis of these findings, we suggest that antitumor activities of lectin-praecoxin A mixiture and lectin-conjugated praecoxin A on survival are better than that of praecoxin A.

• 약학회지
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• 제45권3호
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• pp.302-309
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• 2001

Wheat germ agglutinin (WGA) pectin, which binds to human melanoma cell line, was conjugated with Praecoxin A using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as a cross-linking agent. Physical mixture (PM) of WGA and Praecoxin A was also prepared by using a non-specific binding property of Praecoxin A to WGA. The WGA:Praecoxin A ratio in the conjugate and PM was approximately 1:18 and 1:20, respectively. The results of hemagglutination assay and enzyme-linked lectin assay indicated that the conjugate and PM maintained the lectin-like properties of the WGA. The binding ratio of conjugate was about 70% during 4-24 hr, but the most of Praecoxin A was released within 24 hr in the case of PM. These results lead to the conclusion that the conjugate is potentially useful for the formulation of injection that requires targeting for melanoma as well as sustained release at the site.

• 약학회지
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• 제46권3호
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• pp.197-202
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• 2002

Lectin-conjugated praecoxin A, which has developed as a missile antitumor drug, is the one that has conjugated with wheat germ agglutinin (WGA), a kind of carbohydrate-binding protein (lectin) especially bound to melanoma. Praecoxin A is a kind of tannin extracted and purified from plants. Beside this direct antitumor effect as tannins, we have examined an activation of macrophage by lectin-conjugated praecoxin A. We also confirmed the gene expression of IL-1 $\beta$, both in vitro and in vivo. We added 1, 10, 100 $\mu\textrm{g}$/mι of lectin-conjugated praecoxin A, 10 $\mu\textrm{g}$/mι of lectin, 10 $\mu\textrm{g}$/mι of praecoxin A to normal murine macrophage and analyzed the extracted total RNAs by RT-PCR after 4, 8, 12, 24 hours. Our data demonstrated that lectin-conjugated praecoxin A increased IL-1$\beta$, mRNA expression in a dose dependent manner. However, the effectiveness of lectin-conjugated praecoxin A was not superior to lectin and praecoxin A.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.954-963
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• 2002

Lectin-conjugated praecoxin A is a compound, which is combined Wheat Germ Agglutinin (WGA) Lectin with praecoxin A and also known to have an anti-tumor activity. In our lab, in order to investigate its immune reaction other than the anti-tumor activity ever known, we examined cytokines such as IL-6 and IL-12 through their mRNA expressions, which are generally secreted by macrophage both in vivo and in vitro. To analyze, we used RT-PCR for total RNAs of macrophages. As a result, we obtained that both in vitro and in vivo, lectin-conjugated praecoxin A showed an interesting increase on IL-6 and IL-12 even though it may be little hard to say the conjugated form is absolutely more effective than that of lectin or praecoxin A alone for immune response activities. Those results suggest that the conjugated form may give an additional opportunity in a future therapeutic use over its immuno activation properties.

• 약학회지
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• 제42권4호
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• pp.345-352
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• 1998

Praecoxin A, an ellagitannin, purified from Alnus hirsuta var.microphlla was evaluated on the antitumor activity. Praecoxin A had the significant cytotoxicity to s ix tumor cell lines: human chronic myelogenous leukemia K-562, human promyelocytic leukemia HL-60, mouse leukemia P388, mouse lymphocytic leukemia L-1210, sarcoma-l8O, mouse lymphoma L5178Y except L-1210. And the most sensitive cell line was K-562 ($ED_{50}=2.43{\mu}g/ml$). The $ED_{50} of praecoxin A against HL-60, P388, L-1210, sarcoma7l8O and L5178Y were 6.28, 8.66, 10.00, 7.01, $9.32{\mu}g/ml$, respectively. Praecoxin A showed the increasing effect in life span by 36.8% on the 1st day after treatment of 10mg/kg in mice bearing sarcoma-180 tumor cells (ascitic form) via NCI (National Cancer Institute, U.S.A.) protocol in vivo assay. As a result, praecoxin A is considered to show the antitumor activity.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of the Pharmaceutical Society of Korea
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• pp.166.2-167
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• 2001

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of the Pharmaceutical Society of Korea
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• pp.166.1-166.1
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• 2001

• Journal of Pharmaceutical Investigation
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• 제31권3호
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• pp.197-200
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• 2001

Lectin-conjugated ellagitannin (LET), a newly introduced melanoma-specific antitumor agent which has been synthesized by conjugation of wheat germ agglutinin as a lectin with praecoxin A as an ellagitannin, was encapsulated into sterically stabilized liposomes (SSL). Modified Folin phenol method was established for the quantitation of LET contents in liposomal formulations protein employing the standard calibration curve with bovine serum albumin. After removal of phospholipid by organic solvent extraction, which interferes the specific selectivity of the Folin-Ciocalteu reagent with the protein, recovery of LET was $94.5{\pm}2.3%$ and the encapsulation efficiency was revealed as $37.8{\pm}5.9%$ for 2.5 mg/ml LET solution.