| Brucea javanica oil(BJO) is a kind of fatty oil extracted from the ripe fruit of Brucea javanica, which is usually used in clinic as an anti-cancer drug. Because the oral emulsion shows poor compliance for patient and its poor stability, the clinical application of the drug is limited. Brucea javanica oil shows very poor solubility in water, so our laboratory prepared the Brucea javanica oil suppositories(BJOS) for rectal administration, which can bypass the first pass effect of the liver, accelerate the speed of the drug into the blood, and achieve higher plasma concentration. As a topical formulation, the key of its onset is limited by absorption rate and extent of the drug in the rectum. What’s more, the current absorption mechanism and influence factors of BJO in the rectum have not been reported. In addition, as an anti-cancer drug, the inhibition on tumor cells and pre-clinical safety studies are also crucial. Therefore, this paper studied on the absorption process of the BJOS, providing the basis for further improvements of formulation preparation. The preliminary study of its antitumor efficacy and safety experiment were performed, which laid the foundation for preclinical studies of BJOS.In this paper, in vitro gut sac method was used to investigate the drug concentration on rectal absorption behavior of BJOS. The main component of BJO were oleic and linoleic acid, which were measured by gas chromatography. The results showed that the method presented good specific and linear within the standard curve. In addition, the precision, recovery, repeatability and stability of the method are accurate and feasible, which are in line with the requirements of sample analysis of the drug. In vitro gut sac experiments, 15 male SD rats were divided into three groups and different concentrations of BJOS solution were administered. The samples were taken every 0.5 h, and the cumulative absorption of the drug was measured and analyzed by relative regression. The results showed that the absorption curves correlated well(r2>95%). As the amount of drug increased, the absorption rate constant was no significant difference(P>0.05), which was consistent with the first-order kinetics of drug absorption feature.By using the in situ single pass perfusion method, the effects of drug concentration and absorption enhancers on the rectal absorption behavior of BJO were tested. In the in situ experiment, rats were randomly divided into three groups and different concentrations of BJOS were administered in the rectum after anesthesia by ethyl carbamate. After every 15 min sampling, the drug uptake in the rectum was measured through the exit of the drug. The results showed that with the drug concentration increasing, the absorption rate constant and apparent absorption coefficient changed little and there was no significant difference(P> 0.05) between groups through variance analysis, which indicated that the transmembrane behavior of the drug was without inhibition of its concentration. The EDTA-2Na, β-CD and HP-β-CD were added as the absorption enhancers to compare the absorption rate constant and absorption coefficient with the blank group. The results showed that the three absorption enhancers had no effect on the absorption rate constant, but β-CD and HP-β-CD could significantly improve the BJO absorption in the rectum, which showed better penetration effect.In this paper, the effects of BJOS and BJOE on the cancer cells in vitro were performed. The lung cancer A549 cells and prostate cancer DU145 cells were selected as the model. The results showed that the two cells was inhibited by both BJOS and BJOE at the concentration of 200-2000 μg/m L and gradually increased with time incresed. In addition, BJOS showed stronger inhibitory active than BJOE at each concentration. The IC50 of BJOS of A549 cells was 357.66 ± 122.46, 168.56 ± 31.09 and 62.33 ± 15.95 μg/m L at 24, 48 and 72 h, respectively, while 2395.35 ± 245.76, 2283.54 ± 344.64 and 947.43 ± 206.14 μg/m L of BJOE. The IC50 of BJOS of DU145 cells was 286.56 ± 153.78, 183.53 ± 75.79 and 137.77 ± 32.87 μg/m L at 24, 48 and 72 h, respectively, while 1955.75 ± 308.76, 1106.74 ± 245.77 and 738.45 ± 164.54 μg/m L of BJOE. In the meanwhile, the effects of BJOS on the cell cycle of A549 and DU145 cells were investigated, which found that the group of 100 μg/m L can significantly increase the number of cells in G0/G1 phase, while reducing the ratio of cells in S and G2/M phase, indicating that the drug may inhibite the tumor cell growth by blocking cell division in G0/G1 phase. Finally, the effect of BJOS on tumor cell invasion ability was studied. The results show that with increasing concentration of the drug, the invasion ability of both cells was significant weakening.The paraffin section of the rectal mucosa was observed to evaluate the irritation of BJOS and the acute toxicity test was performed to investigate the influence of drugs on the organs. It was found that clinical doses of BJOS may cause slight dilation on the blood vessels of rectal epithelium, but would not cause severe inflammation and changes in cell morphology mucosa. In the acute toxicity test, low, medium and high clinical dose of suppositories and emulsions will not cause any death of the animal, and the weight of every rat increased when compared with the state before administration.In summary, the results of this study showed that the BJO absorbed in the rectum may be passive transport, which may provide reference for improving the formulasion. The suppositories and emulsions have shown good inhibition for tumor cell growth in vitro. When compared to emulsions, suppositories showed the same effect at a lower concentration. BJOS may show the inhibition effect mainly by blocking cell proliferation phase, and weaken the ability of tumor cell invasion, which provided experimental evidence for the further efficacy study of BJOS. In preliminary safety studies, the suppository did not exhibit severe irritation and systemic toxicity, which is of great significance for the safe application of BJOS. |
PDF Full Text Request