Relevance of irinotecan hydrochloride-induced diarrhea to the level of prostaglandin E2 and water absorption of large intestine in rats

Thymol ameliorates 5-fluorouracil-induced intestinal mucositis: Evidence of down-regulatory effect on TGF-β/MAPK pathways through NF-κB

5-Fluorouracil (5-FU) is a front-line cytotoxic therapy. However, intestinal mucositis is a well-known adverse event of 5-FU, which limits its therapeutic use. Indeed, thymol, which is a monoterpene component of the essential oil derived from thymus, has a potential anti-inflammatory and immunomodulatory activity. Therefore, this study aimed to investigate the potential chemoprotective effect of thymol against 5-FU-induced intestinal mucositis. Rats were either exposed to two doses of 5-FU (150 mg/kg, ip) and/or treated with thymol (60 or 120 mg/kg). Oxidative stress and inflammatory markers, as well as pathological changes, were assessed. 5-FU-induced severe intestinal damages as were evidenced by histopathological changes as well as oxidative and inflammatory responses. Thymol pretreatment inhibited 5-FU-induced oxidative stress by reducing lipid peroxidation and increasing intestinal levels of antioxidant systems. Moreover, inflammatory response markers, such as interleukin-6, prostaglandin E2, and COX-2 were also improved. The immunoblotting analysis also showed that thymol significantly inhibited the 5-FU-induced expression of nuclear factor-κB, tumor necrosis factor-α, and transforming growth factor β-1 (TGF-β1), in addition to the suppression of p38 and phosphorylated c-Jun N-terminal kinases (p-JNK) mitogen-activated protein kinase proteins' expressions. Our study is the first to demonstrate the promising protective effect of thymol against 5-FU-induced intestinal mucositis through inhibition of oxidative, inflammatory pathways, and suppression of TGF-β/p38/p-JNK signaling.

Alleviation of Abdominal Pain due to Irinotecan-Induced Cholinergic Syndrome Using Loperamide: A Case Report

Irinotecan hydrochloride (irinotecan) is a chemotherapeutic agent used in the treatment of solid tumors. In addition to severe neutropenia and delayed diarrhea, irinotecan causes cholinergic syndrome, characterized by abdominal pain and acute diarrhea. The latter symptoms are frequently observed during and after irinotecan treatment. Here, we have discussed the case of a patient who completely recovered from abdominal pain following the administration of loperamide hydrochloride (loperamide) at a dose of 2 mg, before infusing irinotecan. In contrast, anticholinergic drugs were not as effective in alleviating symptoms. A 28-year-old man with stage IV rectal cancer with peritoneal metastasis was prescribed with fluorouracil, irinotecan, and levofolinate calcium (FOLFIRI), in addition to cetuximab. Anticholinergic drugs, such as scopolamine butylbromide (scopolamine) or atropine sulfate (atropine), were administered to treat abdominal pain that was considered as irinotecan-induced cholinergic syndrome, but monotherapy was not effective. Thereafter, oral loperamide (2 mg) with atropine (0.25 mg) was prescribed before irinotecan infusion. Consequently, the patient did not experience any abdominal pain during and after irinotecan treatment. Loperamide is an opioid receptor agonist and decreases the activity of the myenteric plexus of the intestinal wall. It also inhibits the release of both acetylcholine and prostaglandins, resulting in decreased inhibition of peristaltic movement. We assumed that its mechanism solely or in combination contributed to symptom relief. We hypothesized that the synergistic anticholinergic interaction between loperamide and atropine resulted in marked suppression of irinotecan-induced cholinergic syndrome compared to loperamide alone. Thus, loperamide may improve abdominal pain attributed to irinotecan-induced cholinergic syndrome.

Anti-inflammatory effects of Radix Aucklandiae herbal preparation ameliorate intestinal mucositis induced by 5-fluorouracil in mice

ETHNOPHARMACOLOGICAL RELEVANCE

5-Fluorouracil (5-FU) is a chemotherapy agent that is widely used in clinical oncologic practice. However, intestinal mucositis is the most frequently occurring side effect of cancer therapy with 5-FU. Based on a literature survey, Radix Aucklandiae herbal preparation potentially ameliorates intestinal mucositis in 5-FU-treated mice.

AIM OF THE STUDY

The aim of this study was to investigate the inflammation and gastrointestinal regulation of intestinal mucositis induced by 5-FU, including the intestinal morphology, as well as the reduction in food intake, body weight loss, and diarrhea.

MATERIALS AND METHODS

Intestinal mucositis was induced in mice by 5-FU (30 mg/kg, i.p., for 5 consecutive days). The dose-dependent Radix Aucklandiae herbal preparation (0.3, 1, and 3 g/kg/day, p.o.), loperamide (3 mg/kg/day, p.o.) or celecoxib (40 mg/kg/day, p.o.) was concurrently administered until the 7th day. Physical status observation, diarrhea assessment, serum proinflammatory cytokine levels, intestinal villus height and crypt depth, and total goblet cells from tissues were assessed.

RESULTS

The dosage regimen of 5-FU administration caused severe intestinal mucositis in mice, including damage to the intestinal morphology, accompanied by a reduction in food intake, body weight loss, and diarrhea. The high-dose Radix Aucklandiae herbal preparation significantly relieves 5-FU-induced intestinal mucositis by enhancing proliferative activity in epithelial crypts; improving anepithymia, body weight loss, and diarrhea; and displaying protective effects on goblet cells in intestinal mucosal epithelia. Activation of NF-κB in the intestinal mucositis model was also suppressed by the Radix Aucklandiae herbal preparation, suggesting that it is a potent inhibitor of NF-κB and proinflammatory cytokines, such as IL-1β, IL-6, TNF-α, and COX-2.

CONCLUSIONS

Our data support the conclusion that the Radix Aucklandiae herbal preparation could effectively ameliorate 5-FU-induced gastrointestinal toxicity and be applied clinically for the prevention of intestinal mucositis during chemotherapy.

Protective effect of magnolol on oxaliplatin-induced intestinal injury in mice

Oxaliplatin (OXL) is the first line treatment therapy for gastrointestinal (GI) cancers and often combines with other chemotherapy. However, few reports have studied on its GI toxicity. Magnolol (MG), one of the mainly active constituents in Magnolia, has been reported to treat digestive diseases. Therefore, the purpose of this study is to evaluate the intestinal protective effect of MG in OXL treatment group. OXL administration mice showed body weight loss, diarrhea, and intestinal damage characterized by the shortening of villi and destruction of intestinal crypts, as well as the colon length change. MG significantly reduced body weight loss, alleviated diarrhea, reversed histopathological changes, and prevented colon length reduction. Oxidative stress and inflammation were activated after OXL, and these responses were repressed by MG through increasing the activities of superoxide dismutase, glutathione peroxidase, and glutathione, decreasing level of nuclear factor of kappa b and downregulating the following pro-inflammatory cytokines. Although the expression of tight junction protein occludin and numbers of proliferative crypt cells were reduced on ileum and colon after OXL, MG administration promoted these expressions. The fecal gut microbiota composition disturbed by OXL was significantly reversed by MG. Thus, MG could prevent the development and progression of mucositis induced by oxaliplatin through multipathway.

Liposomal Irinotecan for Treatment of Colorectal Cancer in a Preclinical Model

Colorectal cancer (CRC) is the most frequently diagnosed cancer and leading cause of cancer-related deaths worldwide. Because of the use of first-line CRC treatments, such as irinotecan (IRI), is hindered by dose-limiting side effects, improved drug delivery systems may have major clinical benefits for CRC treatment. In this study, we generate and characterize liposomal irinotecan (Lipo-IRI), a lipid-based nanoparticle, which shows excellent bioavailability and pharmacokinetics. Additionally, this formulation allows IRI to be maintained in active form and prolongs its half-life in circulation compared to IRI in solution. Compared with IRI statistically, the level of prostaglandin E2 (PGE2) in colonic tissue decreases, and Bifidobacterium spp. (beneficial intestinal microbiota) content increases in the Lipo-IRI-treated group. Moreover, no damage is observed by the hematoxylin and eosin staining of the normal tissue samples from the Lipo-IRI-treated group. In a xenograft mouse model, CRC tumors shrink markedly following Lipo-IRI treatment, and mice receiving a targeted combination of Lipo-IRI and liposomal doxorubicin (Lipo-Dox) extend their survival rate significantly. Overall, our results demonstrate that this formulation of Lipo-IRI shows a great potential for the treatment of colorectal cancer.

Downregulation of Aquaporin 3 Mediated the Laxative Effect in the Rat Colon by a Purified Resin Glycoside Fraction from Pharbitis Semen

Background

Pharbitis Semen, the seeds of Pharbitis nil, is widely used as a traditional purgative medicine in China, Korea, and Japan. This study investigated the laxative effects of a purified resin glycoside fraction obtained in our previous study from Pharbitis Semen in vivo and in vitro.

Materials and Methods

After orally administering a purified resin glycoside fraction from Pharbitis Semen (RFP) to rats, the content of fecal water, AQP3, NF-κB, COX-2 expression, and the prostaglandin E₂ (PGE₂) concentrations in the colon were examined. Moreover, human intestinal epithelial cells (HT-29) were used to investigate the mechanism of RFP decreasing the AQP3 expression.

Results

Results obtained showed that treatment with RFP increased the feces excretion and fecal water content of rats in a dose-dependent manner. More interestingly, AQP3 expression was suppressed by RFP treatment both in the rat colons and in HT-29 cells, while the NF-κB pathway-mediated PGE₂ production was activated. Interestingly, pretreating rats with BAY-11-7082 (NF-κB inhibitor) or indomethacin (COX-2 inhibitor) and RFP neither induced diarrhea nor decreased the AQP3 expression in the colon.

Conclusions

The purgative property of the purified resin glycoside fraction was attributed to NF-κB activation in the colon, which increased the COX-2-mediated secretion of PGE₂. PGE₂ decreased AQP3 expression which inhibits water absorbed from the intestine to the blood vessel side, resulting in the laxative effect of RFP.

CPT-11-Induced Delayed Diarrhea Develops via Reduced Aquaporin-3 Expression in the Colon

While irinotecan (CPT-11) has a potent anti-cancer effect, it also causes serious diarrhea as an adverse reaction. In this study, we analyzed the pathogenic mechanism of CPT-11-induced delayed diarrhea by focusing on water channel aquaporin-3 (AQP3) in the colon. When rats received CPT-11, the expression level of AQP3 was reduced during severe diarrhea. It was found that the expression levels of inflammatory cytokines and the loss of crypt cells were increased in the colon when CPT-11 was administered. When celecoxib, an anti-inflammatory drug, was concomitantly administered, both the diarrhea and the reduced expression of AQP3 induced by CPT-11 were suppressed. The inflammation in the rat colon during diarrhea was caused via activated macrophage by CPT-11. These results showed that when CPT-11 is administered, the expression level of AQP3 in the colon is reduced, resulting in delayed diarrhea by preventing water transport from the intestinal tract. It was also suggested that the reduced expression of AQP3 might be due to the inflammation that occurs following the loss of colonic crypt cells and to the damage caused by the direct activation of macrophages by CPT-11. Therefore, it was considered that anti-inflammatory drugs that suppress the reduction of AQP3 expression could prevent CPT-11-induced delayed diarrhea.

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

BACKGROUND

Irinotecan hydrochloride (CPT-11), a topoisomerase I inhibitor highly effective for various cancers, has its dosage limited by diffuse mucosal damage with increased prostaglandin (PG) E(2). However, an analysis of intestinal phospholipid fatty acid composition after CPT-11 treatment has not been reported. This study aimed to evaluate intestinal phospholipid fatty acid composition in relation to intestinal mucosal integrity and plasma and mucosal PGE(2) levels after CPT-11 treatment. The effect of dietary vegetable oil supplementation, perilla oil vs corn oil, was also evaluated.

METHODS

Intestinal phospholipid fatty acid composition, PGE(2) level, mucosal diamine oxidase (DAO) activity, diarrhea, and blood tests were evaluated in rats injected with CPT-11 under a conventional diet. The same parameters were compared among 3 different dietary vegetable oil supplementations: perilla oil, corn oil, and a 1:3, respectively, mixture with a semisynthetic diet during 14 days.

RESULTS

CPT-11 treatment caused severe diarrhea, and intestinal mucosal fatty acid composition changed with increased PGE(2) level and decreased DAO activity. Decreases in eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and EPA/arachidonic acid (AA) ratio in colonic mucosa were observed. Perilla oil increased omega-3 polyunsaturated fatty acids, alpha-linolenic acid, EPA, and EPA/AA ratio and decreased plasma PGE(2). But the amounts used were not enough to attenuate intestinal damage from CPT-11 treatment.

CONCLUSIONS

CPT-11 induced changes of intestinal mucosal fatty acid composition with increased PGE(2) level and decreased intestinal integrity; perilla oil shows the possibility of being able to attenuate those changes.

Chemotherapy-Induced Constipation and Diarrhea: Pathophysiology, Current and Emerging Treatments

Gastrointestinal (GI) side-effects of chemotherapy are a debilitating and often overlooked clinical hurdle in cancer management. Chemotherapy-induced constipation (CIC) and Diarrhea (CID) present a constant challenge in the efficient and tolerable treatment of cancer and are amongst the primary contributors to dose reductions, delays and cessation of treatment. Although prevalence of CIC is hard to estimate, it is believed to affect approximately 16% of cancer patients, whilst incidence of CID has been estimated to be as high as 80%. Despite this, the underlying mechanisms of both CID and CIC remain unclear, but are believed to result from a combination of intersecting mechanisms including inflammation, secretory dysfunctions, GI dysmotility and alterations in GI innervation. Current treatments for CIC and CID aim to reduce the severity of symptoms rather than combating the pathophysiological mechanisms of dysfunction, and often result in worsening of already chronic GI symptoms or trigger the onset of a plethora of other side-effects including respiratory depression, uneven heartbeat, seizures, and neurotoxicity. Emerging treatments including those targeting the enteric nervous system present promising avenues to alleviate CID and CIC. Identification of potential targets for novel therapies to alleviate chemotherapy-induced toxicity is essential to improve clinical outcomes and quality of life amongst cancer sufferers.

A novel genetic score model of UGT1A1 and TGFB pathway as predictor of severe irinotecan-related diarrhea in metastatic colorectal cancer patients

PURPOSE

UGT1A1*28/*6 as predictors of severe irinotecan-related diarrhea (SIRD) were duplicated by many studies. However, some patients of lower risk genotype (UGT1A1*1/*1) still suffered SIRD and the extremely low frequency of UGT1A1*6/*6 limited its clinical usage. Previous studies proved that the transforming growth factor (TGFB) family may have some effect on MTX-induced mucositis. However, the associations between TGFB gene variants and SIRD have never been reported so far. Our aim was to improve the predictive value of UGT1A1 gene variants on SIRD.

METHODS

Six SNPs (TGFB1 rs1800469; TGFBR1 rs10733710, rs334354 and rs6478974; TGFBR2 rs3087465; UGT1A1*6) and UGT1A1*28 were selected for genotyping in 160 metastatic colorectal cancer patients treated with irinotecan in a prospective multicenter trial (NCT01282658).

RESULTS

UGT1A1*6, UGT1A1*28, rs1800469 and rs3087465 were all associated with SIRD (p = 0.026, 0.014, 0.047 and 0.045 respectively). A novel genetic score model (with a cut off value of 1.5) based on them was created to predict SIRD (OR = 11.718; 95 % CI 2.489-55.157, p = 0.002). In patients of gene score > 1.5, the risk of SIRD was much higher (23.5 vs. 2.8 %, p = 2.24E-04) and continued in the first 6 cycles of chemotherapy, while in patients with gene score ≤1.5, the risk was much lower and none of them suffered SIRD after the first cycle of chemotherapy (p = 0.0003).

CONCLUSIONS

The novel genetic score model improved the predictive value of UGT1A1 on SIRD. If validated, it will provide valuable information for clinical use of irinotecan.

Reparative activity of costunolide and dehydrocostus in a mouse model of 5-fluorouracil-induced intestinal mucositis

The aim of the study was to investigate the protective effects of costunolide (Co) and dehydrocostus (De) in 5-fluorouracil (5-FU)-induced intestinal mucositis (IM) as well as the potential mechanisms involved.

The Adaptor Protein Myd88 Is a Key Signaling Molecule in the Pathogenesis of Irinotecan-Induced Intestinal Mucositis

Intestinal mucositis is a common side effect of irinotecan-based anticancer regimens. Mucositis causes cell damage, bacterial/endotoxin translocation and production of cytokines including IL–1 and IL–18. These molecules and toll-like receptors (TLRs) activate a common signaling pathway that involves the Myeloid Differentiation adaptor protein, MyD88, whose role in intestinal mucositis is unknown. Then, we evaluated the involvement of TLRs and MyD88 in the pathogenesis of irinotecan-induced intestinal mucositis. MyD88-, TLR2- or TLR9-knockout mice and C57BL/6 (WT) mice were given either saline or irinotecan (75 mg/kg, i.p. for 4 days). On day 7, animal survival, diarrhea and bacteremia were assessed, and following euthanasia, samples of the ileum were obtained for morphometric analysis, myeloperoxidase (MPO) assay and measurement of pro-inflammatory markers. Irinotecan reduced the animal survival (50%) and induced a pronounced diarrhea, increased bacteremia, neutrophil accumulation in the intestinal tissue, intestinal damage and more than twofold increased expression of MyD88 (200%), TLR9 (400%), TRAF6 (236%), IL–1β (405%), IL–18 (365%), COX–2 (2,777%) and NF-κB (245%) in the WT animals when compared with saline-injected group (P<0.05). Genetic deletion of MyD88, TLR2 or TLR9 effectively controlled the signs of intestinal injury when compared with irinotecan-administered WT controls (P<0.05). In contrast to the MyD88^-/- and TLR2^-/- mice, the irinotecan-injected TLR9^-/- mice showed a reduced survival, a marked diarrhea and an enhanced expression of IL–18 versus irinotecan-injected WT controls. Additionally, the expression of MyD88 was reduced in the TLR2^-/- or TLR9^-/- mice. This study shows a critical role of the MyD88-mediated TLR2 and TLR9 signaling in the pathogenesis of irinotecan-induced intestinal mucositis.

Metabolomic study of Chinese medicine Huang Qin decoction as an effective treatment for irinotecan-induced gastrointestinal toxicity

Metabolomic study revealed Chinese medicine HQD reducing irinotecan-induced gastrointestinal toxicity by regulating glutamine, tryptophan and lipid metabolisms.

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.

Nutrition modulation of gastrointestinal toxicity related to cancer chemotherapy: from preclinical findings to clinical strategy

Chemotherapy-induced gut toxicity is a major dose-limiting toxicity for many anticancer drugs. Gastrointestinal (GI) complications compromise the efficacy of chemotherapy, promote overall malnutrition, aggravate cancer cachexia, and may contribute to worsened prognosis. The GI tract is an attractive target for nutrition modulation, owing to its direct exposure to the diet, participation in uptake and metabolism of nutrients, high rate of cell turnover, and plasticity to nutrition stimuli. Glutamine, ω-3 polyunsaturated fatty acids, and probiotics/prebiotics are therapeutic factors that potentially modulate GI toxicity related to cancer treatments. Preclinical and clinical evidence are reviewed to critically define plausible benefits of these factors and their potential development into adjuncts to cancer chemotherapy. Mechanisms underlying the action of these nutrients are being unraveled in the laboratory. Optimal strategies to translate these findings into clinical care still remain to be elucidated. Key questions that remain to be answered include the following: which nutrient or combination of nutrients is selected for which patient and chemotherapy regimen? What mechanisms are responsible for modulation, and how are nutrient(s) administered in a clinically optimal manner? Research exploring interactions between different nutrients in GI protection is ongoing and demands further understanding. How nutrition preparations given to chemotherapy-treated patients are formulated in terms of component selection and dose optimization should be carefully studied and justified.

Antineoplastic effects of n-3 polyunsaturated fatty acids in combination with drugs and radiotherapy: preventive and therapeutic strategies

Many data support the beneficial effect of n-3 polyunsaturated fatty acids (PUFAs) as chemopreventive and chemotherapeutic agents in the treatment of several chronic pathologies including cancer. Different molecular mechanisms have been proposed to explain their effects, including alterations in arachidonic acid oxidative metabolism and metabolic conversion of n-3 PUFAs to novel discovered bioactive derivatives; modification of oxidative stress; changes in cell membrane fluidity and structure and altered metabolism and function of membrane proteins. Considerable knowledge has been recently gathered on the possible beneficial effects of n-3 PUFAs administered in combination with different antineoplastic drugs and radiotherapy against melanoma, leukemia, neuroblastoma, and colon, breast, prostate, and lung cancer. The efficacy of these combinations has been demonstrated both in vivo and in vitro, and clinical trials have also been conducted. The aim of this review is to analyze all the n-3 PUFA combinations investigated so far, their efficacy, and the possible molecular mechanisms involved. It would be highly auspicable that the detailed analysis of the literature in this field could further support the common use of n-3 PUFAs in combination with other chemopreventive agents and warrant more clinical investigations designed to test the effectiveness of n-3 PUFA treatments coupled with conventional antineoplastic therapies.

Nutritional modulation of antitumor efficacy and diarrhea toxicity related to irinotecan chemotherapy in rats bearing the ward colon tumor

PURPOSE

To evaluate and compare the influence of dietary elements on cancer progression, chemotherapy efficacy, and toxicity, particularly severe, late-onset diarrhea related to irinotecan (CPT-11) treatment.

EXPERIMENTAL DESIGN

We used laboratory rats fed a standardized basal diet, Ward colon tumor, and CPT-11 therapy for the study of CPT-11-induced diarrhea. Dietary interventions were selected from nutrients already established to modify other forms of colitis and which have been hypothesized to mitigate chemotherapy-induced gastrointestinal injury (glutamine, n-3 fatty acids, prebiotic oligosaccharides). Animals adapted to test diets were treated with CPT-11 at the maximum tolerated dose (125 mg/kg x 3 days) and diarrhea was followed continuously for 1 week.

RESULTS

The inclusion of n-3 fatty acids in the diet (5%, w/w of total fat) suppressed tumor growth and enhanced CPT-11's efficacy; this treatment did not affect the incidence or severity of diarrhea. By contrast, oral glutamine bolus (0.75 g/kg) administered prior to each CPT-11 treatment reduced the incidence of severe diarrhea (34.1 +/- 4.7% versus 53.8 +/- 4.2%, P < 0.005) and decreased the area under the curve of diarrhea score (16.5 +/- 1.0 versus 18.8 +/- 0.5, P < 0.05). Identical results were obtained with i.v. bolus glutamine administration. Glutamine treatment did not alter CPT-11's antitumor efficacy. The addition of prebiotic oligosaccharides to the diet (8%, w/w of diet) did not mitigate the severity of diarrhea, and it raised the activity of beta-glucuronidase in cecal contents, a key bacterial enzyme mediating CPT-11-related intestinal toxicity.

CONCLUSION

Our experiments suggest that glutamine and n-3 fatty acids might be potentially useful adjuncts to CPT-11 treatment.

Reducing irinotecan-associated diarrhea in children

Irinotecan is increasingly being used in pediatric oncology. Amelioration of diarrhea associated with protracted irinotecan administration may reduce morbidity and improve dose intensity. In this review, we discuss what is known about the pathogenesis of this toxicity as well as potential predisposing genetic factors. We comprehensively summarize the literature regarding available prevention and treatment strategies, and report data on the use of cephalosporin prophylaxis in 51 patients treated on various pediatric trials. This approach is feasible in children and allows for tolerance of higher doses of protracted irinotecan.

Celecoxib and mucosal protection: translation from an animal model to a phase I clinical trial of celecoxib, irinotecan, and 5-fluorouracil

PURPOSE

Chemotherapy-induced diarrhea occurs secondary to mucosal inflammation and may be cyclooxygenase-2 mediated. Cyclooxygenase-2 inhibitors may ameliorate chemotherapy-induced mucosal toxicity and enhance its antitumor effect. We investigated this hypothesis in the Ward colorectal cancer rat model and in a phase I clinical study.

EXPERIMENTAL DESIGN

In the Ward rat model, irinotecan was given daily x 3 or weekly x 4 with or without celecoxib. In the phase I clinical study, we planned to escalate the dose of irinotecan in the FOLFIRI regimen (irinotecan, 5-fluorouracil, and leucovorin) with a fixed dose of celecoxib. Irinotecan was escalated in four dose levels: 180, 200, 220, and 260 mg/m2. Celecoxib was administered as 400 mg, twice daily starting on day 2 of cycle 1. Pharmacokinetics of irinotecan, SN-38, and SN-38G were obtained on days 1 and 14. A standard 3+3 dose escalation scheme was used. Plasma concentrations of irinotecan, SN-38, and SN-38G were measured using high-pressure liquid chromatography.

RESULTS

Celecoxib ameliorated diarrhea, weight loss, and lethality and resulted in synergistic antitumor effect in the rat model. Twelve patients with advanced cancers were enrolled and evaluable for dose-limiting toxicity (DLT). Diarrhea was the cause for discontinuation in one. Grade 2 and 3 diarrhea occurred in three and two patients, respectively. One patient had DLT at dose level 2 (grade 3 diarrhea). Two had a DLT at DL3 (G3 emesis and myocardial infarct). Celecoxib had limited influence on the pharmacokinetics of irinotecan in this data set.

CONCLUSIONS

Maximum tolerated dose of irinotecan in FOLFIRI schedule with celecoxib is 200 mg/m2.

A Phase II Trial of Irinotecan, 5-Fluorouracil and Leucovorin Combined with Celecoxib and Glutamine as First-Line Therapy for Advanced Colorectal Cancer

OBJECTIVES

Preclinical and clinical data indicate that cyclooxygenase-2 (COX-2) is a bona fide molecular target for colorectal cancer (CRC). Glutamine may decrease chemotherapy-associated diarrhea. This study was designed to address whether the addition of celecoxib, a COX-2 inhibitor, and glutamine would improve the efficacy and decrease the toxicities of the irinotecan, fluorouracil and leucovorin (IFL) regimen.

METHODS

All patients received the original IFL regimen plus celecoxib (400 mg, po, every 12 h continuously while on trial) and glutamine (10 g, po, every 8 h continuously while on chemotherapy).

RESULTS

Of the 41 patients enrolled, 40 patients received between 1 and 6 cycles of treatment. This regimen was associated with significant toxicities: 45.0% had grade 3 diarrhea, 35.0% grade 3/4 neutropenia, 22.5% hospitalization, 10.0% deep vein thrombosis and 2 treatment-related deaths. The overall response rate was 47.2%. The median progression-free survival was 6.7 months. The median overall survival was 16.3 months. The 12-month overall survival rate was 54.8%. COX-2 expression was present in 63.2% of the specimens evaluated. There was no significant correlation between COX-2 expression and response to chemotherapy (p = 0.739).

CONCLUSION

The addition of celecoxib and glutamine appears not to improve the efficacy or decrease the toxicities of IFL for the treatment of metastatic CRC.

Prospective, double-blind, placebo-controlled, multicenter, randomized phase III study with orally administered budesonide for prevention of irinotecan (CPT-11)-induced diarrhea in patients with advanced colorectal cancer

BACKGROUND

Unpredictable and severe diarrhea (NCI grade > or =3) remains a life-threatening adverse event in patients treated with irinotecan (CPT-11). The aim of this study was to evaluate the efficacy and safety of orally administered budesonide for prevention of CPT-11-induced delayed diarrhea in patients with advanced colorectal cancer.

PATIENTS AND METHODS

A total of 56 patients with advanced colorectal cancer receiving CPT-11 therapy (125 mg/m2 once weekly) were enrolled in this multicenter trial. Patients were randomly treated with 3 mg budesonide orally 3 times daily versus placebo. Detailed assessment of diarrhea by monitoring stool frequency, stool consistency and loperamide rescue medication was made by keeping a diary.

RESULTS

Diarrhea, defined as number of stools >4 occurring on a single day during the study period, could be prevented in 58.3% of the budesonide-treated patients compared to 38.5% of the patients under placebo. Patients in the budesonide group had less episodes (0.7 vs. 2.2 episodes) and a considerably shorter total duration of diarrhea (1.8 vs. 4.2 days) episodes than patients in the placebo group. Loperamide use was more frequent in the placebo than in the budesonide arm (55.6 vs. 41.7%). Also, exposure to rescue medication of loperamide was higher for placebo (36.2 capsules) than for budesonide (24.9 capsules). A superior prevention of diarrhea was observed for budesonide compared to placebo in the first cycle (14 vs. 10; p = 0.257), with more failures observed in the placebo group (16 vs. 10).

CONCLUSION

This double-blind randomized trial failed to show that budesonide has a significant benefit in preventing CPT-11-induced diarrhea. While a trend exists, further trials are warranted.

New approaches to prevent intestinal toxicity of irinotecan-based regimens

BACKGROUND

Irinotecan is a selective inhibitor of topoisomerase I, an enzyme part of the replication and transcription system of DNA. Irinotecan is employed, with different modalities, in the treatment of metastatic colorectal cancer, and recently it has been officially approved in association with fluorouracil (FU) and leucovorin (LV) as a first-line option in metastatic colorectal cancer.

RESULTS

One of the problems linked to the administration of this drug is the high intestinal toxicity, which constitutes its dose limiting toxicity (DLT). In routine practice, loperamide is employed as symptomatic drug for the treatment of CPT-11-induced diarrhoea, but is not completely adequate to control the problem. The role of the intestinal bacterial microflora in the pathogenesis of CPT-11-induced intestinal toxicity has been recently discovered. The active metabolite of CPT-11, SN38, is generated from CPT-11 by sieric carboxylesterase, and subsequently conjugated to SN38-G by hepatic UDP-glucuronyltransferase. SN38-G is the inactive metabolite of CPT-11 and is excreted into the small intestine, from which it is eliminated in the faeces. Some studies have shown the ability of intestinal bacterial beta-glucoronidases to transform SN38-G into SN38, causing direct damage to the intestinal mucosa. Thus, alternative strategies such as intestinal alkalinization and anti-cyclooxygenase 2 (COX-2) therapy have been explored.

CONCLUSIONS

In this review, we will illustrate the mechanisms which cause the CPT-11-induced diarrhoea and the potential measures available to prevent it.

Consumption of an omega-3 fatty acids product, INCELL AAFA, reduced side-effects of CPT-11 (irinotecan) in mice

INCELL AAFA, an omega-3 polyunsaturated fatty acid product containing a high concentration of long chain fatty acids, was tested for its ability to ameliorate the harmful side effects of CPT-11 chemotherapy including: leukopenia, anaemia, asthenia, weight loss and liver involvement. Four groups of mice were fed an AIN-76 diet modified to contain: 10% w/w corn oil (CO), 0% AAFA; 9% CO, 1% AAFA; 8% CO, 2% AAFA; or 7% CO, 3% AAFA. After 2 weeks on the diets, half of the mice received CPT-11 chemotherapy (60 mg kg(-1) q 4 days, i.v.) the rest of the mice received vehicle for 2 weeks. It was found that 2% AAFA in the diet of the CPT-11 treated mice: decreased apoptotic figures in the duodenal crypts; markedly suppressed the inflammatory eicosanoid, prostaglandin E(2) in the liver; prevented liver hypertrophy; improved white blood cell counts; significantly increased red blood cell counts; decreased numbers of CPT-11 induced immature red blood cell and micronuclei in red blood cells of the peripheral blood; increased eicosapentaenoic acid and docosahexaenoic acid in liver cell membranes and maintained normal grooming behaviour. Thus 2% AAFA in the diet reduced the side effects of CPT-11 treatment in mice.

Excretion into gastrointestinal tract of irinotecan lactone and carboxylate forms and their pharmacodynamics in rodents

PURPOSE

To investigate the excretion of irinotecan hydrochloride (CPT-11) and its active metabolite, SN-38, into the gastrointestinal lumen via the biliary and/or intestinal membrane route after dosing with lactone and carboxylate forms of CPT-11, and to evaluate the toxic and antitumor effects of the two forms.

METHODS

The excretions of CPT-11 and SN-38 were investigated by the in situ perfusion technique using rats. The incidence of delayed diarrhea was evaluated after i.v. dosing (60 mg/kg) with CPT-11 lactone and carboxylate forms for 4 days. Antitumor activity and changes in body weight were investigated in mice with Meth A tumors.

RESULTS

The excretion of CPT-11 into bile was greater in dosing with CPT-11 carboxylate than that with its lactone form, whereas the exsorption across intestinal membrane was greater in dosing with CPT-11 lactone than that with its carboxylate form. Dosing with CPT-11 lactone dose-dependently inhibited the increase in tumor weights in Meth A tumor mice, whereas the dosing with its carboxylate form reduced the antitumor effect.

CONCLUSIONS

The decreased antitumor effect caused by dosing with the CPT-11 carboxylate form could be due to less accumulation in the tissue including tumor cells resulting from the rapid elimination of the form in the body.

Fish oil supplementation enhanced CPT-11 (irinotecan) efficacy against MCF7 breast carcinoma xenografts and ameliorated intestinal side-effects

The cancer chemotherapeutic efficacy of the topoisomerase I inhibitor, CPT-11 (irinotecan) is often limited by the induction of severe delayed diarrhoea. In animal studies, CPT-11 use is associated with histopathological damage to the mucosa of the small and large intestines. Results from the present study demonstrate that 60 mg CPT-11 per kg body weight (i.v. q4d x 6) halted the growth, but did not cause significant regression, of MCF7 human breast carcinoma xenografts in mice fed a diet containing 7% corn oil. However, when the diet of the MCF7-bearing mice was supplemented with 3% or 6% fish oil, the same CPT-11 treatment caused significant regression of the MCF7 xenograft. Histomorphometric analyses of intestinal mucosa of mice treated with CPT-11 and fed the diet containing 7% com oil indicated that treatment with CPT-11 induced structural changes in the intestinal mucosa which persisted at least 5 days after the last dose of CPT-11. The intestinal mucosal architecture of mice that were treated with CPT-11 and fed the diets containing fish oil was largely unchanged from the architecture of the group of mice which did not receive CPT-11. These findings indicate that fish oil supplements may be a useful adjunct to CPT-11 treatment.

Preventive effects of Hange-shashin-to on irinotecan hydrochloride-caused diarrhea and its relevance to the colonic prostaglandin E2 and water absorption in the rat

The possible preventive effect of Kampo medicine Hange-shashin-to (TJ-14) on chronic diarrheal symptoms induced by the administration of the anticancer agent irinotecan hydrochloride (CPT-11) was investigated in the rat. Repeated oral administrations of TJ-14 at 125 and 500 mg/kg significantly prevented the reduction in body weight and the onset of chronic diarrheal symptoms due to CPT-11 in a dose-dependent manner, even though it failed to show a definite effect on acute diarrheal symptoms. In addition, treatment with TJ-14 accelerated the healing of the intestinal tract injured by repeated dosing of CPT-11 and inhibited significantly the increase of colonic prostaglandin E2 (PGE2) which is closely related to the onset of diarrhea. TJ-14 also improved colonic water absorption impaired by repeated dosing of CPT-11 in rats. These results demonstrate that TJ-14 is an effective medicine for the prevention and/or treatment of CPT-11-induced chronic diarrheal symptoms.