Study on extraction process of tannins from Semen Cuscutae and their anti-papilloma activity.
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The objective of this paper was to study the extraction methods of tannin constituents from Semen Cuscutae and their anti-papilloma effects. Single factor test and orthogonal design methods were used to determine the optimal extraction method; the mouse skin papilloma model induced by DMBA/croton oil was established, which was a classic two-stage carcinogenesis model being used to observe and evaluate the anti-carcinogenic effects of tannins extracted from Semen Cuscutae in different stages. The optimal extraction method of Semen Cuscutae was a 20-fold volume of solvent, a temperature of 50 degrees C, three times of extraction, with 20 min each, skin papilloma experiment revealed that the number of bearing tumors gradually reduced, and the inhibition rate gradually increased with the increase of dose, in the high-dose group, its inhibition rate reached 70.2%. Tannin extract from Semen Cuscutae has an obvious inhibitory effect on skin papilloma development. (+info)
Distribution of cefpirome (HR 810) to exudate in the croton oil-induced rat granuloma pouch and its therapeutic effects on experimental infections in the pouch.
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Therapeutic effects of intravenously administered cefpirome on experimental bacterial infections in croton oil-induced rat granuloma pouches were compared with those of ceftazidime, moxalactam, cefoperazone, and cefotaxime. Its pharmacokinetic profile in pouch exudate was also examined. Cefpirome showed bactericidal effects and long-lasting bacterial growth-inhibitory effects in granuloma pouches infected in Escherichia coli Ec-7, and its effects were almost equal to those of the other antibiotics. Against Pseudomonas aeruginosa TM-11 infection, cefpirome was more active than moxalactam, cefoperazone, and cefotaxime and comparable to ceftazidime. Cefpirome had the strongest activity against Staphylococcus aureus Smith infection among the five antibiotics, showing bactericidal effects and long-lasting bacterial growth-inhibitory effects. The level of cefpirome in pouch exudate peaked at 1 h after administration, with a value of 16.4 micrograms/ml, and declined in a pattern similar to that of ceftazidime. When compared in peak level, the exudate level of cefpirome was 1.8 to 2.6 times higher than the values of moxalactam, cefoperazone, and cefotaxime. The in vitro exudate protein binding of cefpirome was 8.8%, which was the lowest among the antibiotics used. (+info)
Suppressing effect of croton oil on intestinal carcinogenesis induced by methylazoxymethanol acetate in rats.
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The effect of croton oil on intestinal carcinogenesis by methylazoxymethanol acetate (MAM) was examined in ACI/N rats. Twenty seven male and 28 female ACI/N rats were given a single intragastric intubation of MAM at a dose of 25 mg/kg body weight, followed by croton oil at 0.25 ml/kg body weight, 3 times a week, by gastric intubation until the termination of this experiment (365 days). The animals had diarrhea with administration of the croton oil, but the diarrhea had no effect on their gain in weight. Rats from all groups surviving more than 216 days were counted as effective animals. Seventeen out of 54 effective rats which were treated with MAM and croton oil developed intestinal tumors and the incidence of the intestinal tumors was significantly less than that of the group treated with MAM alone (30 out of 50 rats, P less than 0.01). The average number of tumors per rat in the experimental group which was treated with MAM and croton oil (0.6 +/- 1.1) was also smaller than that in the group which was treated with MAM alone (1.0 +/- 1.8), although the difference was not significant. These results suggest that croton oil may suppress some tumor growth at the proper dose in intestinal carcinogenesis which is initiated by MAM. (+info)
Two-stage carcinogenesis with rat embryo cells in tissue culture.
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Transformation of rat embryo fibroblasts in vitro has been investigated using initiation with either benzo(a)pyrene (BaP), 7,12-dimethylbena(a)anthracent (DMBA) or benzo(e)pyrene (BeP) and promotion with either phorbol ester (TPA) or croton oil (Cr.Oil). The criteria used to assess in vitro transformation were (a) the efficiency of cloning in liquid medium, (b) abnormal cellular morphology and (c) the development of malignant tumours following s.c. inoculation of newborn rats. The results show that the cloning efficiency, which remained low in the control cells, was increased to a variable extent in the treated groups. Transformation occurred in all groups, but occurred earliest in cells that were initiated and promoted. Initiation with DMBA or BaP and promotion with TPA or Cr.Oil led to the earliest acquisition of malignancy. Correlations were found between the transformation of cells in vitro and the acquisition of malignant potential, and between the carcinogenic action of the compounds in vitro and their action in vivo, but cloning efficiency was not a reliable indicator of in vitro transformation or of malignancy. In most cases in vitro transformation appeared to precede the acquisition of malignancy, but in two cases it occurred later. The studies also show that BeP, which is a tumour initiator in vivo, also acts in this way in vitro. The conclusion drawn from a discussion of these results and of two-stage carcinogenesis in vivo is that two-stage carcinogenesis can be reproduced in tissue culture; this model may be useful in studies of those mechanisms of chemical carcinogenesis that involve the processes of initiation and promotion. (+info)