Deep posteromedial cortical rhythm in dissociation.

Advanced imaging methods now allow cell-type-specific recording of neural activity across the mammalian brain, potentially enabling the exploration of how brain-wide dynamical patterns give rise to complex behavioural states1-12. Dissociation is an altered behavioural state in which the integrity of experience is disrupted, resulting in reproducible cognitive phenomena including the dissociation of stimulus detection from stimulus-related affective responses. Dissociation can occur as a result of trauma, epilepsy or dissociative drug use13,14, but despite its substantial basic and clinical importance, the underlying neurophysiology of this state is unknown. Here we establish such a dissociation-like state in mice, induced by precisely-dosed administration of ketamine or phencyclidine. Large-scale imaging of neural activity revealed that these dissociative agents elicited a 1-3-Hz rhythm in layer 5 neurons of the retrosplenial cortex. Electrophysiological recording with four simultaneously deployed high-density probes revealed rhythmic coupling of the retrosplenial cortex with anatomically connected components of thalamus circuitry, but uncoupling from most other brain regions was observed-including a notable inverse correlation with frontally projecting thalamic nuclei. In testing for causal significance, we found that rhythmic optogenetic activation of retrosplenial cortex layer 5 neurons recapitulated dissociation-like behavioural effects. Local retrosplenial hyperpolarization-activated cyclic-nucleotide-gated potassium channel 1 (HCN1) pacemakers were required for systemic ketamine to induce this rhythm and to elicit dissociation-like behavioural effects. In a patient with focal epilepsy, simultaneous intracranial stereoencephalography recordings from across the brain revealed a similarly localized rhythm in the homologous deep posteromedial cortex that was temporally correlated with pre-seizure self-reported dissociation, and local brief electrical stimulation of this region elicited dissociative experiences. These results identify the molecular, cellular and physiological properties of a conserved deep posteromedial cortical rhythm that underlies states of dissociation.

Ginseng berry polysaccharides on inflammation-associated colon cancer: inhibiting T-cell differentiation, promoting apoptosis, and enhancing the effects of 5-fluorouracil.

BACKGROUND: Ginseng is a commonly used herbal medicine in treating various medical conditions. Chronic gut inflammation is a recognized factor for the development of colorectal cancer (CRC). In this project, Asian ginseng berry polysaccharide preparations were used to assess their effects on CRC and related immune regulation mechanisms. METHODS: Ginseng berry polysaccharide extract (GBPE) and purified ginseng berry polysaccharide portion (GBPP) were used to evaluate their activities on human HCT-116 and HT-29 CRC cell proliferation. Interleukin-8 secretion analysis was performed on HT-29 cells. Naive CD4 cell isolation and T-helper cell differentiation were performed and determined using flow cytometry for Th1 and Treg in addition to cell cycle and apoptotic investigation. RESULTS: GBPE and GBPP significantly inhibited interleukin-8 secretion and cancer cell proliferation, inhibited CD4+IFN-γ+ cell (Th1) differentiation, and decreased CD4+FoxP3+ cell (Treg) differentiation. Compared to the GBPE, GBPP showed more potent antiinflammatory activities on the malignant cells. This is consistent with the observation that GBPP can also inhibit Th1-cell differentiation better, suggesting that it has an important role in antiinflammation, whereas Treg cells hinder the body's immune response against malignancies. Supported by cell cycle and apoptosis data, GBPE and GBPP, at various degrees, remarkably enhanced the anticancer activities of 5-fluorouracil. CONCLUSION: Data from this project suggested that Asian ginseng berry potentially has clinical utility in managing enteric inflammation and suppressing CRC through immunomodulation mechanisms.

American ginseng microbial metabolites attenuate DSS-induced colitis and abdominal pain.

Inflammatory bowel disease (IBD) is a significant public health problem in the United States. Abdominal pain is a major complaint among individuals with IBD. Successful IBD management not only controls enteric inflammation, but also reduces abdominal discomfort. Recently, increased attention has been focused on alternative strategies for IBD management. HPLC/Q-TOF-MS analysis was employed to evaluate the intestinal microbiome's biotransformation of parent American ginseng compounds into their metabolites. Using a DSS mouse model, the effects of American ginseng microbial metabolites on chemically induced colitis was investigated with disease activity index and histological assessment. Expressions of inflammatory cytokines were determined using real-time PCR and ELISA. Abdominal pain was evaluated using the von Frey filament test. After the gut microbiome's biotransformation, the major metabolites were found to be the compound K and ginsenoside Rg3. Compared with the DSS animal group, American ginseng treatment significantly attenuated experimental colitis, as supported by the histological assessment. The enteric microbiome-derived metabolites of ginseng significantly attenuated the abdominal pain. American ginseng treatment significantly reduced gut inflammation, consistent with pro-inflammatory cytokine level changes. The gut microbial metabolite compound K showed significant anti-inflammatory effects even at low concentrations, compared to its parent ginsenoside Rb1. American ginseng intestinal microbial metabolites significantly reduced chemically-induced colitis and abdominal pain, as mediated by the inhibition of pro-inflammatory cytokine expression. Intestinal microbial metabolism plays a critical role in American ginseng mediated colitis management.

Effects of compound K, an enteric microbiome metabolite of ginseng, in the treatment of inflammation associated colon cancer.

Ginsenoside Rb1, a major component of different ginseng species, can be bioconverted into compound K by gut microbiota, and the latter possess much stronger cancer chemopreventive potential. However, while the initiation and progression of colorectal cancer is closely associated with gut inflammation, to date, the effects of compound K on inflammation-linked cancer chemoprevention have not been reported. In the present study, liquid chromatography quadrupole time-of-flight mass spectrometry analysis was applied to evaluate the biotransformation of Rb1 in American ginseng by human enteric microflora. The in vitro inhibitory effects of Rb1 and compound K were compared using the HCT-116 and HT-19 human colorectal cancer cell lines by a MTS assay. Cell cycle and cell apoptosis were assayed using flow cytometry. Using ELISA, the anti-inflammatory effects of Rb1 and compound K were compared for their inhibition of interleukin-8 secretion in HT-29 cells, induced by lipopolysaccharide. The results revealed that compound K is the major intestinal microbiome metabolite of Rb1. When compared with Rb1, compound K had significantly stronger anti-proliferative effects in HCT-116 and HT-29 cell lines (P<0.01). Compound K significantly arrested HCT-116 and HT-29 cells in the G1 phase, and induced cell apoptosis (P<0.01). By contrast, Rb1 did not markedly influence the cell cycle or apoptosis. Furthermore, compound K exerted significant anti-inflammatory effects even at low concentrations (P<0.05), while Rb1 did not have any distinct effects. The data obtained from the present study demonstrated that compound K, an intestinal microbiome metabolite of Rb1, may have a potential clinical value in the prevention of inflammatory-associated colorectal cancer.

Multiple Effects of Ginseng Berry Polysaccharides: Plasma Cholesterol Level Reduction and Enteric Neoplasm Prevention.

The root of Asian ginseng (Panax ginseng C.A. Meyer) has been used for centuries in Oriental medicine to improve general well-being and to relieve various medical conditions. It is commonly understood that ginsenosides are responsible for the pharmacological activities of ginseng. Compared to the root of ginseng, studies on the berry are considerably limited. In this study, we evaluated the effects of polysaccharides from Asian ginseng berries on plasma lipid levels, chemically-induced enteric inflammation and neoplasm, and cancer chemoprevention in different experimental models. We tested two polysaccharide preparations: regular ginseng berry polysaccharide extract (GBPE) and ginseng berry polysaccharide portion (GBPP, removed MV [Formula: see text]). We first observed that both oral GBPE and oral GBPP significantly reduced plasma cholesterol and triglycerides levels in a dose-related manner in ob/ob mice, without obvious body weight changes. Then, in AOM/DSS-induced acute colitis mice, GBPE and GBPP significantly ameliorated the increased gut disease activity index and inhibited the reduction of the colon length. Further, the berry polysaccharides significantly suppressed chemically-induced pro-inflammatory cytokine levels. This is consistent with the observation that GBPE and GBPP attenuated tumorigenesis in mice by significantly and dose-dependently reducing tumor load. Finally, in vitro HCT-116 and HT-29 human colon cancer cells were used. While these berry preparations had better antiproliferation effects on the HCT-116 than the HT-29 cells, the GBPE had significantly stronger inhibitory effects than GBPP. The observed in vitro GBPE's effect could contribute to the actions of its small-molecule non-polysaccharide compounds due to their direct antiproliferative activities. Results obtained from the present study suggest that ginseng berry polysaccharides may have a therapeutic role in the management of high lipid levels, enteric inflammation, and colon malignancies.