7-Ethyl-10-Hydroxycamptothecin

The barks of Camptotheca acuminata Decne

SN-38 is an active metabolite of the Topoisomerase I inhibitor Irinotecan.

In Vitro:The IC50 values for LoVo, HCT116, and HT29 cell lines is 20 nM, 50 nM, 130 nM, respectively. In all three SN-38 resistant cell lines Top1 activity is maintained in the presence of high concentrations of SN-38[2].

In Vivo:SN-38, the active and toxic metabolite of the anticancer prodrug Irinotecan. At 30 minutes after administration, Irinotecan plasma concentrations in Slco1a/1b(−/−) mice are 1.9-fold higher than in the wild-type mice (1.89 vs. 1.01 μM, respectively), whereas SN-38 plasma concentrations of Slco1a/1b(−/−) mice are 8-fold higher compare with wild-type mice (0.4 μg/mL vs. 0.05 μg/mL, respectively). Overall plasma exposure [AUC(5-240)] of Irinotecan is 1.7-fold higher in Oatp1a/1b knockout mice versus wild-type mice (209.8±6.7 vs. 120.9±4.4 μM/min; P<0.01), and 2.9-fold higher for SN-38 (50±2.9 vs. 12±2 μM/min; P<0.001)[3].

References:
[1]. Wallin A, et al. Anticancer effect of SN-38 on colon cancer cell lines with different metastatic potential. Oncol Rep. 2008 Jun;19(6):1493-8. [2]. Jensen NF, et al. Characterization of DNA topoisomerase I in three SN-38 resistant human colon cancer cell lines reveals a newpair of resistance-associated mutations. J Exp Clin Cancer Res. 2016 Mar 31;35:56. [3]. Stewart CF, et al. Disposition of irinotecan and SN-38 following oral and intravenous irinotecan dosing in mice. Cancer Chemother Pharmacol. 1997;40(3):259-65.

[Pharmacokinetics of SN-38 in rats and tissue distribution of 7-ethyl-10-hydroxycamptothecin in mice after intravenous injection of irinotecan hydrochloride nanoparticles].[Pubmed:25233635]

Yao Xue Xue Bao. 2014 Jul;49(7):1029-33.

The paper reported an investigation of the pharmacokinetics of SN-38 (7-ethyl-10-hydroxy-camptothecin) in rats and the tissue distribution in mice after injection of irinotecan hydrochloride nanoparticles (CPT-11) via tail veins. An LC-MS/MS method was established to determine the concentrations of SN-38 in whole blood of rats and in different tissues of mice. The pharmacokinetics and tissue distribution of SN-38 were compared after the intravenous injection of CPT-11 NPs and CPT-11 solution. Compared with irinotecan solution, the elimination half-life of SN-38 was prolonged from 2.17 h to 2.67 h after the intravenous injection of CPT-11 NPs, but its AUC had little change. After the injection of CPT-11 NPs in mice, over time, the concentrations of CPT-11-metabolized SN-38 in CPT-11 NPs were significantly higher in the whole blood, colon and lungs than those in CPT-11 solution, followed by in the spleen and liver, but those in the heart and brain had no change. However, the amount of SN-38 in the kidneys was reduced with time. CPT-11 NPs could prolong SN-38's (one of its metabolites) blood circulation time in rats and significantly increased the concentration of CPT-11-metabolized SN-38 in the whole blood, colon and lungs of mice. CPT-11 NPs made SN-38 efficiently target-bind to the colon and lungs of mice.

Mechanisms of chitosan-coated poly(lactic-co-glycolic acid) nanoparticles for improving oral absorption of 7-ethyl-10-hydroxycamptothecin.[Pubmed:23702815]

Nanotechnology. 2013 Jun 21;24(24):245101.

Chitosan-modified poly(lactic-co-glycolic acid) nanoparticles (CHI/PLGA NPs) loaded with 7-Ethyl-10-Hydroxycamptothecin (SN-38), named CHI/PLGA/SN-38 NPs, were successfully prepared using an oil-in-water (O/W) solvent evaporation method. The physicochemical properties of the novel NPs were characterized by DLS, Zeta potential, SEM, DSC, XRD, and FTIR. The encapsulation efficiency and drug loading content were 71.83 (+/-2.77)% and 6.79 (+/-0.26)%, respectively. In vitro drug release in the simulated gastric juice was lower than that in the intestinal juice. In situ single-pass intestinal perfusion (SPIP) studies indicated a dramatic improvement of drug absorption as a result of the synergistic effect between CHI and PLGA on P-glycoprotein (Pgp) inhibition. CHI/PLGA NPs showed high cellular uptake and low efflux for drugs in Caco-2 cells. The cytotoxicity studies revealed that CHI/PLGA NPs had a transient effect on the membrane integrity, but did not have an influence on cell viability. Based on the in vitro release studies, SPIP, and intracellular drug accumulation and transport investigations, we speculate rationally that CHI/PLGA NPs were mainly internalized in the form of intact NPs, thus escaping the recognition of enterocyte Pgp and avoiding efflux into the apical part of the enterocytes. After partial release of drugs inside the enterocytes, CHI/PLGA interfered with the microenvironment of Pgp and further weakened the Pgp-mediated efflux. Then, the drug-loaded NPs exited via the exocytose effect from the basal part of the enterocytes and entered the blood circulation. These results showed that CHI/PLGA NPs would be smart oral delivery carriers for antineoplastic agents that are also Pgp substrates.

Novel SN-38-incorporating polymeric micelles, NK012, eradicate vascular endothelial growth factor-secreting bulky tumors.[Pubmed:17047068]

Cancer Res. 2006 Oct 15;66(20):10048-56.

7-Ethyl-10-hydroxy-camptothecin (SN-38), a biological active metabolite of irinotecan hydrochloride (CPT-11), has potent antitumor activity but has not been used clinically because it is a water-insoluble drug. For delivery by i.v. injection, we have successfully developed NK012, a SN-38-releasing nanodevice. The purpose of this study is to investigate the pharmacologic character of NK012 as an anticancer agent, especially in a vascular endothelial growth factor (VEGF)-secreting tumor model. The particle size of NK012 was approximately 20 nm with a narrow size distribution. NK012 exhibited a much higher cytotoxic effect against lung and colon cancer cell lines as compared with CPT-11. NK012 showed significantly potent antitumor activity against a human colorectal cancer HT-29 xenograft as compared with CPT-11. Enhanced and prolonged distribution of free SN-38 in the tumor was observed after the injection of NK012. NK012 also had significant antitumor activity against bulky SBC-3/Neo (1,533.1 +/- 1,204.7 mm(3)) and SBC-3/VEGF tumors (1,620.7 +/- 834.0 mm(3)) compared with CPT-11. Furthermore, NK012 eradicated bulky SBC-3/VEGF tumors in all mice but did not eradicate SBC-3/Neo tumors. In the drug distribution analysis, an increased accumulation of SN-38 in SBC-3/VEGF tumors was observed as compared with that in SBC-3/Neo tumors. NK012 markedly enhanced the antitumor activity of SN-38, especially in highly VEGF-secreting tumors, and could be a promising SN-38-based formulation.

Synthesis and antitumor activity of the hexacyclic camptothecin derivatives.[Pubmed:15913996]

Bioorg Med Chem Lett. 2005 Jul 1;15(13):3233-6.

A series of hexacyclic camptothecin derivatives were synthesized to test for antitumor activity as topoisomerase I inhibitor. The strategy of synthesis was used for the formation of additional furan and dihydrofuran rings fused with 9- and 10-positions of camptothecin. All of the hexacyclic camptothecins were assayed for cytotoxicity against four human tumor cell lines, HL60, BEL-7402, HCT-116, and HeLa, and showed very impressive cytotoxicity activity in vitro. Enzyme activity of the hexacyclic camptothecins was evaluated, being equal or superior to that of SN-38. The stability of four compounds was assessed in human plasma. Two of these compounds were chosen to test for antitumor activity in vivo against Sarcoma-180. The results suggested that additional furan and dihydrofuran rings could improve the antitumor activity in vitro and vivo, though the stability of the lactone ring did not increase.

Intracellular roles of SN-38, a metabolite of the camptothecin derivative CPT-11, in the antitumor effect of CPT-11.[Pubmed:1651156]

Cancer Res. 1991 Aug 15;51(16):4187-91.

It is known that 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11), a semisynthesized derivative of camptothecin (CPT), has a potent antitumor activity in vivo, but 7-Ethyl-10-Hydroxycamptothecin (SN-38), a metabolite of CPT-11, shows much stronger cytotoxicity in vitro than CPT-11. In this study, we demonstrated that the relaxation of SV40 DNA plasmids by type I DNA topoisomerase prepared from P388 murine leukemia cells was inhibited by 50% by SN-38 at approximately 1 microM, although CPT-11 at 1 mM slightly inhibited the relaxation. SN-38 and CPT showed strong, time-dependent inhibitory activity against DNA synthesis of P388 cells. However, CPT-11 weakly inhibited DNA synthesis independently of time with coincident inhibition of the total thymidine uptake by the cells. By alkaline and neutral elution assays, it was demonstrated that SN-38 caused much more frequent DNA single-strand breaks in P388 cells than did CPT-11. The same content of SN-38 and a similar frequency of single-strand breaks were detected in the cells treated with SN-38 at 0.1 microM or with CPT-11 at 100 microM. Therefore, single-strand breaks by CPT-11 seem to be due to SN-38 produced from CPT-11 in cells. These results indicate that CPT-11 itself possesses a marginal antiproliferative effect but that SN-38 plays an essential role in the mechanism of action of CPT-11.

SN-38 (NK012) is an active metabolite of the Topoisomerase I inhibitor Irinotecan. SN-38 (NK012) inhibits DNA and RNA synthesis with IC50s of 0.077 and 1.3 μM, respectively.

7-Ethyl-10-Hydroxycamptothecin,86639-52-3,7-Ethyl-10-hydroxycamptothecin,Natural Products, buy 7-Ethyl-10-Hydroxycamptothecin , 7-Ethyl-10-Hydroxycamptothecin supplier , purchase 7-Ethyl-10-Hydroxycamptothecin , 7-Ethyl-10-Hydroxycamptothecin cost , 7-Ethyl-10-Hydroxycamptothecin manufacturer , order 7-Ethyl-10-Hydroxycamptothecin , high purity 7-Ethyl-10-Hydroxycamptothecin