ABSTRACT
Objective: To evaluate the toxicokinetics and in vivo accumulation of norcantharidin lipid microsphere for injection (NCTD-LM) in Beagle's dogs following 90 d repeated iv administration by comparing with sodium demethylcantharidate injection (NCTD-I). Methods: An ultra high performance liquid chromatography-tandem mass spectrum method was employed to determine the NCTD in plasma of Beagle's dog after 1, 44, and 90 d repeated iv administration. The toxicokinetic parameters were calculated from the plasma concentration. Results: After the first iv administration of 0.8, 1.6, and 3.2 mg/kg NCTD-LM to Beagle's dog, the AUC0-t were (2.22 ± 0.53), (4.77 ± 1.13), and (13.43 ± 3.64) h∙mg/L, respectively, while the t1/2 were (1.37 ± 0.18), (1.64 ± 0.42), and (1.98 ± 0.25) h, respectively. After the 90 d repeated iv administration of 0.8, 1.6 and 3.2 mg/kg NCTD-LM to Beagle's dog, the AUC0-t were (3.58 ± 0.95), (11.4 ± 2.0), and (23.5 ± 3.9) h·mg/L, respectively, while the t1/2 were (3.87 ± 1.90), (5.75 ± 3.29), and (5.84 ± 2.45) h, respectively. For NCTD-I, the AUC0-t were (9.07 ± 2.09) and (14.1 ± 3.0) h∙mg/L respectively after 1 and 90 d repeated iv administration, while the t1/2 were (2.84 ± 1.34) and (3.53 ± 1.26) h. 15 and 30 d after the end of administration, the concentration of NCTD in plasma of Beagle's dog in each group were all dropped below the lowest limit of quantification (LLOQ). Conclusion: NCTD displays a nonlinear elimination at the dose range of 0.8-3.2 mg/kg after iv administration of NCTD-LM to Beagle's dog. Over the 90 d repeated iv administration period, the plasma concentration levels, AUC0-t, and t1/2 for both NCTD-LM and NCTD-I are increased with time increasing. However, no accumulation of NCTD is observed for the both formulations.
ABSTRACT
Objective To investigate the effect of norcantharidin on growth inhibition and induction of apoptosis of human rectal cancer Colo 320 cells. Methods Norcantharidin (NCTD) in different concentrations were added to rectal cancer Colo 320 cells. Morphological characteristics of apoptosis were observed using the light microscope and transmission electron microscope. The expressions of Bag-1 and Bcl-2 proteins were tested by Western blotting. The growth inhibition of Colo 320 cells on the cell cycle was observed by flow cytometry. Results The apoptosis morphological changes of Colo 320 cells were observed by the light microscope and transmission electron microscopy. Flow cytometry analysis showed that the cell count of G2/M phase in experimental group was higher than that in control group ( <0.05) but the cell counts of G0/G1 and S phases have decreased in experimental group after treatment with NCTD at the concentrations of 5μg/mL, 10μg/mL and 20 μg/mL, and presented dosage dependence relations. The expressions of Bag-1 and Bcl-2 proteins have decreased. Conclusion Norcantharidin has inhibitory effect on rectal cancer Colo 320 cells, and the effect may be related to the cell cycle arrest and apoptosis.
ABSTRACT
Objective: To study the mechanisms of absorption and transport of lactosyl-norcantharitin (Lac-NCTD) and lactosyl-norcantharitin nanoparticles (Lac-NCTD-NPs) in intestinal membranes. Methods: The Caco-2 cell monolayer model was used to study the transport mechanism of Lac-NCTD and Lac-NCTD-NPs across the membranes. The relative factors for enhancing the absorption of drug carriers, including time, temperature, pH value, drug concentration, enhancers, and inhibitors, were also investigated. The differences between Lac-NCTD and Lac-NCTD-NPs in transport of membranes were explored. Results: Lac-NCTD was not only absorbed simply by active transport but also through paracellular transference as the minor. The Lac-NCTD uptake was not controlled by pH value, but positively correlated to uptake time and negatively correlated to temperature and it was also significantly enhanced by the inhibitor of P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP2). Apparent permeability coefficients (Papp) of basolateral (BL) to apical (AP) was higher than that of AP to BL. Sodium deoxycholate (SDCh) slightly enhanced the drug absorption but oxophenylarsine had no effect. Conclusion: The uptake and absorption of Lac-NCTD are active transport as the dominant process. P-gp and MRP2 have strong efflux effects on the uptake and transepithelial transport of Lac-NCTD. Lac-NCTD-NPs could significantly enhance the drug absorption compared with Lac-NCTD.
ABSTRACT
Objective: To investigate the anticancer activity of the novel lactosyl-norcantharidin nanoparticles (Lac-NCTD-NPs) in vivo and in vitro. Methods: The MTT method was used to study the cytotoxic effects of Lac-NCTD and Lac-NCTD-NPs on HepG2, SMMC-7721, and SGC-7901 cell lines for 12 and 48 h, respectively, and the inhibitory effects of Gal-FBS; Lac-NCTD accumulated in SMMC-7721 cells was assayed by HPLC; The in vivo anticancer activity was evaluated by the tumor-growth inhibition in H22 tumor bearing mice. Results: The in vitro studies showed that the cytotoxic effects of Lac-NCTD-NPs against HepG2 and SMMC-7721 cells were the most powerful, as well as the IC 50 was the lowest, then Lac-NCTD, and they were inhibited remarkably by Gal-FBS; As for SGC-7901 cell line, the cytotoxic effects of Lac-NCTD-NPs and Lac-NCTD were not stronger than that of NCTD, and Gal-FBS had no influence on them at all; The amount of Lac-NCTD accumulated in SMMC-7721 cells was 3. 89 μg (7.02×10-3 μmol, 1×106 cell) after treatment for 12 h; The results of the antitumor activity in vivo suggested that the inhibitory rate of Lac-NCTD-NPs on tumor weight was 63.9%, which was significantly higher than that of NCTD and Lac-NCTD groups at the same molar concentration. Conclusion: The tumor-growth is inhibited effectively by Lac-NCTD-NPs which may be a kind of novel liver-targeting agents and could strongly inhibit the tumor-growth.