Phospholipid Fatty Acid Composition and Diamine Oxidase Activity of Intestinal Mucosa From Rats Treated With Irinotecan Hydrochloride (CPT-11) under Vegetable Oil–Enriched Diets: Comparison Between Perilla Oil and Corn Oil

Therapeutic targeting of CPT-11 induced diarrhea: a case for prophylaxis

CPT-11 (irinotecan), a DNA topoisomerase I inhibitor is one of the main treatments for colorectal cancer. The main dose limiting toxicities are neutropenia and late onset diarrhea. Though neutropenia is manageable, CPT-11 induced diarrhea is frequently severe, resulting in hospitalizations, dose reductions or omissions leading to ineffective treatment administration. Many potential agents have been tested in preclinical and clinical studies to prevent or ameliorate CPT-11 induced late onset diarrhea. It is predicted that prophylaxis of CPT-11 induced diarrhea will reduce sub-therapeutic dosing as well as hospitalizations and will eventually lead to dose escalations resulting in better response rates. This article reviews various experimental agents and strategies employed to prevent this debilitating toxicity. Covered topics include schedule/dose modification, intestinal alkalization, structural/chemical modification, genetic testing, anti-diarrheal therapies, transporter (ABCB1, ABCC2, BCRP2) inhibitors, enzyme (β-glucuronidase, UGT1A1, CYP3A4, carboxylesterase, COX-2) inducers and inhibitors, probiotics, antibiotics, adsorbing agents, cytokine and growth factor activators and inhibitors and other miscellaneous agents.

Effect of the menstrual cycle on serum diamine oxidase levels in healthy women

OBJECTIVES

Serum diamine oxidase (DAO) level is employed as a useful marker of intestinal mucosal integrity. As reported previously, the range of serum DAO levels in women is wider than that in men. We hypothesized that the menstrual cycle may affect DAO levels.

DESIGN AND METHODS

Thirty-six women of Japanese descent were recruited. All participants, aged 20-29 years, were healthy. Food surveys utilized in this study were based on questionnaires validated by dietitians. Complete blood counts, biochemical parameters, female hormones, and serum DAO levels during the follicular and luteal phases were measured in each subject.

RESULTS

Biochemical parameters, except for DAO levels, were comparable between the two phases. However, serum DAO levels during the luteal phase were significantly higher than those during the follicular phase.

CONCLUSIONS

Serum DAO levels were influenced by the menstrual cycle. Furthermore, our findings suggest that serum DAO levels should be interpreted cautiously in premenopausal women.

Plasma diamine oxidase activity is a useful biomarker for evaluating gastrointestinal tract toxicities during chemotherapy with oral fluorouracil anti-cancer drugs in patients with gastric cancer

OBJECTIVES

Diamine oxidase (DAO) is an enzyme that catalyzes oxidation and is highly active in the mature upper villus cells of the intestinal mucosa. This study sought to evaluate plasma DAO activities during adjuvant chemotherapy in patients with gastric cancer.

METHODS

We investigated 20 patients with gastric cancer who were treated with oral fluorouracil anti-cancer drugs as adjuvant chemotherapy. Plasma DAO activity was measured in all patients before chemotherapy and at 2, 4 and 6 weeks after the start of chemotherapy, and quality of life was evaluated simultaneously.

RESULTS

The median DAO activity after 4 weeks of chemotherapy was significantly decreased compared to the pre-chemotherapy levels (6.6 vs. 7.5 U/l; p = 0.038). The changes in the rate of DAO activity at 2 and 6 weeks following the start of chemotherapy in patients with gastrointestinal tract toxicity were significantly lower than in those without toxicity (p =0.021 and 0.047, respectively). The patient cohort showed a slightly positive correlation between DAO activity and global health status and a negative correlation between DAO activity and appetite loss.

CONCLUSIONS

Plasma DAO activities may be useful for monitoring and evaluating gastrointestinal tract toxicities induced by adjuvant chemotherapy with oral fluorouracil in patients with gastric cancer.

An α-linolenic acid-rich formula reduces oxidative stress and inflammation by regulating NF-κB in rats with TNBS-induced colitis

We have previously shown that α-linolenic acid (ALA), a (n-3) PUFA exerts in vitro antiinflammatory effects in the intestine. In this study, we aimed to evaluate its effect on inflammatory and oxidative stress in a colitis model. Colitis was induced in 2 groups at d 0 by intrarectal injection of 2-4-6-trinitrobenzen sulfonic acid (TNBS), whereas the control group received the vehicle. Rats we fed 450 mg . kg(-1) . d(-1) of ALA (TNBS+ALA) while the other colitic group (TNBS) and the control group were fed an isocaloric corn oil formula for 14 d (from d -7 to d 7). RBC fatty acid composition was assessed. Oxidative stress was studied by measuring urinary 8-isoprostanes (8-IP) and colon glutathione (GSH) concentration and inducible nitric oxide synthase (iNOS) expression. Colitis was assessed histologically, by production of proinflammatory mediators, including cytokines, leukotrienes B(4) (LTB(4)), and cyclooxygenase-2 (COX-2) and by nuclear factor-κB (NF-κB) activation. The ALA-rich diet significantly increased the RBC levels of ALA, eicosapentaenoic acid, and docosapentaenoic acid (n-3) compared with the TNBS group (P < 0.01 for all). The beneficial effect of ALA supplementation on oxidative stress was reflected by lower urinary 8-IP levels (P < 0.05), a normalized colon GSH concentration (P < 0.01), and reduced colon iNOS expression (P < 0.05) compared with the TNBS group. ALA also protected against colon inflammation as assessed by lower tumor necrosis factor-α secretion and mRNA level (P < 0.05), reduced NF-κB activation (P = 0.01), and lower colon lipid mediator concentrations such as LTB(4) and COX-2 (P < 0.05) compared with the TNBS group. These findings show that an ALA-rich formula is beneficial to TNBS-induced colitic rats via inhibition of oxidative and inflammatory stress.

Medium-chain triglycerides enhance mucous secretion and cell proliferation in the rat

BACKGROUND

The specific purpose of this study was to investigate the effects of medium-chain triglycerides (MCTs) on intestinal cell proliferation and mucous secretion of the small intestine in the rat.

METHODS

Rats were fed chow diet and given MCTs or the same weight of corn oil (5 g/kg per day) by gavage daily for 2 weeks, and then tissue samples of the small intestines were harvested. Leptin concentration in the small intestine was measured. Cell proliferation and apoptosis in the small intestine was determined by immunohistochemistry. Diamine oxidase (DAO) activity was measured by colorimetric assay.

RESULTS

In rats fed only chow diet (normal rats), the number of goblet cells per villi was 14.2 +/- 0.75 in the jejunum and 15.2 +/- 1.12 in the ileum. The number of goblet cells increased significantly in rats given MCTs compared with rats given corn oil or normal rats. Ki-67-positive cells were detected on the entire villi and the crypts in the small intestine. Furthermore, the proliferative index and the apoptotic index were also significantly greater in rats given MCTs than rats given corn oil or normal rats. Moreover, DAO activity and leptin concentration in the small intestine were significantly greater in rats given MCTs than rats given corn oil or normal rats.

CONCLUSIONS

MCTs enhance cell proliferation of the intestinal epithelium and mucous secretion from goblet cells in the small intestine. These effects may protect the gut in patients suffering from inflammatory bowel disease or enterogenous infection.

Effect of Lianshu preparation on lipopolysaccharide-induced diarrhea in rats

AIM: To investigate the effect of Lianshu preparation on lipopolysaccharide (LPS)-induced diarrhea in rats.

METHODS: A diarrhea model was established in Sprague Dawley rats via injection of 1 mL of 30 mg/kg LPS. A total of 40 rats were randomly divided into normal group, LPS group, LPS + Lianshu group, LPS + berberine group (n = 10 in each group). Their intestinal mucosal barrier and frequency of diarrhea were observed. Levels of glucose, serum Na⁺, K⁺, Cl^- and hematocrit, plasma nitrogen monoxide (NO), diamine oxidase (DAO), and D (-)-lactate were measured. The number of IgA+ plasma cells in small intestine was detected and SIgA levels in the intestinal fluid were measured. The antipyretic activity of Lianshu preparation in rats was evaluated using Brewer’s yeast-induced pyrexia (10 mL/kg of 20% aqueous suspension). Acetaminophen (250 mg/kg, intragastric administration, bid) was used as a standard drug for comparison. Temperature was recorded 1 h before and 6 h after Brewer’s yeast injection. Finally, small intestinal transmission in mice treated with Lianshu was detected after intraperitoneal injection of methyl prostigmin (2 mg/kg). Atropine (10 g/kg) was used as a control. The ink content in intestine was determined and the total length of intestine was measured.

RESULTS: The frequency of diarrhea was higher in LPS group than in LPS + Lianshu group and LPS + berberine group (36.70 ± 5.23 vs 28.50 ± 4.06 and 32.70 ± 9.30 respectively, P < 0.01), and lower in LPS + Lianshu group than in LPS + berberine group (P = 0.03). The levels of Na⁺, glucose, Cl^-, K⁺ were significantly lower in LPS + Lianshu group than in LPS + berberine group (140.35 ± 3.19 mmol/L vs 131.99 ± 4.86 mmol/L, 8.49 ± 1.84 mmol/L vs 6.54 ± 2.30 mmol/L, 106.29 ± 4.41 mmol/L vs 102.5 ± 1.39 mmol/L, 5.08 ± 0.66 mmol/L vs 4.32 ± 0.62 mmol/L respectively, P < 0.05). The level of hematocrit was lower in LPS + Lianshu group than in LPS + berberine group (0.50% ± 0.07% vs 0.59% ± 0.10% respectively, P < 0.05). The plasma levels of NO, DAO and D (-)-lactate were higher in LPS group than in normal group (79.74 ± 7.39 &mgr;mol/L vs 24.94 ± 3.38 &mgr;mol/L, 2.48 ± 0.42 &mgr;/mL vs 0.82 ± 0.33 &mgr;/mL, 5.63 ± 0.85 &mgr;g/mL vs 2.01 ± 0.32 &mgr;g/mL respectively, P < 0.01), and lower in LPS + Lianshu group than in LPS + berberine group (48.59 ± 4.70 &mgr;mol/L vs 51.56 ± 8.38 &mgr;mol/L, 1.43 ± 0.53 &mgr;mol/mL vs 1.81 ± 0.42 &mgr;mol/mL, 4.00 ± 0.54 &mgr;g/mL vs 4.88 ± 0.77 &mgr;g/mL respectively, P < 0.05). The morphology of the intestinal mucosa showed destroyed villi in LPS group and atrophied intestinal mucosa in other groups. The pathological intestinal mucosal changes were less in LPS + Lianshu group than in LPS group. The number of IgA+ plasma cells and amount of SIgA were higher in LPS + Lianshu group than in LPS group (1.16 ± 0.19/&mgr;m²vs 1.09 ± 0.28/&mgr;m², P = 0.026; 0.59 ± 0.12 mg/L vs 0.15 ± 0.19 mg/L respectively, P = 0.000). Lianshu had counteractive effects on yeast-induced pyrexia and enterokinesia in rats.

CONCLUSION: Lianshu preparation has therapeutic effects on LPS-induced diarrhea and enterokinesia in rats.

The intestine as source of cytotoxic mediators in shock: free fatty acids and degradation of lipid-binding proteins

Shock and multiple organ failure remain primary causes of late-stage morbidity and mortality in victims of trauma. During shock, the intestine is subject to extensive cell death and is the source of inflammatory factors that cause multiorgan failure. We (34) showed previously that ischemic, but not nonischemic, small intestines and pancreatic protease digested homogenates of normal small intestine can generate cytotoxic factors capable of killing naive cells within minutes. Using chloroform/methanol separation of rat small intestine homogenates into lipid fractions and aqueous and sedimented protein fractions and measuring cell death caused by those fractions, we found that the cytotoxic factors are lipid in nature. Recombining the lipid fraction with protein fractions prevented cell death, except when homogenates were protease digested. Using a fluorescent substrate, we found high levels of lipase activity in intestinal homogenates and cytotoxic levels of free fatty acids. Addition of albumin, a lipid binding protein, prevented cell death, unless the albumin was previously digested with protease. Homogenization of intestinal wall in the presence of the lipase inhibitor orlistat prevented cell death after protease digestion. In vivo, orlistat plus the protease inhibitor aprotinin, administered to the intestinal lumen, significantly improved survival time compared with saline in a splanchnic arterial occlusion model of shock. These results indicate that major cytotoxic mediators derived from an intestine under in vitro conditions are free fatty acids. Breakdown of free fatty acid binding proteins by proteases causes release of free fatty acids to act as powerful cytotoxic mediators.