Pharmacokinetics of Guanosine in Rats following Intravenous or Intramuscular Administration of a 1:1 Mixture of Guanosine and Acriflavine, a Potential Antitumor Agent

신대환,최규석,조병석,송석길,문동철,홍진태,이종길,정연복 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.10

A 1:1 mixture of acriflavine (ACF; CAS 8063-24-9) and guanosine is under evaluation in preclinical studies as a possible antitumor agent. Guanosine is known to potentiate the anti-cancer activity of ACF. We therefore investigated the pharmacokinetics of guanosine following administration of the ACF/guanosine mixture in rats. Rats were given guanosine (1 or 5 mg/kg) or ACF/guanosine (2 or 10 mg/kg) by i.v. bolus; or guanosine (3 or 15 mg/kg) or ACF/guanosine (6 or 30 mg/kg) by i.m. injection. We found that guanosine was rapidly cleared from the blood and transferred to tissues after i.m. administration of ACF/guanosine. The mean plasma half-lives (t1/2) at the α and β phases were 0.091 and 6.86 h, or 0.092 and 7.51 h at a dose of 1 or 5 mg/kg guanosine, respectively. ACF had no effect on the plasma disappearance of guanosine following either i.v. bolus or i.m. administration of the combination mixture. Moreover, the ACF combination with guanosine did not significantly alter the values of MRT, Vdss, and CLt of guanosine. Guanosine exhibited linear pharmacokinetics over the dose range from 1 to 5 mg/kg for i.v. doses and 3 to 15 mg/kg for i.m. doses. The bioavailability of guanosine after i.m. administration was 84% for 3 mg/kg dose and 88% for 15 mg/kg dose. ACF had no effects on biliary and urinary excretion of guanosine after i.m. administration. The cumulative amount of guanosine in urine after i.m. administration was about 5-fold larger than that in bile, indicating that guanosine is mostly excreted into the urine. Guanosine was widely distributed in all tissues examined in this study, but was most highly concentrated in the kidney after i.m. administration, followed by slow excretion to bile or urine. ACF had no effect on the tissue distribution of guanosine following i.m. administration. These characterizations of the pharmacokinetics of guanosine after administration of the CF/guanosine combination will be useful in providing preclinical and clinical bases for the potential application of this combination to the treatment of cancer.

Pharmacokinetics of Guanosine in Rats following Intravenous or Intramuscular Administration of a 1:1 Mixture of Guanosine and Acriflavine, a Potential Antitumor Agent

Shin, Dae-Hwan,Choi, Kyu-Seok,Cho, Byung-Suk,Song, Suk-Gil,Moon, Dong-Cheul,Hong, Jin-Tae,Lee, Chong-Kil,Chung, Youn-Bok 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.10

A 1:1 mixture of acriflavine (ACF; CAS 8063-24-9) and guanosine is under evaluation in preclinical studies as a possible antitumor agent. Guanosine is known to potentiate the anti-cancer activity of ACF. We therefore investigated the pharmacokinetics of guanosine following administration of the ACF/guanosine mixture in rats. Rats were given guanosine (1 or 5 mg/kg) or ACF/guanosine (2 or 10 mg/kg) by i.v. bolus; or guanosine (3 or 15 mg/kg) or ACF/guanosine (6 or 30 mg/kg) by i.m. injection. We found that guanosine was rapidly cleared from the blood and transferred to tissues after i.m. administration of ACF/guanosine. The mean plasma half-lives ($t_{1/2}$) at the $\alpha$ and $\beta$ phases were 0.091 and 6.86 h, or 0.092 and 7.51 h at a dose of 1 or 5 mg/kg guanosine, respectively. ACF had no effect on the plasma disappearance of guanosine following either i.v. bolus or i.m. administration of the combination mixture. Moreover, the ACF combination with guanosine did not significantly alter the values of MRT, $V_{dss}$. and $CL_t$ of guanosine. Guanosine exhibited linear pharmacokinetics over the dose range from 1 to 5 mg/kg for i.v. doses and 3 to 15 mg/kg for i.m. doses. The bioavailability of guanosine after i.m. administration was 84% for 3 mg/kg dose and 88% for 15 mg/kg dose. ACF had no effects on biliary and urinary excretion of guanosine after i.m. administration. The cumulative amount of guanosine in urine after i.m. administration was about 5-fold larger than that in bile, indicating that guanosine is mostly excreted into the urine. Guanosine was widely distributed in all tissues examined in this study, but was most highly concentrated in the kidney after i.m. administration, followed by slow excretion to bile or urine. ACF had no effect on the tissue distribution of guanosine following i.m. administration. These characterizations of the pharmacokinetics of guanosine after administration of the ACF/guanosine combination will be useful in providing preclinical and clinical bases for the potential application of this combination to the treatment of cancer.

Effects of Guanosine on the Pharmacokinetics of Acriflavine in Rats Following the Administration of a 1:1 Mixture of Acriflavine and Guanosine, a Potential Antitumor Agent

이풍석,신대환,Kyoung Mi Lee,송석길,유환수,문동철,홍진태,정연복 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.3

Preclinical studies are currently underway to examine the potential antitumor effects of a 1:1 mixture of acriflavine (ACF; CAS 8063-24-9) and guanosine. Guanosine potentiates the anti-cancer activity of some compounds. However, the effects of guanosine on the pharmacokinetics of ACF in mammals are unknown. Therefore, this study investigated the effects of guanosine on the pharmacokinetics of ACF after administering a 1:1 mixture of ACF and guanosine in rats. The rats were given either 10 mg/kg of the mixture or 5 mg/kg ACF via an intravenous bolus injection; or 30 mg/kg of the mixture or 15 mg/kg ACF intramuscularly. An HPLC-based method, which was validated in this laboratory, was used to analyze the levels of trypaflavine (TRF) and proflavine (PRF) in the plasma, bile, urine, and tissue homogenates. It was found that TRF and PRF were rapidly cleared from the blood and transferred to the tissues after the i.v. bolus or i.m. injection of the combination mixture. Both TRF and PRF were found to be most highly concentrated in the kidneys after the i.v. bolus or i.m. injection, followed by slow excretion to the bile or urine. Guanosine had no effect on the plasma disappearance of TRF or PRF after the i.v. bolus injection, However, guanosine led to a prolongation of the plasma levels of PRF after the i.m. administration of the combination mixture, resulting in a2 fold increase in the bioavailability (BA) of PRF. The concentrations of TRF and PRF in all the tissues examined were similar in the groups given the mixture and ACF. However, guanosine led to a prolongation of the biliary and urinary excretions of both TRF and PRF after the i.v.bolus (1.25 fold) or i.m. (1.5-2.4 folds) injection. These prolonged effects of guanosine on the plasma disappearance or urinary excretion of TRF and PRF might be one reason for the enhanced antitumor effects of ACF. However, more study will be needed to further examine this potential mechanism

Effects of Guanosine on the Pharmacokinetics of Acriflavine in Rats Following the Administration of a 1:1 Mixture of Acriflavine and Guanosine, a Potential Antitumor Agent

Lee, Pung-Sok,Shin, Dae-Hwan,Lee, Kyoung-Mi,Song, Suk-Gil,Yoo, Hwan-Soo,Moon, Dong-Cheul,Hong, Jin-Tae,Chung, Youn-Bok 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.3

Preclinical studies are currently underway to examine the potential antitumor effects of a 1:1 mixture of acriflavine (ACF; CAS 8063-24-9) and guanosine. Guanosine potentiates the anti-cancer activity of some compounds. However, the effects of guanosine on the pharmacokinetics of ACF in mammals are unknown. Therefore, this study investigated the effects of guanosine on the pharmacokinetics of ACF after administering a 1:1 mixture of ACF and guanosine in rats. The rats were given either 10 mg/kg of the mixture or 5 mg/kg ACF via an intravenous bolus injection; or 30 mg/kg of the mixture or 15 mg/kg ACF intramuscularly. An HPLC-based method, which was validated in this laboratory, was used to analyze the levels of trypaflavine (TRF) and proflavine (PRF) in the plasma, bile, urine, and tissue homogenates. It was found that TRF and PRF were rapidly cleared from the blood and transferred to the tissues after the i.v. bolus or i.m. injection of the combination mixture. Both TRF and PRF were found to be most highly concentrated in the kidneys after the i.v. bolus or i.m. injection, followed by slow excretion to the bile or urine. Guanosine had no effect on the plasma disappearance of TRF or PRF after the i.v. bolus injection, However, guanosine led to a prolongation of the plasma levels of PRF after the i.m. administration of the combination mixture, resulting in a2 fold increase in the bioavailability (BA) of PRF. The concentrations of TRF and PRF in all the tissues examined were similar in the groups given the mixture and ACF. However, guanosine led to a prolongation of the biliary and urinary excretions of both TRF and PRF after the i.v.bolus (1.25 fold) or i.m. (1.5-2.4 folds) injection. These prolonged effects of guanosine on the plasma disappearance or urinary excretion of TRF and PRF might be one reason for the enhanced antitumor effects of ACF. However, more study will be needed to further examine this potential mechanism.

Guanosine Regulates Germinal Vesicle Breakdown (GVBD) in Mouse Oocytes

Cheon Yong-Pil 한국동물생명공학회(구 한국동물번식학회) 2004 Reproductive & developmental biology Vol.28 No.4

Maturation of oocytes is maintained by complex procedures along with follicular genesis and is a critical step for embryonic development. Purine known as an oocyte maturation regulator is present in follicular fluid. In this study, the roles of guanosine as a strong inhibitor of GVBD and a modulator of cyclic GMP concentration in ooyctes were revealed. Denuded immature oocytes were treated with guanosine, and the maturation rates and cGMP concentration of oocytes were measured. GVBD was blocked in a concentration dependent manner by guanosine, but this effect was reversible. However, GVBD was lagged yet not significant by adenosine. Both guanosine and adenosine modified cGMP concentration in oocytes. The characteristic of the guanosine-treated oocyte was significantly higher cGMP compared with the adenosine-treated oocyes at initial time of the maturation. Based these results, guanosine may be a strong and reversible GVBD inhibitor. Although the precise mechanism of guanosine presently is unclear, the results suggest that guanosine may lead the accumulation of cGMP in oocyte cytoplasm, which in turn suppresses GVBD.

Ehrlich 암세포를 이식한 흰생쥐의 가슴샘 겉질의조직상에 미치는 항암제의 영향

박경호(Kyung-Ho Park),염광섭(Kwang-Sup Yum),고정식(Jeong-Sik Ko),안의태(E-Tay Ahn),김진국(Jin-Gook Kim) 대한해부학회 2002 Anatomy & Cell Biology Vol.35 No.1

Acriflavine은 핵소체와 세포질에서의 단백질 합성을 저해하며, guanosine은 다른 항암제들과 함께 투여하면 항암 효과 가 증진된다고 한다. 특히 acriflavine과 guanosine을 함께 사용하면 acriflavine을 단독 사용했을 때에 비하여 일반세포에 대한 세포독성은 약화되고 항암효과는 높아진다고 한다. 본 실험에서는 Ehrlich 암세포를 이식한 후 실험적 종양을 치료할 때 사용하는 항암제 가운데 대표적으로 많이 사용되 고 있는 대사길항제인 5-fluorouracil과 새로이 개발되어 항암효과는 높으나 세포독성이 적다는 acriflavine-guanosine복합제(AG60)가 면역계통의 중심기관인 가슴샘에 미치는 영향을 형태학적으로 비교 연구하고자 했다. 실험동물은 ICR 흰생쥐로서 체중 20 g 내외의 동물을 사용하였다. 각 동물의 샅부위 피하에 Ehrlich 암세포 1×107개를 이식하고, 다음날부터 격일 간격으로 생리식염수 (10 ml/kg)를 투여한 대조군과 실험군별로 5-fluorouracil (30 mg/kg)과 AG60 (30 mg/kg)을 각각 피하 주사하되 약물을 7회 투여한 후 다음날 동물을 희생시켰다. 각 동물의 가슴샘은 2.5% glutaraldehyde-1.5% paraformaldehyde액에 1차 고정하고, osmium tetroxide액으로 2차 고정하였다. 수세와 탈수과정을 거쳐 araldite혼합액에 포매하였고, 1 μm 절편을 만들어 toluidine blue로 염색하여 광학현미경으로 비교 관찰하였으며, 적정부위를 택하여 미세절편을 작성한 다음 uranyl acetate와 lead citrate액으로 염색한 후 전자현미경으로 관찰하였다.광학현미경적 관찰에서 AG60투여군의 경우는 가슴샘겉질의 구조가 암세포만 이식한 대조군의 것과 유사하였으나 5- fluorouracil 투여군의 경우는 가슴샘의 겉질부분에 분포하는 가슴샘세포의 수가 적었기 때문에 상피세망세포의 영역이 넓어져서 밝게 보였다. 전자현미경적 관찰에서 대조군과 AG60투여군의 경우에는 가슴샘세포가 상피세망세포의 세포질돌기에 싸여 있었으며 유사분열하는 모습을 보이는 등 별다른 차이가 없었다. 그러나 5-fluorouracil 투여군의 경우에는 가슴샘세포들이 상피세망세포로부터 분리되어 있는 것이 자주 관찰되었는데 상피세망세포로부터 분리된 가슴샘세포의 표면에는 미세융모들이 돋아있었다. 그러나 부위에 따라서는 가슴샘세포가 없이 상피세망세포로만 이루어진 부위도 있었다. 이상의 결과로 보아 Ehrlich암세포를 이식시킨 흰생쥐에 5-fluorouracil을 투여하면 가슴샘겉질의 가슴샘세포가 급격히 감소하고, 상피세망세포에 손상을 주는 등 가슴샘조직이 빨리 퇴화되어, T 림프구의 성숙과 분화에 지장을 초래하여 면역기능이 약화된다고 생각된다. 그러나 acriflavine-guanosine 복합제인 AG60을 투여하면 가슴샘조직에 손상을 입히지 않아서, AG60투여가 생체의 면역기능을 약화시키지는 않는 것으로 생각된다. In cancer therapy, immunological disorder is one of most severe problem. Since thymic cortex is the home of T-cell proliferation and “education”, thymic morphology following administration of certain drugs can be used as a parameter of immunological safety of the drug. In this study, morphology of thymic cortex, following administration of 5-fluorouracil or AG60, was studied. AG60 is a newly developed anti-cancer remedy, the compound of acriflavine and guanosine (1 : 1). ICR mice were subcutaneously inoculated with Ehrlich carcinoma cells (107 cells/mouse) in their inguinal areas. Each mouse in 5-fluorouracil group was injected subcutaneously with a single dose of 30 mg/kg of 5-fluorouracil every other day, and the mouse in AG60 group, with 30 mg/kg of AG60 (Taerim Pharm. Co., Seoul) every other day. The control mouse was injected with saline. The mice were sacrificed on the day after 7th injection. Tissues of thymic cortices were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde solution (0.1 M Millonig’s phosphate buffer, pH 7.3), and refixed in 2% osmium tetroxide solution (0.1 M Millonig’s phosphate buffer, pH 7.3). Tissue blocks were dehydrated, and were embedded in araldite mixture. For the overview-comparison, semithin sections stained with toluidine blue solution were photographed. And the typical portions were cut with ultratome, stained and observed with electron microscope. In light microscopy, thymic cortical morphology of AG60-injected mouse was similar with that of control mouse. But the cortical morphology of 5-fluorouracil-injected mouse was impressively different from those of the control or AG60 group mice. Thymocytes in the thymic cortex of 5-fluorouracil-injected mice were severely depleted. In electron microscopy, thymocytes in the thymic cortices of the control or AG60 group mice were crowded, and small groups of thymocytes were surrounded by the cytoplasmic processes of epithelial reticular cells. Mitotic figures were randomly seen. Thymocytes of 5-fluorouracil-injected mouse were naked out from the epithelial reticular cells, and were completely depleted out from the cortex composed mainly of enlarged epithelial reticular cells. Numerousmicrovilli were protruded from the naked thymocytes. The results were interpreted as that 5-fluorouracil induce leukopenia, and homing of lymphocytes to thymic cortex is severely depressed. 5-fluorouracil also disturb the normal protective and supportive function of epithelial reticular cells for thymocytes. Whereas the complex of acriflavine-guanosine compound (AG60) is immunologically safe, as seen in thymic cortical morphology.

Binding Properties of Guanosine-2',3',5' triisobutyrate

Yu, Byung-Sul,Kim, Kyoung-Mi,Sohn, Dong-Hwan The Pharmaceutical Society of Korea 1988 Archives of Pharmacal Research Vol.11 No.2

To study the behavior of nucleic acid base in a nonpolar organic solvent, chloreform, we synthesized a derivative of guanosine. This erivative, guanosine-2', 3', 5'- trisobutyrate was obtained by reaction of guanosine with isobutyric anhydride, and identified by TLC, EA, IR and NMR. Hydrogen bonding specificity of this compound was revealed by IR and NMR. The molecules of guanosine 2',3',5'-trisobutyrate are self-associated in nonpolar solvent, and hydrogen bonds by imino protent become important as the concentration increases. In the presence of a cytosine derivative, the self-association of theguanosine drivative is destroyed, resulting from interaction with cytosine derivative.

Ehrlich 암세포에 대한 Acriflavine-Guanosine 복합제 (AG60)의 항암효과 -광학현미경적, 자기방사법적 및 전자현미경적 연구-

안의태,고정식,김형진,김상건,이경영,강종구,유보림,정영신,홍은경,한영복 대한해부학회 1999 Anatomy & Cell Biology Vol.32 No.2

Acriflavine-Guanosine 복합제 (AG60)의 조직내 분포에 대한 형광현미경적 연구

고정식,임수재,안의태,김진국,김상건,이경영,강종구,홍은경,정영신,유보림,한영복 대한해부학회 1999 Anatomy & Cell Biology Vol.32 No.1

Acriflavine-Guanosine 복합제(AG60) 저용량투여가 흰생쥐에 이식된 Ehrlich 암세포의 DNA합성과 미세구조에 미치는 영향

안의태,정기수,고정식,박경호,김진국 대한해부학회 2000 Anatomy & Cell Biology Vol.33 No.6