Thermoresponsive gel containing bilirubin nanoparticles exerts anti-inflammatory effects by inhibiting neutrophil infiltration and augmenting interleukin-10 levels in carrageenan-induced rat paw edema.

BACKGROUND: Topical corticosteroids treat cutaneous inflammation but have side effects. In earlier studies, bilirubin exhibited anti-inflammatory effect, but its hydrophobicity and poor absorption limit its potential. AIM: Synthesis of bilirubin nanoparticles (BNP) and bilirubin nanoparticles gels (BNP gel) to study the anti-inflammatory effect of topical BNP gel against carrageenan-induced rat paw edema in Wistar rats. MATERIALS AND METHODS: BNP were synthesized, and BNP gels were prepared by mixing BNP of different concentrations with pluronic F-127 (PF-127). A different group for each formulation was assigned with five rats in each group. After 1 h of carrageenan (1% [w/v]) injection in each group, different gels were applied topically to their respective groups. Paw edema size, percent inflammation, percent edema inhibition, and inhibition time50 were evaluated. Interleukin-10 (IL-10) levels and neutrophil infiltration in rat paw tissue were evaluated by enzyme-linked immunosorbent assay and hematoxylin and eosin, respectively. RESULTS: Synthesized spherical-shaped BNP had negative zeta potential. BNP gels markedly reduced paw edema size and % inflammation as compared to carrageenan and bulk bilirubin gel (Bulk B gel) treated group and significantly increased IL-10 levels and inhibited neutrophil infiltration. CONCLUSION: BNP gels exhibited a better anti-inflammatory effect than bulk B gel and comparable anti-inflammatory potential with clobetasol.

Substance P, a Neuropeptide, Promotes Wound Healing via Neurokinin-1 Receptor.

Substance P (SP), an endogenous neuropeptide, mediates intracellular signaling, mainly through a tachykinin receptor. The tachykinin receptors family consists of neurokinin-1 (NK-1), neurokinin-2 (NK-2), and neurokinin-3 receptors. Our previous studies on SP have shown its wound healing potentials. But the exact mechanism of wound healing by SP is not exactly known. In view of this, the present study was aimed at evaluating the in vitro wound healing effect of SP alone and in the presence of NK-1, NK-2, and both receptor antagonists. Scratch assay, transwell assay, and tumor growth factor-beta 1 (TGF-ß1) assay were performed on buffalo fetal fibroblast culture. The cotreatment of fibroblast cultures with SP alone during the 24 h caused the significant proliferation and migrations of cells in both horizontal and vertical directions. The SP in the presence of spantide II (NK-1 antagonist) failed to stimulate this migration. The treatment of cells with SP in the presence of NK-2 antagonist treatment also showed a significant reduction of migration of cells with respect to SP treatment alone. The SP in the presence of both NK-1 and NK-2 antagonists failed to stimulate the horizontal migration of cells and most of the ineffectiveness of SP was observed in this combination. The TGF-ß1 levels were significantly higher in the supernatants of cells that were exposed to SP alone. All other treatments have significantly lower TGF-ß1 levels than SP alone treatment. It is concluded that different actions on fibroblast cells by SP were mainly mediated through the NK-1 receptor.

Acceleration of wound healing by quercetin in diabetic rats requires mitigation of oxidative stress and stimulation of the proliferative phase.

Increased oxidative stress in diabetic wound areas impairs wound healing. Quercetin exhibits significant antioxidant properties. We investigated the effects of topical quercetin on antioxidant status in diabetic wound areas and its effect on wound healing in rats. A 2 cm2 cutaneous wound was produced on the back of streptozotocin induced diabetic and normal rats. Rats were divided into three groups of 20: normal healthy control group, diabetic group and quercetin treated diabetic group. The control and diabetic groups were treated topically with ointment base once daily for 21 days. The quercetin treated diabetic rats were treated similarly with ointment containing quercetin. The quercetin treated diabetic group exhibited increased levels of catalase, glutathione peroxidase, superoxide dismutase and total thiols compared to the diabetic group. Nitrite levels in the diabetic group were decreased significantly on day 3 compared to the healthy control group. Malondialdehyde levels were decreased in the quercetin treated diabetic group compared to the diabetic group. The expression of proliferating cell nuclear antigen) (PCNA) was greater in the quercetin treated diabetic group on day 7 compared to healthy control and diabetic groups. Formation of granulation tissue and the quality of healed tissue was improved in the quercetin treated diabetic group compared to the diabetic group. Quercetin improves antioxidant status in wounds of diabetic rats and stimulates the proliferation phase, which accelerates wound healing.

Novel preparation of bilirubin-encapsulated pluronic F-127 nanoparticles as a potential biomaterial for wound healing.

Cutaneous wounds deteriorate the health of patients and liable for high economic loss. Previous studies showed promising wound healing potentials of bilirubin, however, this macromolecule constrained with poor water solubility and skin penetration. In this study, Pluronic F-127, a non-ionic copolymer surfactant, was used for the encapsulation of the wound healing agent the bilirubin. With this strategy, spherical shaped bilirubin nanoparticles of ∼100-150 nm with zeta potential ranging from -13.43 ± 0.56 to -17.53 ± 0.43 mV were obtained. Topical applications of bilirubin nanoparticle (0.3%) on cutaneous wounds of rats showed promising wound healing in comparison with other topical treatments. This topical nano-formulation also modulates the cytokine and growth factor responses in the treated group. On day 7 of healing, bilirubin nanoparticles treatment significantly reduced TNF-α and increased IL-10 levels with increased VEGF and TGF-ß1 expressions. Simultaneously, prominent pro-healing activities could be observed histopathologically. These include increased blood vessels, reduced inflammatory cells, more myofibroblasts, increased deposition of collagen fibres, and early re-epithelialization. The changes were prominent in bilirubin nanoparticles (0.3%) treated group indicating better granulation tissue, quality of healing and wound maturity. In conclusion, the proposed new encapsulated bilirubin nanoparticles strategy significantly improved wound healing by modulation of cytokines and growth factors response in comparison with native bulk bilirubin. These observations support its potential as a novel biomaterial for wound healing in the future.

Temporal Effects of Different Vehicles on Wound Healing Potentials of Quercetin: Biochemical, Molecular, and Histopathological Approaches.

Development of novel drugs or formulations to accelerate the wound healing process is the need of current era. Quercetin (Q), a bioflavonoid, at 0.3% concentration has showed some wound healing potential in our preliminary studies. The present study was aimed to explore the wound healing potential of 0.3% quercetin formulated in 3 different vehicles, that is, dimethyl sulfoxide (DMSO; 10%), ointment base, and corn oil. Ninety experimentally wounded rats were grouped in 6 groups. The 0.3% quercetin mixed with DMSO, ointment base, and corn oil was topically applied once daily for 21 days on the wounds of groups 2, 4, and 6, respectively. DMSO, ointment base, and corn oil alone was applied similarly in groups 1, 3, and 5, respectively. Gross evaluation and wound contraction results revealed accelerated wound closure in all quercetin-treated groups. The mRNA expressions of vascular endothelial growth factor, transforming growth factor-ß1, and interluekin-10 were markedly upregulated in healing tissues of quercetin-treated groups. Tumor necrosis factor-α mRNA expression and protein levels were lowered by quercetin treatment. Quercetin-treated groups also showed increased activities of SOD (superoxide dismutase) and catalase, and levels of total thiols in wound tissues on day 7. Levels of superoxide anion radicals and malondialdehyde were markedly lower in quercetin-treated groups. Histologically, wound sections of quercetin-treated groups showed early dominance of fibroblasts, increased blood vessels, marked collagen deposition, and regenerated epithelial layer. The significant effects were more pronounced in ointment + Q group among all the quercetin-treated groups. In conclusion, 0.3% quercetin mixed in ointment base produced the fastest and better wound healing in rats.

Topical application of quercetin improves wound repair and regeneration in diabetic rats.

Purpose: There is an urgent need of effective drug/formulation to speed up the healing process in diabetic wounds. In our earlier studies, quercetin has accelerated the healing of nondiabetic wounds. So, we investigated the wound-healing potentials of quercetin in diabetic rats.Materials and methods: A square-shaped cutaneous wound (≈400 mm2) was created on the back of nondiabetic and diabetic rats. They were divided into three groups, viz. healthy control (nondiabetic), diabetic control and diabetic-treated group. Ointment base was topically applied for 21 days in healthy and diabetic control groups. Quercetin (0.3%) ointment was similarly applied in third group. Effects of quercetin on repair and regenerations of diabetic wounds in terms of wound closure, inflammation, angiogenesis, fibroblast proliferation, collagen synthesis, epithelialization, axonal regeneration etc was studied.Results: Quercetin accelerated the wound closure and increased the expressions of IL-10, VEGF and TGF-ß1 in granulation/healing tissue of diabetic wound. However, quercetin decreased the expression of TNF-α, IL-1ß, and MMP-9. Histopathological evaluation revealed amelioration of persistence of inflammatory cells by quercetin in diabetic wounds. There was good quality of granulation tissue, marked fibroblast proliferation, well organized collagen deposition, early regeneration of epithelial layer etc. in the quercetin treated diabetic wounds in comparison to diabetic control group. Results of immunohistochemistry showed more angiogenesis, faster phenotypic switching of fibroblast to myofibroblasts and increased GAP-43 positive nerve fibers in quercetin-treated diabetic wounds.Conclusion: Quercetin ointment at 0.3% w/w concentration modulates cytokines, growth factors and protease, thereby improved repair and regenerations of cutaneous diabetic wounds in rats.

Nanomaterials of Natural Bioactive Compounds for Wound Healing: Novel Drug Delivery Approach.

Wound healing is a biological phenomenon of the body involving sequential biochemical processes that are primarily involved in restoring the cellular integrity of the organ. The market related to wound-care products has extensively been expanded and crossed over fifteen billion US dollars, along with twelve billion US dollars for treating wound scars. Different bioactive compounds have shown their various pharmacological actions including wound healing activity. Natural bioactive agents have gained much attention in wound management due to their beneficial nature of possessing least side effects. Some of the bioactive compounds which have shown pronounced wound healing potentials,such as curcumin, quercetin, lawsone, resveratrol, aloe vera, astragaloside, essential oils, growth factors, andrographolide, bilirubin, etc. Most of the natural bioactive agents have limited applicability in clinical practices due to poor aqueous solubility, fast degradation rate and low bioavailability. These problems have been overcome in last few years by encapsulating them into nano-formulations. The nanomaterials of bioactive agents offer discrete advantages like high surface area to volume ratio and nanoscale size offering alternations in physical and chemical properties. These nanomaterials also have sustained controlled release delivery, which seems to be very effective for the lengthy process of wound healing. Many investigations by the global researchers have focused on the emergence of nanomaterials in wound healing applications. In the present review, different natural bioactive agents in the form of nanoformulations have been discussed for wound healing potentials.

Quercetin accelerated cutaneous wound healing in rats by modulation of different cytokines and growth factors.

Quercetin on wounds could be favorable for healing based on its variety of biological effects. Eighty wounded rats were divided into four groups i.e. dimethyl sulfoxide, 0.03% quercetin, 0.1% quercetin, and 0.3% quercetin-treated. Different treatments were topically applied for 20 days. Quercetin (0.3%) caused the fastest wound closure and markedly improved the oxidative stress. Quercetin treatment increased the expressions of IL-10, VEGF, TGF-ß1, CD31, α-SMA, PCNA, and GAP-43, and decreased the expressions of TNF-α. Early infiltration of inflammatory cells and formation of good quality granulation tissue dominated by fibroblast proliferation, angiogenesis, and collagen deposition in quercetin treated groups was also evident. All these effects were more pronounced at 0.3% quercetin concentration. The earliest regeneration of epithelial layer was also observed in 0.3% quercetin-treated wounds. In conclusion, 0.3% quercetin accelerates wound healing efficiently by modulating antioxidant system of wound, cytokines, growth factors, other proteins and cells involved in healing.

Quercetin loaded chitosan tripolyphosphate nanoparticles accelerated cutaneous wound healing in Wistar rats.

Previous studies have shown that quercetin on topical application improved cutaneous wound healing in rats, but hydrophobic nature and less skin penetration limits its potential as topical healing agent. Therefore, present study was planned to investigate wound healing potential of chitosan based quercetin nanoparticles. Quercetin loaded nanoparticles were synthesized by ionic gelation method and characterized by various standard techniques. A 2 × 2 cm2 square shaped wound was created on the thoraco-lumbar part of rats. Wounded rats were divided into 6 groups namely, gel (20%), blank nanoparticle (0.16%), bulk quercetin (0.3%), quercetin nanoparticles (0.03%), quercetin nanoparticles (0.1%) and quercetin nanoparticles (0.3%) treated groups. Different formulations of quercetin nanoparticles were applied on the wounds for the duration of study and healing tissues were collected on 7th, 14th and 21st day to study various parameters. Quercetin loaded nanoparticles were 361.16 ± 9.72 nm size and spherical in shape. We observed quercetin nanoparticles (0.03%) treatment caused marked reduction in the tumor necrosis factor-alpha, whereas expressions of interleukin 10, vascular endothelial growth factor and transforming growth factor beta1 was increased significantly with treatment. The granulation tissue of quercetin nanoparticles (0.03%) treated group showed better quality healing and maturity as supported by the increased blood vessels density, decreased inflammatory cells, increased number of myofibroblasts, deposition and arrangement of collagen fibers and re-epithelialization. In conclusion, quercetin nanoparticles (0.03%) treatment significantly improved wound healing by modulation of cytokines and growth factors involved in inflammatory and proliferative phases of wound healing.

Hemin attenuated oxidative stress and inflammation to improve wound healing in diabetic rats.

Oxidative stress and persistent inflammation play crucial role in the progression of diabetic wound complications. Hemeoxgenase-1 (HO-1) by degrading hemin has been shown to display anti-oxidant and anti-inflammatory effects. Further, hemin is a potent HO-1 inducer. Thus, the current study was aimed to evaluate the effect of topical application of hemin on diabetic wound in rats. Four hundred square millimeter open excision wound were created 2 weeks after induction of diabetes with single intraperitoneal injection of streptozotocin (60 mg/kg), and the diabetic rats were divided into three groups namely diabetic control, hemin, and tin protoporphyrin (SnPPIX). Ointment base, hemin (0.5% in ointment base), and SnPPIX (0.5% in ointment base) were applied topically to wounded area in diabetic control, hemin, and SnPPIX group rats, respectively, twice daily for 19 days. Hemin significantly increased the wound contraction in comparison to control and SnPPIX-treated rats. Time-dependent analysis revealed significant increase in anti-oxidants with concomitant decrease in oxidants in hemin-treated rats as compared to diabetic control rats. Further, mRNA expression decreased for inflammatory cytokine and increased for anti-inflammatory cytokine in hemin group as compared to diabetic control rats. Expression of HO-1 also increased in hemin group as compared to diabetic control rats. However, SnPPIX group results were in disagreement with results of hemin which is clearly reflected in histopathology. Results indicate the ability of hemin to accelerate wound healing in diabetic rats by combating inflammation and oxidative stress probably via HO-1.

Combined effect of substance P and curcumin on cutaneous wound healing in diabetic rats.

BACKGROUND: Our earlier studies demonstrated that topically applied substance P (SP) or curcumin on excision skin wound accelerated the wound healing in streptozotocin-induced diabetic rats. In the present study, we aimed to evaluate the wound healing potential of combination of SP and curcumin in diabetic rats. MATERIALS AND METHODS: Open cutaneous excision wound was created on the back of each of the 60 diabetic rats. Wound-inflicted rats were equally divided into three groups namely, control, gel treated, and SP + curcumin treated. Normal saline, pluronic gel, and SP (0.5 × 10-6M) + curcumin (0.15%) were topically applied once daily for 19 d to these control, gel-treated, and SP + curcumin groups, respectively. RESULTS: SP + curcumin combination significantly accelerated wound closure and decreased messenger RNA expressions of tumor necrosis factor-alpha, interleukin-1beta, and matrix metalloproteinase-9, whereas the combination markedly increased the expressions of interleukin-10, vascular endothelial growth factor, transforming growth factor-beta1, hypoxia-inducible factor 1-alpha, stromal cell-derived factors-1alpha, heme oxygenase-1 and endothelial nitric oxide synthase, and activities of superoxide dismutase, catalase, and glutathione peroxidase in granulation-healing tissue, compared with control and gel-treated groups. In combination group, granulation tissue was better, as was evidenced by improved fibroblast proliferation, collagen deposition, microvessel density, growth-associated protein 43-positive nerve fibers, and thick regenerated epithelial layer. CONCLUSIONS: The combination of SP and curcumin accelerated wound healing in diabetic rats and both the drugs were compatible at the doses used in this study.

Bilirubin modulated cytokines, growth factors and angiogenesis to improve cutaneous wound healing process in diabetic rats.

Bilirubin has shown cutaneous wound healing potential in some preliminary studies. Here we hypothesize that bilirubin facilitates wound healing in diabetic rats by modulating important healing factors/candidates and antioxidant parameters in a time-dependent manner. Diabetes was induced in male Wistar rats by streptozotocin. In all diabetic rats wounds were created under pentobarbitone anesthesia. All the rats were divided into two groups, of which one (control) was treated with ointment base and other with bilirubin ointment (0.3%). Wound closer measurement and tissue collection were done on days 3, 7, 14 and 19 post-wounding. The relative expressions of hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 alpha (SDF-1α), transforming growth factor- beta1 (TGF-ß1()), tumor necrosis factor-α (TNF-α) and interlukin-10 (IL-10) mRNA and proteins and the mRNA of interlukin-1 beta (IL-1ß) and matrix metalloprteinase-9 (MMP-9) were determined in the wound tissues. CD-31 staining and collagen content were evaluated by immunohistochemistry and picrosirius red staining, respectively. Histopathological changes were assessed by H&E staining. The per cent wound closer was significantly higher from day 7 onwards in bilirubin-treated rats. HIF-1α, VEGF, SDF-1α, TGF-ß1, IL-10 mRNA and protein levels were significantly higher on days 3, 7 and 14 in bilirubin-treated rats. The mRNA expression and protein level of TNF-α and the mRNA of IL-1ß and MMP-9 were progressively and markedly reduced in bilirubin-treated rats. The collagen deposition and formation of blood vessels were greater in bilirubin-treated rats. Bilirubin markedly facilitated cutaneous wound healing in diabetic rats by modulating growth factors, cytokines, neovasculogenesis and collagen contents to the wound site. Topical application of bilirubin ointment might be of great use in cutaneous wound healing in diabetic patients.

Pro-healing effects of bilirubin in open excision wound model in rats.

Bilirubin, a by-product of heme degradation, has an important role in cellular protection. Therefore, we speculated that bilirubin could be of potential therapeutic value in wound healing. To validate the hypothesis, we used a full-thickness cutaneous wound model in rats. Bilirubin (30 mg/kg) was administered intraperitoneally every day for 9 days. The surface area of the wound was measured on days 0, 2, 4, 7 and 10 after the creation of the wound. The granulation tissue was collected on day 10 post-wounding for analysing various parameters of wound healing. Bilirubin treatment accelerated wound contraction and increased hydroxyproline and glucosamine contents. mRNA expression of pro-inflammatory factors such as intercellular cell adhesion molecule-1 (ICAM-1) and tumour necrosis factor-α (TNF-α) were down-regulated and that of anti-inflammatory cytokine interleukin-10 (IL-10) was up-regulated. The findings suggest that bilirubin could be a new agent for enhancing cutaneous wound healing.

Effect of atorvastatin, a HMG-CoA reductase inhibitor in monosodium iodoacetate-induced osteoarthritic pain: implication for osteoarthritis therapy.

BACKGROUND: Oxidative stress is one of the main causes of pain and cartilage degradation in osteoarthritis. This study on atorvastatin, a HMG-CoA reductase inhibitor used in the treatment of hypercholesterolemia and prevention of coronary heart disease aimed to investigate its effect on hyperalgesia and cartilage damage in monosodium iodoacetate (MIA)-induced osteoarthritis model in rats. METHODS: Osteoarthritis was induced by a single intra-articular injection of 3mg MIA. After daily administration of atorvastatin (3, 10 and 30 mg/kg) for 20 days by oral gavage, pain was assessed on days 0, 1, 3, 7, 14 and 21. Histopathology of ipsilateral knee joint; oxidative markers and antioxidants in plasma were assessed on day 21. RESULTS: Atorvastatin attenuated hyperalgesia. The increased level of lipid peroxidation, superoxide, protein carbonyl; decreased activity of catalase, glutathione-S-transferase, reduced glutathione and total thiol levels in MIA rats were restored to the normal levels, however, superoxide dismutase and nitric oxide levels remained unaltered by atorvastatin. Further, atorvastatin reduced the MIA-induced histopathological alteration in the knee joint. CONCLUSION: Our study demonstrated that atorvastatin attenuates MIA-induced osteoarthritic pain and protect cartilage degradation through inhibition of oxidative stress suggesting its importance in osteoarthritic pain management.

Topical application of substance P promotes wound healing in streptozotocin-induced diabetic rats.

Substance P (SP) is known to stimulate angiogenesis, fibroblasts proliferation and expressions of cytokines and growth factors involved in wound healing. However, SP level reduces in dermis in diabetics and, hence, it was hypothesized that exogenously applied SP could be helpful in improving wound healing in diabetic rats. Excision skin wound was created on the back of diabetic rats and rats were divided into three groups i.e. (i) saline-, (ii) gel- and (iii) SP-treated. Normal saline, pluronic gel and SP (10(-6)M) in gel were topically applied once daily for 19days. SP treatment significantly increased the wound closure, levels of interleukin-10, and expressions of vascular endothelial growth factor, transforming growth factor-beta1, heme oxygenase-1 and endothelial nitric oxide synthase, whereas it significantly decreased the expression of tumor necrosis factor-alpha, interleukin-1beta and matrix metalloproteinases-9 in the granulation/healing tissue. The inflammatory cells were present for long time in normal saline-treated group. Histological evaluation revealed better extracellular matrix formation with marked fibroblast proliferation and collagen deposition in SP-treated group. Early epithelial layer formation, increased microvessel density and greater growth associated protein-43 positive nerve fibers were also evidenced in SP-treated group. In conclusion, SP treatment markedly accelerated cutaneous wound healing in diabetic rats.

Anti-inflammatory and chondroprotective effects of atorvastatin in a cartilage explant model of osteoarthritis.

OBJECTIVE: This study aimed to assess the chondroprotective potential of atorvastatin in rat's cartilage explant culture model of osteoarthritis, stimulated by interleukin-1ß (IL-1ß). MATERIALS AND METHODS: The cartilage explants were treated with 20 ng/ml IL-1ß alone or with 20 ng/ml IL-1ß + various concentration of atorvastatin (1, 3, or 10 µM dissolved in DMSO) and incubated at 37 °C for 24 h. Also, control (0.25% DMSO), stimulated (20 ng IL-1ß) and treatment (atorvastatin 10 µM) cartilage explants were incubated without and with 1400W (10 µM). After 24 h of incubation, TNF-α, PGE2, MMP-13, TIMP-1, NO, and superoxide anion formation (O2(-)) concomitant with glycosaminoglycans (GAGs) were estimated in the medium. RESULTS: Atorvastatin inhibited IL-1ß-induced GAGs release, TNF-α, MMP-13, and O2(-) with no effect on TIMP-1 and NO. In addition, the source of NO in normal and atorvastatin-treated cartilage was eNOS, while for IL-1ß-stimulated cartilage it was iNOS. The cartilage degradation was associated with the combined effects of increased NO and O2 (-) rather than only NO. CONCLUSION: The present study suggests that atorvastatin has the ability to protect cartilage degradation following IL-1ß-stimulated cartilage in in vitro OA model and supports additional therapeutic application of atorvastatin in OA.

Curcumin-induced angiogenesis hastens wound healing in diabetic rats.

BACKGROUND: Neovasculogenesis, vital for wound healing, gets compromised in diabetics patients, which consequently delayed wound healing. Previous studies have shown curcumin as both a stimulatory and an inhibitory agent in the neovasculogenesis process. So, present study was aimed to investigate the effects of curcumin on wound healing in diabetic rats and to explore the expressions of the various factors involved in neovasculogenesis. MATERIALS AND METHODS: Open excisional diabetic wound was created in sixty rats and divided into three groups viz. i) control, ii) pluronic gel-treated, and iii) curcumin-treated. The pluronic F-127 gel (25%) and curcumin (0.3%) in the pluronic gel were topically applied once daily for 19 d. The wound healing and neovasculogenesis among these groups were evaluated by gross appearance of wounds and microscopically by hematoxylin and eosin staining, immunohistochemistry for CD31, messenger RNA expressions of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-ß1, hypoxia-inducible growth factor-1 alpha, stromal cell-derived growth factor-1 alpha, and heme oxygenase-1, and Western blotting studies of VEGF and TGF-ß1 in granulation and/or healing tissue on days 3, 7, 14, and 19. RESULTS: Curcumin application caused markedly fast wound closure with well-formed granulation tissue dominated by fibroblast proliferation, collagen deposition, and complete early regenerated epithelial layer. Immunohistochemistry for CD31 revealed well-formed blood vessels with increased microvessel density on days 3, 7, and 14 in the curcumin-treated group. Expressions of VEGF and TGF-ß1 on days 3, 7, and 14, hypoxia-inducible growth factor-1 alpha, stromal cell-derived growth factor-1 alpha, and heme oxygenase-1 on days 3 and 7 were increased in curcumin-treated diabetic rats, as compared with other groups. CONCLUSIONS: Curcumin enhanced the neovasculogenesis and accelerated the wound healing in diabetic rats by increased expressions of various factors.

Chitosan-based copper nanocomposite accelerates healing in excision wound model in rats.

Copper possesses efficacy in wound healing which is a complex phenomenon involving various cells, cytokines and growth factors. Copper nanoparticles modulate cells, cytokines and growth factors involved in wound healing in a better way than copper ions. Chitosan has been shown to be beneficial in healing because of its antibacterial, antifungal, biocompatible and biodegradable polymeric nature. In the present study, chitosan-based copper nanocomposite (CCNC) was prepared by mixing chitosan and copper nanoparticles. CCNC was applied topically to evaluate its wound healing potential and to study its effects on some important components of healing process in open excision wound model in adult Wistar rats. Significant increase in wound contraction was observed in the CCNC-treated rats. The up-regulation of vascular endothelial growth factor (VEGF) and transforming growth factor-beta1(TGF-ß1) by CCNC-treatment revealed its role in facilitating angiogenesis, fibroblast proliferation and collagen deposition. The tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were significantly decreased and increased, respectively, in CCNC-treated rats. Histological evaluation showed more fibroblast proliferation, collagen deposition and intact re-epithelialization in CCNC-treated rats. Immunohistochemistry of CD31 revealed marked increase in angiogenesis. Thus, we concluded that chitosan-based copper nanocomposite efficiently enhanced cutaneous wound healing by modulation of various cells, cytokines and growth factors during different phases of healing process.

Antioxidant and anti-inflammatory potential of curcumin accelerated the cutaneous wound healing in streptozotocin-induced diabetic rats.

Prolonged inflammation and increased oxidative stress impairs healing in diabetics and application of curcumin, a well known antioxidant and anti-inflammatory agent, could be an important strategy in improving impaired healing in diabetics. So, the present study was conducted to evaluate the cutaneous wound healing potential of topically applied curcumin in diabetic rats. Open excision skin wound was created in streptozotocin induced diabetic rats and wounded rats were divided into three groups; i) control, ii) gel-treated and iii) curcumin-treated. Pluronic F-127 gel (25%) and curcumin (0.3%) in pluronic gel were topically applied in the gel- and curcumin-treated groups, respectively, once daily for 19 days. Curcumin application increased the wound contraction and decreased the expressions of inflammatory cytokines/enzymes i.e. tumor necrosis factor-alpha, interleukin (IL)-1beta and matrix metalloproteinase-9. Curcumin also increased the levels of anti-inflammatory cytokine i.e. IL-10 and antioxidant enzymes i.e. superoxide dismutase, catalase and glutathione peroxidase. Histopathologically, the curcumin-treated wounds showed better granulation tissue dominated by marked fibroblast proliferation and collagen deposition, and wounds were covered by thick regenerated epithelial layer. These findings reveal that the anti-inflammatory and antioxidant potential of curcumin caused faster and better wound healing in diabetic rats and curcumin could be an additional novel therapeutic agent in the management of impaired wound healing in diabetics.

Atorvastatin attenuates neuropathic pain in rat neuropathy model by down-regulating oxidative damage at peripheral, spinal and supraspinal levels.

Atorvastatin is an HMG-CoA reductase inhibitor used in the treatment of hypercholesterolemia and prevention of coronary heart disease. Oxidative stress is considered to be one of the main causes of neuropathic pain after nerve injury. This study aimed to investigate the effect of atorvastatin on oxidative stress and hyperalgesia in chronic constriction injury (CCI) model of neuropathic pain. Pain behaviour in rats was evaluated before and after atorvastatin administration using mechanical and heat hyperalgesia. The markers for oxidative stress in sciatic nerve, spinal cord and pre-frontal cortex (PFC) area of brain were biochemically detected in vehicle and atorvastatin-treated neuropathic CCI rats. Atorvastatin attenuated hyperalgesia. We found a significant increase in malondialdehyde (MDA), nitric oxide (NO), superoxide anion (O2(-)) and protein carbonyl along with a reduction in catalase (CAT), reduced glutathione (GSH), total thiol (SH) and glutathione-S-transferase (GST) and; increase in superoxide dismutase (SOD) levels in the sciatic nerve, spinal cord and PFC of the CCI-induced neuropathic rats. Reduced levels of enzymatic and non enzymatic antioxidants were restored by atorvastatin. The levels of MDA, O2(-), and protein carbonyl in these tissues were significantly reduced in the atorvastatin-treated CCI rats compared to the untreated CCI rats. Our study demonstrated that atorvastatin attenuates neuropathic pain through inhibition of oxidative stress in sciatic nerve, spinal cord and brain suggesting antioxidants as potential drugs in neuropathic pain management. This study provides a new application of atorvastatin in treatment of neuropathic pain.