Is it safe to take Radix Salvia Miltiorrhiza - Radix Pueraria Lobate product with warfarin and aspirin? A pilot study in healthy human subjects.

ETHNOPHARMACOLOGICAL RELEVANCE: Radix Salvia Miltiorrhiza (Danshen) and Radix Pueraria Lobate (Gegen) are officially listed in the Chinese Pharmacopoeia and have long been used together as a Compound Chinese Traditional Medicine (CCTM) for treatment of coronary heart diseases, which are often co-administered with aspirin or warfarin to patients suffering from cardiovascular diseases. AIM OF STUDY: Since significant pharmacokinetic and pharmacodynamic interactions between Danshen-Gegen (DG) formula and aspirin/warfarin have been observed in our previous rat studies, the current study was proposed aiming to further verify such pharmacokinetic and pharmacodynamic interactions in healthy human subjects and explore related mechanisms. MATERIALS AND METHODS: A 5-day, multiple dose, five-session clinical trial has been carried out (n = 14) with 2-week washout periods between sessions, during which the subjects would receive different combinations of the medications. Plasma samples were collected for pharmacokinetic evaluation, and whole blood samples were collected for pharmacodynamic evaluation. In addition, an in-vitro mechanistic study is conducted to investigate the role of danshensu on the anti-thrombotic and anti-platelet aggregation effects of warfarin and aspirin respectively. RESULTS: Significant pharmacokinetic and pharmacodynamic herb-drug interactions were observed in healthy human subjects. pharmacokinetically, co-administration of DG with aspirin or warfarin could lead to a moderately increased AUC0→t of aspirin and a decreased AUC0→t of 7-hydroxyl warfarin respectively. The systemic exposure of danshensu (DSS, the marker component of DG) would be significantly increased after co-administration with warfarin. Pharmacodynamically, a reduction in systemic thromboxane B2 concentration was noticed after administration of DG with aspirin, which could be associated with the increased systemic exposure of aspirin and the synergistic effect of danshensu, aspirin and salicylic acid on cyclooxygenase (COX) inhibition. An offset on the warfarin induced soluble thrombomodulin induction was observed after its co-administration with DG, which could be partially attributed to the COX-2 inhibition effect of danshensu. CONCLUSION: Our results indicated that co-administration of DG with aspirin/warfarin would lead to significant pharmacokinetic and pharmacodynamic herb-drug interactions in healthy human subjects.

A case of simvastatin-induced myopathy with SLCO1B1 genetic predisposition and co-ingestion of linagliptin and Stevia rebaudiana.

WHAT IS KNOWN AND OBJECTIVE: SLCO1B1 T521>C variant carriers are susceptible to simvastatin-induced myopathy. We report a patient who developed rhabdomyolysis possibly triggered by a drug-drug and/or herb-drug interaction. CASE DESCRIPTION: A 69-year-old man presented with myalgia and weakness progressing to severe rhabdomyolysis. He had been taking 40 mg simvastatin daily for 10 years and recently consumed supplements, including Stevia rebaudiana and linagliptin. Genotyping revealed he carried one copy of SLCO1B1 T521>C and two copies of ABCG2 C421>A. WHAT IS NEW AND CONCLUSION: Despite apparent long-term safe administration, co-ingestion of simvastatin and other CYP3A4 inhibitors may result in severe myopathy in those at increased genetic risk.

Anti-tumour and pharmacokinetics study of 2-Formyl-8-hydroxy-quinolinium chloride as Galipea longiflora alkaloid analogue.

The quinolinium chloride salt of 8-hydroxyqinolinecarbaldehyde (2-Formyl-8-hydroxy-quinolinium chloride) was prepared as Galipea longiflora alkaloid analogue and its anticancer activity was evaluated both in vitro and in vivo. This chloride salt was found to show certain degree of selectivity between hepatoma cells and normal hepatocytes in vitro. Athymic nude mice Hep3B xenograft model further demonstrated that this 2-Formyl-8-hydroxy-quinolinium chloride could execute strong anti-tumour activity with the identification of extensive necrotic feature from the tumour xenograft and limited adverse toxicological effect.

Preparation of Galipea officinalis Hancock type tetrahydroquinoline alkaloid analogues as anti-tumour agents.

The preparation of chiral tetrahydroquinolines using Ir-catalysed asymmetric hydrogenation and their possible cytotoxic potential anti-cancer activity were reported. Both of the in vitro cytotoxicity assay on a series of human cancer cell lines including A549 small cell lung cancer, MDA-MB-231 breast cancer, SaoS2 sacroma, SKHep-1 hepatoma and Hep3B hepatocellular carcinoma as well as in vivo animal model using Hep3B hepatocellular tumour xenograft on athymic nude mice suggest that 1,2,3,4-tetrahydroquin-8-ol is a potential anti-tumour alkaloid which may be further developed as a novel cancer chemotherapeutic agent.

A novel green gelatin-agar microencapsulation system with P. urinaria as an improved anti-A. niger model.

In this study, a novel green microencapsulation system was used to develop Phyllanthus urinaria (PU) extract containing microcapsules. Agar was used with gelatin as the wall matrix materials of microcapsules to prevent the use of toxic crosslinker formaldehyde. Microencapsulated PU extract was developed to improve the potential antifungal activities of PU water extracts. The active components and surface morphology of PU extract containing microcapsules were analyzed by liquid chromatography/mass spectrometry and scanning electron microscopy, respectively. The in vitro release study demonstrated that approximately 80% of drug was released after 120 h. PU loaded microcapsules were shown to have a stronger anti-Aspergillus niger activity than the free drug.

In vivo anti-tumour activity of corilagin on Hep3B hepatocellular carcinoma.

We have investigated the potential in vivo anti-tumour activity of corilagin using the Hep3B hepatocellular carcinoma cell line and an athymic nude mice xenograft model. The purity of corilagin was confirmed by high performance liquid chromatographic analysis. Corilagin was administrated intraperitoneally for a continuous period of 7 days at a concentration of 15 mg/kg of body weight per day. A significant inhibition of tumour growth was observed when treated mice are compared with control groups. Furthermore, analysis of enzymes markers of liver function, including alanine aminotransferase and asparate aminotransferase, suggested that current therapeutic dosage of corilagin did not exert adverse effect on liver. Our observations support the view that corilagin is considerably effective to retard the in vivo growth of xenografted Hep3B hepatocellular carcinoma.

Novel use of silymarin as delayed therapy for acetaminophen-induced acute hepatic injury.

AIM: Recently, we have demonstrated that silymarin has a comparable pharmaceutical activity as Phyllanthus urinaria extract when used to rescue mice from acetaminophen-induced acute liver injury. In the present study, we further compared the therapeutic action of silymarin with N-acetyl cysteine (commonly used in clinical practice for emergency treatments) as a rescuer in mice after administering a lethal dose of acetaminophen for 24 h. METHODS: Acute liver injury was induced in the treatment groups by intraperitoneally administered acetaminophen at a dose of 550 mg/kg body weight on day 1. The control group received an equal volume of physiological saline intraperitoneally. From day 2 to 4, the treatment groups received various doses of silymarin or N-acetyl cysteine orally once daily, while the control group and the acetaminophen group received an equal volume of water orally. The mortality rate was recorded in all groups. On day 5, all mice were sacrificed for examination. RESULTS: Silymarin greatly improved the counteracting effects on mortality rate as compared to N-acetyl cysteine. CONCLUSION: Silymarin should be further considered as an antidote for patients with acetaminopheninduced acute hepatic injury and delayed treatment.

Phyllanthus urinaria extract attenuates acetaminophen induced hepatotoxicity: involvement of cytochrome P450 CYP2E1.

Acetaminophen is a commonly used drug for the treatment of patients with common cold and influenza. However, an overdose of acetaminophen may be fatal. In this study we investigated whether mice, administered intraperitoneally with a lethal dose of acetaminophen, when followed by oral administration of Phyllanthus urinaria extract, may be prevented from death. Histopathological analysis of mouse liver sections showed that Phyllanthus urinaria extract may protect the hepatocytes from acetaminophen-induced necrosis. Therapeutic dose of Phyllanthus urinaria extract did not show any toxicological phenomenon on mice. Immunohistochemical staining with the cytochrome P450 CYP2E1 antibody revealed that Phyllanthus urinaria extract reduced the cytochrome P450 CYP2E1 protein level in mice pre-treated with a lethal dose of acetaminophen. Phyllanthus urinaria extract also inhibited the cytochrome P450 CYP2E1 enzymatic activity in vitro. Heavy metals, including arsenic, cadmium, mercury and lead, as well as herbicide residues were not found above their detection limits. High performance liquid chromatography identified corilagin and gallic acid as the major components of the Phyllanthus urinaria extract. We conclude that Phyllanthus urinaria extract is effective in attenuating the acetaminophen induced hepatotoxicity, and inhibition of cytochrome P450 CYP2E1 enzyme may be an important factor for its therapeutic mechanism.

Antiproliferative ability of a combination regimen of crocodile egg extract, wild radix ginseng and natural Ganoderma lucidum on acute myelogenous leukemia.

Chinese practitioners have employed the use of traditional Chinese medicine as an anti-cancer agent since the ancient period. Different combinations have been formulated for various purposes. Some have been claimed for post-chemotherapy use but their direct actions on cancer cells may not be significantly reported. In the present study, we have tested the possible anti-leukemia potential of a combination regimen including crocodile egg extract, wild radix ginseng and natural Ganoderma lucidum (CGG extract) on acute myelogenous leukemia (AML) in vitro. A water soluble CGG extract was prepared and its antiproliferative activity was tested on the KG1a AML cell line and two freshly prepared bone marrow aspirate samples isolated from patients with de novo AML during presentation by a MTS/PMS assay. Furthermore, the possible activity of the CGG extract on the regeneration potential of KG1a cells was also investigated using a semi-solid methyl-cellulose colony formation assay. Lastly, the acute toxicity of CGG extract was further examined by a single high-dose oral feeding to rats. We found that the CGG extract could possess significant antiproliferative activity on AML cells. A strong colony formation inhibition was further demonstrated on KG1a cells. After feeding the rats with an excessive dose of CGG extract, we observed no development of acute toxicity. We concluded that the CGG extract has growth inhibitory potential on KG1a cells and AML bone marrow samples in vitro. An in vivo toxicity test revealed that no acute toxicity was observed after feeding the rats a high dosage of the CGG extract. Further animal model tests are necessary to investigate the possible chronic toxicity of the CGG extract.

Antiangiogenic activity of a concentrated effective microorganism fermentation extract.

We have previously demonstrated the possible growth inhibitory activity of both first generation of the effective microorganism fermentation extract (EM-X) as well as the second generation (EM-X2) on cancer cell lines in vitro. The possible anti-angiogenic potential of EM-X has not been reported. Herein we show that using the concentrated EM-X, the growth of human umbilical cord endothelial cells (HUCE) was significantly inhibited in vitro. Enzyme linked immunosorbent assay suggested that the concentrated EM-X is able to reduce the level of vascular endothelial growth factor (VEGF) from Hep3B hepatocellular carcinoma (HCC) cells. The conditioned culture medium obtained from the concentrated EM-X incubated Hep3B HCC cells possessed significant antiproliferative effect on the HUCE cells. Moreover, in vivo chick chorioallantoic membrane assay further demonstrated that the concentrated EM-X is able to greatly inhibit the basic fibroblast growth factor induced angiogenesis from chick embryo experiment. We speculate that the anti-cancer potential of this concentrated EM-X involved growth inhibition on cancer cell and antiangiogenic effect on HUCE cells.

Apoptotic potential of the concentrated effective microorganism fermentation extract on human cancer cells.

The effective microorganism fermentation extract (EM-X, the first generation) was claimed to possess strong anti-oxidation property. On the other hand, we have shown that the second generation of the effective microorganism fermentation extract (EM-X2) possessed growth inhibition on human cancer cells involving MDA-MB231 breast cancer and K-562 chronic myelogenous leukaemia cells. Elevation of super oxide dismutase activity from EM-X2 treated cancer cell extract was observed. However, the possible anti-cancer activity of the first generation of the EM-X was not reported. Here we demonstrate that the concentrated form of the EM-X from its original fluid also possess antiproliferation ability together with induction of apoptosis on the human cancer cell lines including Hep3B hepatocellular carcinoma (HCC) and KG1a acute myelogenous leukaemia (AML). Similar effect could also be demonstrated on primary cultured bone marrow samples isolated from patients with AML. Morphological inspection revealed that common apoptotic feature was found on these concentrated EM-X treated cancer cells. Both the anchorage-dependent clonogenicity assay on Hep3B HCC and methyl-cellulose colony formation assay on KG1a cells and bone marrow cells from AML patients further revealed the ability of the concentrated EM-X on reducing their colony formation ability. Incubating KG1a with concentrated EM-X readily induced apoptosis as demonstrated by flow cytometric analysis. Interestingly, few growth inhibition effect of the concentrated EM-X was observed on both the SV40 transformed THLE-2 liver epithelial cells and primary cultured non-malignant haematological disordered bone marrow. Collectively, this concentrated EM-X is effective in inducing cell death and reducing the regeneration potential of both Hep3B HCC and KG1a AML cells in vitro.

Antiproliferative and apoptosis-inducing activity of Brucea javanica extract on human carcinoma cells.

We have recently demonstrated the antiproliferative and apoptotic activities of herbal traditional Chinese medicines, including the analomous fruit extract of Gleditsia sinensis, the fresh juice of Scutellaria barbata and the warmed water extract of Radix Sophorae Tonkinensis on a series of human carcinoma cells. Here, we further report the potential anti-cancer activity of the warmed water extract of Brucea javanica (BJE). Four cancer cell lines, including A549 non-small cell lung cancer, Hep3B hepatocellular carcinoma, MDA-MB231 breast cancer and SLMT-1 oesophageal squamous cell carcinoma, were incubated with BJE and strong apoptotic induction was observed under inverted microscopic investigation for all of the four cell lines tested. Using the MDA-MB231 breast cancer cell line as an experimental model, additional analyses supported the hypothesis that the mitochondrial membrane potential depolarization pathway was induced by BJE. The APO-1/Fas receptor death induction pathway was not activated under the influence of BJE, as studied by staining with Fas ligand and Fas receptor specific antibodies. Accordingly, only weak activation of caspase 8 was observed upon BJE treatment. On the other hand, caspase 3 activity was stimulated up to five-fold in BJE-treated cells compared to untreated controls. Oligonucleosomal DNA fragmentation formation was detected by labelling the nucleic acid ladders with TdT-mediated dUTP nick end labelling. Collectively, BJE-induced cancer cell death proceeds through a mitochondrial dependent pathway associated with caspase 3 activation.

Inhibition of proteasome activity in Gleditsia sinensis fruit extract-mediated apoptosis on human carcinoma cells.

The anomalous fruit extract of Gleditsia sinensis (GSE) was shown to possess anticancer potential on various solid tumour and leukaemia cell lines in vitro. We have recently demonstrated that the mitochondrial-dependent apoptotic pathway including mitochondrial membrane potential depolarization, changes in the level of reactive oxygen species and activation of caspase 3 were recruited in GSE-induced apoptosis. Whether receptor-dependent APO-1/Fas apoptotic pathway is also involved remains uncertain. Using two solid tumour cell lines, the HepG2 hepatoblastoma carcinoma cells and MDA-MB231 breast cancer cells, we demonstrated that the Fas ligand and Fas receptor protein levels did not have significant variation after GSE incubation. Caspase 8 activity increased only weakly when compared with that of caspase 3. The chrymotrypsin-like activity of proteasome was partially inhibited up to 30-40% when compared with the untreated control. Taken together, we believe that GSE- mediated apoptosis on HepG2 and MDA-MB231 carcinoma cells is mainly dictated by the mitochondrial-dependent pathway while inhibition of proteasome activity may also be involved in GSE-induced apoptosis.

Activities of fresh juice of Scutellaria barbata and warmed water extract of Radix Sophorae Tonkinensis on anti-proliferation and apoptosis of human cancer cell lines.

The possible antiproliferative and apoptotic inducing potentials of fresh juice prepared from Scutellaria barbata (SBJ) and warmed water extract of Radix Sophorae Tonkinensis (RSTE) have been tested on a series of cancer cell lines, including HepG2 hepatoblastoma, Hep3B hepatocellular carcinoma, MDA-MB231 breast carcinoma, A549 lung cancer and KG-1 acute myelogenous leukaemia in vitro. Both SBJ and RSTE were able to inhibit the growth of cancer cell lines and induce apoptosis. Further analysis of the action of RSTE on HepG2 cells suggested that the activity of the central machinery of apoptosis, caspase 3, was significantly elevated. Oligo-nucleosomal length DNA fragments formation was readily detected by TdT-mediated dUTP nick end labelling assay after RSTE treatment. Taken together, we believe that, although Radix Sophorae Tonkinensis was demonstrated to have toxic components including matrine and oxymatrine, it is still worthwhile to further investigate its anti-cancer potential under a safety toxicological precaution.

Gleditsia sinensis fruit extract-induced apoptosis involves changes of reactive oxygen species level, mitochondrial membrane depolarization and caspase 3 activation.

Recently, we have shown that the anomalous fruit extract of Gleditsia sinensis (GSE) processes apoptotic activity on numerous solid tumour and leukaemia cell lines as well as primary cultured leukaemia cells obtained from bone marrow aspirate of patients. GSE treated cancer cells exhibited apoptotic features as readily illustrated by morphological investigation, DNA fragmentation analysis and TUNEL labelling methods. Elevation of intracellular superoxide dismutase activity was observed. However, the detailed mechanism still remains undefined. Here we further demonstrated that cell cycle arrest, increment of hydrogen peroxide production, changes of intracellular acid-base equilibrium and mitochondrial membrane potential depolarization (DeltaPsi(m)) were induced from cancer cells after GSE incubation. Caspase 3 protease activity was significantly enhanced upon GSE treatment. Taken together, a defined signaling pathway for the mechanistic action of GSE on cancer cells was worked out.

Growth inhibitory potential of effective microorganism fermentation extract (EM-X) on cancer cells.

The effective microorganism (EM-X) fermentation extract is derived from rice bran and seaweed extract. It has been shown to possess anti-oxidation activity both in vitro and in vivo. To our knowledge, the possible in vitro anti-cancer potential of EM-X has not been demonstrated. Here we showed that the double concentrate of EM-X (EM-X2) at concentrations of 20-30% by volume, had growth inhibitory activity on MDA-MB231 breast cancer cell line and K-562 chronic myelogenous leukaemia cell lines by [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2-H-tetrazolium, inner salt] (MTS) assay. No characteristic features of apoptosis could be observed morphologically. Colony formation assay illustrated that both MDA-MB231 breast cancer and K-562 CML cells lost part of their regeneration potential after treatment with EM-X2 at 30% concentration by volume for 24 h. At these concentrations, only slight growth inhibitory effect was observed in 293 human kidney fibroblast cells and in three non-malignant bone marrows. Intracellular nitro blue tetrazolium (NBT) reduction assay showed that both MDA-MB231 breast cancer and K-562 CML cells had about 30% reduction of intracellular NBT after incubation with 30% of EM-X2. Increased activity of superoxide dismutase (SOD) could be detected from both MDA-MB231 and K-562 cell lines after incubating with 30% of EM-X2. Taken together, our data suggested that EM-X could inhibit growth and reduce the regeneration potential of cancer cells, possibly through its antioxidation activity.

Superoxide anion is involved in the early apoptosis mediated by Gleditsia sinensis fruit extract.

Changes in the intracellular level of reactive oxygen species (ROS) including superoxide anion, hydroxyl radical, hydrogen peroxide and finally cellular acid-base equilibrium are reported to play an important role in the early step of apoptosis. All of which would precede the loss of mitochondrial membrane potential and releasing of those apoptotic inducing factors such as cytochrome c as well as caspases activation. Any potential chemotherapeutic agent that could drive such changes in ROS would be particularly attractive. Recently we have reported the potential use of Gleditsia sinensis extract (GSE) in cancer therapy including solid tumour and leukaemia cell lines as well as primary cultured leukaemia cells in vitro. We demonstrated that apoptotic activity is involved. Here we further showed that the mechanism of GSE induced apoptosis, including an early decreasing of intracellular superoxide anion as measured by nitroblue tetrazolium (NBT) reduction assay. This phenomenon readily occurred before any shrinkage of cancer cells including MDA-MB231 breast cancer, CNE-2 nasopharyngeal carcinoma, K-562 chronic myelogenous leukaemia and KG1-a, acute myelogenous leukaemia. Cell viability was determined by morphological investigation and the [3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) assay. Furthermore, the superoxide dismutase activity from those cellular extracts after GSE treatment seemed to be increased. Taken together, we speculate that the GSE-induced apoptosis, via ROS pathway, involves an early decrease of intracellular superoxide anion.

Gleditsia sinensis fruit extract induced growth inhibition involves basic fibroblast growth factor and nitric oxide.

Recently we have shown the antiproliferative activity of Gleditsia sinensis fruit extract (GSE) on various solid tumour and leukaemia cell lines as well as primary cultured bone marrow cells isolated from patients with acute and chronic myelogenous leukaemia. We further studied whether the growth inhibitory effect of GSE involves basic fibroblast growth factor (bFGF) in cancer cell lines including breast cancer MDA-MB231, nasopharyngeal cancer CNE-2 and prostate cancer LNCaP. We also investigated whether GSE could alter the production of nitric oxide (NO) pattern from these cancer cell lines. Growth inhibition assay was quantitated by sulforhodamine B protein staining method. Enzyme linked immunosorbent assay (ELISA) was used to quantitate the total bFGF protein. The amount of NO secreted into culture medium in terms of nitrite ion concentration was measured by the Greiss method. ELISA showed that GSE could stimulate total bFGF protein level which was dose- dependent. NO production was also stimulated from these cancer cell lines after treating with GSE. Both of the increment in total bFGF and NO levels were correlated with the degree of growth inhibition. Changes involving cell shrinkage and detachment of cancer cells could readily be observed. Taken together, our results here suggest that growth inhibition induced by GSE in these solid tumour cell lines may involve both bFGF and NO regulations.

Anti-angiogenic potential of Gleditsia sinensis fruit extract.

Blood supply plays a crucial role in solid tumour development and leukaemogenesis. It has been suggested that blocking of angiogenesis could be possible in cancer therapy. We have demonstrated the antiproliferative activity of Gleditsia sinensis fruit extract (GSE) on various human solid tumour cancer cell lines as well as leukaemia cell lines and primary cultured leukaemia cells obtained from leukaemia patients. However, the antiangiogenic potential of GSE has not been demonstrated. Here we demonstrated that GSE could reduce vascular endothelial growth factor (VEGF) mRNA expression in dose- and time course-dependently in MDA-MB231 breast cancer and HepG2 hepatoblastoma cell lines as measured by reverse transcriptase polymerase chain reaction. Enzyme-linked immunosorbent assay further showed that GSE could reduce the VEGF secretion from various cancer cell lines including MDA-MB231, HepG2, HL-60 (acute promyelocytic leukaemia) and eleven primary cultured leukaemia cells obtained from acute myelogenous leukaemia patients. In vivo chick chorioallantoic membrane assay illustrated that GSE could reduce the angiogenic activity of basic fibroblast growth factor. Taken together, the information suggested that GSE could be potentially used as an angiogenic inhibitor in both solid tumour and leukaemia therapy.

Gleditsia sinensis fruit extract is a potential chemotherapeutic agent in chronic and acute myelogenous leukemia.

The anti-leukemia activity of the saponin rich Gleditsia sinensis Lam. fruit extract (GSE) was investigated on cancer cell lines and bone marrow cells obtained from consented patients with chronic myelogenous leukemia (CML) and acute myelogenous leukemia (AML) during presentation. The growth inhibitory activity of the extract was determined by [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) assay. Colony formation assay was performed to investigate the regeneration potential. Cellular morphology change was studied. Apoptosis was demonstrated by DNA electrophoresis, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. The mean concentration to inhibit the cell growth by 50% (MTS50) was 18+/-1.6 micro g/ml for K562 CML cell line and 12+/-1.3 micro g/ml for HL-60 acute promyelocytic leukemia cell line. Patient samples showed a mean MTS50 of 13-28 micro g/ml. Non-malignant hematological disorder bone marrow samples showed a mean MTS50 from 45 to 53 micro g/ml. Loss of regeneration property after treatment with GSE of these two cancer cell lines were confirmed by colony formation assay. GSE was able to induce cell shrinkage in K-562. DNA laddering was observed by incubating the leukemia cells with GSE. RT-PCR demonstrated that the pro-apoptic gene bax was induced while the anti-apoptic gene bcl-2 and cell cycle active gene PCNA were reduced. Flow cytometric analysis showed that the apoptotic effect of GSE on leukemia cell line was time- and dose-dependent. Thus GSE might be potentially used as a chemotherapeutic drug to treat patients with acute and chronic myelogenous leukemia.