Could paraprobiotics be a safer alternative to probiotics for managing cancer chemotherapy-induced gastrointestinal toxicities?

Clinical oncology has shown outstanding progress improving patient survival due to the incorporation of new drugs. However, treatment success may be reduced by the emergency of dose-limiting side effects, such as intestinal mucositis and diarrhea. Mucositis and diarrhea management is symptomatic, and there is no preventive therapy. Bacterial and fungal-based compounds have been suggested as an alternative for preventing the development of diarrhea in cancer patients. Using probiotics is safe and effective in immunocompetent individuals, but concerns remain during immunosuppressive conditions. Paraprobiotics, formulations composed of non-viable microorganisms, have been proposed to overcome such limitation. The present literature review discusses current evidence regarding the possible use of paraprobiotics as an alternative to probiotics to prevent gastrointestinal toxicity of cancer chemotherapy.

Could paraprobiotics be a safer alternative to probiotics for managing cancer chemotherapy-induced gastrointestinal toxicities?

Clinical oncology has shown outstanding progress improving patient survival due to the incorporation of new drugs. However, treatment success may be reduced by the emergency of dose-limiting side effects, such as intestinal mucositis and diarrhea. Mucositis and diarrhea management is symptomatic, and there is no preventive therapy. Bacterial and fungal-based compounds have been suggested as an alternative for preventing the development of diarrhea in cancer patients. Using probiotics is safe and effective in immunocompetent individuals, but concerns remain during immunosuppressive conditions. Paraprobiotics, formulations composed of non-viable microorganisms, have been proposed to overcome such limitation. The present literature review discusses current evidence regarding the possible use of paraprobiotics as an alternative to probiotics to prevent gastrointestinal toxicity of cancer chemotherapy.

Correction to: α-Phellandrene attenuates tissular damage, oxidative stress, and TNF-α levels on acute model ifosfamide-induced hemorrhagic cystitis in mice.

The published online version contains figure in poor quality.

α-Phellandrene attenuates tissular damage, oxidative stress, and TNF-α levels on acute model ifosfamide-induced hemorrhagic cystitis in mice.

Hemorrhagic cystitis (HC) is the major dose-limiting adverse effect of the clinical use ifosfamide (IFOS). The incidence of this side effect can be as high as 75%. Mesna has been used to reduce the risk of HC, although 5% of patients who get IFOS treatment may still suffer from HC. In previous studies, our group demonstrated that α-phellandrene (α-PHE) possesses anti-inflammatory activity, which opens the door for its study in the attenuation of HC. The objective of this study was to investigate the potential uroprotective effect of the α-PHE in the mouse model of IFOS-induced HC. In order to analyze the reduction of the urothelial damage, the bladder wet weight, hemoglobin content, and the Evans blue dye extravasation from the bladder matrix were evaluated. To investigate the involvement of neutrophil migration and lipid peroxidation and involvement of enzymatic and endogenous non-enzymatic antioxidants, the tissue markers myeloperoxidase (MPO), malondialdehyde, nitrite/nitrate (NOx), superoxide dismutase (SOD), and reduced glutathione (GSH) were evaluated. TNF-α and IL-1ß were measured by ELISA immunoassay technique. The results show that pretreatment with α-PHE significantly reduced urothelial damage that was accompanied by a decrease in the activity of MPO, MDA, and NOx levels and prevention of the depletion of SOD and GSH in bladder tissues. In the assessment of cytokines, α-PHE was able to significantly reduce TNF-α level. However, it does not affect the activities of IL-1ß. These data confirm that α-PHE exerts potent anti-inflammatory properties and demonstrates that α-PHE represents a promising therapeutic option for this pathological condition.

Amifostine reduces inflammation and protects against 5-fluorouracil-induced oral mucositis and hyposalivation.

Oral mucositis (OM) is a common and dose-limiting side effect of cancer treatment, including 5-fluorouracil (5-FU) and radiotherapy. The efficacy of the therapeutic measures to prevent OM is limited and disease prevention is not fully observable. Amifostine is a cytoprotective agent with a described anti-inflammatory potential. It is clinically used to reduce radiotherapy and chemotherapy-associated xerostomia. This study investigated the protective effect of amifostine on an experimental model of OM. Hamsters were divided into six groups: saline control group (5 mL/kg), mechanical trauma (scratches) of the right cheek pouch; 5-FU (60 and 40 mg/kg, ip, respectively, administered on days 1 and 2); amifostine (12.5, 25, or 50 mg/kg) + 5-FU + scratches. Salivation rate was assessed and the animals were euthanized on day 10 for the analysis of macroscopic and microscopic injury by scores. Tissue samples were harvested for the measurement of neutrophil infiltration and detection of inflammatory markers by ELISA and immunohistochemistry. 5-FU induced pronounced hyposalivation, which was prevented by amifostine (P<0.05). In addition, 5-FU injection caused pronounced tissue injury accompanied by increased neutrophil accumulation, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1ß) tissue levels, and positive immunostaining for TNF-α, IL-1ß, and inducible nitric oxide synthase (iNOS). Interestingly, amifostine prevented the inflammatory reaction and consequently improved macroscopic and microscopic damage (P<0.05 vs 5-FU group). Amifostine reduced inflammation and protected against 5-FU-associated oral mucositis and hyposalivation.

Amifostine reduces inflammation and protects against 5-fluorouracil-induced oral mucositis and hyposalivation

Oral mucositis (OM) is a common and dose-limiting side effect of cancer treatment, including 5-fluorouracil (5-FU) and radiotherapy. The efficacy of the therapeutic measures to prevent OM is limited and disease prevention is not fully observable. Amifostine is a cytoprotective agent with a described anti-inflammatory potential. It is clinically used to reduce radiotherapy and chemotherapy-associated xerostomia. This study investigated the protective effect of amifostine on an experimental model of OM. Hamsters were divided into six groups: saline control group (5 mL/kg), mechanical trauma (scratches) of the right cheek pouch; 5-FU (60 and 40 mg/kg, ip, respectively, administered on days 1 and 2); amifostine (12.5, 25, or 50 mg/kg) + 5-FU + scratches. Salivation rate was assessed and the animals were euthanized on day 10 for the analysis of macroscopic and microscopic injury by scores. Tissue samples were harvested for the measurement of neutrophil infiltration and detection of inflammatory markers by ELISA and immunohistochemistry. 5-FU induced pronounced hyposalivation, which was prevented by amifostine (P<0.05). In addition, 5-FU injection caused pronounced tissue injury accompanied by increased neutrophil accumulation, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) tissue levels, and positive immunostaining for TNF-α, IL-1β, and inducible nitric oxide synthase (iNOS). Interestingly, amifostine prevented the inflammatory reaction and consequently improved macroscopic and microscopic damage (P<0.05 vs 5-FU group). Amifostine reduced inflammation and protected against 5-FU-associated oral mucositis and hyposalivation.

Immune cell profile of dental pulp tissue treated with zoledronic acid.

AIM: To characterize the pulp immune cell profile in the teeth of rats treated with zoledronic acid (ZA). METHODOLOGY: Male Wistar rats (n = 6 per group) received four intravenous infusions of ZA at doses of 0.04, 0.20 or 1.00 mg kg-1 ZA or saline (control). On the 70th experimental day, they were euthanized. The first right molar was examined microscopically and submitted to toluidine blue reaction and immunohistochemical for CD68, tumour necrosis Factor (TNF)-α, interleukin (IL)-1ß, inducible nitric oxide synthase (iNOS), nuclear factor kappa B (NF-kB) and IL-18 binding protein (IL-18 bp). The presence of ectasic/dilated vessels and inflammatory cells was analysed, and mast cells and mononuclear CD68-positive cells were counted along with the intensity of immunostaining (0-3) for inflammatory markers in odontoblasts and nonodontoblasts pulp cells. The Kruskal-Wallis/Dunn's test (scores or quantitative data) and the chi-squared test (categorical data) were used (GraphPad Prism 5.0, P < 0.05). RESULTS: There was no differences in the number of animals exhibiting dilated/ectasic blood vessels (P = 0.242) and inflammatory cells (P = 0.489) or in the number of mast cells (P = 1.000). However, there was an increase in mononuclear CD68-positive cells (P = 0.026), immunostaining of TNF-α (P = 0.020), IL-1ß (P = 0.027) and iNOS (P = 0.001) in odontoblasts, and IL-1ß (P = 0.013) in nonodontoblast pulp cells dose-dependently. NFkB (nucleus and cytoplasm) and IL-18 bp did not differ between groups. CONCLUSION: ZA modified the immune cell profile in the dental pulp, increasing the number of macrophages and expression of pro-inflammatory markers independent of NFkB.

Bothrops jararacussu snake venom-induces a local inflammatory response in a prostanoid- and neutrophil-dependent manner.

Local tissue reactions provoked by Bothrops venoms are characterized by edema, hemorrhage, pain, and inflammation; however, the mechanisms of tissue damage vary depending upon the species of snake. Here, we investigated the mechanisms involved in the local inflammatory response induced by the Bothrops jararacussu venom (BjcuV). Female Swiss mice were injected with either saline, BjcuV (0.125-8 µg/paw) or loratadine (an H1 receptor antagonist), compound 48/80 (for mast cell depletion), capsaicin (for C-fiber desensitization), infliximab (an anti-TNF-α antibody), indomethacin (a non-specific COX inhibitor), celecoxib (a selective COX-2 inhibitor) or fucoidan (a P- and L-selectins modulator) given before BjcuV injection. Paw edema was measured by plethysmography. In addition, paw tissues were collected for the measurement of myeloperoxidase activity, TNF-α and IL-1 levels, and COX-2 immunoexpression. The direct chemotactic effect of BjcuV and the in vitro calcium dynamic in neutrophils were also investigated. BjcuV caused an edematogenic response with increased local production of TNF-α and IL-1ß as well as COX-2 expression. Both edema and neutrophil migration were prevented by pretreatment with indomethacin, celecoxib or fucoidan. Furthermore, BjcuV induced a direct in vitro neutrophil chemotaxis by increasing intracellular calcium. Therefore, BjcuV induces an early onset edema dependent upon prostanoid production and neutrophil migration.

Targeted inhibition of IL-18 attenuates irinotecan-induced intestinal mucositis in mice.

BACKGROUND AND PURPOSE: Intestinal mucositis is a common side-effect of irinotecan-based cancer chemotherapy regimens. This mucositis is associated with cytokine activation and NO synthesis. Production of IL-18 is up-regulated in patients suffering from inflammatory bowel disease. Therefore, we have investigated the role of IL-18 in the pathogenesis of irinotecan-induced intestinal mucositis. EXPERIMENTAL APPROACH: Wild type (WT), IL-18 or caspase-1 knockout mice were treated with either saline or irinotecan (60 mg·kg⁻¹ per 4 days, i.p.) or the IL-18 binding protein (IL-18bp, 10 mg·kg⁻¹) before irinotecan. On day 5, diarrhoea was monitored and proximal intestinal strips were obtained for histopathology, in vitro gut contractility, myeloperoxidase (MPO) and inducible NOS (iNOS) activity, and detection of IL-18 expression. KEY RESULTS: Irinotecan induced severe diarrhoea accompanied by intestinal injury (villi shortening and increased crypt depth). Additionally, irinotecan treatment increased MPO and iNOS activity, iNOS immunostaining and IL-18 expression in WT mice compared with saline treatment. The IL-18 production was associated with macrophages. In vitro, intestinal smooth muscle strips were hyperresponsive to ACh after irinotecan treatment. Increases in MPO and iNOS activity, intestinal contractility and diarrhoea were prevented in caspase-1 knockout and IL-18 knockout mice, and in IL-18bp-treated WT mice. Furthermore, the Survival of irinotecan-treated mice was increased and iNOS immunoexpression and IL-18 production prevented in IL-18 knockout mice. CONCLUSIONS AND IMPLICATIONS: Targeting IL-18 function may be a promising therapeutic approach to decreasing the severity of intestinal mucositis during irinotecan treatment regimens.

Blockade of TRPA1 with HC-030031 attenuates visceral nociception by a mechanism independent of inflammatory resident cells, nitric oxide and the opioid system.

BACKGROUND: Some studies have shown a somatic nociceptive response due to the activation of transient receptor potential A1 channels (TRPA1), which is modulated by the TRPA1 antagonist HC-030031. However, a few studies report the role of TRPA1 in visceral pain. Therefore, we investigated the participation of TRPA1 in visceral nociception and the involvement of nitric oxide, the opioid system and resident cells in the modulation of these channels. METHODS: Mice were treated with vehicle or HC-030031 (18.75-300 mg/kg) before ifosfamide (400 mg/kg), 0.75% mustard oil (50 µL/colon), acetic acid 0.6% (10 mL/kg), zymosan (1 mg/cavity) or misoprostol (1 µg/cavity) injection. Visceral nociception was assessed through the electronic von Frey test or the writhing response. Ifosfamide-administered mice were euthanized for bladder analysis. The involvement of nitric oxide and the opioid system were investigated in mice injected with ifosfamide and mustard oil, respectively. The participation of resident peritoneal cells in acetic acid-, zymosan- or misoprostol-induced nociception was also evaluated. RESULTS: HC-030031 failed to protect animals against ifosfamide-induced bladder injury (p > 0.05). However, a marked antinociceptive effect against ifosfamide, mustard oil, acetic acid, zymosan and misoprostol was observed (p < 0.05). Neither L-arginine (600 mg/kg) nor naloxone (2 mg/kg) could reverse the antinociceptive effect of HC-030031. The reduction of the peritoneal cell population inhibited the acetic acid and zymosan-related writhes without interfering with the misoprostol effect. CONCLUSIONS: Our findings suggest that the blockade of TRPA1 attenuates visceral nociception by a mechanism independent of the modulation of resident cells, nitric oxide and opioid pathways.