Burn Injury In Rats Research Articles

Autologous Platelet-Rich Plasma Repairs Burn Wound and Reduces Burn Pain in Rats.

To investigate the effects of autologous platelet-rich plasma (PRP) on burn wound and burn pain in rats. Rats were treated with high-temperature copper rod to induce skin burn. During treatment, the wound area of rats was recorded on days 0, 3, 7, 10, 14 and healing rates were calculated. After 14-day treatment, the paw withdrawal mechanical threshold (PWMT) as well as paw withdrawal thermal latency were measured. In addition, CD31 expression in burn wound was detected by immunohistochemistry. The contents of TNF-α and IL-1β in wound tissues were detected by ELISA. Moreover, the mRNA and protein expression levels of VEGF, MMP-9, and TGF-β1 in wound tissues were detected by RT-qPCR together with Western blot. Burn wound of rats in the PRP group gradually got better with a decreased wound area. Compared with the NS group, the wound area of the PRP group was significantly reduced and the healing rate was significantly increased. Meanwhile, PWMT of the rats in the PRP group was obviously increased compared with the NS group. Compared with the NS group, the rate of CD31-positive cells in the wound tissue of burned rats was increased; while the contents of TNF-α and IL-1β were significantly decreased after a subcutaneous injection of PRP. In addition, the mRNA and protein expression levels of VEGF, MMP-9, and TGF-β1 in the wound tissue of rats from PRP group were evidently increased. Autologous platelet-rich plasma not only shortened the healing time, but also relieved the burn pain.

671 Burn Wound Healing Effect of Bromelain-loaded Chitosan Nanofibers

Abstract Introduction Bromelain is a mixture of proteolytic enzymes present in all tissues of pineapple (Ananas comosus). It is known as an efficient debriding agent in burn treatment and has been shown to effectively and selectively debride burn eschar. In this study, the efficiency of bromelain-loaded chitosan nanofibers for burn wounds repair was investigated in animal model. Methods Chitosan nanofibers containing bromelain were prepared by electrospinning method. The physicochemical characteristics of the synthetized nanofibers, release profile and activity of bromelain loaded in nanofibers were evaluated. The burn healing effect of bromelain-loaded nanofibers were studied in the induced burn wounds in rats for 21 days. The efficacy of treatment was assessed by evaluating changes in wound closer and histological analysis at different time point. Results Successful electrospinning of bromelain-loaded chitosan nanofibers resulted in uniform and bead-less nanofibers which released bromelain up to 48h. The formulation kept bromelain enzyme activity after 6-month storage at 4 °C and did not show any cytotoxicity on human dermal fibroblasts. Moreover, in vivo study in a rat burn model confirmed the safety and efficacy of applying bromelain loaded nanofibers in burn wound healing when a significant improve in wound closer was observed in bromelain loaded group and histopathological studies showed more effects on re-epithelialization, debridement and more reduction of necrosis compared to chitosan alone. Conclusions Together, these results suggest that bromelain chitosan nanofiber possesses great wound healing activity and could be considered as an effective natural topical burn wound healing treatment.

Effect of Curcuma xanthorrhiza Gel on Methicillin-Resistant Staphylococcus aureus-Infected Second-Degree Burn Wound in Rats

Methicillin-resistant Staphylococcus aureus (MRSA) infection often complicates burn wounds. Mupirocin is the antibiotic of choice for superficial MRSA infection, and its resistance is on the rise due to its frequent and widespread use. This study aimed to develop and evaluate Curcuma xanthorriza extract (CXE)- containing gel as a topical agent against MRSA-infected second-degree burn wound in rats. CXE was obtained using maceration with 96% ethanol. Xanthorrhizol level, antibacterial, and antioxidant activity were evaluated using a standardized method. In vivo, the wound’s healing and bacterial load were evaluated every three days, whereas the histopathology of the wound was examined on day 12 of treatment. One-Way ANOVA and Kruskal- Wallis test were used to analyze the data. In this study, 27.0% and 7.10% of the obtained CXE were xanthorrhizol and curcumin, respectively. Additionally, an IC50 of 64.27 ppm was shown in antioxidant activity measurement, and MIC against MRSA was 5 mg/ml. Treatment with CXE-containing gels showed a significant reduction in bacterial load and proliferation of connective tissue in a dose-dependent manner. In conclusion, CXE-containing gel showed a greater reduction of bacterial load and more advanced wound healing phase than mupirocin.

Ampelopsis grossedentata Leaf Extract Induced Gold Nanoparticles as Wound Healing Dressing for Abdominal Wound Dehiscence in Nursing Care

In contemporary therapeutics, the drugs fabricated chemically were proved to cause adverse effects such as swelling, itching, allergic reactions and rashes. Since few decades, application of metal nanoparticles was widely seen in the field of medicine because of their wound healing and antimicrobial properties. In this work, leaf extract of Ampelopsis grossedentata (A. grossedentata) plant was used as a bio-reducing agent for the synthesis of gold nanoparticles (Au NPs) from HAuCl4. Characterization of the NPs was done by using techniques such as fourier transform- infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) provided with energy dispersive X-ray (EDX). The fabricated NPs were found to be 30–50 nm in size and spherically shaped. Fabrics of cotton dress saturated with synthesized gold nanoparticles (Au NPs) and compared with fabrics of cotton applied with a commercially available ointment (silver sulfadiazine) and were investigated for a period of 18 days for assessing their capability of rapid wound healing in burn wounds of rats. Noticeable difference in body weight of rat was not seen in case of treatment with NPs, when compared to the rats of normal group. Scanning electron microscopy (SEM) images of cotton fabrics confirmed the Au NPs distribution onto the cotton fabric. Additionally, it was found that the efficacy of wound healing in dressing applied with the commercial ointment was a bit low when compared with the dressing of 100 μg/kg b.w. of Au NPs. Furthermore, the area of wound contraction was found to be higher than the group treated with 100 μg/kg b.w. of AuNPs, which implies the relatively finer quality of Au NPs ointments by looking into their properties of healing the burn wounds. All these results concluded the utilization of AuNPs based ointments for abdominal wound healing in nursing care.

Conjugation of imipenem to silver nanoparticles for enhancement of its antibacterial activity against multidrug-resistant isolates of Pseudomonas aeruginosa

Due to the broad-spectrum of antibiotic resistance, herein we investigated the possibility of using imipenem-conjugated silver nanoparticles (IMP-AgNPs) against multidrug-resistant isolates of Pseudomonas aeruginosa. For this purpose, 200 clinical isolates were tested against different antibiotics to determine the antimicrobial susceptibility. To identify blaVIM and blaIMP resistance genes, PCR was used. The synthesized AgNPs and conjugants were characterized using UV-vis spectroscopy, XRD, SEM, TEM, DLS, and FTIR. The stability, drug release kinetics, cytotoxicity, hemolytic and apoptotic effects of NPs were also investigated. MIC of the imipenem, AgNPs, and conjugants were evaluated versus P. aeruginosa isolates. Finally, the effects of the IMP-AgNPs to heal burn wounds in rats was evaluated. According to the results, about 68% of isolates showed resistance to imipenem (MIC ≥ 64 μg/ml to ≥ 512 μg/ml). Analytical results verified the synthesis of AgNPs and IMP-AgNPs. A Dose-dependent decrease happened in terms of the MIC values of IMP-AgNPs were also affected by the existence of resistant genes. Low cytotoxic was observed regarding AgNPs which lead to apoptosis. The histopathological results showed a considerable epithelization in treated groups with IMP-AgNPs. Accordingly, IMP-AgNPs can be considered as a powerful antibacterial agent to treat the infections caused by multidrug-resistant P. aeruginosa.

Properties of Langmuir and immobilized layers of betulin diphosphate on aqueous solutions of zinc sulfate and on the surface of zinc oxide nanoparticles

This work examines the specific features of interaction of betulin diphosphate (BDP), exhibiting antitumor and wound-healing properties, with zinc cations during its immobilization on ZnO nanoparticles. The properties of Langmuir and transferred BDP monolayers from an aqueous subphase of zinc sulfate onto the surface of a solid substrate (CaF2, quartz) by the Langmuir—Schaefer method are investigated using IR and UV spectroscopy. It is shown that there is a twofold increase of the molecular area in the immobilized layers, while the compressibility modulus decreases by a factor of 1.5. Zinc oxide nanoparticles with immobilized BDP 10–20 nm in size (surface concentration of BDP is 100 mg g−1) retain the original hexagonal wurtzite structure. The efficiency of betulin diphosphate immobilized on the surface of zinc oxide nanoparticles is demonstrated in in vivo experiments for burn wounds in rats.

Application of Nano-Composite Technology for Multi-Empty Carbon Nanotubes in Dressing Change Care

Using good biocompatibility and antibacterial properties, this project synthesized nano-silver-multiempty carbon nanotube composite nano-carriers. The purpose is to improve the water dispersibility of drug particles and enhance their drug selectivity. This approach improves efficiency and resilience in dressing changes. Two different drugs, nano-silver antibacterial gel and nano-silver-multi-empty carbon nanotube composite anti-bacterial gel, were used to change the wounds by establishing a rat burn wound model. Explore the different effects of these two drugs on burn wound healing, infection, and tissue inflammation in rats, and provide a reference for clinical wound dressing change. The experimental results show that the nano-silver-multi-empty carbon nanotube composite antibacterial gel has a better anti-infective effect on burn wounds. And can effectively reduce the number of dressing changes.

Pharmacological Screening for Burn Wound Healing Potential of Traditional PlantCassia fistuliain Rats

Skin is a vital organ which performs several functions such as thermoregulation, homeostasis, metabolic, neurosensory and immunologic functions. Burns, with their devastating consequences, are known as one of the most common forms of injury. Herbal products could be extensively preferable for treating many ailments due to their widespread accessibility and the vast experiential data retrieved from traditional medicine. Cassia fistula has been traditionally used to treat skin disorders and injuries. In the present study, the healing effect of aqueous and ethanolic extracts of leaves of Cassia fistula has been evaluated in second-degree burn wound in rats. The preliminary phytochemical screening revealed the presence of tannins, alkaloids, cardiac glycosides, steroids, carbohydrates, flavonoids, saponins, and phenols as phytoconstituents. From day 4 to day 21, both aqueous and ethanolic extracts of Cassia fistula leaves were observed to have a significant effect during treatment and also the test drugs were found to play a role in accelerating the rate of epithelialization. Cell viability in both cell lines was significantly decreased when compared to the control cells. The hydroxyproline level was found to be substantially elevated in aqueous and ethanolic extracts of Cassia fistula leaves treated groups. The efficacy of Cassia fistula leaves in improving wound healing was also discovered by histopathological analysis of the cream-treated rat wound tissues.

The Effect of Educated Platelets on the Healing Process of Burn Wounds in Rats: Educated Platelets in Rat Burn Wound Healing

Burns are serious life-threatening health problems. This study was performed to determine the effect of educated platelets on burn wound healing process. 28 female wistar albino 200-220 gr rats were randomly divided into four groups. Group A1 rats(n:7) were the first-line burnt group from which blood samples are extracted to develop platelet-rich plasma(PRP) with the educated platelets that have a response to burn injury. Group B1 rats(n:7) were the unburnt group with ordinary platelets. Group A2 rats(n:8) were the second-line burnt group which was given PRP with educated platelets. Group B2 rats(n:6), as control group, were the second-line burnt group which was given PRP with ordinary platelets. Photos of rats' dorsum were taken by digital camera on the first day and 21st day of the study. Wound healing was determined by scar surface area. In the study group (Group A2) mean wound area was 53±37 mm², in the control group (Group B2) mean wound area was 114±55 mm² on the last day of the experiment. The sizes of the wounded areas were significantly lower in the study group compared with the control group (p: 0.039). Educated platelets seem to facilitate the recovery period of burn wound healing in rats.

BFGF ameliorates intestinal mucosal permeability and barrier function through tight junction proteins in burn injury rats

BackgroudTo investigate the protective effect of exogenous basic fibroblast growth factor (bFGF) treatment on the intestinal mucosa in scalded rats. MethodsThirty-six SD rats were randomly divided into 3 groups (n = 12): sham group, scald group and bFGF group (0.5 mg/kg). Intestinal barrier dysfunction was evaluated by permeability of intestinal mucosa to fluorescein isothiocyanate (FITC)-dextran and Chiu’s grading system. H&E staining was used to detect the morphological changes of intestinal mucosa. Immunohistochemistry was used to observe zonula occludens-1 (ZO-1) and occludin. Western blot assay was used to detect the expression of ZO-1, Claudin-1, occludin and myosin light-chain kinase (MLCK). ResultsThe results demonstrated that following bFGF treatment, permeability of the intestinal epithelium barrier of was significantly decreased compared to scald group. H&E staining and Chiu’s grading were consistent with previous result. The expression of ZO-1, Claudin-1, occludin in bFGF group were significantly increased compared to scald group, while MLCK protein was decreased. ConclusionsbFGF ameliorates permeability of intestinal mucosa after burns. The possible mechanism may be relate to bFGF could increase the expression level of tight junction proteins (TJPs).

Umbilical Cord Mesenchymal Stem Cells for Inflammatory Regulation After Excision and Grafting of Severe Burn Wounds in Rats.

Severe burns predispose to shock and necessitate escharectomy and skin grafting. Previous studies show that mesenchymal stem cells are effective for burn wound healing and immune regulation. In this study, we combined escharectomy and skin grafting after burn injury with stem cell application, so as to examine the immune regulation of stem cells and the effect on the transplanted skin graft. SD rats were randomly divided into normal group, sham group, normal + hUCMSCs group, and normal + SB203580 group. Normal saline, hUCMSCs, and SB203580 were injected into the tail vein of each group, and serum inflammatory factors were detected by ELISA. The expression of p38 MAPK/NF-κB pathway proteins in rat liver was detected by western blot. Skin activity was detected by Trypan blue staining and western blot. Skin graft inflammatory infiltration was detected by histological analysis. We found that hUCMSCs could regulate the phosphorylation levels of P38MAPK and NF-B P65 proteins in the liver to reduce the inflammatory response. These effects could continue to reduce the production of inflammatory factors HMGB-1, IL-6, and TNF-α, and increase the anti-inflammatory factor IL-10. The infiltration of inflammatory cells in skin graft was significantly reduced in the normal + hUCMSCs group, and the macrophages in the hUCMSCs group polarized to the anti-inflammatory M2 direction in 3 days. However, the changes of skin graft activity and necroptosis markers protein RIP3 were not observed. The present study demonstrates the immunomodulatory effects of hUCMSCs on the systemic and skin graft microenvironment after excision.

Simvastatin accelerates the healing process of burn wound in Wistar rats through Akt/mTOR signaling pathway

Statins, apart from cholesterol-lowering properties, have wound healing effects. Hereby, we aimed to assess the impact of Simvastatin (SMV), one of the most commonly used statins, on Akt/mTOR signaling pathway during burn wound healing process. After creating a second-degree burn on the dorsal area of adult male Wistar rats (n = 60), they were randomly divided into the control, SMV, vehicle of Simvastatin (SMV-Veh), Rapamycin (RM), vehicle of Rapamycin (RM-Veh), and combined SMV and RM (SMV + RM) groups. The animals were sacrificed on the 7th and 14th post-burn days and wound tissue samples were collected for histologic, immunohistochemical, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot investigations. Rapamycin (RM) was also used to treat animals as an mTOR inhibitor. Topical administration of SMV resulted in a faster healing rate, elevated collagen deposition, and increased myofibroblast population compared to other experimental groups. Moreover, qRT-PCR findings showed that the wounds treated with SMV alone had the highest expression levels of CD31, VEGF, Akt, mTOR, and p70S6K after 7 and 14 days of burn model (p < 0.001). According to western blot findings, daily topical treatment with SMV further increased protein levels of P-AktThr308, P-mTORSer2448, and P-p70S6 KThr389 compared with other treatments, at both follow-up time points (p < 0.001). In contrast, inhibition of Akt/mTOR signaling pathway by RM reduced SMV-induced wound healing process. Seemingly, SMV promotes burn wound healing, at least in part, through activating Akt/mTOR signaling pathway, suggesting topically applied SMV as an alternative therapeutic approach for managing burn wound healing.

Sulfated polysaccharide ascophyllan from Padina tetrastromatica enhances healing of burn wounds by ameliorating inflammatory responses and oxidative damage.

Sulfated polysaccharide ascophyllan from marine brown algae has been identified to have burn wound healing properties. Thus, we examined the effects of ascophyllan fraction (AF3) on the inflammatory response and oxidative damage in burn wounds. Full-thickness burn wounds in rats were then treated twice per day with topical AF3 ointment (5%), while control groups were treated with 10% povidone-iodine (positive control) and petroleum jelly-based ointment (negative control). The activity of cyclooxygenase-2 and myeloperoxidase and levels of C-reactive protein, nitric oxide, and proinflammatory cytokines (tumor necrosis factor-α, interleukin-6, and interleukin-1β) were observed to have significantly decreased in peripheral blood mononuclear cells, serum, and wound tissue of the group treated with AF3 ointment on day 8 after wounding. The expression of inducible nitric oxide synthase, endothelial nitric oxide synthase, and vascular endothelial growth factor at the mRNA level was determined to be upregulated in the wound tissue of the AF3 ointment-treated group. After treatment with AF3 ointment, the antioxidant enzyme activity and level of reduced glutathione were upregulated, whereas the content of thiobarbituric acid reactive substances decreased. Treatment of burn wounds using 5% AF3 ointment decreases oxidative damage associated with inflammation deceptively via inhibition of inflammatory enzymes, regulation of proinflammatory cytokines, upregulation of angiogenesis, and activity of antioxidant enzymes.

Dual drug delivery system based on pH-sensitive silk fibroin/alginate nanoparticles entrapped in PNIPAM hydrogel for treating severe infected burn wound

Herein, the pH-sensitive vancomycin (VANCO) loaded silk fibroin-sodium alginate nanoparticles (NPs) embedded in poly(N-isopropylacrylamide) (PNIPAM) hydrogel containing epidermal growth factor (EGF) are introduced for treating chronic burn wound infections. The hybrid system was developed to control the release rates of an antibiotic and growth factor for optimal treatment of burn infections. VANCO had a pH responsive release behavior from the nanoparticle (NP) and showed higher release rate in an alkaline pH compared to the neutral pH during 10 d. About 30% of EGF was also released from the hydrogel within 20 d. The released VANCO and EGF preserved their bioactivity more than ∼ 80%. The suitable physico-chemical properties and cellular behaviors of PNIPAM hydrogel supported the proliferation and growth of the fibroblast cells. Furthermore, the higher re-epithelialization with good wound contraction rate, neovascular formation, and expression of transforming growth factor-beta were observed in S. aureus infected rat burn wound by using the hydrogel containing VANCO and EGF compared with untreated wounds and hydrogel alone. The wound infection was also significantly reduced in the groups treated with the hydrogels containing VANCO. Overall, in vitro and in vivo results suggested that developed hybrid system would be a promising construct to treat severe wound infection.

Potential Healing Effect Of Mulberry Leaf Extract Oinment on Burn Injury in rats

Objective: Mulberry leaf contains Vitamin C, Flavonoids, Oxyresveratrol and Saponin, which accelerated reepithelialization and increases wound contraction in burn healing. This study was designed to asses the effect of mulberry leaf extract ointment (Morus Alba L) on number of fibroblast and collagen fraction area in second degree burns.Materials and methods: This was an experimental design for 6 days with 24 male in Sprague dawley rat randomly selected and divided into 4 groups. The back of Sprague dawley male rats were shaved and given burns using 4 x 2cm iron plate which was put in 98o boiling water for 5 minutes and pasted for 10 seconds and smeared with distilled water, and ointment of mulberry leaf extract. Group I was a positive control (silver sulfadiazide ointment), Group II was a negative control (ointment base), Group III (mulberry leaf extract ointment 10%) and Group IV (mulberry leaf extract ointment 20%). The number of fibroblasts and collagen was evaluated with staining of hematoxylin eosin and staining mallory trichrome.Result and discussion: The mean of fibroblasts I, II, III,and IV was 21.33 ± 1.74, 13.28 ± 1.48, 17.56 ± 1.75, and 23.11 ± 2.38, respectively. The mean collagen fraction area I, II, III, and IV was 21, 11±7,42 , 16,18 ±7,72, 26,078 ± 8, 00 , and 25,79±8,33 respectively. One way Anova followed LSD test showed significant different in mean of between each treatment group obtained significant differences (p &lt;0.05). The mean number of fibroblast in the 10% and 20% ointment extract were significantly different compared with negative controls. Collagen fraction area in treatment group with 10 and 20% ointment were significantly different from that of negative control group, and was not significantly different from silver sulfadiazine groupConclusion: The mulberry leaf extract can be an alternative treatment for second degree burnsInternational Journal of Human and Health Sciences Vol. 05 No. 02 April’21 Page: 235-239

Modification and utility of a rat burn wound model.

This study aimed to improve the conventional rat burn wound model and to validate its utility. In total, 60 Sprague-Dawley rats were divided equally into the control and experimental groups. Altogether, 60 burn wound models with zones of stasis were created in each group. Gross visual assessments of the burn wounds were performed at 0, 24, and 48 hours after burn creation. The rates of necrosis in the zones of stasis were calculated, and the blood flow from the wounds was examined. Wound tissues were collected 48 hours after the burn and subjected to hematoxylin and eosin staining to determine whether the models were successfully established. The model success rates were calculated. The success rate of the burn wound models was significantly different between the control group and the experimental group (93.33% [56/60] vs 100%; P = .042). The Cronbach's alpha values and the respective correlation coefficients indicated that the stability of the zones of stasis in the models on the two sides of the spine was higher in the experimental group than in the control group. The standard deviations of the rate of necrosis, blood flow, and density of necrotic cells and apoptosis cell density, and inflammatory factor content in the zones of stasis were smaller in the experimental group than in the control group at 48 hours after model construction. This suggested that the stability of repeated procedures was higher in the experimental group than in the control group. The novel device for creating burns in animal models facilitated the effective creation of zones of stasis for rat burn wound models. Both the model success rate and stability were higher compared with the conventional model construction method. In addition, the use of the novel device can better align with the requirements of self-controlled studies.

Efficiency of Ampicillin-Associated Biogenic Ferrihydrite Nanoparticles in Combination with a Magnetic Field for Local Treatment of Burns.

We studied the effectiveness of using magnetic ferrihydrite nanoparticles of bacterial origin carrying ampicillin for local treatment of burn wounds in rats using a magnetic field. It was found that the use of these nanoparticles in combination with a magnetic field accelerated wound healing and reduced the titer of microorganisms in comparison with the corresponding parameters in the untreated animals and animals treated with nanoparticles or ampicillin alone.

Melatonin nanogel promotes skin healing response in burn wounds of rats.

Aim: Development of a melatonin nanogel intended for wound healing (WH) application. Materials & methods: The main components of the nanogel were poloxamer 407, chitosan and hyaluronic acid. The nanogel was characterized by the assessment of physical interactions, swelling, wettability, rheological properties and internal structure. The drug release, antimicrobial efficacy against different strains and biocompatibility with human keratinocytes were also tested. Finally, the WHefficacy was evaluated in rats. Results: The nanogel showed optimal physicochemical properties and an internal network of interconnected channels from which melatonin was released following first order kinetics. Antimicrobial activity was similar to commercial reference material and it promoted epidermis growth with evident wound contraction. Conclusion: Melatonin nanogel can be proposed as a promising system for WH.

Comparison Among Bone Marrow and Wheat Flour's Mixture and Standard Treatment on Healing Second-Degree Burn Wound in Rats.

The treatment of extensive skin burns remains as a challenge for health care personnel. This study aimed to compare the combination of bone marrow and wheat flour with standard treatment on animal models. In this experimental study, 45 male rats were randomly assigned into three groups as follows: The first group was control (no treatment), the second group received bone marrow and wheat flour combination topically, and the third group received standard treatment (1% silver sulfadiazine). The treatment lasted for up to 21 days. On the 22nd day, the rats were killed. The number of blood vessels and hair follicles was measured in the burn wound bed. The area and depth of the wound were also measured. Data were analyzed using SPSS software version 16. The results showed that, complete closure of the wound was better in the bone marrow treated group compared with the group receiving the silver sulfadiazine and the control group. Furthermore, the wound healing was better in the silver sulfadiazine group compared with the control group. Microscopic examination revealed a significant increase in the number of hair follicles and blood vessels in the bone marrow and silver groups compared with the control group. The results showed that, the group treated with bone marrow, because of the presence of mesenchymal and stem cells can cause stimulating angiogenesis and producing vegetative tissue, hence it improved maturation, shrinkage, and contraction of the wound in comparison with the silver sulfadiazine and control groups.

Effect of lycopene on pain facilitation and the SIRT1/mTOR pathway in the dorsal horn of burn injury rats

To explore the effect of intrathecal injection of lycopene on pain facilitation, glial activation, and the SIRT1/mTOR pathway in the dorsal horn of rats with burn injury pain (BIP).Here we found that the mechanical pain threshold increased in the lycopene group compared with that of the control group, (P < 0.05). Compared with expression in the sham group, mTOR, pS6, p4EBP, GFAP, and Iba-1 decreased and SIRT1 increased in the lycopene group (P < 0.01). Glial activation in the spinal dorsal horn of BIP rats was alleviated by lycopene (P < 0.01). The SIRT1 and mTOR were mainly distributed in neurons in the spinal dorsal horn in the BIP model. Intrathecal injection of 3-MA (a mTOR agonist) or EX-527 (an inhibitor of Sirt1) partially antagonized lycopene-induced analgesia. Intrathecal injection of rapamycin (an mTOR inhibitor) or SRT1720 (an agonist of Sirt1) induced analgesia in BIP rats. 3-MA abrogated the SRT1720-induced analgesic effects.The present data indicated that the SIRT1/mTOR pathway changed in the spinal dorsal horn of BIP rats; Lycopene alleviated the pain sensitization of BIP rats by regulating the SIRT1/mTOR pathway and glial activation in the spinal dorsal horn.