Effects of Panax ginseng extract on lipid metabolism in humans.

The purpose of this study was to examine the effects of Panax ginseng extract (PGE) on lipid metabolism in humans by measuring cholesterol, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT). Serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and plasma MDA levels were decreased by administration of PGE for 8 weeks (6g per day), however, high density lipoprotein (HDL) was increased. Those results suggest that hypolipidemic effect of PGE is associated with a decrease in TC, TG, LDL, MDA levels and an increase in HDL. These findings support scientific claims that ginseng has the hypolipidemic potential. Administration of PGE increased SOD and CAT activities while decreased MDA level indicating that antioxidant potential of PGE might induce hypolipidemic effect as one of action mechanism.     

Inhibition of benzo(a)pyrene induced lung adenoma by panax ginseng extract, EFLA400, in Swiss albino mice

In the present investigation the chemopreventive action of Panax ginseng extract, EFLA400, in Swiss albino mice has been evaluated. We used a 9-week medium term anticarcinogenicity test model of lung adenomas [Yun et al.1)]. Lung adenomas were induced by single subcutaneous injection in the subscapular region with 0.02 ml of benzo(a)pyrene (BP) (0.5 mg suspension in 1% aqueous gelatin) in newborn mice (less than 24 h old). Also chromosomal aberrations and micronuclei induction were evaluated in bone marrow cells. These genotoxicity end-points were compared with adenoma incidence at the same dose levels of BP and EFLA400. The oral administration of EFLA400 (10 mg/kg body weight) showed significant reduction in number of adenomas and weight of the lungs induced by BP. A significant reduction (p<0.001) in lung adenoma incidence in EFLA400-treated mice was observed as compared to the 68.3+/-2.96% lung adenoma incidence in BP-alone group. The inhibition rate was 72.05+/-1.36% in EFLA400-treated group with respect to the reference group (BP-alone group). However, tumor multiplicity was observed as 0.91+/-0.08 and 0.25+/-0.01 in BP alone and BP+EFLA400-treated groups respectively. In EFLA400-treated group significantly reduced frequencies of chromosomal aberrations and micronuclei induced by BP were observed. The results of the present investigation suggest the chemopreventive action and antimutagenic effect of EFLA400 in Swiss albino mice induced by BP in newborn mice.     

Effects of benzo(e)pyrene and benzo(a)pyrene on P-glycoprotein-mediated transport in Caco-2 cell monolayer: a comparative approach.

The previous studies from our laboratory reported that benzo(a)pyrene (Bap) influenced efflux transport of rhodamine 123 (Rho-123) by induction of P-glycoprotein (P-gp) in Caco-2 cells. The present study investigated whether induction of P-gp and the enhanced efflux transport of Rho-123 were caused by benzo(e)pyrene (Bep), which has a structure similar to Bap, but is not a carcinogenic compound. In Caco-2 monolayer exposed to 50 microM Bep for 72 h, the ratio of the apparent permeability coefficient (P(app)) of Rho-123 efflux increased significantly compared to that of the control monolayer. Similarly, a significant increase in expression of MDR1 mRNA and of P-gp at the protein level were detected by RT-PCR and by Western blot analysis, respectively, in Caco-2 cells exposed to Bep, compared to that of the control. Caco-2 cells exposed to Bep showed oxidative stress that was detected by fluorescence microscopy using aminophenyl fluorescein. However, the oxidative stress was weaker compared with that of Bap. The cellular GSH content was decreased to 80% or 59% of control cells, respectively, in Caco-2 cells exposed to either Bep or Bap. Our results further show that Bep or Bap-induced P-gp in Caco-2 cells might have been the result of oxidative stress rather than DNA damage.     

Action of xanthine-xanthine oxidase system on microsomal benzo(a)pyrene metabolism in vitro

The effect of superoxide anion-radical and other reactive oxygen species on the metabolism of benzo(a)pyrene was studied with isolated mouse liver microsomes. Reactive oxygen species were generated in vitro by xanthine-xanthine oxidase plus Fe3+ X FeEDTA and benzo(a)pyrene metabolism was followed by reverse-phase high pressure liquid chromatography. The following results were obtained: The reactive oxygen species induced one-electron oxidation of benzo(a)pyrene and increased production of free epoxide as well as protein-binding intermediates. The reactive oxygen species triggered microsomal lipid peroxidation in the presence of Fe3+ X FeEDTA. As a result of microsomal lipid peroxidation a decreased activity of cytochrome P-450, epoxide hydrolase and UDP-glucuronyltransferase was found. It is suggested that active oxygen species changed the balance between bioactivation and conjugation of benzo(a)pyrene metabolites causing accumulation of the epoxide and protein-binding intermediates. The role of iron ions and chelates in this process is discussed.     

3-Hydroxybenzo(a)pyrene as a biomarker of dermal exposure to benzo(a)pyrene

The aim of this study was to determine the percutaneous absorption flux of BaP (20 μg/cm² in ethanol) and the usefulness of urinary 3-OHBaP as a bio-indicator of dermal exposure to BaP. The percutaneous absorbed dose and absorption flux were estimated by comparison with intravenous administration of BaP (0.01 and 0.05 mg/kg in Cremophor^®) as reference way. A percutaneous absorption flux of 0.37 μg/cm²/h was determined by killing groups of rats, following exposure time of 4.5 and 24 h. [¹⁴C] skin content was 3.1 μg/cm², after 24 h exposure to BaP. Total urinary 3-OHBaP accounted for 0.4% of the real absorbed dose, which was fourfold higher than the percentage of an intravenous dose excreted as 3-OHBaP. This finding reveals that percutaneous absorption of BaP, based on the ratio of urinary excretion of 3-OHBaP following percutaneous exposure compared to percutaneous absorption following intravenous administration of BaP, is overestimated in the rat. In vitro, BaP was intensively metabolised by rat skin. Unchanged BaP and 3-OHBaP in receptor fluid accounted for 50 and 30% of the total radioactivity. This percutaneous first past effect of BaP in rats could, in part, explain the higher urinary excretion ratio of 3-OHBaP compared to the value based on intravenous administration of BaP. Conversely, BaP was largely lower metabolised as 3-OHBaP during percutaneous absorption by humans, so BaP absorption flux should be overestimated to a lesser extent in humans than in rats.     

Effects of benzo(a)pyrene exposure on killifish (Fundulus heteroclitus) aromatase activities and mRNA

Cytochrome P450 aromatase (CYP19) plays an important role in steroid homoeostasis by converting androgens to estrogens. To evaluate the effects of benzo(a)pyrene (BaP), a model carcinogenic PAH and AhR ligand, on aromatase mRNA expression and enzyme activity, adult Fundulus were exposed to water-borne BaP (1 and 10 microg/L) for 15 days, and embryos were exposed to 10 microg/L for 10 days. Effects of BaP were examined by tissue, gender, and season in adults. Constitutively, the sexes did not have significantly different CYP19A2 mRNA levels, however females had higher brain aromatase activity. Female control killifish had more than 700-fold more CYP19A1 mRNA in their gonads compared to males. Within brain tissue of both sexes, there was 100-fold more CYP19A2 mRNA compared to CYP19A1. In ovary, CYP19A1 predominated by approximately 30-fold over the CYP19A2, but in testis there was relatively more CYP19A2. In embryos there was approximately 5-fold higher CYP19A2 expression. Due to high inter-individual variability, a significant effect of BaP treatment by gender, season or age was not observed for either aromatase mRNA. However, ovarian aromatase activity was significantly decreased by 10 microg/L BaP, while female brain activity was increased following winter exposure. These findings suggest that the aromatase enzyme is a potential target for disruption of fish developmental and reproductive physiology by BaP.     

The effect of paraquat on the mutagenicity of benzo(a)pyrene

Elevated activities of superoxide dismutase (SOD) were detected in histidine-requiring strains of Salmonella typhimurium after the bacteria were preincubated for 1 h at 37 degrees C with S-9 mix and paraquat (methylviologen, PQ2+) at 10(-4) M. A fivefold increase in SOD level was found for strains TA 98 and TA 100. These elevated levels of SOD activity were correlated with a significant reduction of the mutagenicity of metabolically activated benzo(a)pyrene (B(a)P) in these tester bacteria when evaluated in a preincubation assay system. A 69.0-92.5% and 23.5-66.9% reduction was noticed when 0.5-4.0 micrograms per plate of B(a)P was used in TA 98 and TA 100, respectively. However, exogenous superoxide dismutase at 10-100 micrograms ml-1 added to top agar had no significant effect on the number of revertants produced by activated B(a)P. These data indicate a major role of intracellular superoxide anion in promoting mutagenicity of B(a)P.     

Age-related changes in benzo(a)pyrene metabolism and epoxide-metabolizing enzyme activities in rat skin

The postnatal development of microsomal aryl hydrocarbon hydroxylase (AHH), 7-ethoxycoumarin O-deethylase (ECD), epoxide hydrolase (EH) [benzo(a)pyrene (BP)-4,5-oxide as substrate], and cytosolic glutathione S-transferase (GST) was studied in skin of Sprague-Dawley rats. Animals were treated with skin application of 3-methylcholanthrene (MCA) (40 mg/kg, 24 hr before sacrifice) or acetone. Enzyme activities were detected in animals of all ages. AHH and ECD in control rats showed slight age-dependent variation. Age-dependent differences in inducibility of skin AHH and ECD by topically applied MCA were observed. At 4, 6, 10, 18, 24, 32, and 55 days of age, the inducibility of AHH was 11, 18, 18, 19, 20, 23, and 21-fold, respectively. A similar pattern was observed for ECD. EH activity in 24-day-old skin was twice that in 4-day-old animals. GST activity remained constant throughout maturation. EH and GST activities were not altered by MCA. BP metabolism was studied in control and MCA-induced neonatal (4-day-old), young (18-day-old), and adult (55-day-old) animals. MCA treatment increased the rate of metabolism of BP at all ages studied. Higher rates of BP metabolism occurred in adult skin as compared to younger or neonatal rat skin. Inducibility of trans-7,8-diol formation by topically applied MCA was highest in the adult (19-fold) rat skin as compared to younger (12-fold) or neonatal rat skin (10-fold). These studies suggest that xenobiotic metabolism in skin of rats undergoes variable changes during aging which could exert some influence on pharmacologic responses to topically applied agents in cutaneous tissue.     

Drug interaction potential of soy extract and Panax ginseng

To determine if soy extract or Panax ginseng increases the urinary excretion of the 6-beta-hydroxycortisol/cortisol ratio as a marker of cytochrome P450 (CYP) 3A enzyme induction, subjects received a soy extract containing 50 mg isoflavones twice daily (n = 20) or Panax ginseng 100 mg standardized to 4% ginsenosides twice daily (n = 20) for 14 days. Neither Panax ginseng nor soy extract significantly altered the urinary 6-beta-OH-cortisol/cortisol ratio, suggesting that unlike St. John's wort, they are not CYP3A inducers. Studies in vitro using human liver microsomes were performed to determine the effect of soy extract on probe substrates of CYP and UDP glucuronosyltransferase (UGT). Unhydrolyzed soy extract produced very little inhibition of CYP1A2, CYP2A6, and CYP2D6 and a trend of activation of CYP3A4. Hydrolyzed soy extract showed inhibition of all of the CYPs tested, particularly CYP2C9 and CYP3A4. UGT2B15 was the only UGT significantly inhibited. Even though both soy extract and ginseng have been shown to activate CYP3A4 in vitro, there is a lack of an in vitro correlation with the in vivo effects.     

Effects of hydroxylated flavonoids on the ethoxyresorufin O-deethylase and benzo(α)pyrene hydroxylase

In order to understand the mechanism of action of flavonoids on the drug metabolizing enzyme, cytochrome P4501A1, this study was undertaken to examine the effect of chrysin, morin, myricetin and aminopyrine on the activities of ethoxyresorufin O-deethylase and benzo(α) pyrene hydroxylase in the liver. In the isolated perfused rat liver that was pretreated with 3-methylcholanthrene (3MC), chrysin, morin, myricetin and aminopyrine inhibited the activity of ethoxyresorufin O-deethylase with concentration dependent manner. The isolated liver perfusion with chrysin, morin, myricetin and aminopyrine showed inhibition on the induction of ethoxyresorufin O-deethylase by 3MC. And also, in mouse liver hepa I cells, 3MC-stimulated the benzo(α)pyrene hydroxylase activity which was inhibited by chrysin, morin, myricetin and aminopyrine. These results strongly suggested that hydoxylated flavonoids interfered not only the induction of cytochrome P450IA1 enzymes by 3MC but also the interaction of substrates and enzyme.     

Depletion of mitochondrial enzyme system in liver,lung, brain,stomach and kidney induced by benzo(a)pyrene

Mitochondrial dysfunction has recently received considerable attention as it plays an important role in adult human pathology caused by various drugs, endogenous agents and environmental agents. Benzo(a)pyrene (BaP), is a ubiquitous environmental contaminant mainly derived from anthropogenic activity during incomplete combustion of organic materials from various sources. The present study aimed to evaluate the effects of benzo(a)pyrene (BaP) on mitochondrial enzymes in the multiple organs including liver, lung, brain, stomach and kidney. ICR mice were exposed to different doses of BaP (2.5, 5 and 10 mg/kg body weight) through oral gavage and intraperitoneal injection treatment for 13 weeks consecutively. The induced mitochondrial damage in the examined organs was assayed in terms of significant increase in lipid peroxidation (LPO) and prominent decrease in antioxidant enzymes. Non enzymatic antioxidants and Krebs cycle’s enzymes were also significantly decreased in mitochondria. Additionally, BaP induced the body growth retardation and decrease in relative liver weight, increase in relative lung, stomach, kidney and brain weights, and this was further certified through histopathological lesions. Liver and lungs were more prominently damaged by BaP. The mitochondrial depletion increased in BaP dose-dependent manner.     

Cardiac arrhythmogenic action of benzo(a)pyrene in the rabbit

Rabbits treated with benzo(a)pyrene developed cardiac arrhythmias when exposed by inhalation to 8100 ppm trichloroethylene or 15000 ppm halothane to a greater extent and at lower doses of epinephrine challenge than did controls. Benzo(a)pyrene and 3-methylcholanthrene both increased the metabolism of trichloroethylene, but 3-methylcholanthrene did not increase its cardiotoxic effect. The basis of the arrythmogenic action of benzo(a)pyrene appears to be unrelated to its ability to induce xenobiotic metabolism.     

Epidermis: the major site of cutaneous benzo(a)pyrene and benzo(a)pyrene 7,8-diol metabolism in neonatal BALB/c mice

The metabolism of benzo(a)pyrene (BP) and benzo(a)pyrene-7,8-diol (BP-7,8-diol) by microsomes prepared from whole skin, dermis, and epidermis of neonatal BALB/c mice pretreated with topically applied 3-methylcholanthrene (MCA) was compared. In control animals, microsomes prepared from epidermis showed higher rates of metabolism of BP and BP-7,8-diol (1.4-2.6-fold) than did microsomes prepared from whole skin or dermis. A single topical application of MCA increased the rate of metabolism of BP and BP-7,8-diol in microsomes prepared from whole skin, dermis, and epidermis. The greatest increase occurred in the epidermis. The in vivo covalent binding of [3H]BP, [3H]BP-7,8-diol, and 7,12-[3H]dimethylbenz(a)anthracene ([3H]DMBA) to DNA was found to be greater in epidermis (8.7-15.4-fold) than in whole skin or in dermis. A single topical application of MCA to BALB/c mice enhanced the in vivo binding of [3H]BP, [3H]BP-7,8-diol and [3H]DMBA to DNA of whole skin, dermis, and epidermis more than 2-fold. Exposure of Salmonella tester strains TA98 and TA100 to 2-aminoanthracene, a skin carcinogen, in the presence of an epidermal metabolic activation mixture resulted in a greater mutagenic response when compared to activation mixtures derived from whole skin or dermis. These results indicate that epidermis is the major site of polycyclic aromatic hydrocarbon metabolism and of enzyme-mediated covalent binding of polycyclic aromatic hydrocarbon carcinogens to DNA in skin of BALB/c mice and that topically applied MCA has maximum enzyme induction effects in this skin compartment.     

Predicting color kinetics during red Asian ginseng (Panax ginseng) preparation

A red Asian ginseng preparation was prepared as follows: fresh Asian ginseng (Panax ginseng) roots were first steamed for half an hour to several hours, and then the steamed roots were dried into died roots (red Asian ginseng, 10% moisture content, on a dry basis). During steaming, the color of ginseng (white) turned yellow and brown during subsequent steaming. Color is an important index for grading red Asian ginseng. In this study, the effects of drying time and temperature on the surface color formation (L, a/b) of the Asian ginseng, and the color formation (L, a/b) of the red Asian ginseng powder were investigated. The value of L decreased, while the value of a/b increased as drying proceeded; the value of L was slightly influenced by the drying temperature, but the value of a/b was markedly influenced. With respect to the color of the final product (red ginseng), the value of L was slightly influenced by steaming time and temperature, while the value of a/b was increased as steaming time and drying temperature increased. Based on the nth-order rate equation and Arrhenius equation, a kinetic model for describing these effects was established, and the results were satisfactorily fitting.     

Prenatal induction of benzo(a)pyrene hydroxylases in mice

1. Benzo(a)pyrene hydroxylase (BPH) activity was measured in homogenates of fetal liver (day 18) or of whole-embryos of mice on day 9, 10 or 12 of gestation after maternal pretreatment with B(a)P on 3 consecutive days. A³H-liberation assay with³H-B(a)P labelled either generally or at the 6-position was used. The values obtained with the embryonic/fetal tissues were compared with those found in maternal liver. 2. Three oral doses of 17.5 mg B(a)P/kg body wt were found to just significantly induce BPH in maternal liver. An induction was observed after pretreatment with 24 mg B(a)P/kg body wt in 9-, 10-or 12-day-old whole-embryos, but the V_max reached was only 10–20% (1% on day 9) of that of adult non-induced liver. The K_m (6-hydroxylation) for all tissues tested were in the same range (600–900 nM). The induction was demonstrable in embryos at tissue levels about one order of magnitude lower than those required for induction in maternal liver. 3. Treatment with 25 mg B(a)P/kg body wt on 3 consecutive days was required to induce BPH in fetal liver on day 18 of gestation. The required B(a)P tissue concentrations were about one half of those necessary for induction in maternal liver. 4. Among a variety of other polycyclic hydrocarbons only chrysene showed an inducing potency similar to that of B(a)P in adult and fetal liver. For all compounds tested there was no correlation found in the inducing potency between adult and fetal liver (e.g. coronene). 5. The doses required to induce BPH in the maternal or fetal liver or in whole embryos of rodents are significantly higher (mg range) than those of usual average human exposure or those taken up by smokers (ng range).Abbreviations AHH aryl hydrocarbon hydroxylase - B(a)P benzo(a)pyrene - BPH benzo(a)pyrene hydroxylases - PAH polycyclic aromatic hydrocarbons     

Pharmacological activity of sanchi ginseng (Panax notoginseng)

The pharmacological activity and constituents of the sanchi ginseng Panax notoginseng have been reviewed. The bulk of pharmacological findings have been based on the saponins or steryl glycosides, although polysaccharides with immunopotentiating activity, proteins with antifungal, ribonuclease and xylanase activity, and a triacylglycerol (trilinolein) with antioxidant activity have been reported. Protective actions against cerebral ischaemia, beneficial effects on the cardiovascular system, and haemostatic, antioxidant, hypolipidaemic, hepatoprotective, renoprotective and estrogen-like activities have been described. Various methods for authentication of P. notoginseng are available.