Abstract A71: Isolation of aglycons and glycosides from Scutellaria baicalensis and exploration of responsible constituents on human breast cancer chemoprevention

Numerous effective anticancer drugs have been developed from botanical sources. Although the anticancer properties of Scutellaria baicalensis extract (SbE) have been reported, in some of our studies, SbE did not inhibit the growth of breast cancer cells significantly. In certain concentrations, it increased cancer cell growth. To identify the active anticancer constituents in SbE, we isolated a baicalin-knockout fraction (SbF1) and a baicalin-fraction (SbF3). We evaluated the anti-breast cancer activities of the fractions and their constituents on human breast cancer MCF-7 cells. Using a Waters 2960 high performance liquid chromatography (HPLC) instrument and a Phenomenex Prodigy ODS(2) column, we determined the contents in the extract and fractions: scutellarin, baicalin, baicalein and wogonin. The antiproliferative effects were assayed using the modified trichrome stain (MTS) method. The active properties of the fraction/constituents on the cancer cell cycle and on apoptosis were evaluated using a BD FACScan flow cytometer. A one-way ANOVA was used to measure statistical significance. HPLC data showed that the content of scutellarin, baicalin, baicalein and wogonin in SbE were 0.03, 15.67, 5.19 and 1.42%, respectively. The major constituents of SbF1 are the aglycons, baicalein (40.54%) and wogonin (12.35%). SbF3 contains only the glycoside baicalin (16.68%). SbF1 showed a significant antiproliferative effect. Treatment with 100 g/ml of SbF1 for 72 h inhibited MCF-7 cell growth by 81.6% (P<0.01); at the same treatment concentration, SbF3 increased cell growth by 22.6% (P<0.01). Therefore, SbF1 is the active fraction of SbE. Compared to control (48% of G1-phase, 33% of M-phase, and 10% of G2/M-phase), after treatment with 50 g/mL of SbF1 for 72 h, 27% of cells were in G-phase, 41% of cells were in M-phase, and 23% of cells were in G2/M-phase. SbF1 increased the S- and G2/M-phases in MCF-7 cells. After treatment for 48 h, the percentage of early apoptotic cells induced by 50 g/mL of SbF1 was 12.4%; by 100 g/mL, the percentage was 24.2%. SbF1 significantly increased induction of cell apoptosis compared to control, 6.7%. Studying the effects of four flavonoids in SbE, two glycosides (scutellarin and baicalin) and two aglycons (baicalein and wogonin), on MCF-7 cell proliferation showed that baicalein and wogonin significantly inhibited MCF-7 cell growth at 10–100 µM. In contrast, at certain concentrations (5–50 µM), the glycosides scutellarin and baicalin increased cancer cell growth. These phytochemical and biological data suggest that the active anticancer constituents in SbE are flavonoid aglycons. Since the two glycosides promoted MCF-7 cells at certain concentrations, these compounds should be removed from the S. baicalensis extract to ensure chemopreventive activities.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A71.

Selective fraction of Scutellaria baicalensis and its chemopreventive effects on MCF-7 human breast cancer cells

Based on our previous observation, the whole Scutellaria baicalensis extract (SbE) did not show significant breast cancer cell inhibitory effect. In this study, we isolated a baicalin-deprived-fraction (SbF1) of Scutellaria baicalensis, and baicalin-fraction (SbF3), and evaluated their anti-breast cancer properties using MCF-7 cells. The content of four flavonoids in extract/fractions were determined using high performance liquid chromatography. Analytical data showed that in SbF1, the major constituents are baicalein and wogonin, while SbF3 only contains baicalin. The antiproliferative effects of fractions and SbE were assayed using modified trichrome stain method. SbF1 showed significant antiproliferative effect. Treated with 100mug/ml of SbF1 for 72h inhibited MCF-7 cell growth by 81.6%, while in the same treatment concentration, SbF3 increased cell growth by 22.6%. SbF1 was recognized as an active fraction of SbE. The effects of four flavonoids in SbE, scutellarin, baicalin, baicalein and wogonin, were determined, and data showed that baicalein and wogonin significantly inhibited MCF-7 cell growth. In contrast, in certain concentrations, scutellarin and baicalin increased cancer cell growth. The effects of SbF1 on cell cycle and apoptosis were assayed using flow cytometry. SbF1 arrested MCF-7 cells in S- and G2/M-phases, and significantly increased induction of cell apoptosis. These combined phytochemical and biological data provide evidence for further chemopreventive studies of the baicalin-deprived SbE on breast cancer.

Methylnaltrexone potentiates body weight and fat reduction with leptin

OBJECTIVE

Leptin increases energy expenditure by enhancing systemic and brown adipose metabolism. In a neonatal rat model, retroperitoneal fat pad weight decreased significantly in leptin-treated animals, which reduced body weight. As opioids increase feeding, opioid antagonists may decrease food intake and body weight. However, interactions between leptin and the activity of peripheral opioids on body weight and fat accumulation have not been investigated. In this study, the authors evaluated the effects of naloxone (a nonselective opioid antagonist) and methylnaltrexone (a peripherally acting opioid antagonist) on the action of leptin in neonatal rats.

RESULTS

Compared with control, the weight gain of pups given a single daily intraperitoneal injection of leptin 0.5 mg/kg, leptin 0.5 mg/kg plus naloxone 0.3 mg/kg, or leptin 0.5 mg/kg plus methylnaltrexone 3.0 mg/kg for 8 consecutive days was significantly reduced (all p < 0.01). Naloxone or methylnaltrexone significantly potentiated leptin's effect on body weight (p < 0.05 or p < 0.01, respectively). After coadministration of leptin plus naloxone or leptin plus methylnaltrexone, weight reduction in the right retroperitoneal fat pads was also significant compared with the reduction after leptin alone (p < 0.05 or p < 0.01, respectively).

CONCLUSIONS

The data suggest the existence of a peripheral opioid-related mechanism in leptin-active modulation of body weight.

Grape seed proanthocyanidins protect cardiomyocytes from ischemia and reperfusion injury via Akt-NOS signaling

Ischemia/reperfusion (I/R) injury in cardiomyocytes is related to excess reactive oxygen species (ROS) generation and can be modulated by nitric oxide (NO). We have previously shown that grape seed proanthocyanidin extract (GSPE), a naturally occurring antioxidant, decreased ROS and may potentially stimulate NO production. In this study, we investigated whether GSPE administration at reperfusion was associated with cardioprotection and enhanced NO production in a cardiomyocyte I/R model. GSPE attenuated I/R-induced cell death [18.0 +/- 1.8% (GSPE, 50 microg/ml) vs. 42.3 +/- 3.0% (I/R control), P < 0.001], restored contractility (6/6 vs. 0/6, respectively), and increased NO release. The NO synthase (NOS) inhibitor Nomega-nitro-L-arginine methyl ester (L-NAME, 200 microM) significantly reduced GSPE-induced NO release and its associated cardioprotection [32.7 +/- 2.7% (GSPE + L-NAME) vs. 18.0 +/- 1.8% (GSPE alone), P < 0.01]. To determine whether GSPE induced NO production was mediated by the Akt-eNOS pathway, we utilized the Akt inhibitor API-2. API-2 (10 microM) abrogated GSPE-induced protection [44.3% +/- 2.2% (GSPE + API-2) vs. 27.0% +/- 4.3% (GSPE alone), P < 0.01], attenuated the enhanced phosphorylation of Akt at Ser473 in GSPE-treated cells and attenuated GSPE-induced NO increases. Simultaneously blocking NOS activation (L-NAME) and Akt (API-2) resulted in decreased NO levels similar to using each inhibitor independently. These data suggest that in the context of GSPE stimulation, Akt may help activate eNOS, leading to protective levels of NO. GSPE offers an alternative approach to therapeutic cardioprotection against I/R injury and may offer unique opportunities to improve cardiovascular health by enhancing NO production and increasing Akt-eNOS signaling.

Evaluation of a new eastern blotting technique for the analysis of ginsenoside Re in American ginseng berry pulp extracts

A new eastern blotting technique has been established for ginsenoside Re (G-Re) contained in American ginseng berry pulp extracts. G-Re in American ginseng berry pulp was extracted using 100% methanol, 100% ethanol, 50% aqueous methanol, and 50% aqueous ethanol. The combined crude extracts were applied onto a polyethersulfone membrane and developed using the methanol-water-acetic acid solvent system (45:55:1 v/v). Separated components were immunostained using anti-G-Re monoclonal antibody. G-Re was first specifically detected and then quantitatively analyzed using NIH Imaging software. We also confirmed that the most suitable solvent was 50% aqueous methanol for extracting G-Re from American ginseng berry pulp.

American ginseng berry enhances chemopreventive effect of 5-FU on human colorectal cancer cells

In this study, we investigated the possible synergistic chemopreventive effects of American ginseng berry extract (AGBE) and 5-fluorouracil (5-FU) on human colorectal cancer cell lines, SW-480, HCT-116 and HT-29. We used high-performance liquid chromatography to determine the contents of major ginsenosides, the active components of American ginseng, in AGBE. The anti-proliferative effects were evaluated by the cell counting method. AGBE (0.1-1.0 mg/ml) significantly inhibited SW-480, HCT-116 and HT-29 cell growth in a concentration-dependent manner. Cell growth decreased more with the combined treatment of 5-FU and AGBE than with 5-FU or AGBE applied alone, suggesting that AGBE can reduce the dose of 5-FU needed to achieve desired effects and thereby decrease the dose-related toxicity of the chemotherapy agent. Cell apoptosis assay showed that AGBE markedly reduced the number of viable SW-480 cells at 0.5 and 1.0 mg/ml, but did not increase cell apoptosis significantly. Neither 5-FU nor co-treatment with 5-FU and AGBE induced cell apoptosis markedly. Cell cycle assay showed that AGBE mainly arrested SW-480 cells in the G2/M phase. 5-FU increased the percentage of SW-480 cells at the S phase of the cell cycle. The assay of combined treatment groups indicated that AGBE can heighten the arrest of SW-480 cells in the S phase induced by 5-FU, and increase the cell distribution in G2/M phase compared with 5-FU applied alone. The trend of increasing cyclin A was similar to the increase of S and G2/M phase cells in all treated groups. The enhancement of S and G2/M phase arrest, rather than cell apoptosis, should be the mechanism of synergistic effects of AGBE on 5-FU. Further in vivo and clinical trials are needed to test AGBE as a valuable chemo-adjuvant.

Methylnaltrexone reduced body weight gain in ob/ob mice

OBJECTIVE

Opioids may function to regulate food intake and body weight, an activity that could be predominantly centrally mediated. In this study, the authors evaluated the effects of a peripherally acting opioid receptor antagonist, methylnaltrexone, on weight changes in adult obese ob/ob mice.

RESULTS

After a 12-day treatment with naloxone 0.3 mg/kg, weight was reduced from 63.7 +/- 1.1 g in the control group to 59.2 +/- 0.9 g in the naloxone group (p < 0.05). After a 12-day treatment with methylnaltrexone 3.0 mg/kg, weight increase completely ceased. The body weight was 63.9 +/- 1.0 g in the control group when compared with 55.9 +/- 1.2 g in the drug group (p < 0.01). The effect of methylnaltrexone (1.0 mg to 3.0 mg/kg) on weight changes was dose-dependent (p < 0.01). Methylnaltrexone significantly reduced daily food intake (p < 0.05), but did not affect body temperature and energy expenditure. Using HPLC analysis, no detectable naltrexone levels were found in association with methylnaltrexone administration. Whether the observed methylnaltrexone effects are primarily related to the antagonism of endorphinergic system remains to be investigated.

CONCLUSIONS

Our results suggest that the peripheral opioid mechanism contributes to modulating food ingestion and methylnaltrexone may have clinical importance in obesity management.

Antioxidants potentiate American ginseng-induced killing of colorectal cancer cells

Colorectal cancer is the third leading cause of cancer-related deaths in the United States. Novel prevention or therapeutic agents are needed to better manage this disease. American ginseng is a commonly used herb and is believed to have lots of health benefits, including anti-cancer activities. However there have been very few in-depth studies of the activities of this herb at the molecular level. In this report we showed that 4h-steamed American ginseng root extract (S4h) induced mitochondrial damage, increased reactive oxygen species (ROS), and apoptosis in colorectal cancer cells. We showed that the NF-kappaB pathway was activated by S4h and that removal of ROS inhibited S4h-induced NF-kappaB activation. We further showed that both antioxidants and a specific inhibitor of the NF-kappaB pathway enhanced S4h-induced cell death. Finally, we showed that protecting the mitochondria decreased both the level of ROS and apoptosis. Taken together, these results indicate that S4h-induced apoptosis in colorectal cancer cells is mediated by mitochondria damage and that damage to the mitochondria activates both the apoptosis pathway and the ROS/NF-kappaB mediated survival pathway. These results further suggest that the anti-cancer effect of steamed ginseng can be enhanced by antioxidants or inhibitors of the NF-kappaB pathway.

Protease inhibitor-induced nausea and vomiting is attenuated by a peripherally acting, opioid-receptor antagonist in a rat model

BACKGROUND

Protease inhibitors such as ritonavir can cause nausea and vomiting which is the most common reason for discontinuation. Rats react to nauseous and emetic stimuli by increasing their oral intake of non-nutritive substances like kaolin, known as pica behavior. In this study, we evaluated the effects of methylnaltrexone, a peripherally acting mu-opioid receptor antagonist that does not affect analgesia, on ritonavir-induced nausea and vomiting in a rat pica model.

RESULTS

We observed that 24 to 48 hr after administration of oral ritonavir 20 mg/kg, kaolin consumption increased significantly in rats (P < 0.01). This increase was attenuated by pretreatment with an intraperitoneal injection of methylnaltrexone (0.3-3.0 mg/kg) in a dose dependent manner (P < 0.01) and also with naloxone (0.1-0.3 mg/kg) (P < 0.01). The areas under the curve for kaolin intake from time 0 to 120 hr were significantly reduced after administration of the opioid antagonists. Food intake was not significantly affected. Plasma naltrexone levels were measured after methylnaltrexone injection, and no detectable levels were found, indicating that methylnaltrexone was not demethylated in our experimental paradigm.

CONCLUSION

These results suggest that methylnaltrexone may have potential clinical utility in reducing nausea and vomiting in HIV patients who take ritonavir.

Methylnaltrexone, a peripherally acting opioid receptor antagonist, enhances tumoricidal effects of 5-Fu on human carcinoma cells

BACKGROUND

Methylnaltrexone, a novel peripherally acting opioid receptor antagonist, is used to treat opiate-induced constipation in cancer patients. Its effects on the activities of chemotherapeutic agents, however, have not been evaluated. In this study, the effect of methylnaltrexone on the action of 5-fluorouracil (5-FU) was tested in three human cancer cell lines.

MATERIALS AND METHODS

Treatment was for 72 h and the effects on cell proliferation were measured in human SW-480 colorectal cancer cells, MCF-7 breast cancer cells and non-small cell lung cancer cells in vitro. The apoptotic effect was analyzed by using flow cytometry. The cell cycle and expression of cyclin A were assayed after staining with propidium iodide and cyclin A-fluorescein isothiocyanate.

RESULTS

5-FU decreased the cancer cell growth significantly in all three cancer cell lines in a concentration-dependent manner and methylnaltrexone enhanced the actions of 5-FU. Compared to 5-FU 10 muM alone on SW-480 cells (63.5+/-1.1%), on MCF-7 cells (58.3+/-3.1%), or on non-small cell lung cancer cells (81.3+/-1.6%), 5-FU 10 muM plus methylnaltrexone 1.0 muM reduced cancer cell growth in all three cell lines to 50.2+/-2.9% for SW-480 cells (p<0.05), 50.0+/-1.7% for MCF-7 cells (p<0.05) and 68.7+/-2.2% for lung cancer cells (p<0.01). Methylnaltrexone alone also showed anti-proliferative activity in the three cell lines. Methylnaltrexone at 1.0 muM, reduced SW-480 cell growth to 81.9+/-3.7% (p<0.01), MCF-7 cell growth to 85.9+/-2.4% (p<0.01) and lung cancer cell growth to 85.5+/-2.2% (p<0.01). Apoptosis was not induced by treatment of SW-480 cells with 1.0 or 10 muM methylnaltrexone for 48 h. However, methylnaltrexone increased the number of cells in the G(1)-phase and decreased the expression of cyclin A.

CONCLUSION

At its therapeutic concentrations for opioid-induced constipation, methylnaltrexone does not attenuate and in fact may enhance the tumoricidal activity of 5-FU. Enhanced 5-FU activity may be attributed to the distinct pathways of 5-FU and methylnaltrexone, an effect that could give methylnaltrexone a complementary role in the treatment of cancer with chemotherapeutic agents.

The mitochondrial pathway is involved in American ginseng-induced apoptosis of SW-480 colon cancer cells

Numerous effective anticancer drugs have been developed from botanical sources, and there remains a significant untapped resource in herbal medicines. In this study, we evaluated the chemical composition of extracts from American ginseng after steaming, the antiproliferative effects of the ginsenosides in the extracts on SW-480 human colorectal cancer cells, and their apoptotic mechanisms. American ginseng roots were steamed at 120 degrees C for 2 or 4 h. Representative ginsenosides in the unsteamed and steamed extracts were determined using HPLC. The antiproliferative effects of the ginsenosides Rb1, Rg3 and Rh2 on SW-480 cells were determined by the MTS method. The effect of extract steamed for 4 h on apoptosis of SW-480 cell was assayed by flow cytometry after staining with annexin V/PI. The expression of 84 apoptotic-related genes, including TNF, mitochondria and p53 pathways, was determined using real-time quantitative PCR array analysis. The mitochondrial membrane potential (Deltapsim) was analyzed after staining with FC-1. Steaming of American ginseng increased Rg3 and Rh2 content and antiproliferative activity significantly. The quantitative PCR array data demonstrated that multiple genes in mitochondrial pathway are involved in American ginseng-induced apoptosis of SW-480 cells and the expression profiling was validated by the cellular functional assay. The mitochondrial pathway may play a key role in American ginseng-mediated cancer cell apoptosis.

Asian ginseng enhances the anti-proliferative effect of 5-fluorouracil on human colorectal cancer: comparison between white and red ginseng

Previous studies showed that Asian ginseng, Panax ginseng C.A. Meyer, may have anti-cancer properties. However, there is limited data exploring the use of Asian ginseng as an adjuvant to chemotherapy, and minimal mechanistic studies related to their possible synergistic activities. In this study, the content of 8 ginsenosides, Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1 and Rg3, in the extracts of white ginseng (WG) and red ginseng (RG) were determined by HPLC. Using HCT-116 human colorectal cancer cells, we compared the efficacy of WG and RG. We evaluated the synergy between ginseng and 5-fluorouracil (5-FU), and explored the mechanism of their anti-proliferative effects. As single extract, WG or RG used at concentrations of 0.1, 0.2 and 0.3 mg/mL, inhibited HCT-116 cell proliferation in a concentration-related manner. WG at 0.2 mg/mL did not show obvious synergy with 5-FU co-treatment, while RG at 0.2 and 0.3 mg/mL significantly enhanced the anti-proliferative effects of 5-FU at concentrations of 10, 50 and 100 microM (P < 0.05). Using flow cytometric assay, RG 0.3 mg/mL did not affect cancer cell apoptotic induction activity. However, the RG induced cell cycle arrest in the G1 phase, while 5-FU arrested the cell in the S phase. Different ginsenoside profiles are responsible for the observed differences in pharmacological effects. The effects of 8 ginsenosides on HCT-116 cells were assayed. Rd and Rg3 showed positive anti-proliferative effect. Our data suggested a potential for RG as an adjuvant therapy in the treatment of colorectal cancer, via a synergistic action.

Anti-diabetic effect of American ginseng may not be linked to antioxidant activity: comparison between American ginseng and Scutellaria baicalensis using an ob/ob mice model

Antioxidants have been considered as a useful remedy in diabetes therapeutics, and thus, herbal medicines with antioxidant properties may play major role in treating diabetes. In this report, we performed a comparative study using American ginseng and Scutellaria baicalensis to test whether the anti-diabetic effect of American ginseng is associated with its antioxidant activity. We used a simple water extraction procedure to prepare American ginseng root extract (AGE) and S. baicalensis extract (SbE), and utilized these two antioxidant herbs to evaluate their anti-diabetic effect in obese diabetic ob/ob mice. HPLC analysis was used to identify major constituents in the AGE and SbE. After 12 days of daily intraperitoneal injection, AGE at 300 mg/kg showed significant effects on fasting blood glucose levels (P<0.01) and glucose tolerance test (P<0.01) compared to vehicle-treated mice. Animal body weights also reduced significantly after 12-day treatment (P<0.01). However, SbE, a very strong antioxidant extract, administered at 5-50 mg/kg (based on our previous studies without adverse events) for 12 days did not show any significant effects on blood glucose and body weight changes. No effects were shown when baicalein, an effective antioxidant constituent in SbE, was administered at 1-5 mg/kg. It appears that the anti-diabetic effect of American ginseng may not be linked to its antioxidant actions. The mechanisms of American ginseng's effects on reducing high blood glucose levels and body weight remain to be investigated in future experiments.

Potential role of ginseng in the treatment of colorectal cancer

Colorectal cancer remains one of the most prevalent cancer and a leading cause of cancer related death in the US. Many currently used chemotherapeutic agents are derived from botanicals. Identifying herbal sources, including those from ginseng family, to develop better anti-cancer therapies remains an essential step in advancing the treatment of the cancer. In this article, potential roles of ginseng herbs, especially American ginseng and notoginseng, in colorectal cancer therapeutics are presented. The major pharmacologically active constituents of ginsengs are ginsenosides, which can be mainly classified as protopanaxadiol and protopanaxatriol groups. Structure-activity relationship between their chemical structures and pharmacological activities are discussed. In addition, various steaming temperature and time treatment of the ginseng herbs can change ginsenoside profiles, and enhance their anti-cancer activities. This heat treatment process may increase the role of ginseng in treating colorectal cancer.

Antiproliferative effects of different plant parts of Panax notoginseng on SW480 human colorectal cancer cells

The chemical constituents and antiproliferative effects on SW480 human colorectal cancer cells of different plant parts of P. notoginseng were evaluated. The contents of saponins in extracts from root, rhizome, flower and berry of P. notoginseng were determined using high performance liquid chromatography. The contents and proportions of saponins were different among the four plant parts. Using the cell counting method, the antiproliferative effects were evaluated and the results indicated all four extracts, at 0.05-1.0 mg/mL, showed concentration-related antiproliferative effects on the cancer cells. The flower extract had stronger effects compared with the other three extracts; at 1.0 mg/mL, it inhibited the cell growth by 93.1% (p < 0.01). The antiproliferative effects of major saponins in notoginseng, notoginsenoside R1, ginsenosides Rb1, Rb3 and Rg1, were also evaluated, and the observed effects of major constituents support the pharmacological activities of extracts. The effects of notoginseng extracts on cell cycle and apoptosis of SW480 cells were determined using flow cytometry. Notoginseng extract can arrest the cells in S and G2/M phases. Remarkably apoptosis induction activities of notoginseng extracts were observed with the flower extract possessing the most potent effect, supporting the antiproliferative effect.

Antioxidant protection by American ginseng in pancreatic beta-cells

Hyperglycemia in diabetic conditions may cause oxidative stress in pancreatic beta-cells, leading to their dysfunction and insulin resistance within peripheral tissues. Previous studies suggest that American ginseng berry extract may have hypoglycemic effects, as well as offer antioxidant protection. We examined effects of American ginseng berry extract and ginsenoside Re in a pancreatic beta-cell line, MIN-6, to determine if these two properties are related. Cells were exposed to oxidative stress via hydrogen peroxide incubation and oxidative stress was measured by oxidation of 2',7'-dichlorofluorescin diacetate. These cells showed a concentration-related response to hydrogen peroxide at 100-500 microM. In acute conditions where cells were treated with the extract for 10 min, we observed reduced oxidant injury suggesting direct scavenging effects. Chronic incubation of cells with the extract for 48 hours also demonstrated attenuation of oxidative stress. At high concentrations, Re showed a mild antioxidant effect in MIN-6 cells. Our insulin release observations also showed that the extract may help to increase insulin secretions from the cells. Our data suggest that the observed ability of ginseng to reduce blood glucose levels may be linked to its antioxidant effects on pancreatic beta-cells.

Reversal of opioid-induced gastric dysfunction in a critically ill burn patient after methylnaltrexone

Peripheral-acting mu opiate receptor antagonists have been extensively studied for the treatment of opiate-induced constipation in advanced illness for the prophylaxis of postoperative ileus. We document the first intensive care patient to receive methylnaltrexone in an attempt to facilitate enteral nutrition. Gastric residuals markedly decreased and enteral feeding increased after administration of i.v. methylnaltrexone. The patient's ileus resolved coincident with the first injection.

Chemopreventive effects of heat-processed Panax quinquefolius root on human breast cancer cells

BACKGROUND

Former studies have shown that extract from American ginseng (Panax quinquefolius) may possess certain antiproliferative effects on cancer cells. In this study, the chemical constituents of both untreated and heat-processed American ginseng and their antiproliferative activities on human breast cancer cells were evaluated.

MATERIALS AND METHODS

American ginseng roots were steamed at 120 degrees C for 1 h or 2 h. The major ginsenosides in the two steamed and in the unsteamed extracts were quantitatively determined using high performance liquid chromatography (HPLC). The antiproliferative activities of these extracts and individual ginsenosides on MCF-7 and MDA-MB-231 breast cancer cells were assayed using the MTS method. The effects of the extracts and the ginsenosides on the induction of cell apoptosis, the expression of cyclins A and D1, and cell cycle arrest were evaluated.

RESULTS

Compared to the untreated extract, heat-processing reduced the content of ginsenosides Rb1, Re, Rc and Rd, and increased the content of Rg2 and Rg3. After 2 h steaming, the percent content of ginsenoside Rg3 was increased from 0.06% to 5.9%. Compared to the unsteamed extract, the 2 h steamed extract significantly increased the antiproliferative activity and significantly reduced the number of viable cells. The steamed extract also significantly reduced the expression of cyclin A and cyclin D1. The cell cycle assay showed that the steamed extract and ginsenoside Rg3 arrested cancer cells in G1-phase.

CONCLUSION

Heat-processing of American ginseng root significantly increases antiproliferative activity and influences the cell cycle profile.

Pharmacokinetic and metabolic effects of American ginseng (Panax quinquefolius) in healthy volunteers receiving the HIV protease inhibitor indinavir

BACKGROUND

Complementary and alternative medicine (CAM) use is prevalent among HIV-infected patients to reduce the toxicity of antiretroviral therapy. Ginseng has been used for treatment of hyperglycemia and insulin resistance, a common side effect of some HIV-1 protease inhibitors (PI). However, it is unknown whether American ginseng (AG) can reverse insulin resistance induced by the PI indinavir (IDV), and whether these two agents interact pharmacologically. We evaluated potential pharmacokinetic interactions between IDV and AG, and assessed whether AG improves IDV-induced insulin resistance.

METHODS

After baseline assessment of insulin sensitivity using the insulin clamp technique, healthy volunteers received IDV 800 mg q8 h for 3 days and then IDV and AG 1g q8h for 14 days. IDV pharmacokinetics and insulin sensitivity were assessed before and after AG co-administration.

RESULTS

There was no difference in the area-under the plasma-concentration-time curve after the co-administration of AG, compared to IDV alone (n = 13). Although insulin-stimulated glucose disposal per unit of insulin (M/I) decreased by an average of 14.8 +/- 5.9% after 3 days of IDV (from 0.113 +/- 0.012 to 0.096 +/- 0.014 mg/kgFFM/min per muU/ml of insulin, p = 0.03, n = 11), M/I remained unchanged after co-administration of IDV and AG.

CONCLUSION

IDV decreases insulin sensitivity, which is unaltered by AG co-administration. AG does not significantly affect IDV pharmacokinetics.

Characterization of gene expression regulated by American ginseng and ginsenoside Rg3 in human colorectal cancer cells

American ginseng (Panax quinquefolius L., Araliaceae) possesses anti-cancer potential and is one of the most commonly used herbal medicines in the United States. Ginsenoside Rg3, one of the saponins in American ginseng, has been shown to inhibit tumor growth. In this study, we sought to characterize the downstream genes targeted by American ginseng extracts in HCT-116 human colorectal cancer cells. We first demonstrated that the content of Rg3 in American ginseng steamed at 120 degrees C for 2 h (referred to as S2h) was significantly increased when compared with that of the unsteamed ginseng. Both S2h and Rg3 exhibited antiproliferative effects on HCT-116 cells. Using the Affymetrix high density genechips containing more than 40,000 genes and ESTs, the gene expression profiling of HCT-116 cells were assayed. Microarray data indicated that the expression levels of 76 genes were changed significantly after treatment with S2h or Rg3, whereby it was found that 52 of the 76 genes were up-regulated while the remaining 24 were down-regulated. Ingenuity pathways analysis of top functions affected by both S2h and Rg3 were carried out. The most effected pathway is the Ephrin receptor pathway. To validate the microarray data, quantitative real-time PCR of six candidate target genes was conducted, whereby it was found that three genes were up-regulated (AKAPA8L, PMPCB and PDE5A) and three were down-regulated (PITPNA, DUS2L and RIC8A). Although further studies are needed to elucidate the mechanisms of action, our findings should expand the understanding of the molecular framework of American ginseng as an anti-cancer agent.

American ginseng berry juice intake reduces blood glucose and body weight in ob/ob mice

Diabetes is a serious chronic metabolic disease and has a significant impact on patients' lives and the health care system. We previously observed that the organic solvent extract of American ginseng berry possessed significant antidiabetic effects in obese diabetic ob/ob mice after intraperitoneal injection. If American ginseng berry is useful as a dietary supplement, simple preparation and oral intake would be a convenient, safe, and practical means for consumers. In this study, the simply prepared berry juice was first analyzed using high-performance liquid chromatography, and then administered orally in the ob/ob mice. The animals received daily berry juice 0.6 mL/kg or vehicle for 10 consecutive days. The results indicated that oral juice administration significantly lowered fasting blood glucose levels, and this effect continued for at least 10 d after cessation of the treatment. Data from intraperitoneal glucose tolerance test demonstrated that there was a notable improvement in glucose tolerance in the juice treated group. In addition, the berry juice significantly reduced body weight. Our data suggest that ginseng berry juice, as a dietary supplement, may have functional efficacy in consumers with diabetes.

Commonly used antioxidant botanicals: active constituents and their potential role in cardiovascular illness

Cardiovascular disease continues to be the leading cause of death in the US. Recent studies found that reactive oxygen species (ROS) have been incriminated in the pathogenesis of both acute and chronic heart disease. Many botanicals possess antioxidant properties, and these herbal antioxidants may protect against cardiovascular diseases by contributing to the total antioxidant defense system of the human body. In this article, we reviewed the antioxidant components and properties of four putative antioxidant botanicals (i.e., grape seeds, green tea, Scutellaria baicalensis, and American ginseng), and their potential role in treating cardiovascular illness. The antioxidant activities of the herbal active constituents, and the relationship between their chemical structures and biological functions were also discussed. Further investigations are needed on the mechanisms of action of these botanicals as they affect salient cellular and molecular pathways involved in major diseases. Data obtained from future studies will have the potential for translation into practical benefits for human health.

Chemopreventive effects of Panax notoginseng and its major constituents on SW480 human colorectal cancer cells

In this study, we evaluated the effects of Panax notoginseng root extract (NGRE) and its major constituents on SW480 human colorectal cancer cells. We used high performance liquid chromatography to determine the contents of major saponins in NGRE. The anti-proliferative effects were evaluated by the cell counting method, and concentration-related anti-proliferative effects were observed. At 1.0 mg/ml, NGRE inhibited cell growth by 85.8% (P<0.01), probably linked to the higher concentration of ginsenosides Rb1 and Rg1. The pharmacologic activities of notoginsenoside R1 and ginsenosides Rg1 and Rb1 on the cells were antiproliferative. We tested the effects of NGRE on DNA synthesis by measuring [3H]-thymidine incorporation. NGRE induced cell apoptosis at 0.5 and 1 mg/ml. Two-day treatment with 300 microM of notoginsenoside R1, ginsenosides Rg1 and Rb1 increased cell apoptosis significantly. Cell cycle and cyclin A assay showed that NGRE arrested cells in the synthesis phase and increased the expression of cyclin A remarkably. NGRE also enhanced the actions of two chemotherapeutic agents, 5-fluorouracil and irinotecan. Cell growth decreased more with the combined treatment of NGRE and 5-fluorouracil (or irinotecan) than with the chemotherapy agent applied alone, suggesting that notoginseng can reduce the dose of 5-fluorouracil (or irinotecan) needed to achieve desired effects. Further in vivo and human trials are warranted to test whether notoginseng is a valuable chemo-adjuvant with clinical validity.

Scutellaria baicalensis and a constituent flavonoid, baicalein, attenuate ritonavir-induced gastrointestinal side-effects

Ritonavir, a protease inhibitor drug, is commonly used in AIDS therapy. As with other chemotherapeutic drugs that cause gastrointestinal adverse effects, ritonavir treatment is associated with significant nausea and vomiting. This study investigated whether Scutellaria baicalensis, and its active flavonoid constituent, baicalein, attenuate the gastrointestinal effects of ritonavir. The effects of herb administration were evaluated in ritonavir-treated rats using a rat pica model, which simulates nausea and vomiting in humans. The effects of herb administration on gastric emptying in rats were also measured. Ritonavir treatment resulted in increased kaolin intake or severe pica, the intensity of which was reduced significantly with S. baicalensis administration (1 mg kg(-1); P<0.05). High-performance liquid chromatography analysis of S. baicalensis showed the presence of an extremely potent flavonoid constituent, baicalein. The study aimed to determine if baicalein contributed to the anti-pica effect of the extract. It was observed that baicalein dose-dependently decreased pica in ritonavir-treated rats (P<0.001). In addition to inducing pica, ritonavir also significantly delayed gastric emptying, which could contribute to ritonavir-induced gastrointestinal dysfunction. When S. baicalensis extract was administered to ritonavir-treated rats the delayed gastric emptying was significantly attenuated (P<0.05). The results suggest that S. baicalensis and the constituent baicalein reduce the gastrointestinal dysfunction caused by ritonavir. It is concluded that S. baicalensis may potentially have a role to play in reducing drug-induced adverse effects.

Simultaneous identification of Bulbus Fritillariae cirrhosae using PCR-RFLP analysis

Bulbus Fritillariae (BF) is the most commonly used antitussive herb in China. There are nine species of Fritillaria recorded as the drug BF in the Chinese Pharmacopoeia. Bulbus Fritillariae cirrhosae (BF cirrhosae) is a group that includes four species of BF; these four species come from wild sources with higher efficiency and lower toxicity compared to the other five species of BF. Due to reasons of carelessness and reduced costs, the other five species are often sold as BF cirrhosae. Analysis through appearance, microscopic and chemical techniques has limitations. Identifying botanical resources is a primary step in the standardization of herbal medicine. In the present article, the internal transcribed spacer 1 (ITS1) regions of the nuclear ribosomal DNA (nrDNA) of nine species and one variety of Fritillaria genus have been sequenced. A mutation site in the ITS1 region among BF cirrhosae and other species of BF has been found and can be recognized by the restriction endonuclease SmaI. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the nuclear ribosomal ITS1 region was used to differentiate BF cirrhosae from other species of BF and is a successful method in distinguishing the subgroups.

Red American ginseng: ginsenoside constituents and antiproliferative activities of heat-processed Panax quinquefolius roots

Red Asian ginseng ( Panax ginseng C. A. Meyer, Araliaceae) is used in many Oriental countries. In this study, the saponin constituents and anticancer activities of steamed American ginseng ( Panax quinquefolius L.) roots were evaluated. The contents of 12 ginsenosides in the roots were determined using high performance liquid chromatography (HPLC). After the steaming treatment (100 - 120 degrees C for 1 h and 120 degrees C for 0.5 - 4 h), the quantity of 7 ginsenosides decreased and that of 5 others increased. The content of ginsenoside Rg3, a previously recognized anticancer compound, increased significantly when the root was steamed at 120 degrees C for 0.5 - 3 h. The antiproliferative effects of unsteamed and steamed (120 degrees C for 1 h and 2 h) American ginseng root extracts were assayed by the modified trichrome stain (MTS) method using three cancer cell lines (SW-480, HT-29, NSCLC). Heat-processing increased the antiproliferative effect of American ginseng significantly, and the activity of the extract from roots steamed for 2 h was greater than that of roots steamed for 1 h. Chemical constituents and antiproliferative activities of white and red Asian ginseng have also been evaluated. Five representative ginsenosides, Rb1, Rd, Re, Rg2 and Rg3, were studied. Ginsenoside Rg3 had the most potent effect. The antiproliferative activities of red American ginseng are augmented when ginsenoside Rg3 is increased.

Discrimination of Lonicera japonica THUNB. from different geographical origins using restriction fragment length polymorphism analysis

Lonicera japonica THUNB. is a commonly used anti-inflammatory herbal medicine. The therapeutic effectiveness of L. japonica depends significantly on its geographical origin. However, it is difficult to define criteria for confirming geographical authenticity using microscopic and chemical characteristics. In the present study, the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA loci of L. japonica from different origins and related species was sequenced. The mutation site found in the ITS region from geo-authentic L. japonica can be recognized by the restriction endonuclease EcoN I. Since PCR products from geo-authentic L. japonica cannot be digested completely, a quantitative restriction fragment length polymorphism analysis method was developed. The cleavage rate of PCR products by EcoN I was determined to be more than 70% in all geo-authentic L. japonica and less than 20% in non-geo-authentic L. japonica and other species from genus Lonicera. The rate correlated remarkably with the geographical origin of L. japonica. Therefore, this method can be used to classify geo-authentic L. japonica.

Methylnaltrexone mechanisms of action and effects on opioid bowel dysfunction and other opioid adverse effects

OBJECTIVE

To review the mechanisms of action of methylnaltrexone and its effects on opioid bowel dysfunction, as well as its effects on other opioid-induced adverse effects (ADEs), and its potential roles in clinical practice.

DATA SOURCES

A literature search using the MEDLINE and Cochrane Collaboration databases for articles published between 1966 and March 2007 was performed. Additional data sources were obtained from manual searches of recent journal articles, book chapters, and monographs. An updated literature search showed no additional publications.

STUDY SELECTION AND DATA EXTRACTION

Abstracts and original preclinical and clinical research reports published in the English language were identified for review. Review articles, commentaries, and news reports of this compound were excluded. Literature related to opioids, opioid receptors, opioid antagonists, methylnaltrexone, opioid-induced bowel dysfunction, constipation, nausea, and vomiting was evaluated and selected based on consideration of the support shown for the proof of concept, mechanistic findings, and timeliness. Fifty-eight original articles from preclinical studies and clinical trials using methylnaltrexone were identified. Pharmacologic action, benefits, and ADEs of methylnaltrexone were reviewed, with a focus on its effects on bowel dysfunction after opioids. Emphases were placed on its receptor binding activities and therapeutically relevant sites of action (peripheral vs central), in which peripheral opioid receptors in the body contribute to physiological and drug-induced effects.

DATA SYNTHESIS

Morphine and related opioids are associated with a number of limiting ADEs, including opioid-induced bowel dysfunction. Methylnaltrexone, a quaternary derivative of naltrexone, blocks peripheral effects of opioids while sparing central analgesic effects. It is currently under late-stage clinical investigation for the treatment of opioid-induced constipation in patients with advanced illness. Reported results showed the drug to be generally well-tolerated. The rapid reversal of constipation is very encouraging. Hastening postoperative discharge may also be possible.

CONCLUSIONS

Methylnaltrexone has the potential to prevent or treat opioid-induced peripherally mediated ADEs on bowel dysfunction without interfering with central analgesia. The study of methylnaltrexone leads to a greater understanding of the mechanisms of action of opioid pharmacology.

Comparative effects of flavonoids on oxidant scavenging and ischemia-reperfusion injury in cardiomyocytes

Since flavonoids scavenge reactive oxygen species, they may potentially protect against ischemia/reperfusion injury. This study compared the scavenging capacity of specific flavonoids towards different reactive oxygen species. Whether the differential oxidant scavenging capacity correlated with their protective efficacy in ischemia/reperfusion injury of cardiomyocytes was determined. The free radical scavenging capacity of five flavonoids (wogonin, baicalin, baicalein, catechin and procyanidin B2) was analyzed using electron spin resonance spectrometry for 3 radicals: 1,1-diphenyl-2picrylhydrazyl (DPPH), superoxide and hydroxyl radical. A well-established chick cardiomyocyte model of ischemia (1 h)/reperfusion (3 h) was used to evaluate flavonoid-induced protection against ischemia/reperfusion injury in chronic treatment (pretreated 72 h and treated through ischemia/reperfusion) and acute treatment protocols (during ischemia/reperfusion or only at reperfusion). The cell viability was assessed by propidium iodide. The DPPH scavenging was most significant with catechin, followed by procyanidin B2, baicalein, baicalin, and wogonin. The superoxide scavenging was, similarly, most significant with catechin, followed by baicalein, procyanidin B2, and baicalin. For hydroxyl radical, only baicalein showed a significant scavenging capacity (>50% reduction in ESR signal). For the cardiomyocyte studies, all flavonoids but wogonin showed protection against ischemia/reperfusion injury in the chronic treatment protocol. When flavonoids were administered only during ischemia/reperfusion, baicalein, procyanidin B2, and catechin significantly reduced cell death. If flavonoids were administered just at reperfusion, only baicalein and procyanidin B2 had protective effects, and the efficacy was less. Flavonoids possess specific but differential radical scavenging capacity, which, in conjunction with the timing of treatment, affects their protective efficacy in cardiomyocytes exposed to ischemia/reperfusion.

Steamed American ginseng berry: ginsenoside analyses and anticancer activities

This study was designed to determine the changes in saponin content in American ginseng berries after treatment by heating and to assess the anticancer effects of the extracts. After steaming treatment (100-120 degrees C for 1 h, and 120 degrees C for 0.5-4 h), the content of seven ginsenosides, Rg1, Re, Rb1, Rc, Rb2, Rb3, and Rd, decreased; the content of five ginsenosides, Rh1, Rg2, 20R-Rg2, Rg3, and Rh2, increased. Rg3, a previously identified anticancer ginsenoside, increased significantly. Two hours of steaming at 120 degrees C increased the content of ginsenoside Rg3 to a greater degree than other tested ginsenosides. When human colorectal cancer cells were treated with 0.5 mg/mL steamed berry extract (120 degrees C 2 h), the antiproliferation effects were 97.8% for HCT-116 and 99.6% for SW-480 cells. At the same treatment concentration, the effects of unsteamed berry extract were 34.1% for HCT-116 and 4.9% for SW-480 cells. After staining with Hoechst 33258, apoptotic cells increased significantly by treatment with steamed berry extract compared with unheated extracts. Induction of apoptosis activity was confirmed by flow cytometry after staining with annexin V/PI. The steaming of American ginseng berries augments ginsenoside Rg3 content and increases the antiproliferative effects on two human colorectal cancer cell lines.

Chronic pretreatment with American ginseng berry and its polyphenolic constituents attenuate oxidant stress in cardiomyocytes

The acute anti-oxidant and protective effect of American ginseng berry extract (AGBE) has been demonstrated in cultured cardiomyocytes in our previous study. In the current study we evaluated if a chronic pretreatment of cultured cardiomyocytes with AGBE can alter the cellular antioxidant potential. Chick embryo cardiomyocytes were treated with AGBE (0.5-2.5 mg/ml) for up to 72 h. The treated cells were then exposed to exogenously added hydrogen peroxide (H(2)O(2); 500 microM). The oxidant-mediated injury was measured using a fluorescent probe 2',7'-dichlorofluorescin diacetate (DCFH/DA) while cell death was measured using propidium iodide (PI) staining. The non-treated (control) cells exposed to H(2)O(2) showed significant increase in DCF- and PI-mediated fluorescence suggesting significant oxidative injury and cell death. Pretreatment with AGBE demonstrated a significant attenuation of DCF fluorescence (p<0.005) with AGBE 0.5 mg/ml showing a 17% decrease, AGBE 1.0 mg/ml showing a 26% decrease, and AGBE 2.5 mg/ml showing a 49% decrease from control DCF fluorescence following a 72 h pretreatment. Cell death caused by H(2)O(2) was also significantly attenuated in AGBE-pretreated cells in a concentration- and time-dependent manner (p<0.005). We also demonstrated that active polyphenolic constituents in AGBE, caffeic acid and chlorogenic acid, appear to contribute significantly to AGBE's protective effects. Finally, catalase inhibition resulted in a significantly increased fluorescence in AGBE-treated cells compared to the control. The results suggest that pretreatment with AGBE upregulates peroxide detoxifying mechanisms, which could affect intracellular oxidant dynamics in cardiomyocytes.

Notoginseng enhances anti-cancer effect of 5-fluorouracil on human colorectal cancer cells

PURPOSE

Panax notoginseng is a commonly used Chinese herb. Although a few studies have found that notoginseng shows anti-tumor effects, the effect of this herb on colorectal cancer cells has not been investigated. 5-Fluorouracil (5-FU) is a chemotherapeutic agent for the treatment of colorectal cancer that interferes with the growth of cancer cells. However, this compound has serious side effects at high doses. In this study, using HCT-116 human colorectal cancer cell line, we investigated the possible synergistic anti-cancer effects between notoginseng flower extract (NGF) and 5-FU on colon cancer cells.

METHODS

The anti-proliferation activity of these modes of treatment was evaluated by MTS cell proliferation assay. Apoptotic effects were analyzed by using Hoechst 33258 staining and Annexin-V/PI staining assays. The anti-proliferation effects of four major single compounds from NGF, ginsenosides Rb1, Rb3, Rc and Rg3 were also analyzed.

RESULTS

Both 5-FU and NGF inhibited proliferation of HCT-116 cells. With increasing doses of 5-FU, the anti-proliferation effect was slowly increased. The combined usage of 5-FU 5 microM and NGF 0.25 mg/ml, significantly increased the anti-proliferation effect (59.4 +/- 3.3%) compared with using the two medicines separately (5-FU 5 microM, 31.1 +/- 0.4%; NGF 0.25 mg/ml, 25.3 +/- 3.6%). Apoptotic analysis showed that at this concentration, 5-FU did not exert an apoptotic effect, while apoptotic cells induced by NGF were observed, suggesting that the anti-proliferation target(s) of NGF may be different from that of 5-FU, which is known to inhibit thymidilate synthase.

CONCLUSIONS

This study demonstrates that NGF can enhance the anti-proliferation effect of 5-FU on HCT-116 human colorectal cancer cells and may decrease the dosage of 5-FU needed for colorectal cancer treatment.

Curry leaf (Murraya koenigii Spreng.) reduces blood cholesterol and glucose levels in ob/ob mice

We observed that curry leaf (Murraya koenigii) extract possesses the property to decrease blood cholesterol and blood glucose levels in diabetic ob/ob mice. Mice received daily intraperitoneal injections of 80 mg/kg curry leaf extract for 10 consecutive days. The extract significantly decreased blood cholesterol level from 277.6 +/- 16.6 mg/d (day 0) to 182.0 +/- 15.3 mg/d (day 10, p < 0.01 compared with the change in vehicle group). The extract also significantly decreased blood glucose level from 387.0 +/- 15.6 mg/dl (day 0) to 214.0 +/- 26.6 mg/dl (day 10, p < 0.01). In addition, body weight was reduced after extract treatment. Our data suggest that curry leaf may be proved to be of clinical importance in improving the management of high cholesterol level and type 2 diabetes.

Cisplatin's tumoricidal effect on human breast carcinoma MCF-7 cells was not attenuated by American ginseng

PURPOSE

We previously observed that American ginseng berry and ginsenoside Re attenuated cisplatin-induced emesis in a rat model, suggesting that the herb may have a value in treating chemotherapy-induced nausea/vomiting. However, it is not clear whether consuming ginseng concurrently with chemotherapy affects the efficacy of chemotherapeutic agents. In this study, we explored if the ginseng extract and its constituents, ginsenosides Rb1, Rb3, and Re, alter tumoricidal activity of cisplatin in human cancer cells.

METHODS

Tumoricidal effects of cisplatin, and/or American ginseng berry extract (AGBE) and ginsenosides Rb1, Rb3, and Re, on human breast carcinoma MCF-7 cells were measured as cell proliferation in vitro. Cell counts were performed in MCF-7 cells pretreated with test agents for 72 h.

RESULTS

Cisplatin decreased MCF-7 cell proliferation significantly in a concentration-dependent manner. Compared to control group, cisplatin reduced the cell proliferations to 56.5+/-3.3% at 1 microg/ml, to 36.6+/-2.4% at 5 microg/ml, and to 26.9+/-2.4% at 15 microg/ml (P<0.01). AGBE also inhibited the cell proliferation significantly, although in a less extended manner. When the berry extract at 0.5 mg/ml was used with cisplatin at 1 microg/ml, a significant enhancement of cisplatin's activity was observed (35.8+/-2.5%; P<0.05). We also observed that Rb1 did not change cisplatin's activity; Rb3, at a higher concentration, increased cisplatin's anti-proliferation activity (48.0+/-1.2%; P<0.05); Re increased cisplatin's activity (Re 0.1 mg/ml, 48.0+/-2.8%; Re 0.3 mg/ml, 31.9+/-2.2%, P<0.01).

CONCLUSION

Our data suggest that AGBE and the tested ginsenosides do not attenuate cisplatin's tumoricidal activity in MCF-7 cells, but in fact may actually enhance it. Additionally, the ginseng extract and ginsenoside Re by themselves exerted anti-proliferative activity against MCF-7 cells. The herb might potentially serve a complementary role with the chemotherapeutic agents in treating cancer, in addition to decreasing chemotherapy-induced nausea/vomiting.

Polyphenol contents in grape-seed extracts correlate with antipica effects in cisplatin-treated rats

BACKGROUND

Grape-seed (Vitis spp.) extract (GSE) is a widely used antioxidant dietary supplement. Chemotherapeutic agents such as cisplatin induce oxidative damage in the gastrointestinal tract and cause nausea and vomiting.

MATERIALS AND METHODS

A rat model of simulated emesis was used to observe that cisplatin significantly increased kaolin consumption (or pica). Three GSEs from different sources were used in this study.

RESULTS

High-performance liquid chromatographic analysis of five major constituents (gallic acid, catechin, epicatechi, procyanidin B2, and epicatechin gallate) revealed that each constituent had different levels in the three GSEs. Extract #1, prepared in the laboratory of the investigators, had the lowest total polyphenol content (27.27 mg/g); Extract #2, obtained from a dietary supplement company in the United States, had a somewhat higher level (35.84 mg/g); and Extract #3, obtained from China, had the highest level (194.21 mg/g). Subsequently these GSEs were intraperitoneally administered in rats to evaluate their ability to decreasing cisplatin induced pica. At 10 mg/kg all three GSEs, with varying degrees of effect, decreased cisplatin-induced pica. The areas under the curves of kaolin intake from time 0 to 72 hours, compared to those in the cisplantin-only group, were reduced 45% for Extract #1 (p < 0.01), 54% for Extract #2 (p < 0.01), and 66% Extract #3 (p < 0.001).

CONCLUSIONS

The study data showed variable polyphenol contents and proportions in the three GSEs correlated to variable pharmacologic effects, indicating the importance of standardization of herbal product preparations. However further increasing of the GSE doses reversed the antipica effects of GSEs, probably because of their pro-oxidant effects. Results from this study suggest that an appropriate dose of GSE has therapeutic value in treating cisplatin-induced emesis.

Methylnaltrexone, a novel peripheral opioid receptor antagonist for the treatment of opioid side effects

Methylnaltrexone is an investigational peripheral opioid receptor antagonist, a quaternary derivative of naltrexone. Methylnaltrexone has greater polarity and lower lipid solubility, thus it does not cross the blood-brain barrier in humans. Methylnaltrexone offers the therapeutic potential to block or reverse the undesired side effects of opioids that are mediated by receptors located in the periphery (e.g., in the gastrointestinal tract), without affecting analgesia or precipitating the opioid withdrawal symptoms that are predominantly mediated by receptors in the CNS. This article reviews preclinical studies and clinical opioid bowel dysfunction trial data, and briefly discusses other potential roles of this compound in clinical practice.

Saponins composition in American ginseng leaf and berry assayed by high-performance liquid chromatography

The root of American ginseng is a commonly used herbal medicine in the United States. However, the compositions of American ginseng leaves and berries are not clear to date. In this study, we improved a method for the analysis of 12 ginsenosides based on solid phase extraction and high-performance liquid chromatography-ultraviolet. Good resolution was obtained for all tested ginsenosides: Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1, Rg2, 20(R)-Rg2, Rg3, Rh1, and Rh2. Ginsenosides Rh1, Rg2, and 20(R)-Rg2 were easily separated with this column. The modified gradient elution program resulted in satisfactory linearity and precision. Solid phase extraction made the analysis accurate and efficient. Other investigators recently observed that ginsenoside Rb3 is a potent neuroprotective compound; it can promote learning and memory. In this report, we found that the major ginsenoside in American ginseng leaves and berries was ginsenoside Rb3, while Rb3 only had limited amounts in the root of American ginseng and other species of the Panax genus. Ginsenoside Rb3 was quantified as 4.71% in American ginseng leaves and 5.35% in berries, suggesting that American ginseng leaves and berries are new sources of ginsenoside Rb3.

Ganoderma lucidum extract inhibits proliferation of SW 480 human colorectal cancer cells

AIM

Ganoderma lucidum is a commonly used Chinese herb and an important ingredient in traditional Chinese medicine herbal formulations for immune dysfunction related illnesses. The effects of this medicinal mushroom on human colorectal cancer cells have not yet been evaluated. In this study, we investigated the effects of Ganoderma lucidum extract using SW 480 human colorectal cancer cell line.

MATERIALS AND METHODS

Two different fractions of Ganoderma lucidum extract, i.e., a fraction containing mainly polysaccharides (GLE-1), and a triterpenoid fraction without polysaccharides (GLE-2) were analyzed. Their antiproliferative activity was evaluated by cell proliferation assay and 3H-thymidine incorporation assay. Scavenging effects of DPPH radical were assessed using ESR-spectroscopy.

RESULTS

Our data showed that both GLE-1 and GLE-2 significantly inhibited the proliferation of SW 480 cells. The inhibitory effect of GLE-2 was much stronger than that of GLE-1. GLE-1 inhibited DNA synthesis in the cells and reduced the formation of DPPH radicals.

CONCLUSION

Ganoderma lucidum extract inhibits proliferation of human colorectal cancer cells and possesses antioxidant properties.

Antioxidant effects of ginsenoside Re in cardiomyocytes

We have previously demonstrated that American ginseng berry extract exhibited significant protection against oxidant-mediated injury in cardiomyocytes. To extend this work, we sought to investigate the antioxidant effects of Re, a protopanaxatriols-type and single chemical integrant present in American ginseng berry extract, using the same chick cardiomyocyte model of oxidant injury as well as ESR spectroscopy in a cell-free chemical system. In cells exposed to 2 h of H2O2 (0.5 mM), pretreatment with Re (0.05, 0.1, or 0.5 mg/ml for 2 h) significantly attenuated 2',7'-dichlorofluorescein (DCF) fluorescence by 51% (from 1345+/-67 to 658+/-46 a.u., P<0.001), and remarkably reduced cell death (from 51.5+/-3.0% to 11.8+/-1.5%, P<0.001, compared to the control). Similar results were also observed in cells exposed to antimycin A (100 microM), a mitochondrial electron transport chain site III inhibitor which increases endogenous oxidative stress. In the ESR study, however, Re failed to reduce the formation of the superoxide/DMPO adduct and DPPH radicals. These results suggest that ginsenoside Re functions as an antioxidant, protecting cardiomyocytes from oxidant injury induced by both exogenous and endogenous oxidants, and that its protective effects may be mostly attributed to scavenging H2O2 and hydroxyl radicals.

Effects of ganoderma lucidum extract on chemotherapy-induced nausea and vomiting in a rat model

Chemotherapy is highly cytotoxic, causing a number of severe adverse effects such as nausea and vomiting. Herbal medicines, which can often be used on a daily basis for prolonged treatment, may be clinically beneficial. Ganoderma lucidum or Lingzhi mushroom has been recognized as a remedy in treating a number of medical conditions, including balancing immunity and decreasing drug-induced side effects. It has been shown that rats react to emetic stimuli, like the chemotherapy agent cisplatin, by increased consumption of kaolin, known as pica; and this rat model has been utilized to evaluate novel anti-emetic compounds. In this study, we evaluated the effects of a G. lucidum extract (SunRecome, the most commonly used Lingzhi mushroom extract in China) in attenuating cisplatin-induced nausea and vomiting in the rat pica model. We observed that intraperitoneal cisplatin injection caused a significant increase in kaolin intake at 24, 48, 72 and 96 hours, reflecting cisplatin's nausea and vomiting action. This cisplatin-induced kaolin intake dose-dependently decreased after 1, 3 and 10 mg/kg G. lucidum extract injection (p < 0.01). In addition, there was a significant reduction of food intake after cisplatin. The cisplatin-induced food intake reduction improved significantly after G. lucidum extract administrations in a dose-related manner (p < 0.01), suggesting a supportive effect of the extract on general body condition. Future controlled clinical trials are needed to evaluate the safety and effectiveness of this herbal medication.

Opioid-induced gastrointestinal dysfunction

Use of opioid analgesics is associated with a number of side effects, especially opioid-induced gastrointestinal dysfunction. The extensive use of these compounds and the significant negative impact of the resulting gastrointestinal dysfunction on patients' quality of life make it an important clinical issue. In recent years our understanding of the mechanisms of opioid-induced gastrointestinal dysfunction has advanced greatly. This article reviews the underlying pathophysiological mechanisms of specific gastrointestinal adverse effects of opioids. The role of endogenous opioid peptides in certain gastrointestinal diseases is also discussed. A better understanding of the pathophysiological mechanisms of opioid-induced bowel dysfunction should lead to the development of newer opioid analgesics and improved regimens resulting in reduced gastrointestinal adverse effects.