In this study, we evaluated anti-hyperglycemic effect and body weight reduction activity of
Gymnema yunnanense extract in obese
ob/
ob and diabetic
db/
db mice. Animals received daily intraperitoneal ...injections of the extract 100
mg/kg for 12 days. On Day 5, the extract-treated
ob/
ob mice had significantly lower fasting blood glucose levels compared to vehicle-treated mice (161±14.5
mg/dl versus 238±21.5
mg/dl,
P<0.01). On Day 12, the extract-treated
ob/
ob mice had normal fasting blood glucose levels, compared with vehicle-treated mice (119±3.3
mg/dl versus 240±12.9
mg/dl,
P<0.01). Glucose tolerance improved significantly. This was demonstrated by overall glucose excursion calculated as area under the curve (AUC) during the 2
h intraperitoneal glucose tolerance test (IPGTT), which decreased by approximately 22% (
P<0.01) compared to vehicle-treated
ob/
ob mice. In addition, extract-treated
ob/
ob mice lost weight significantly from 51.7±1.9
g on Day 0 to 45.7±1.2
g on Day 12 (
P<0.05 compared to vehicle-treated mice). In
db/
db mice, after treatment with same dose of the extract, fasting blood glucose levels also decreased significantly from Day 0 of 247±13.9
mg/dl to Day 5 of 172±7.5
mg/dl and to Day 12 of 190±2.7
mg/dl (both
P<0.01 compared to vehicle-treated group from Day 0 of 239±12.1
mg/dl to Day 5 of 230±8.5
mg/dl and Day 12 of 247±18.9
mg/dl, respectively). After 12 days of extract treatment, body weight in
db/
db mice reduced from 61.8±1.4
g on Day 0 to 59.8±1.1
g on Day 12 (
P<0.05). Our results support an in vivo anti-hyperglycemic and body weight reduction activity of
G. yunnanense extract that may prove to be of clinical importance in improving the management of type 2 diabetes.
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.
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.
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).
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.
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
2O
2; 500 μM). 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
2O
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
2O
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.
ABSTRACT
Galaxy cluster masses, rich with cosmological information, can be estimated from internal dark matter (DM) velocity dispersions, which in turn can be observationally inferred from satellite ...galaxy velocities. However, galaxies are biased tracers of the DM, and the bias can vary over host halo and galaxy properties as well as time. We precisely calibrate the velocity bias, bv – defined as the ratio of galaxy and DM velocity dispersions – as a function of redshift, host halo mass, and galaxy stellar mass threshold ($M_{\rm \star , sat}$), for massive haloes ($M_{\rm 200c}\gt 10^{13.5} \, {\rm M}_\odot$) from five cosmological simulations: IllustrisTNG, Magneticum, Bahamas + Macsis, The Three Hundred Project, and MultiDark Planck-2. We first compare scaling relations for galaxy and DM velocity dispersion across simulations; the former is estimated using a new ensemble velocity likelihood method that is unbiased for low galaxy counts per halo, while the latter uses a local linear regression. The simulations show consistent trends of bv increasing with M200c and decreasing with redshift and $M_{\rm \star , sat}$. The ensemble-estimated theoretical uncertainty in bv is 2–3 per cent, but becomes percent-level when considering only the three highest resolution simulations. We update the mass–richness normalization for an SDSS redMaPPer cluster sample, and find our improved bv estimates reduce the normalization uncertainty from 22 to 8 per cent, demonstrating that dynamical mass estimation is competitive with weak lensing mass estimation. We discuss necessary steps for further improving this precision. Our estimates for $b_v(M_{\rm 200c}, M_{\rm \star , sat}, z)$ are made publicly available.
We present Classification of Cluster GAlaxy MEmbers (C\(^2\)-GaMe), a classification algorithm based on a suite of machine learning models that differentiates galaxies into orbiting, infalling, and ...background (interloper) populations, using phase space information as input. We train and test C\(^2\)-GaMe with the galaxies from UniverseMachine mock catalog based on Multi-Dark Planck 2 N-body simulations. We show that probabilistic classification is superior to deterministic classification in estimating the physical properties of clusters, including density profiles and velocity dispersion. We propose a set of estimators to get an unbiased estimation of cluster properties. We demonstrate that C\(^2\)-GaMe can recover the distribution of orbiting and infalling galaxies' position and velocity distribution with \(<1\%\) statistical error when using probabilistic predictions in the presence of interlopers in the projected phase space. Additionally, we demonstrate the robustness of trained models by applying them to a different simulation. Finally, adding a specific star formation rate and the ratio of the galaxy's halo mass to the cluster's halo mass as additional features improves the classification performance. We discuss potential applications of this technique to enhance cluster cosmology and galaxy quenching.
We extend the analysis of a physical model within the standard cosmology that robustly predicts a high star-formation efficiency (SFE) in massive galaxies at cosmic dawn due to feedback-free ...starbursts (FFBs). It implies an excess of bright galaxies at z>~10 compared to the standard models based on the low SFE at later epochs, an excess indicated by JWST observations. Here we provide observable predictions based on the analytic FFB scenario. These can be compared with simulations and JWST observations. We approximate the SFE as a function of redshift and mass, assuming a maximum SFE of 0.2~1 in the FFB regime. From this, we derive the evolution of the galaxy mass and luminosity functions as well as the evolution of stellar and star-formation densities. We then predict the star-formation history (SFH), galaxy sizes, outflows, gas fractions, metallicities, and dust attenuation, all as functions of mass and redshift in the FFB regime. The major distinguishing feature is the occurrence of FFBs above a mass threshold that declines with redshift. The luminosities and star formation rates in bright galaxies are predicted to be in excess of extrapolations of standard empirical models and cosmological simulations, an excess that grows from z~9 to higher redshifts. The FFB phase of ~100 Myr is predicted to show a characteristic SFH that fluctuates on a timescale of ~10 Myr. The stellar systems are compact (Re~0.3 kpc at z~10 and declining with z). The galactic gas consists of a steady wind driven by supernovae from earlier generations, with high outflow velocities (FWHM~1400-6700km/s), low gas fractions (<0.1), low metallicities (<~0.1 solar), and low dust attenuation (\(A_{UV}\)~0.5 at z~10 and declining with z). We make tentative comparisons with current JWST observations for initial insights, anticipating more complete and reliable datasets for detailed quantitative comparisons in the future.
Recent advances in simulations and observations of galaxy clusters suggest that there exists a physical outer boundary of massive cluster-size dark matter haloes. In this work, we investigate the ...locations of the outer boundaries of dark matter and gas around cluster-size dark matter haloes, by analyzing a sample of 65 massive dark matter halos extracted from the Omega500 zoom-in hydrodynamical cosmological simulations. We show that the location of accretion shock is offset from that of the dark matter splashback radius, contrary to the prediction of the self-similar models. The accretion shock radius is larger than all definitions of the splashback radius in the literature by 20-100%. The accretion shock radius defined using the steepest drop in the entropy pressure profiles is approximately 2 times larger than the splashback radius defined by the steepest slope in the dark matter density profile, and it is ~1.2 times larger than the edge of the dark matter phase-space structure. We discuss implications of our results for multi-wavelength studies of galaxy clusters.
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.
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