Nigella Sativa’s Protection Against 7,12 Dimethylbenz [A] Anthracene -Induced Colon Carcinogenesis in Rats

Colon cancer is the third most common cause of death from cancer worldwide. Recently, natural products have been widely used as an alternative therapy for colon cancer. Previous studies have reported that Nigella sativa has chemopreventive activity in vitro and in vivo.This study aimed to evaluate the effect of Nigella sativa seed (NSS) on rat-colon cell after initiation of 7,12-dimethylbenz [a] anthracene. Rats were divided into five groups, 12 rats in each group: Group I was given 7,12dimetilbenz [a] anthracene (DMBA) orally 20 mg/kgBW twice a week for five weeks, group V is the solvent control group was given corn oil. The other three groups were given DMBA + NSS, at the dosage of 250 mg/kgBW, 500 mg/kgBW and 750 mg/kgBW. NSS extract was dissolved in corn oil and administered daily per oral during the next two weeks before and during the initiation of DMBA. After 16 weeks, all rats were sacrificed. H&E staining showed that necrosis activity was lower in treated groups compared to DMBA group. AgNOR staining showed mAgNOR was significantly decrease following the increasing dose of NSS (250 mg/kgBW, 500 mg/kgBW and 750 mg/kgBW) were subsequently 1.62 ± 0.086, 1.60 ± 0.101 and 1.39 ± 0.049 (p<0.05). The results showed that NNS reduce the damage of colon cells and inhibit colon cell proliferation in DMBA induced rats.

Laxative Effects of a Standardized Extract of Dendropanax morbiferus H. Léveille Leaves on Experimental Constipation in Rats

Background and Objectives: This study aimed at investigating the laxative effects of a standardized aqueous extract of Dendropanax morbiferus H. Lév. on two different constipation rat models. Materials and Methods: Animal studies were conducted with low-fiber diet-induced and loperamide-induced constipation animal models, and isolated colons were used in ex vivo analysis to determine the changes in colonic motility caused by D. morbiferus H. Lév. leaf extract (DPL). Results: The results showed that DPL administration significantly improved certain reduced fecal parameters (number, weight, and water content of the stools) in a both low-fiber diet and loperamide-induced constipation models without adverse effects of diarrhea. The laxative effect of DPL was confirmed to improve the charcoal excretion time upon DPL treatment in a low-fiber diet or loperamide-induced constipation model through gastrointestinal (GI) motility evaluation using the charcoal meal test. In addition, when DPL was administered to RAW264.7 cells and loperamide-induced constipation model rats, the production of prostaglandin E2 (PGE2) increased significantly in cells and tissue. Furthermore, DPL dose-dependently stimulated the spontaneous contractile amplitude and frequency of the isolated rat colon. Conclusion: Although our study did not provide information on the acute or chronic toxicity of DPL, our results demonstrated that DPL can effectively promote defecation frequency and rat colon contraction, providing scientific evidence to support the use of DPL as a therapeutic application. However, further toxicity studies of DPL are needed prior to the initiation of clinical trials and clinical applications.

A systems-level analysis of bile acids effects on rat colon epithelial cells

Bile acid diarrhoea is a chronic condition caused by increased delivery of bile acids to the colon. The underlying mechanisms remain to be elucidated. To investigate genes involved in bile acid diarrhoea, systems-level analyses were employed on a rat bile acid diarrhoea model. Twelve male Wistar Munich rats, housed in metabolic cages, were fed either control or bile acid-mixed (1% w/w) diets for ten days. Food intake, water intake, urine volume, bodyweight and faecal output were monitored daily. After euthanasia, colonic epithelial cells were isolated using calcium-chelation and processed for systems-level analyses, i.e. RNA-sequencing transcriptomics and mass spectrometry proteomics. Bile acid-fed rats suffered diarrhoea, indicated by increased drinking, faeces weight and faecal water content compared with control rats. Urine output was unchanged. With bile acid-feeding, RNA-sequencing revealed 204 increased and 401 decreased mRNAs; mass spectrometry 183 increased and 111 decreased proteins. Among the altered genes were genes associated with electrolyte and water transport (including Slc12a7, Clca4 and Aqp3) and genes associated with bile acid transport (Slc2b1, Abcg2, Slc51a, Slc51b and Fabps). Correlation analysis showed a significant positive correlation (Pearson's r=0.28) between changes in mRNA-expression and changes in protein-expression. However, caution must be exercised in making a direct correlation between experimentally determined transcriptomes and proteomes. Genes associated with bile acid transport responded to bile acid-feeding, suggesting that colonic bile acid transport also occur by regulated protein facilitated mechanisms in addition to passive diffusion. In summary, the study provides annotated rat colonic epithelial cell transcriptome and proteome with response to bile acid-feeding.

Complementary mechanisms of modulation of spontaneous phasic contractions by the gaseous signalling molecules NO, H2S, HNO and the polysulfide Na2S3 in the rat colon

Objectives Reactive oxygen and nitrogen species may be produced during inflammation leading to the formation of NO, H2S or HNO. Enzymes such as iNOS, CSE and CBS might also be responsible for polysulfide production. Since these signalling molecules might have an impact on colonic motility, the aim of this study was to compare their effect on rat colonic slow phasic contractions (SPC). Methods Organ bath measurements with strips obtained from rat proximal colon were performed using the polysulfide Na2S3, sodium nitroprusside (NaNP), sodium hydrogen sulfide (NaHS), Angeli’s salt as NO, H2S, and HNO donors, respectively. TTX (1 µM) was used to block neuronal activity. Results All four molecules, concentration-dependently, inhibited the amplitude and frequency of SPC both in the circular and longitudinal muscle layer. The relative potency was NaNP>Angeli’s salt>NaHS>Na2S3. The inhibitory response induced by NaNP (1 µM) and Angeli’s salt (50 µM) was reversed by ODQ (10 µM) whereas the inhibitory effect of NaHS (1 mM) was reversed by apamin (1 µM) and glibenclamide (10 µM). Na2S3 (1 mM) response was partially reversed by apamin (1 µM) and glibenclamide (10 µM). High concentrations of Na2S3 caused an increase in tone. Low concentrations of NaHS or Na2S3 did not potentiate NaNP responses. Conclusions All signalling molecules inhibit SPC in both muscle layers. The effect is independent of neural activity and involves guanylyl cyclase (NO and HNO) and SKCa and KATP channels (NaHS or Na2S3). Other pathways might also be involved in Na2S3 responses. Accordingly, complementary mechanisms of inhibition might be attributable to these signalling molecules.

Electroacupuncture and Moxibustion Modulate the BDNF and TrkB Expression in the Colon and Dorsal Root Ganglia of IBS Rats with Visceral Hypersensitivity

Objective. To evaluate the effects of electroacupuncture and moxibustion on brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase receptor B (TrkB) protein and mRNA expressions in the colon and dorsal root ganglia of IBS rats with visceral hypersensitivity and to explore their underlying therapeutic mechanisms. Method. Forty Sprague Dawley rats were randomly divided into normal, model, model + mild moxibustion (MM), model + electroacupuncture (EA), and model + pinaverium bromide (PB) groups, with eight rats in each group. Chronic visceral hypersensitive IBS rat models were established by colorectal distension (CRD) with mustard oil clyster. Rats in the MM and EA groups, respectively, received moxibustion and electroacupuncture treatments on the Tianshu (ST25) and Shangjuxu (ST37) acupoints once daily for 7 days, and rats in the PB group received pinaverium bromide by oral gavage once daily for 7 consecutive days. After treatment, rats underwent abdominal withdrawal reflex (AWR) scoring under CRD and colon histopathological examination. Immunohistochemistry and real-time quantitative PCR (RT-qPCR) were used to study the protein and mRNA expressions of BDNF and TrkB in the rat colon and dorsal root ganglia. Results. Compared with the normal group, AWR scores and body weight were clearly increased in the model group rats (both P < 0.01 ). The body weights were significantly elevated ( P < 0.01 , P < 0.05 ), but the AWR scores were reduced ( P < 0.05 , P < 0.01 ), after electroacupuncture and mild moxibustion treatment. Compared with levels in normal rats, BDNF and TrkB protein and mRNA expressions were significantly elevated in the IBS model rats ( P < 0.01 ) but were downregulated after mild moxibustion, electroacupuncture, and Western medicine treatment ( P < 0.01 ). Conclusion. Electroacupuncture and moxibustion improved visceral hypersensitivity of IBS rats possibly by reducing BDNF and TrkB protein and mRNA expressions in the colon and dorsal root ganglia.

Effects of 1,2-Dimethylhydrazine on Barrier Properties of Rat Large Intestine and IPEC-J2 Cells

Colon cancer is accompanied by a decrease of epithelial barrier properties, which are determined by tight junction (TJ) proteins between adjacent epithelial cells. The aim of the current study was to analyze the expression of TJ proteins in a rat model of 1,2-dimethylhydrazine (DMH)-induced colorectal cancer, as well as the barrier properties and TJ protein expression of IPEC-J2 cell monolayers after incubation with DMH. Transepithelial electrical resistance and paracellular permeability for sodium fluorescein of IPEC-J2 were examined by an epithelial volt/ohm meter and spectrophotometry. The expression and localization of TJ proteins were analyzed by immunoblotting and immunohistochemistry. In the colonic tumors of rats with DMH-induced carcinogenesis, the expression of claudin-3 and -4 was significantly increased compared to controls. The transepithelial electrical resistance of IPEC-J2 cells increased, while paracellular permeability for sodium fluorescein decreased, accompanied by an increased expression of claudin-4. The increase of claudin-4 in rat colon after chronic DMH exposure was consistent with the acute effect of DMH on IPEC-J2 cells, which may indicate an essential role of this protein in colorectal cancer development.

Evaluation of Anti-Inflammatory Effect of Wedelolactone on Indomethacin Induced Colitis in Rats: Involvement of IL-6/STAT3 Pathway

The present study was carried out to study coumestan derivative wedelolactone in Indomethacin-induced enterocolitis in rats. Wistar rats were randomly divided into three groups containing six animals per group. Group I served as normal control. Group II, Group III & Group IV receive 7.5 mg/kg, s.c, indomethacin on two consecutive days. Group III and Group IV have received a wedelolactone dose of 50 mg/kg, and 100 mg/kg per oral, respectively, for 14 days after the induction with indomethacin. The protective effect was measured based on intestinal parameters of the disease activity index, colitis score, myeloperoxidase (MPO) activity in the colon. The inflammation biomarkers were quantified by ELISA in the rat colon. Further, activity was ascertained by histopathology. Pro-inflammatory functions IL-1a, IL-1b, IL-2, TNF, INFγ, STAT3, and CCL-5 play an important role in the variation of the intestinal immune system. Wedelolactone showed significantly decreased Disease activity index, Colitis score, Myeoloperoxidase activity. Expression of pro-inflammatory was increased in indomethacin-induced groups and was significantly suppressed in animals administered with wedelolactone at 50 mg/kg & 100 mg/kg dose (p<0.01 & p<0.001). Histological reports also revealed that treated groups have comparatively less damage than that of the induced groups. We concluded that wedelolactone showed an anti-inflammatory effect by downregulation of the IL-6/STAT3 inflammatory signaling pathway and the equilibrium production of pro-inflammatory cytokines.

Autoimmunity Profiles as Prognostic Indicators in Patients with Colorectal Cancer versus Those with Cancer at Other Sites: A Prospective Study

Colorectal cancer represents a paradigmatic model of inflammatory carcinogenesis accompanied by the production of several kinds of tumor-associated autoantibodies (TAABs). The specific aim of this study is to define the clinical impact of the presence of non-specific circulating TAABs in a cohort of cancer patients and to establish whether significant differences were present between colorectal cancer and cancers at other sites. For this aim a prospective study was developed and a five-year survival analysis performed. Indirect immunofluorescence on rat tissues for non-organ specific autoantibodies (NOSAs: liver-kidney-stomach), on rat colon substrates (colon-related autoantibodies, CAAs) and on HEp-2 cell lines was performed. NOSA positivity was more frequent in patients with colorectal cancer than in those with cancer at other sites. Survival analysis demonstrated a significantly worse prognosis in cancer patients positive for TAABs. CAA positivity is a predictor of survival, independently from the presence of comorbidities, and HEp-2 reactivity was a strong predictor of survival in a stepwise Cox-regression model, including stage at diagnosis. Overall overproduction of TAABs is associated with advanced oncological disease, the presence of metastasis, and poorer prognosis of cancer patients.