Effects of the non-peptidyl low molecular weight radical scavenger IAC in DNBS-induced colitis in rats

Optimization and validation of polyherbal formulation by applying Box-Behnken design for the treatment of Inflammatory bowel disease in experimental animals

Background:

The use of herbal medicine in inflammatory bowel disease (IBD) had been increased significantly. Allopathic treatment of IBD leads too many side effects therefore use of the herbal formulation is promising. Aegle Marmelos, Bombax malabericum, and Hollarrhena antidysentrica plants have been used to treat IBD.

Objective:

To evaluate a designed polyherbal formulation in experimentally induced inflammatory bowel disease in rats and To validate mathematical model derived by Box-Behnken experimental design for optimized polyherbal formulation for the treatment of IBD in experimental rats by checkpoint analysis.

Method:

Three-level Box-Behnken design was selected to optimize the dose. Polyherbal formulation consist of plant extract of Aegle Marmelos (X1), Bombax malabericum (X2), and Hollarrhena antidysentrica (X3) in different ratios were selected as independent variable. Polynomial equations were established based on Analysis of variance (ANOVA). To validate the chosen polynomial equation checkpoint analysis were performed. The percentage of predictive error is presented.

Results:

ANOVA reveals that X2 plant does not have any significant impact on the response surface. The checkpoint batch showed the experimental value of CMDI and Disease activity index (DAI) as 1.33 and 0.66 respectively. It is worthwhile to note that the observed values were quite close to the calculated values of CMDI. A little difference in the value of DAI may be attributed to the inherent variation observed in animal studies.

Conclusion:

From this study, it was concluded that a dose of Aegle marmelos 100 mg/kg, a dose of Bombax malabericum 300 mg/kg, and a dose of Holarrhena antidysentrica 200 mg/kg will always be effective in IBD patients.

Antioxidant therapy for treatment of inflammatory bowel disease: Does it work?

Oxidative stress (OS) is considered as one of the etiologic factors involved in several signals and symptoms of inflammatory bowel diseases (IBD) that include diarrhea, toxic megacolon and abdominal pain. This systematic review discusses approaches, challenges and perspectives into the use of nontraditional antioxidant therapy on IBD, including natural and synthetic compounds in both human and animal models. One hundred and thirty four papers were identified, of which only four were evaluated in humans. Some of the challenges identified in this review can shed light on this fact: lack of standardization of OS biomarkers, absence of safety data and clinical trials for the chemicals and biological molecules, as well as the fact that most of the compounds were not repeatedly tested in several situations, including acute and chronic colitis. This review hopes to stimulate researchers to become more involved in this fruitful area, to warrant investigation of novel, alternative and efficacious antioxidant-based therapies.

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Major biomarkers used for evaluation of antioxidant therapy were MPO, TBARS/MDA and glutathione levels.

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Challenges were identified for the yet poor use of antioxidant therapy in IBD.

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This review stimulates the investigation of alternative and efficacious antioxidant therapies.

Anti-diabetic properties of a non-conventional radical scavenger, as compared to pioglitazone and exendin-4, in streptozotocin-nicotinamide diabetic mice

We previously showed that the innovative radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate (IAC) improves metabolic dysfunctions in a diabetic mouse model. Here, we compared the in vivo effects of IAC with those of the anti-diabetic drugs pioglitazone (PIO) and exendin-4 (EX-4). Diabetes was induced in C57Bl/6J mice by streptozotocin and nicotinamide administration. Paralleled by healthy controls, diabetic animals (D) were randomly assigned to four groups and treated daily for 7 consecutive weeks: D+saline, ip; D+IAC 30mg/kgb.w., ip; D+PIO 10mg/kgb.w. per os; and D+EX-4, 50μg/kgb.w., ip. Our results show that IAC reduced basal hyperglycemia and improved glucose tolerance better than PIO or EX-4. Interestingly, in the heart of diabetic mice, IAC treatment normalized the increased levels of GSSG/GSH ratio and thiobarbituric acid reactive substances, indexes of oxidative stress and damage, while PIO and EX-4 were less effective. As supported by immunohistochemical data, IAC markedly prevented diabetic islet β-cell reduced density, differently from PIO and EX-4 that had only a moderate effect. Interestingly, in diabetic animals, IAC treatment enhanced the activity of pancreatic-duodenal homeobox 1 (PDX-1), an oxidative stress-sensitive transcription factor essential for maintenance of β-cell function, as evaluated by quantification of its nuclear immunostaining, whereas PIO or EX-4 treatments did not. Altogether, these observations support the improvement of the general redox balance and β-cell function induced by IAC treatment in streptozotocin-nicotinamide diabetic mice. Furthermore, in this model, the correction of diabetic alterations was better obtained by treatment with the radical scavenger IAC than with pioglitazone or exendin-4.

A novel composition for in vitro and in vivo regeneration of skin and connective tissues

The particular combination of polydeoxyribonucleotides, l-carnitine, calcium ions, proteolytic enzyme and other ingredients acts in a synergetic way in the regeneration of skin and connective tissues. This new formulation of active principles was tested in vitro as a cell and tissue culture medium and in vivo for various preparations in support of tissue regeneration. In vitro, the new blend allowed the maintenance of skin biopsies for more than 1 year in eutrophic conditions. Immunocytochemical analyses of fibroblasts isolated from these biopsies confirmed a significant increase of the epidermal and connective wound-healing markers such as collagen type I, collagen type IV, cytokeratin 1 (CK1), CK5, CK10 and CK14 versus controls. To examine the effects of the new compound in vivo, we studied impaired wound healing in genetically diabetic db/db mice. At day 18, diabetic mice treated with the new composition showed 100% closure of wounds and faster healing than mice treated with the other solutions. This complex of vital continuity factors or life-keeping factors could be used as a tissue-preserving solution or a cosmetic/drug/medical device to accelerate wound healing in the treatment of patients with deficient wound repair to promote the regeneration of cutaneous and connective tissues (injuries-wound, dermatitis) and prevent the recurrent relapses.

Anti-inflammatory activity of the non-peptidyl low molecular weight radical scavenger IAC in carrageenan-induced oedema in rats

OBJECTIVE

In this research we investigated the anti-inflammatory activity of a non-peptidyl low molecular weight radical scavenger (IAC) in an acute and chronic animal model of inflammation.

METHODS

For this purpose the effect of IAC (10, 25, 50 mg/kg) was tested in rats on the associated behavioral responses to subsequent inflammatory and noxious challenges, such as hind paw oedema induced by intra-plantar injection of carrageenan and granuloma induced by subcutaneous implant of a cotton pellet, using indometacin (2.5 mg/kg) as reference drug. Moreover, the serum level of several cytokines was tested in the animal treated (or not) with IAC (50 mg/kg) both in the absence and presence of carrageenan-induced inflammation.

KEY FINDINGS

IAC showed a significant anti-inflammatory activity in both in acute and chronic models of inflammation. In addition IAC down regulated significantly the serum levels of interleukin (IL) 2 and IL6 whereas it increased the serum concentration of IL1α and glutathione.

CONCLUSION

Although it remains to be elucidated whether or not the antioxidant property of IAC is directly responsible for the modulation of the tested cytokines, these results suggest IAC to be a possible candidate for a novel anti-inflammatory compound.

Non-peptidyl low molecular weight radical scavenger IAC attenuates DSS-induced colitis in rats

AIM: To investigate the effects of the free radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate (IAC) in the dextran sodium sulphate (DSS) experimental model of ulcerative colitis.

METHODS: Colitis was induced in Sprague Dawley male rats by administration of 5% DSS in drinking water. IAC (30 mg/kg, lipophilic or hydrophilic form) was administered daily (orally or ip) for 6 d until sacrifice. Colonic damage was assessed by means of indirect (Disease Activity Index score) and direct measures (macroscopic and microscopic scores) and myeloperoxidase (MPO) activity. Neutrophil infiltration within the tissue and glutathione S-transferase activity were also investigated.

RESULTS: DSS-induced colitis impaired body weight gain and markedly increased all inflammatory parameters. Six-day treatment with lipophilic IAC significantly reduced intestinal damage caused by inflammation, induced a down-regulation in MPO activity (0.72 ± 0.12 and 0.45 ± 0.12 with lipophilic IAC po and ip, respectively, vs 1.10 ± 0.27 in untreated DSS colitis animals) and minimized DSS-induced neutrophil infiltration, while hydrophilic IAC administered orally did not ameliorate DSS-induced damage.

CONCLUSION: These results support the hypothesis that reactive oxygen metabolites contribute to inflammation and that the radical scavenger IAC has therapeutic potential in inflammatory bowel disease.

Persistent correction of hyperglycemia in streptozotocin-nicotinamide-induced diabetic mice by a non-conventional radical scavenger

We previously reported that in a diabetes mouse model, characterised by moderate hyperglycaemia and reduced β-cell mass, the radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate di-hydrochloride (IAC), a non-conventional cyclic hydroxylamine derivative, improves metabolic alterations by counteracting β-cell dysfunction associated with oxidative stress. The aims of this study were to ascertain whether the beneficial effects of IAC treatment could be maintained after its discontinuation and further elucidate the underlying mechanisms. Diabetes was induced in C57Bl/6J mice by streptozotocin (STZ) and nicotinamide (NA) administration. Diabetic mice were treated for 7 weeks with various doses of IAC (7.5, 15, or 30 mg/kg b.w./die i.p.) and monitored for additional 8 weeks after suspension of IAC. Then, pancreatic tissue was used for determination of β-cell mass by immunohistochemistry and β-cell ultrastructural analysis. STZ-NA mice showed moderate hyperglycaemia, glucose intolerance and reduced β-cell mass (25% of controls). IAC-treated STZ-NA mice (at both doses of 15 and 30 mg/kg b.w.) showed long-term reduction of hyperglycaemia even after discontinuation of treatment, attenuation of glucose intolerance and partial preservation of β-cell mass. The lowest IAC dose was much less effective. Plasma nitrotyrosine levels (an oxidative stress index) significantly increased in untreated diabetic mice and were lowered upon IAC treatment. At ultrastructural level, β cells of IAC-treated diabetic mice were protected against degranulation and mitochondrial alterations. In the STZ-NA diabetic mouse model, the radical scavenger IAC induces a prolonged reduction of hyperglycaemia associated with partial restoration of β-cell mass and function, likely dependent on blockade of oxidative stress-induced damaging mechanisms.

Evidence for a potential role of metallothioneins in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) are a group of chronic, relapsing, immune-mediated disorders of the intestine, including Crohn's disease and ulcerative colitis. Recent studies underscore the importance of the damaged epithelial barrier and the dysregulated innate immune system in their pathogenesis. Metallothioneins (MTs) are a family of small proteins with a high and conserved cysteine content that are rapidly upregulated in response to an inflammatory stimulus. Herein, we review the current knowledge regarding the expression and potential role of MTs in IBD. MTs exert a central position in zinc homeostasis, modulate the activation of the transcription factor nuclear factor (NF)-kappaB, and serve as antioxidants. In addition, MTs could be involved in IBD through their antiapoptotic effects or through specific immunomodulating extracellular effects. Reports on MT expression in IBD are contradictory but clearly demonstrate a deviant MT expression supporting the idea that these aberrations in IBD require further clarification.