Reduced use of emergency care and hospitalization in patients with post-stroke cognitive impairment treated with traditional Chinese medicine.

BACKGROUND: The effect of traditional Chinese medicine (TCM) on the outcomes of dementia remains unclear. Our purpose is to compare the use of emergency care and hospitalization in patients with post-stroke cognitive impairment (PSCI) with or without treatment of TCM. METHODS: In a stroke cohort of 67 521 patients with PSCI aged over 40 years obtained from the 23 million people in Taiwan's national health insurance between 2000 and 2007, we identified 6661 newly diagnosed PSCI patients who were treated with TCM and 6661 propensity score-matched PSCI patients who were not treated with TCM. Under the control of immortal time bias, we calculated the adjusted rate ratios (RRs) and 95% CIs of the 1-year use of emergency care and hospitalization associated with TCM. RESULTS: The means of the emergency care medical visits (0.40 ± 0.98 vs. 0.47 ± 1.01, P = 0.0001) and hospitalization (0.72 ± 1.29 vs. 0.96 ± 1.49, P < 0.0001) were lower in the PSCI patients treated with TCM than in those without the TCM treatment. The RRs of emergency care and hospitalization associated with TCM were 0.87 (95% CI = 0.82-0.92) and 0.81 (95% CI = 0.78-0.84), respectively. The PSCI patients treated with a combination of acupuncture and herbal medicine had the lowest risk of emergency care visits and hospitalization. CONCLUSIONS: Our study raises the possibility that TCM use was associated with reduced use of emergency care and hospitalization after PSCI. However, further randomized clinical trials are needed to provide solid evidence of this benefit and identify the underlying mechanism.

Utilization of Western medicine and traditional Chinese medicine among patients with Alzheimer's disease in Taiwan: a nationwide population-based study.

BACKGROUND AND PURPOSE: Large-scale studies of utilization of medical services among patients with Alzheimer's disease (AD) are lacking. We aimed to investigate the usage of Western medicine and traditional Chinese medicine (TCM) among these patients in Taiwan. METHODS: We analyzed one million samples from the National Health Insurance Research Database in Taiwan. Patients (n = 1814) newly diagnosed with AD in 2001-2010 were divided into TCM users (n = 528) and non-TCM users (n = 1286). RESULTS: Compared with non-TCM users, TCM users were younger, had a higher female:male ratio and higher utilization rate of Western medicine. The median interval between diagnosis and the first TCM consultation was 7.92 months. Donepezil and rivastigmine were commonly prescribed medications. Chinese herbal medicine was the most popular treatment among TCM users. CONCLUSIONS: This study revealed the specific usage patterns of TCM and non-TCM medical services among patients with AD. The information could be used for improving the healthcare of patients with AD.

Inhibitions of mast cell-derived histamine release by different Flos Magnoliae species in rat peritoneal mast cells.

Flos Magnoliae (FM) is a commonly used Chinese medicinal herb for symptomatic relief of allergic rhinitis, sinusitis and headache. A number of FM species have been used as substitutes or adulterants for clinical application, although the differences in their pharmacological actions have not been reported. The present study investigated the effects of six identified FM species M. biondii, M. denudata, M. kobus, M. liliflora, M. sargentiana and M. sprengeri, as well as the marker compounds magnolin and fargesin on compound 48/80-induced histamine release in rat peritoneal mast cells (RPMC) in vitro. Ethanolic extracts of all FM species produced a concentration-dependent inhibition of compound 48/80-induced histamine release in RPMC. The rank order of the IC(50)s was M. biondii

Effects of electroacupuncture in reducing weight and waist circumference in obese women: a randomized crossover trial.

OBJECTIVE: To compare the effects of weight control on simple obese women between electroacupuncture and sit-up exercise. DESIGN: Randomized and crossover trial conducted from 1 January 2002 to 31 December 2002. The subjects were randomly divided into groups A and B. Group A received electroacupuncture treatment first while group B received sit-up exercise treatment first. After 6 weeks of treatment and 7 days of washout, group A switched to sit-up exercise treatment and group B received electroacupuncture treatment for another 6 weeks. PATIENTS: In total, 54 simple obese women, with waist circumference (WC)>90 cm and body mass index (BMI)>30 kg/m(2), and who had not received any other weight control maneuver within the last 3 months. MEASUREMENT: The measurements of body weight (BW), BMI and WC were performed at the beginning, 6, 8 and 13 weeks. The data at different time periods were compared and expressed as % reductions. RESULTS: Electroacupuncture (n=46) showed significant differences in the % reductions in BW (P=0.001), BMI (P=0.003) and WC (P=0.005) compared with sit-up exercise. At the end of 13 weeks, there were no significant difference between groups A (n=24) and B (n=22) in all the measurements. At the end of the study, groups A and B showed significant differences in the % reductions in BW (P=0.004; 0.001), BMI (P=0.003; 0.021) and WC (P< or =0.001; 0.001) compared with the initial values. CONCLUSIONS: Electroacupuncture treatment is more effective than sit-up exercise in reducing weight and WC, making it an alternative treatment option for weight and WC control on obese women.

Effects of garlic components diallyl sulfide and diallyl disulfide on arylamine N-acetyltransferase activity and 2-aminofluorene-DNA adducts in human promyelocytic leukemia cells.

Two components of garlic, diallyl sulfide (DAS) and diallyl disulfide (DADS), inhibited arylamine N-acetyltransferase (NAT) activity and 2-aminofluorene-DNA adduct in human promyelocytic leukemia cells (HL-60). The NAT activity was measured by high performance liquid chromatography assaying for amounts of N-acetyl-2-aminofluorene (2-AAF) and remaining 2-aminofluorene (2-AF). Cellular cytosols and intact cell suspensions were assayed. The inhibition of NAT activity and 2-AF-DNA adduct formation in human leukemia cells by DAS and DADS were dose-dependent and were directly proportional. The data also indicated that DAS and DADS decrease the apparent values of Km and Vmax from human leukemia cells in both assays. This is the first report of garlic components affecting human leukemia cell NAT activity and 2-AF-DNA adduct formation.

Effects of xiao-qing-long-tang (XQLT) on bronchoconstriction and airway eosinophil infiltration in ovalbumin-sensitized guinea pigs: in vivo and in vitro studies.

BACKGROUND: Xiao-qing-long-tang (XQLT sho-seiru-to), a traditional Chinese medicine, has been used to treat patients with bronchial asthma in Oriental countries for several centuries. However, the therapeutic mechanisms of this Chinese medicine remain a matter of considerable debate. Therefore, a series of experiments using ovalbumin-sensitized guinea pigs was performed to elucidate the possible antiasthmatic effect of XQLT. METHODS: The effect of XQLT on ovalbumin-induced airway inflammation in a guinea pig model of allergic asthma was examined, and early and late asthmatic responses were measured in terms of airway resistance and extent of eosinophil infiltration. Furthermore, the bronchorelaxing effect of XQLT was measured in isolated guinea pig trachea. RESULTS: XQLT significantly inhibited the antigen-induced immediate asthmatic response (IAR) and late asthmatic response (LAR) in actively sensitized guinea pigs. Cumulative administration of XQLT caused concentration-dependent relaxation of the carbachol-precontracted guinea pig trachea. The bronchorelaxing effect of XQLT was reversed by ICI-118551, a selective beta2-adrenoceptor antagonist. Furthermore, examination of bronchoalveolar lavage fluid (BALF) revealed that XQLT significantly suppressed the increase in eosinophils (24 h after antigen challenge) in the airway. In addition, XQLT significantly attenuated the increase in eosinophils at 1, 6, 24, 48, and 72 h after antigen challenge when it was administered once daily from the day of sensitization to the day of challenge. Histopathologic examination results showed that XQLT suppressed eosinophil infiltration into lung tissue. CONCLUSIONS: These results demonstrate that the antiasthmatic effects of XQLT appear to be partly mediated by stimulation of beta2-adrenoceptors, leading to bronchorelaxation, and that XQLT inhibits the infiltration of eosinophils into the airway. Thus, XQLT may be useful for the prevention or treatment of asthma.

Identification of Atractylodes plants in Chinese herbs and formulations by random amplified polymorphic DNA.

AIM: An efficient, precise, and sensitive method for identifying Atractylodes plants has been established and will contribute significantly to quality control and scientific analysis in Chinese traditional medicine. METHODS: Twenty primers were applied for setting up the RAPD (randomly amplified polymorphic DNA) markers of Atractylodes plants, Atractylodes lancea DC (A lancea DC), Atractylodes japonica Koidz (A japonica K), and Atractylodes ovata DC (A ovata DC). The primer OPF03, OPF05, and OPF14 could discriminate them successfully. The results were also able to apply on the Chinese formulations with Atractylodes purchased from local markets. RESULTS: RAPD was used to investigate phylogenetic relationships among and within closely related species. RAPD analysis reflects heritable changes in the nucleotides sequence in both the coding and noncoding regions, because it is conducted directly from the DNA level. This work first conducted RAPD analysis of Atractylodes plants to establish their RAPD makers. CONCLUSION: The RAPD markers could be applied extensively in the Chinese herbal formulations.

Effects of huangqi jianzhong tang on hematological and biochemical parameters in judo athletes.

AIM: The purpose of the study was to investigate the effects of Huangqi Jianzhong Tang (HQJZT) on hematological and biochemical parameters in judo athletes. METHODS: Sixteen male and eight female judo athletes in Hsin-Ming senior high school were randomly and stratified divided into control and experimental group, which received placebo and HQJZT respectively during the five-week training program. The measurement of the hematological and biochemical parameters was performed twice, just before and after the training. The data was analyzed with paired-t test and ANOVA. RESULTS: The values of RBC, Hb, and Hct were obvious decreased after intervention, while the value of GOT, GPT, BUN, and CK was elevated. CONCLUSION: The results indicated the hematological and biochemical changes were caused by the physical training but not the effects of HQJZT. The HQJZT had no adverse effects on the judo athletes in our study.

Prophylactic effect of four prescriptions of traditional Chinese medicine on alpha-naphthylisothiocyanate and carbon tetrachloride induced toxicity in rats.

AIM: To study the prophylactic effects of four Chinese traditional prescriptions against experimental liver injury. METHODS: Liver toxins, alpha-naphthylisothiocyanate (ANIT), and carbon tetrachloride (CCl4) were used to induce acute liver injury. Simo Yin(SMY), Guizhi Fuling Wan (GFW), Xieqing Wan (XQW), and Sini San (SNS) were fed (500 mg/kg, in saline, po) to the rats before toxin administration. All the animals were killed 48 h after toxin insulted. Serum index of liver function and hepatic lipid peroxidation (LPO) were estimated. Histopathological observation was conducted simultaneously. RESULTS: The rats treated with ANIT exhibited elevations of serum total bilirubin (TBI), alkaline phosphatase (ALP), glutamate-oxalate- transaminase (GOT), glutamate-pyruvate-transaminase (GPT), as well as cholestasis and parenchyma necrosis. In rats, challenged with ANIT, receiving the pre-treatment of prescriptions of SMY, XQW, and SNS, the biochemical and morphological parameters of liver injury were significantly reduced. The increased LPO level in liver tissue, associated with the provoked serum GOT and GPT levels were the salient features observed in CCl4-insulting rats. Pre-treatment of four prescriptions showed a remarkable protective effect, and also was effective in counteracting the free radical toxicity by bringing about a significant decrease in peroxidative level. CONCLUSION: These recipes ameliorate liver damage induced by both ANIT and CCl4 despite the differences in their mechanisms of injury. Therefore they may be able to exert hepatoprotective effects through more than one mechanism of action because they contained a mixture of anti-hepatotoxic ingredients with mutual reinforcement and assistance.

Effect of Rhizoma Corydalis on focal cerebral infarct in ischemia-reperfusion injured rats.

AIM: To investigate the effect of Rhizoma Corydalis (RC) on focal cerebral infarct. METHODS: A total of 30 Sprague-Dawley (SD) rats were studied. Focal cerebral infarct was established b y occluding the bilateral common carotid arteries and the right middle cerebral artery for 90 min. After 24 h reperfusion, the neurological status was evaluated and then the rats were killed and the brain tissue was stained with 2,3,5-triphenyl-tetrazolium chloride. The neurological status and the changes in the area of cerebral infarct were used as an index to evaluate the effect of RC on cerebral infarct. In addition, the whole blood was examined 24 h after RC treatment in the other 24 SD rats. RESULTS: Pretreatment with RC 100 mg/kg can improve neurological status and also can reduce the area of cerebral infarct in ischemia-reperfusion injured rats. The counts of erythrocyte and the amount of hematocrit increased in whole blood of RC-treated rats. CONCLUSION: RC can improve neurological status and reduce the area of cerebral infarct in ischemia-reperfusion injured rats.

The effects of Ma-Xing-Gan-Shi-Tang on respiratory resistance and airway leukocyte infiltration in asthmatic guinea pigs.

Ma-Xing-Gan-Shi-Tang (MXGST), a traditional Chinese medicine, has been used in treatment of the bronchial asthma for several centuries. However, the therapeutic mechanisms of this Chinese medicine are still far from clear. To understand the mechanism of anti-asthmatic property of MXGST, a guinea pig model of allergic asthma was used to investigate the effects of MXGST on Dermatophagoides pteronyssinus-induced early and late asthmatic responses and airway inflammation, and examine direct beta2-adrenoceptor agonist activity in guinea-pig isolated trachea. Administration of MXGST (10 g/kg) extracts significantly inhibited the antigen induced immediate asthmatic responses (IAR) in actively sensitized guinea pig. MXGST caused concentration-dependent relaxation in strips of guinea pig trachea contracted with carbachol, and ICI-118551, a selective beta2-adrenoceptor antagonist, significantly inhibit the relaxation caused by MXGST. Furthermore, examination of bronchoalveolar lavage fluid (BALF) revealed that MXGST significantly inhibited the increase in neutrophil in the airway at 1, 6 and 24 hr after antigen challenge. Histopathologic examination results showed that MXGST suppressed the neutrophil infiltration into lung tissue. In conclusion, we suggest that the anti-asthmatic effects of MXGST are mainly due to its stimulation of beta2-adrenoceptors on bronchial smooth muscle and its anti-inflammatory ability to inhibit the neutrophil into the airway. The precise mechanism of action of MXGST in asthma remains to be elucidated.

The Chinese medicine Bu-Zhong-Yi-Qi-Tang inhibited proliferation of hepatoma cell lines by inducing apoptosis via G0/G1 arrest.

Bu-Zhong-Yi-Qi-Tang (BZYQT), a Chinese herbal medicine, inhibited the proliferation of human hepatoma cell lines (Hep3B, HepG2 and HA22T) dose-dependently. The IC50s of BZYQT on the proliferation of Hep3B, HepG2 and HA22T were 432.5+/-31.8 microg/ml, 455.4+/-24.2 microg/ml, and 2284.3+/-77.2 microg/ml respectively on day 3. However, BZYQT did not significantly inhibit the proliferation of normal human hepatocytes (Chang liver, CCL-13) at the concentration under 5,000 microg/ml. Major compounds of BZYQT, including astragaloside IV, ginsenoside Rb1 and Rg1, saikosaponin a and c, and glycyrrhizin, have been identified. To investigate the key inhibitors of BZYQT. Hep3B cells were treated with BZYQT, individual major compounds of BZYQT, and mixture of major compounds in the same ratio as present in BZYQT. Significant inhibition of proliferation was detected in BZYQT and its major compounds mixture in a comparable level. Not any individual major compound examined could suppress the proliferation of Hep3B cells. This data indicated that there could be synergistic or additive effects of the ingredients in BZYQT. BrdU incorporation, cell cycle analysis and DNA fragmentation assay revealed that BZYQT suppressed the proliferation of hepatoma cells via G0/G1 cell cycle arrest and inhibition of DNA synthesis followed by apoptosis.

Effects of percutaneous electrical stimulation on peripheral nerve regeneration using silicone rubber chambers.

The purpose of this study was to determine whether 0.8-1 mA, 2 Hz of percutaneous electrical stimulation could affect the regeneration of a 10-mm gap of rat sciatic nerve created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes. Six weeks after implantation, though the group receiving the electrical stimulation had a lower success percentage of regeneration (57%) compared with the controls receiving no stimulation (70%), quantitative histology of the successfully regenerated nerves revealed that the mean values of the axon density, blood vessel number, blood vessel area, and percentage of blood vessel area in total nerve area in the group with the electrical stimulation were all significantly larger than those in the controls (p < 0.05). These results showed that the electrical stimulation could elicit rehabilitating effects on the regenerated nerves.

The effectiveness of Tsu-San-Li (St-36) and Tai-Chung (Li-3) acupoints for treatment of acute liver damage in rats.

This study investigated the effects of acupuncture on carbon tetrachloride (CCl4) induced acute liver injury in male rats (n=36). The experimental groups were injected with CCl4 before, during, or after acupuncture therapy. Acupoints similar to the human Tsu-San-Li (St-36) and Tai-Chung (Li-3) were needled bilaterally. Rats treated with CCl4 had higher levels of serum glutamate-oxalate-transaminase (sGOT) and serum glutamate-pyruvate-transaminase (sGPT). Comparing the experimental groups, biochemical and pathological parameters of liver injury were significantly reduced when rats were acupunctured after, not before, CCl4-induced hepatotoxicity. Acupuncture at the Tsu-San-Li and Tai-Chung acupoints cannot prevent acute liver injury but may be effective in treating liver injury induced by carbon tetrachloride in rats.

Electroacupuncture-induced neural activation detected by use of manganese-enhanced functional magnetic resonance imaging in rabbits.

OBJECTIVE: To investigate the effects of acupuncture on neural activity detected by use of manganese-enhanced functional magnetic resonance imaging (fMRI) and elucidate the relationship between somatic acupoint stimulation and brain activation. ANIMALS: 40 New Zealand White rabbits. PROCEDURE: Manganese-enhanced fMRI was performed in anesthetized rabbits manipulated with electroacupuncture (EA) on Zusanli (ST-36) and Yanglingquan (GB-34) acupoints. Image acquisition was performed on a 1.5T superconductive clinical scanner with a circular polarized extremity coil. T1-weighted images were acquired sequentially as follows: baseline, after mannitol injection, after manganese infusion, and 5 and 20 minutes after initiation of EA. RESULTS: Changes in focal neural activity were detected by use of manganese-enhanced fMRI. Stimulation on Zusanli (ST-36) for 5 minutes resulted in activation of the hippocampus, whereas stimulation on Yanglingquan (GB-34) resulted in activation of the hypothalamus, insula, and motor cortex. Activation became less specific after 20 minutes of EA. Furthermore, stimulation on ipsilateral acupoints led to bilateral brain activation. CONCLUSIONS AND CLINICAL RELEVANCE: Each acupoint has a corresponding cerebral linkage, and stimulation on these points resulted in time-dependent neural activation. Understanding the linkage between peripheral acupoint stimulation and central neural pathways may provide a useful guide for clinical applications of acupuncture.

Effect of acupuncture stimulation on peripheral nerve regeneration using silicone rubber chambers.

The purpose of this study was to determine whether acupuncture could affect the regeneration of a 10-mm gap of rat sciatic nerve created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes. Empty silicone rubber tubes with no further treatment were used as controls. Six weeks after implantation, the animals received the acupuncture or the electroneedling treatment exhibited a more mature ultrastructural nerve organization with significantly higher numbers in the axon density, the blood vessel area, and the percentage of blood vessel area occupied in total nerve area than the controls. In addition, the electroneedling could combine both the needling and the electrical stimulation to potentiate the nerve-growth promoting effect of the acupuncture treatment. These results showed that acupuncture treatment could elicit positive effects on regenerated peripheral nerves.

Effects of buyang huanwu decoction on peripheral nerve regeneration using silicone rubber chambers.

This study investigated the effect of buyang huanwu decoction on the regeneration of a 10-mm gap of rat sciatic nerve created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes. Empty silicone rubber tubes with no further treatment were used as controls. Six weeks after implantation, 89% of the animals orally administered the buyang huanwu decoction exhibited regeneration across the nerve gaps, whereas only 70% had regenerated in the control group. Both qualitative and quantitative histology of the regenerated nerves revealed a more mature ultrastructural organization with significantly higher numbers of myelinated axons, larger endoneurial areas, higher axon densities and a larger percentage of axon area per total nerve area in the buyang huanwu group than in the controls. These results showed that the buyang huanwu decoction had a growth-promoting effect on the regenerated nerves.

Effect of manual acupuncture and transcutaneous electrical nerve stimulation on the H-reflex.

Several studies find that manual acupuncture and transcutaneous electrical nerve stimulation (TENS) are via different mechanisms and generate different effect on the central nervous system, therefore, the aim of the present study was to compare the effect of manual acupuncture (MA) and TENS on the spinal cord using H-reflex recordings. A total of 13 healthy adult volunteers were studied. The electrical stimuli were delivered to the posterior tibial nerve transcutaneously at the left popliteal fossa to evoke the soleus H-reflex. MA, 2Hz TENS, 100 Hz TENS, respectively, was applied to the surface of the right first dorsal interosseous muscle exactly at the Hegu acupoint (LI.4). Four assessments were performed randomly, separated by an interval of at least three days in all the subjects as follows: 1) Control assessment: a pair of electrodes placed on the surface of the right Hegu acupoint (LI.4), but no electrical stimulation was delivered throughout the test; 2) MA assessment: MA was done at the right Hegu acupoint (LI.4) for 15 minutes; 3) TENS assessment at 2Hz: electrical stimulation (40 mA in intensity) at 2Hz was applied to the surface of the right Hegu acupoint (LI.4) for 15 minutes; 4) TENS assessment at 100 Hz: electrical stimulation (20 mA in intensity) at 100 Hz was applied to the surface of the right Hegu acupoint (LI.4) for 15 minutes. Each assessment was divided into three periods as follows: 1) Baseline period: H-reflexes recorded prior to MA or TENS; 2) TENS period: six H-reflex recordings after MA or TENS for a duration of 4-5 min, 9-10 min and 14-15 min, respectively; 3) Post TENS period: H-reflex recordings of 6 after TENS period 4-5 min and 9-10 min, respectively. Our results indicate that both 2Hz TENS and 100 Hz TENS increased the amplitude of the H-reflex, and that these increases may be retained longer with 100 Hz TENS than with 2 Hz TENS, whereas MA could not increase the amplitude of the H-reflex. MA, TENS at 2 Hz or 100 Hz didn't change the latencies of the H-reflexes. We conclude that both 2Hz and 100 Hz TENS increased the amplitude of the H-reflex, suggesting that TENS enhances the excitability of the motoneuron pool in the spinal cord, and 100 Hz TENS has a greater effect than 2Hz TENS, whereas MA was not similar effect to TENS on spinal cord.

Immunomodulation of Bu-Zhong-Yi-Qi-Tang on in vitro granulocyte colony-stimulating-factor and tumor necrosis factor-alpha production by peripheral blood mononuclear cells.

Bu-Zhong-Yi-Qi-Tang (BZYQT) is a Chinese medicine, and has been used for the treatment of hepatocellular carcinoma (HCC) patients. At present, we still do not fully understand the effects of BZYQT on the cellular physiology. Present in vitro study demonstrated that BZYQT is capable of increasing granulocyte colony-stimulating-factor (G-CSF) and tumor necrosis factor-alpha (TNF-alpha) production by peripheral blood mononuclear cells (PBMC) in healthy volunteers and patients with HCC. The productions of G-CSF and TNF-alpha by PBMC of volunteers were significantly stimulated by more than 125 microg/ml of BZYQT. G-CSF levels stimulated by PBMC of healthy volunteers were higher than in PBMC of the HCC patients when more than 625 microg/ml of BZYQT was administrated. The reason may be due to the impaired immunologic reactivity of mononuclear cells in HCC patients. However, the production levels of TNF-alpha in HCC patients can be stimulated to levels as high as those in healthy volunteers. When adding high concentration (3.125 mg/ml) of BZYQT to the cultured PBMC, the increments of G-CSF and TNF-alpha production decreased although there were no obvious changes in the number of metabolic active PBMC changed. TNF-alpha andG-CSF are known to play important roles in the biological defensive mechanism. These findings show that BZYQT is a unique formula for the stimulation of PBMC to produce G-CSF and TNF-alpha. Administration of BZYQT may be beneficial for patients with HCC to modulate these cytokines.

Effects of berberine on arylamine N-acetyltransferase activity and 2-aminofluorene-DNA adduct formation in human leukemia cells.

Berberine is an alkaloid occurring in the plant genera Berberis and Coptis. Although berberine had been demonstrated to have antineoplastic function by inhibiting DNA-synthesis in activated lymphocytes, there is no available information to address berberine affects on human leukemia cell N-acetyltransferase (NAT) activity and 2-aminofluorene (AF)-DNA adduct formation. Thus, berberine was tested for inhibition of arylamine NAT activity and AF-DNA adduct formation in human leukemia cells. The NAT activity was measured by a high performance liquid chromatography assaying for the amounts of N-acetyl-2-aminofluorene (AAF) and N-acetyl-p-aminobenzoic acid (N-Ac-PABA) and the remaining AF and p-aminobenzoic acid (PABA). The NAT activity and AF-DNA adduct formation in human leukemia cells were inhibited by berberine in a dose-dependent manner, i.e. the higher the concentration of berberine, the higher the inhibition of NAT activity and AF-DNA adduct. The data also indicate that berberine decreased the apparent values of Km and Vmax from human leukemia cells in both cytosol and intact cells.