Studies

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Curcumin suppresses ovalbumin-induced allergic conjunctivitis.

PURPOSE:

Allergic conjunctivitis (AC) from an allergen-driven T helper 2 (Th2) response is characterized by conjunctival eosinophilic infiltration. Because curcumin has shown anti-allergic activity in an asthma and contact dermatitis laboratory models, we examined whether administration of curcumin could affect the severity of AC and modify the immune response to ovalbumin (OVA) allergen in an experimental AC model.

METHODS:

Mice were challenged with two doses of topical OVA via the conjunctival sac after systemic sensitization with OVA in aluminum hydroxide (ALUM). Curcumin was administered 1 h before OVA challenge. Several indicators for allergy such as serum immunoglubulin E (IgE) antibodies production, eosinophil infiltration into the conjunctiva and Th2 cytokine production were evaluated in mice with or without curcumin treatment.

RESULTS:

Mice challenged with OVA via the conjunctival sac following systemic sensitization with OVA in ALUM had severe AC. Curcumin administration markedly suppressed IgE-mediated and eosinophil-dependent conjunctival inflammation. In addition, mice administered curcumin had less interleukin-4 (IL-4) and interleukin-5 (IL-5) (Th2 type cytokine) production in conjunctiva, spleen, and cervical lymph nodes than mice in the non-curcumin-administered group. OVA challenge resulted in activation of the production of inducible nitric oxide (iNOS), and curcumin treatment inhibited iNOS production in the conjunctiva.

CONCLUSIONS:

We believe our findings are the first to demonstrate that curcumin treatment suppresses allergic conjunctival inflammation in an experimental AC model.

Source: Chung SH, Choi SH, Choi JA, Chuck RS, Joo CK. Mol Vis. 2012;18:1966-72. Epub 2012 Jul 18.

For complete article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3413438/

 

Curcumin attenuates allergen-induced airway hyperresponsiveness in sensitized guinea pigs.

Anti-asthmatic property of curcumin (diferuloylmethane), a natural product from the rhizomes of Curcuma longa, has been tested in a guinea pig model of airway hyperresponsiveness. We sensitized guinea pigs with ovalbumin (OVA) to develop certain characteristic features of asthma: allergen induced airway constriction and airway hyperreactivity to histamine. Guinea pigs were treated with curcumin during sensitization (to examine its preventive effect) or after developing impaired airways features (to examine its therapeutic effect). Status of airway constriction and airway hyperreactivity were determined by measuring specific airway conductance (SGaw) using a non-invasive technique, constant-volume body plethysmography. Curcumin (20 mg/kg body weight) treatment significantly inhibits OVA-induced airway constriction (p<0.0399) and airway hyperreactivity (p<0.0043). The results demonstrate that curcumin is effective in improving the impaired airways features in the OVA-sensitized guinea pigs.

Source: Ram A, Das M, Ghosh B. Biol Pharm Bull. 2003 Jul;26(7):1021-4.

 

Involvement of p38 MAPK, JNK, p42/p44 ERK and NF-kappaB in IL-1beta-induced chemokine release in human airway smooth muscle cells.

Asthma is an inflammatory disease, in which eotaxin, MCP-1 and MCP-3 play a crucial role. These chemokines have been shown to be expressed and produced by IL-1beta-stimulated human airway smooth muscle cells (HASMC) in culture. In the present study we were interested to unravel the IL-1beta-induced signal transduction leading to chemokine production. Using Western blot, we observed an activation of p38 MAPK, JNK kinase and p42/p44 ERK when HASMC were stimulated with IL-1beta. We also observed a significant decrease in the expression and the release of eotaxin, MCP-1 and MCP-3 in the presence of SB203580, an inhibitor of p38 MAPK (71 +/- 6%, P < 0.05, n = 8 and 39 +/- 10% P < 0.01, n = 10 respectively), curcumin, an inhibitor of JNK kinase (83 +/- 4.9% and 88 +/- 3.4% respectively, P < 0.01, n = 4). U0126, an inhibitor of p42/p44 ERK, also produced a significant decrease in chemokine production (46.3 +/- 9%, P < 0.01 n = 10 and 67.8 +/- 12%, P < 0.01, n = 12). Pyrrolydine dithiocarbamate, an inhibitor of NF-kappaB was also able to reduce the eotaxin, MCP-1 and MCP-3 expression and production (50 +/- 13%, P < 0.05, n = 10 and 23 +/- 7%, P < 0.05, n = 12). We conclude that p38 MAPK, JNK kinase, ERK and NF-kappaB are involved in the IL-1beta-induced eotaxin, MCP-1, and MCP-3 expression and release in HASMC.

Source: Wuyts WA, Vanaudenaerde BM, Dupont LJ, Demedts MG, Verleden GM. Respir Med. 2003 Jul;97(7):811-7.

 

Immune response modulation by curcumin in a latex allergy model.

BACKGROUND:

There has been a worldwide increase in allergy and asthma over the last few decades, particularly in industrially developed nations. This resulted in a renewed interest to understand the pathogenesis of allergy in recent years. The progress made in the pathogenesis of allergic disease has led to the exploration of novel alternative therapies, which include herbal medicines as well. Curcumin, present in turmeric, a frequently used spice in Asia has been shown to have anti-allergic and inflammatory potential.

METHODS:

We used a murine model of latex allergy to investigate the role of curcumin as an immunomodulator. BALB/c mice were exposed to latex allergens and developed latex allergy with a Th2 type of immune response. These animals were treated with curcumin and the immunological and inflammatory responses were evaluated.

RESULTS:

Animals exposed to latex showed enhanced serum IgE, latex specific IgG1, IL-4, IL-5, IL-13, eosinophils and inflammation in the lungs. Intragastric treatment of latex-sensitized mice with curcumin demonstrated a diminished Th2 response with a concurrent reduction in lung inflammation. Eosinophilia in curcumin-treated mice was markedly reduced, co-stimulatory molecule expression (CD80, CD86, and OX40L) on antigen-presenting cells was decreased, and expression of MMP-9, OAT, and TSLP genes was also attenuated.

CONCLUSION:

These results suggest that curcumin has potential therapeutic value for controlling allergic responses resulting from exposure to allergens.

Source: Kurup VP, Barrios CS, Raju R, Johnson BD, Levy MB, Fink JN. Clin Mol Allergy. 2007 Jan 25;5:1.

For complete article: http://www.clinicalmolecularallergy.com/content/5/1/1

Beneficial role of curcumin in skin diseases 

In recent years, considerable interest has been focused on curcumin a compound, isolated from turmeric. Curcumin is used as a coloring, flavoring agent and has been traditionally used in medicine and cuisine in India. The varied biological properties of curcumin and lack of toxicity even when administered at higher doses makes it attractive to explore its use in various disorders like tumors of skin, colon, duodenum, pancreas, breast and other skin diseases. This chapter reviews the data on the use of curcumin for the chemoprevention and treatment of various skin diseases like scleroderma, psoriasis and skin cancer. Curcumin protects skin by quenching free radicals and reducing inflammation through nuclear factor-KB inhibition. Curcumin treatment also reduced wound-healing time, improved collagen deposition and increased fibroblast and vascular density in wounds thereby enhancing both normal and impaired wound-healing. Curcumin has also been shown to have beneficial effect as a proangiogenic agent in wound-healing by inducing transforming growth factor-beta, which induces both angiogenesis and accumulation of extracellular matrix, which continues through the remodeling phase of wound repair. These studies suggest the beneficial effects of curcumin and the potential of this compound to be developed as a potent nontoxic agent for treating skin diseases.

SourceThangapazham RL, Sharma A, Maheshwari RK. Adv Exp Med Biol. 2007;595:343-57.

 

Curcumin improves wound healing by modulating collagen and decreasing reactive oxygen species

Wound healing consists of an orderly progression of events that re-establish the integrity of the damaged tissue. Several natural products have been shown to accelerate the healing process. The present investigation was undertaken to determine the role of curcumin on changes in collagen characteristics and antioxidant property during cutaneous wound healing in rats. Full-thickness excision wounds were made on the back of rat and curcumin was administered topically. The wound tissues removed on 4th, 8th and 12th day (post-wound) were used to analyse biochemical and pathological changes. Curcumin increased cellular proliferation and collagen synthesis at the wound site, as evidenced by increase in DNA, total protein and type III collagen content of wound tissues. Curcumin treated wounds were found to heal much faster as indicated by improved rates of epithelialisation, wound contraction and increased tensile strength which were also confirmed by histopathological examinations. Curcumin treatment was shown to decrease the levels of lipid peroxides (LPs), while the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), activities were significantly increased exhibiting the antioxidant properties of curcumin in accelerating wound healing. Better maturation and cross linking of collagen were observed in the curcumin treated rats, by increased stability of acid-soluble collagen, aldehyde content, shrinkage temperature and tensile strength. The results clearly substantiate the beneficial effects of the topical application of curcumin in the acceleration of wound healing and its antioxidant effect.

SourcePanchatcharam M, Miriyala S, Gayathri VS, Suguna L. Mol Cell Biochem. 2006 Oct;290(1-2):87-96. Epub 2006 Jun 13.

 

Dermal wound healing processes with curcumin incorporated collagen films

The wound healing process involves extensive oxidative stress to the system, which generally inhibits tissue remodeling. In the present study, an improvement in the quality of wound healing was attempted by slow delivery of antioxidants like curcumin from collagen, which also acts as a supportive matrix for the regenerative tissue. Curcumin incorporated collagen matrix (CICM) treated groups were compared with control and collagen treated rats. Biochemical parameters and histological analysis revealed that increased wound reduction, enhanced cell proliferation and efficient free radical scavenging in CICM group. The higher shrinkage temperature of CICM films suggests increased hydrothermal stability when compared to normal collagen films. Spectroscopic studies revealed that curcumin was bound to the collagen without affecting its triple helicity. Further we adopted the antioxidant assay using 2,2'-azobisisobutyronitrile to assess in vitro antioxidant activity of CICM. The antioxidant studies indicated that CICM quenches free radicals more efficiently. This study provides a rationale for the topical application of CICM as a feasible and productive approach to support dermal wound healing.

Source: Gopinath D, Ahmed MR, Gomathi K, Chitra K, Sehgal PK, Jayakumar R. Biomaterials. 2004 May;25(10):1911-7.

 

Curcumin enhances wound healing in streptozotocin induced diabetic rats and genetically diabetic mice

Tissue repair and wound healing are complex processes that involve inflammation, granulation and tissue remodeling. Interactions of different cells, extracellular matrix proteins and their receptors are involved in wound healing, and are mediated by cytokines and growth factors. Previous studies from our laboratory have shown that curcumin (diferuloylmethane), a natural product obtained from the rhizomes of Curcuma longa, enhanced cutaneous wound healing in rats and guinea pigs. In this study, we have evaluated the efficacy of curcumin treatment by oral and topical applications on impaired wound healing in diabetic rats and genetically diabetic mice using a full thickness cutaneous punch wound model. Wounds of animals treated with curcumin showed earlier re-epithelialization, improved neovascularization, increased migration of various cells including dermal myofibroblasts, fibroblasts, and macrophages into the wound bed, and a higher collagen content. Immunohistochemical localization showed an increase in transforming growth factor-beta1 in curcumin-treated wounds compared to controls. Enhanced transforming growth factor-beta1 mRNA expression in treated wounds was confirmed by in situ hybridization, and laser scan cytometry. A delay in the apoptosis patterns was seen in diabetic wounds compared to curcumin treated wounds as shown by terminal deoxynucleotidyl transferase-mediated deoxyuridyl triphosphate nick end labeling analysis. Curcumin was effective both orally and topically. These results show that curcumin enhanced wound repair in diabetic impaired healing, and could be developed as a pharmacological agent in such clinical settings.

SourceSidhu GS, Mani H, Gaddipati JP, Singh AK, Seth P, Banaudha KK, Patnaik GK, Maheshwari RK. Wound Repair Regen. 1999 Sep-Oct;7(5):362-74.

 

Effect of curcumin on radiation-impaired healing of excisional wounds in mice

OBJECTIVE:

To study the effect on wound contraction of pretreatment with various doses of curcumin (the most important active ingredient of the spice turmeric) in mice exposed to 6 Gy whole-body gamma radiation.

METHOD:

A full-thickness skin wound was produced on the dorsum of Swiss albino mice treated with and without 25, 50, 100, 150 or 200 mg/kg body weight of curcumin before exposure to 6 Gy gamma radiation. Progression of wound contraction was monitored using video images of the wound at various days post-irradiation until full healing occurred. Mean wound healing times were also calculated.

RESULTS:

Irradiation caused significant delay in wound contraction and healing times. However, treatment with curcumin resulted in a dose-dependent increase in contraction when compared with a control. Greatest contraction was observed for 100 mg/kg curcumin, with statistically significant results at days three (p < 0.009), six (p < 0.05) and nine (p < 0.05) post-irradiation for this dose. Complete healing was achieved by day 23 post-irradiation in the curcumin-treated irradiation group.

CONCLUSION:

Pretreatment with curcumin has a conductive effect on irradiated wounds. It could be a substantial therapeutic agent for ameliorating radiation-induced delay in wound repair in cases of combined injuries.

SourceJagetia GC, Rajanikant GK. J Wound Care. 2004 Mar;13(3):107-9.