Evaluation of the genotoxicity of extracts of Houttuynia cordata Thunb.

The present study was conducted to evaluate the activity of methanol extracts from Houttuynia cordata Thunb. (HC) in a reverse mutation assay in Salmonella typhimurium, and a chromosome aberration assay in the Chinese hamster ovary (CHO) cell line and to evaluate its effect on the occurrence of polychromatic erythrocytes in mice. In the reverse mutation assay using Salmonella typhimurium TA98, TA100, TA1535, and TA1537 and Escherichia coli WP2urvA(-), methanol extracts of HC (5, 2.5, 1.25, 0.62, or 0.312 mg/plate) did not induce reverse mutations in the presence or absence of an S9 metabolic activation mixture. In the chromosome aberration test using CHO cells, methanol extracts (1.25, 2.5 or 5 µg/ml) caused a few incidences of structural and numerical aberrations, in both of absence or presence of an S9 metabolic activation mixture, but in comparison with the positive control group, these incidences were not significantly increased. In the mouse micronucleus test, no significant increases in the occurrence of micronucleated polychromatic erythrocytes were observed in male ICR mice that were orally administered methanol extracts of HC at doses of 2.0, 1.0, or 0.5 g/kg. From these results, we concluded that the methanol extracts of HC did not induce harmful effects on genes in bacteria, a mammalian cell system or in mouse bone marrow cells. Thus, HC's use for health promotion and/or a sick remedy for humans may be safe.

[Analysis of adverse events caused by irrational application of Houttuynia injection].

OBJECTIVE: To analyze irrational clinical application of Houttuynia Injection (HI) and the risk of adverse event (AE) occurrence, thus providing references for after-sales reevaluation and rational clinical application of HI. METHODS: Literatures concerning unreasonable application of HI were searched (terminated by June 2010) from PubMed, EMBASE, Chinese Biomedical Disc (CBMdisc), Chinese National Knowledge Infrastructure (CNKI), Chinese Science and Technology Journal Full-text Database (VIP), and etc. for case report, cross-sectional study, and clinical control study. RESULTS: A total of 342 papers with a total of 416 AE cases were retrieved. Of them, AE happened to 294 cases (including 290 children) of the 132 papers concerning contraindications, and 48 with allergic shock; AE happened to 57 cases in 9 papers reporting over-dose, and 6 with high risk combined medication. Sixteen irrational administration ways were reported in 195 papers. Of them, AE happened to 59 cases of seven administration ways (twenty cases by intracavitary injection, thirteen by aerosol inhalation, ten by rinse, eight by oral administration, one by enema, one by acupoint injection, and one by rectal administering). AE was not reported in the rest ten reports. CONCLUSION: The risk of AE occurrence was increased by changing clinical administration ways of HI without authorization, over-dose medication, high risk combined medication, and application in people with contraindications.

[Anaphylactoid reactions inducing effect of polysorbate 80 and polysorbate 80 contained Houttuynia cordata injection on beagle].

OBJECTIVE: To evaluate the sensitization effect of polysorbate 80 and polysorbate 80 contained Houttuynia cordata Injection in different concentrations on Beagle. METHODS: Beagles, a kind of animal highly sensitive to sensitizing agents, were randomly divided into 18 groups, 3 in each group. They received respectively the intravenous infusion of polysorbate 80 made by different factories in different concentrations (0.25%, 0.10%, 0.05%), and Houttuynia cordata Injection containing polysorbate 80 in concentration of 0.25% or 0.30%, with the constant infusing speed of 5 mL/min and volume of 10 mL/kg. Changes of animals' condition were observed before infusion and in the 24 h after infusion, time of symptom appearance and disappearance was recorded, and the grade of response was determined. Moreover, blood samples of animals were collected before infusion and 10 min after ending infusion for measuring histamine content in plasma using ELISA. Then the sensitization effect was comprehensively estimated by combined consideration of the responding grade and histamine level. RESULTS: No typical symptom of anaphylactoid reaction and over 1-fold increase of histamine level was found in all groups that received intravenous infusion of polysorbate 80 or polysorbate 80 contained Houttuynia cordata Injection in different concentrations. Estimation showed that all test solutions didn't induce typical anaphylactoid reaction on Beagle. CONCLUSIONS: Considering both the appearance of symptoms and the elevation of blood content of histamine could be taken as the criteria for comprehensive diagnosis of anaphylactoid reactions. The solubilization effect and safety (for foreclose anaphylactoid reaction) of polysorbate 80 could be ensured by controlling its quality and concentration below 0.25% or 0.30%.