Effects of Korean red ginseng extract on cisplatin-induced nausea and vomiting

Ginseng, the root of Panax ginseng C.A. Meyer, is well known as a tonic medicine for restoring and enhancing human health. In traditional medicine, ginseng is utilized for the alleviation of emesis, which includes nausea and vomiting. However, it has not yet been demonstrated whether ginseng exhibits in vivo anti-nausea and anti-vomiting properties. In this study, we examined the anti-emetic effect of Korean red ginseng total extract (KRGE) on cisplatin-induced nausea and vomiting using ferrets. Intraperitoneal administration (i.p.) of cisplatin (7.5 mg/kg) induced both nausea and vomiting with one-hour latency. The episodes of nausea and vomiting reached a peak after 1.5 h and persisted for 3 h. Treatment with KRGE via oral route significantly reduced the cisplatin-induced nausea and vomiting in a dose-dependent manner. The anti-emetic effect was 12.7 +/- 8.6, 31.8 +/- 6.9, and 67.6 +/- 4.0% with doses of 0.3, 1.0, and 3.0 g/kg of KRGE, respectively. Pretreatment with KRGE via oral route 1 and 2 h before cisplatin administration also significantly attenuated the cisplatin-induced nausea and vomiting. However this did not occur with a pretreatment 4 h before cisplatin administration. These results are supportive of KRGE being utilized as an anti-emetic agent against nausea and vomiting caused by chemotherapy (i.e. cisplatin).     

Effects of Korean red ginseng extract on acute renal failure induced by gentamicin and pharmacokinetic changes by metformin in rats

Aim of the studyKorean red ginseng is one of the best selling dietary supplements and its individual constituents enhance renal function. Acute renal failure (ARF) is a predisposing complication of diabetes mellitus as a result of combination drug therapy. The combination of antibiotic–antidiabetic drugs can entail toxicities and drug interactions because of the antibiotic resistance in patients with severe bacterial infection. Currently, gentamicin–metformin combination therapy is commonly prescribed for treating bacterial infections and diabetes, even though both drugs are mainly excreted via the kidney. Thus, this study was designed to investigate whether a Korean red ginseng extract (KRG) prevents renal impairment and pharmacokinetic changes by metformin in rats with renal failure induced by gentamicin.Materials and methodsThe in vivo pharmacokinetics and in vitro hepatic/intestinal metabolism of metformin were assessed using control (CON), control with Korean red ginseng extract (KRG-CON), acute renal failure induced by gentamicin (ARF), and ARF with Korean red ginseng (KRG-ARF) rats.Results and conclusionsPharmacokinetic changes of metformin did not occur in KRG-ARF rats because KRG reduce the renal accumulation of gentamicin compared to ARF rats. Thus, KRG seemed to prevent acute renal failure induced by gentamicin treatment.     

Effect of Korean red ginseng on blood pressure and nitric oxide production

AIM: To investigate the effect of crude saponin and non-saponin fraction of Korean red ginseng (KRG) on the blood pressure and nitric oxide (NO) production in the conscious rats and cultured endothelial cell line, ECV 304 cells. METHODS: Systolic blood pressure and heart rate were monitored in the conscious rats. Nitric oxide levels and the expression of nitric oxide synthase were measured by a spectrophotometric assay using Griess reagents and Western blotting, respectively. Nitric-oxide synthase activity was measured based on the conversion rate of [3H]arginine to [3H]citrulline. RESULTS: Systolic blood pressure was decreased by crude saponin (100 mg/kg, iv) of KRG in the conscious control and one-kidney, one-clip Goldblatt hypertensive (IK, 1C-GBH) rats. The hypotensive effect induced by crude saponin of KRG reached maximum at 2 - 4 min and slowly recovered after 20 min to the initial level in both groups. Crude saponin of KRG induced tachycardia in the conscious rats but induced bradycardia in the a     

Effects of lipid vehicle and P-glycoprotein inhibition on the mesenteric lymphatic transport of paclitaxel in unconscious,lymph duct-cannulated rats

The present study examined the effects of lipid vehicle and intestinally based efflux processes on intestinal lymphatic transport of paclitaxel (PTX) in the mesenteric lymph duct-cannulated anesthetized rat model. PTX solution alone, PTX solution pretreated with the P-glycoprotein (P-gp) inhibitor verapamil and/or PTX and a 2:1 (w/w) mixture of linoleic acid:glycerol monooleate were administered intraduodenally to anesthetized rats. Coadministration of a mixture of linoleic acid–monoolein significantly increased the extent of intestinal lymphatic transport of PTX, but it had little impact on the absolute oral bioavailability of PTX. In contrast, pretreatment with verapamil increased both the extent of lymphatic transport (3.5-fold) and absolute oral bioavailability (1.8-fold). Further increase in the lymphatic transport (6.5-fold) and absolute oral bioavailability (1.8-fold) was achieved by the combination of pretreatment with verapamil and coadministration with the linoleic acid–monoolein mixture. These data indicate that the application of lipid vehicle holds promise for selectively targeted lymphatic delivery of PTX. P-gp inhibition can result in both increased intestinal lymphatic levels and absolute oral bioavailability of PTX.     

Simultaneous quantification of 14 ginsenosides in Panax ginseng C.A. Meyer (Korean red ginseng) by HPLC-ELSD and its application to quality control

A new method of high-performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous quantification of 14 major ginsenosides, which are the marker compounds of Panax ginseng C.A. Meyer (Korean red ginseng). Various types of ginseng samples were extracted, and the amounts of the 14 ginsenosides (Rg1, Re, Rf, Rh1, Rg2, Rb1, Rc, Rb2, Rb3, Rd, Rg3, Rk1, Rg5, and Rh2) were determined by reverse-phase HPLC-ELSD using digoxin as an internal standard. The mobile phase consisted of a programmed gradient of aqueous acetonitrile. Calibration curves for each ginsenoside were determined for the quantification. The method was validated for linearity, precision, accuracy, limit of detection, and limit of quantification. This quantification method was applied to several finished ginseng products including white ginseng, red ginseng powder, and red ginseng concentrate. The amounts of the 14 ginsenosides in the various ginseng samples could be analyzed simultaneously. This validated HPLC method is expected to provide a new basis for the quality assessment of ginseng products.     

Enhancement of anti-inflammatory and antinociceptive actions of red ginseng extract by fermentation

Objectives This work aimed to compare some pharmacological properties of red ginseng extract (RG) and fermented red ginseng extract (FRG). Methods Antinociceptive activity was analysed using the acetic acid‐induced abdominal constriction response. Anti‐inflammatory activity was evaluated using acetic acid‐induced vascular permeability and carrageenan‐induced inflammation in the air pouch, and analysed through the measurement of nitrite content in the lipopolysaccharide (LPS)‐stimulated macrophage cells. Anti‐angiogenic activity was determined using the chick chorioallantoic membrane assay. Key findings In‐vivo anti‐inflammatory activity of FRG was stronger than that of RG in two animal models, vascular permeability and air‐pouch models. In the vascular permeability model, the doses of RG and FRG required for half‐maximal inhibition (IC50) were 181 and 59 mg/kg, respectively. FRG exhibited significantly stronger antinociceptive activity than RG. In the acetic acid‐induced abdominal constriction response, the IC50 values of RG and FRG were 153 and 27 mg/kg, respectively. Although both RG and FRG were able to suppress production of nitric oxide in the LPS‐stimulated RAW264.7 macrophage cells, the suppressive activity of FRG appeared to be stronger than that of RG. However, RG and FRG showed similar anti‐angiogenic activity. Conclusions FRG possesses enhanced anti‐inflammatory and antinociceptive activity but similar anti‐angiogenic activity than RG.     

Inhibition of P-glycoprotein leads to improved oral bioavailability of compound K, an anticancer metabolite of red ginseng extract produced by gut microflora

Ginsenosides are hydrolyzed extensively by gut microflora after oral administration, and their metabolites are pharmacologically active against lung cancer cells. In this study, we measured the metabolism of various ginsenosides by gut microflora and determined the mechanisms responsible for the observed pharmacokinetic behaviors of its active metabolite, Compound K (C-K). The results showed that biotransformation into C-K is the major metabolic pathway of ginsenosides after the oral administration of the red ginseng extract containing both protopanaxadiol and protopanaxatriol ginsenosides. Pharmacokinetic studies in normal mice showed that C-K exhibited low oral bioavailability. To define the mechanisms responsible for this low bioavailability, two P-glycoprotein (P-gp) inhibitors, verapamil and cyclosporine A, were used, and their presence substantially decreased C-K's efflux ratio in Caco-2 cells (from 26.6 to <3) and significantly increased intracellular concentrations (by as much as 40-fold). Similar results were obtained when transcellular transport of C-K was determined using multidrug resistance 1 (MDR1)-overexpressing Madin-Darby canine kidney II cells. In MDR1a/b(-/-) FVB mice, its plasma C(max) and AUC(0-24h) were increased substantially by 4.0- and 11.7-fold, respectively. These increases appear to be due to slower elimination and faster absorption of C-K in MDR1a/b(-/-) mice. In conclusion, C-K is the major active metabolite of ginsenosides after microflora hydrolysis of primary ginsenosides in the red ginseng extract, and inhibition/deficiency of P-gp can lead to large enhancement of its absorption and bioavailability.     

Pharmacokinetics and tissue distribution of ginsenoside Rh2 and Rg3 epimers after oral administration of BST204, a purified ginseng dry extract,in rats

Abstract

1. BST204, a purified ginseng dry extract containing a high concentration of racemic Rh2 and Rg3 mixtures, is being developed for supportive care use in cancer patients in Korea. This study investigates the pharmacokinetics and tissue distribution of BST204 in rats.

2. After oral administration of BST204, only the S epimers, S-Rh2 and S-Rg3, could be determined in rat plasma. The poor absorption of the R-epimers, R-Rh2 and R-Rg3, may be attributed to lower membrane permeability and extensive intestinal oxygenation and/or deglycosylation into metabolites. The AUC and C_max values of both S-Rh2 and S-Rg3 after BST204 oral administration were proportional to the administered BST204 doses ranged from 400?mg/kg to 2000?mg/kg, which suggested linear pharmacokinetic properties.

3. There were no statistically significant differences in the pharmacokinetics of S-Rh2 and S-Rg3 after oral administration of pure S-Rh2 (31.5?mg/kg) and S-Rg3 (68?mg/kg) compared with oral administration of BST204, 1000?mg/kg. These indicated that the presence of other components of BST204 extract did not influence the pharmacokinetic behavior of S-Rh2 and S-Rg3.

4. After oral dosing of BST204, S-Rh2 and S-Rg3 were distributed mainly to the liver and gastrointestinal tract in rats.

5. Our finding may help to understand pharmacokinetic characteristics of S-Rh2, R-Rh2, S-Rg3, and R-Rg3, comprehensively, and provide useful information in clinical application of BST204.

     

Suppressive effect of tobacco smoke extracts on oral P-glycoprotein function and its impact in smoke-induced insult to oral epidermal cells

P-glycoprotein (Pgp) participates in the export of numerous toxins, drugs, and physiological compounds. To examine the involvement of Pgp in smoke-induced oral cell insult, the effects of extracts of the mainstream tobacco smoke (TS) on Pgp were studied in an oral epidermal carcinoma cell line, OECM-1. TS was first extracted with cyclohexane (CTS) and the residues were further extracted with isopropanol (ITS). For comparison, cells were exposed to CTS and ITS at the concentrations according to their relative extraction yield. ITS but not CTS decreased the efflux of a Pgp substrate, rhodamine (Rh) 123, in a concentration- and time-dependent manner. The efflux was also decreased by co-exposure to CTS and ITS. However, immunoblot analysis revealed that the protein level of Pgp was not affected by ITS. Naphthalene, mainly detected in the ITS, decreased Rh 123 efflux. However, the efflux activity was not affected by benzo(a)pyrene and nicotine, which were present in the CTS and both extracts, respectively. Co-exposure to CTS in combination with ITS, naphthalene, or verapamil enhanced cell insult compared to single exposure. These results demonstrated that smoke and its constituent, naphthalene, diminished Pgp-mediated efflux. The reduction in Pgp function could be a stimulatory factor of TS-induced oral cell insult.