Identification of bioactive anti-angiogenic constitutes targeting tumor endothelial cells in Shenmai Injection using multidimensional pharmacokinetics

OBJECTIVE To identify the bioactive anti-angiogenic constitutes targeting tumor endothelial cells(TECs)in Shenmai Injection(SMI).METHEODS For pharmacokinetic(PK)studies,Balb/c mice harboring human colorectal cancer(LoVo)xenografts were treated with SMI 10 mL·kg^-1 daily for 1 or 8 d.Multidimensional PK profiles of ginsenosides in plasma,subcutaneous tumors,and TECs were investigated.For PD studies,the tumor-bearing mice Intravital multi-photon imaging and CD31 immunofluorescence staining were used to evaluate the number of microves⁃sels and braches.Double staining of CD31 and α-SMA was performed to evaluate pericytes coverage ratios around vessels.ELISA was performed to determine the concentrations of VEGF and FGF in tumor tissues.For synergistic anti-tumor study,the tumor-bearing mice were treated with SMI 10 mL·kg^-1 daily,Rd 5 mg·kg^-1 daily with or without 5-FU 15 mg·kg^-1 every 3 d for 20 d.HPLC-MS/MS was used to determine the concentrations of 5-FU in plasma and tumor tissues.RESULTS SMI decreased the number of microvessels(P<0.05)and vessel branches(P<0.05)and improved vascular pericytes coverage(P<0.05).PK studies showed that the concentrations of protopanaxadiol-type(PPD)ginsenosides(Rb1,Rb2/Rb3,Rc,and Rd)in both,plasma and tumors,were higher than those of protopanaxatriol-type(Rg1 and Re)and oleanane-type(Ro)ginsenosides.Among PPD ginsenosides,Rd exhibited the greatest concentrations in tumors and TECs after repeated injection.In fact,the proportion of Rd in the detectable components of SMI gradually increased in the following order:SMI formula(2.8%),plasma(16.0%),tumor tissues(34.3%),and TECs(40.3%).In vivo bioactivity results showed that Rd 5 mg·kg^-1 daily significantly decreased the number of microvessels(P<0.05)and vessel branches(P<0.05)and increased pericytes coverage(P<0.05)while Rd 0.5 mg·kg^-1 daily,Rb1 and Rg1 had no significant effect on them.Rd 5 mg·kg^-1 suppressed the expression of VEGF and FGF simultaneously.Rd 5 mg·kg^-1 enhanced the antitumor effect of 5-FU via increasing the distribution of 5-FU in tumor tissues(P<0.05)in xenograft mice.CONCLUSION Ginsenoside Rd may be the major bioactive anti-angiogenic constituent targeting TECs after SMI treatment.

Identification of bioactive anti-angiogenic components targeting tumor endothelial cells in Shenmai injection using multidimensional pharmacokinetics

Shenmai injection(SMI)is a well-defined herbal preparation that is widely and clinically used as an adjuvant therapy for cancer.Previously,we found that SMI synergistically enhanced the activity of chemotherapy on colorectal cancer by promoting the distribution of drugs in xenograft tumors.However,the underlying mechanisms and bioactive constituents remained unknown.In the present work,the regulatory effects of SMI on tumor vasculature were determined,and the potential anti-angiogenic components targeting tumor endothelial cells(TECs)were identified.Multidimensional pharmacokinetic profiles of ginsenosides in plasma,subcutaneous tumors,and TECs were investigated.The results showed that the concentrations of protopanaxadiol-type(PPD)ginsenosides(Rb1,Rb2/Rb3,Rc,and Rd)in both plasma and tumors,were higher than those of protopanaxatriol-type(Rg1 and Re)and oleanane-type(Ro)ginsenosides.Among PPD-type ginsenosides,Rd exhibited the greatest concentrations in tumors and TECs after repeated injection.In vivo bioactivity results showed that Rd suppressed neovascularization in tumors,normalized the structure of tumor vessels,and improved the anti-tumor effect of 5-fluorouracil(5 FU)in xenograft mice.Furthermore,Rd inhibited the migration and tube formation capacity of endothelial cells in vitro.In conclusion,Rd may be an important active form to exert the anti-angiogenic effect on tumor after SMI treatment.