Surface Of Paw Research Articles

10 kHz spinal cord stimulation improves metrics of spinal sensory processing in a male STZ rat model of diabetes

To explore why clinical 10 kHz spinal cord stimulation (10 kHz SCS) might improve neurological function in a model of painful diabetic neuropathy (PDN), the short-term behavioral, electrophysiological, and histological effects of 10 kHz SCS were studied using adult male streptozotocin (STZ)-induced diabetic Sprague-Dawley rats. Four testing groups were established: Naïve controls (N = 8), STZ controls (N = 7), STZ+Sham SCS (N = 9), and STZ+10 kHz SCS (N = 11). After intraperitoneal injection (60 mg/kg) of STZ caused the rats to become hyperglycemic, SCS electrodes were implanted in the dorsal epidural space over the L5-L6 spinal segments in the STZ+Sham SCS and STZ+10 kHz SCS groups and were stimulated for 14 days. The von Frey filament paw withdrawal threshold was measured weekly. At termination, animals were anesthetized and the electrophysiologic response of dorsal horn neurons (receptive field size, vibration, radiant warmth) of the ipsilateral foot was measured. Tissue from the plantar paw surface was obtained post-euthanization for intraepidermal nerve fiber density measurements. In comparison to other control groups, while no significant effect of 10 kHz SCS on peripheral intraepidermal nerve fiber density was observed, 10 kHz SCS ‘normalized’ the central neural response to vibration, receptive field, and paw withdrawal threshold, and elevated the neural response to tissue recovery from warm stimuli. These results suggest that short-term, low intensity 10 kHz SCS operates in the spinal cord to ameliorate compromised sensory processing, and may compensate for reduced peripheral sensory functionality from chronic hyperglycemia, thereby treating a broader spectrum of the sensory symptoms in diabetic neuropathy.

Anti-rheumatic and Memory-enhancing Effect of Memantine on Complete Freund’s Adjuvant-induced Rheumatoid Arthritis Compared to Methotrexate in Wistar Rats

Objectives To evaluate the anti-inflammatory and memory-enhancing effects of memantine (MEM) in complete Freund’s adjuvant (CFA)-induced rheumatoid arthritis (RA) in Wistar rats. The effect of MEM on cognition in CFA-induced RA was also evaluated. Materials and Methods The rats were randomly assigned to one of five groups: sham control (SC), disease control (DC)—CFA 0.1 mg, positive control (PC)—methotrexate (MTX) 1 mg/kg, low dose MEM—20 mg/kg, and high dose MEM (HD-M)—50 mg/kg. All groups received a subcutaneous injection of CFA in the left paw on day 0, except for the SC group, which received a distilled water (DW) injection. The study drugs, MEM and MTX, were administered orally from days 15 to 28. The SC group received DW orally from days 15 to 28. Variables for physical (paw volume, paw surface temperature, and ankle joint diameter) and behavior (open field test, grip strength test, and water corn test) were performed on days 1, 0, 7, 14, 21, and 28. On day 28, blood was collected for serum inflammatory markers, tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. Ex vivo radiological changes in the ankle joint were recorded using a digitalized X-ray machine. Histopathology of the ankle joint was performed. Results When compared to the DC group, the HD-M group showed a significant improvement in all physical and behavioral characteristics ( p < 0.001). When compared to the DC group, TNF-α, IL-6 levels, and histopathological scores were significantly lower in the HD-M group ( p < 0.01). Conclusion MEM reduces inflammation and improves memory in Wistar rats with CFA-induced RA. MEM can be used as an anti-inflammatory drug in elderly patients at risk of dementia.

Assessing nystatin cream treatment efficacy against Leishmania (L.) amazonensis infection in BALB/c model

The current scenario for cutaneous leishmaniasis treatment includes the use of first and second-choice drugs, both therapeutic strategies presenting several adverse effects and being related to an increment of treatment-refractory parasite strains. These facts encourage the search for new treatment approaches, including repositioning drugs, such as nystatin. Although in vitro assays show that this polyene macrolide compound has leishmanicidal activity, no in vivo evidence for a similar activity has been shown so far for the commercial nystatin cream formulation. This work assessed the effects of nystatin cream (25,000 IU/g) administered on mice in an amount to completely cover the paw surface of BALB/c mice infected with Leishmania (L.) amazonensis once a day, until a total of up to 20 doses. The data presented herein points to unequivocal evidence that treatment with this formulation causes a statistically significant reduction of swelling/edema in mice paws when compared to animal groups not submitted to this treatment regimen after the fourth week of infection: lesion sizes at the sixth (p = 0.0159), seventh (p = 0.0079) and eighth (p = 0.0079) week. Furthermore, swelling/edema reduction relates to a decrease in parasite load in the footpad (∼48%) and in draining lymph nodes (∼68%) at eight weeks post-infection. This is the first report of the effectiveness of nystatin cream used as a topical treatment in BALB/c model for cutaneous leishmaniasis.

Synergistic interaction and activation of the opioid receptor-NO-cGMP-K+ channel pathway on peripheral antinociception induced by the α-Bisabolol-diclofenac combination.

Introduction: The local peripheral combination of analgesic drugs with herbal derivatives may have beneficial effects. Information on the action mechanism of these interactions between drugs is scarce. Therefore, the main of the present study was to determine the pharmacological interaction and action mechanism of the combination α-Bisabolol and diclofenac. Methods: Rats were injected in the dorsal surface of the right hind paw with 1% formalin. Rats received subcutaneous injections in the dorsal surface of paw of vehicles or increasing doses of α-Bisabolol, diclofenac or their combination before formalin injection into the paw. Antinociception of the α-Bisabolol + diclofenac combination was evaluated with and without the local treatment of naloxone, metformin, NG-nitro-L-arginine methyl ester (L-NAME), 1H- (1,2,4)-oxadiazolo (4,2-a) quinoxalin-1-one (ODQ), glibenclamide, glipizide, 4-aminopyridine, tetraethylammonium, apamin, or charybdotoxin. Results: α-Bisabolol, diclofenac or α-Bisabolol-diclofenac combinations produced significant antinociception in the rat (p < 0.05). The experimental effective dose (ED) value of 109.2µg/paw was different significantly of the theoretical effective dose (ED) of 245.7µg/paw (synergism). Blockers significantly reverted the antinociception produced by the synergistic combination of α-Bisabolol and diclofenac. Discussion: Data showed a synergism of the α-Bisabolol-diclofenac combination and the activation of the opioid receptor-Nitric Oxide-cyclic GMP-K+ channels pathway and a biguanide-dependent mechanism in order to produce the potentiation of its peripheral antinociception in the formalin test.

Electrical Stimulation of the Auricular Branch Vagus Nerve Using Random and Alternating Frequencies Triggers a Rapid Onset and Pronounced Antihyperalgesia via Peripheral Annexin A1-Formyl Peptide Receptor 2/ALX Pathway in a Mouse Model of Persistent Inflammatory Pain.

This study evaluated the antihyperalgesic and anti-inflammatory effects of percutaneous vagus nerve electrical stimulation (pVNS) by comparing the effects of alternating and random frequencies in an animal model of persistent inflammatory hyperalgesia. The model was induced by Freund's complete adjuvant (CFA) intraplantar (i.pl.) injection. Mice were treated with different protocols of time (10, 20, or 30min), ear laterality (right, left or both), and frequency (alternating or random). Mechanical hyperalgesia was evaluated, and some groups received i.pl. WRW4 (FPR2/ALX antagonist) to determine the involvement. Edema, paw surface temperature, and spontaneous locomotor activity were evaluated. Interleukin-1β, IL-6, IL-10, and IL4 levels were verified by enzyme-linked immunosorbent assay. AnxA1, FPR2/ALX, neutrophil, M1 and M2 phenotype macrophage, and apoptotic cells markers were identified using western blotting. The antihyperalgesic effect pVNS with alternating and random frequency effect is depending on the type of frequency, time, and ear treated. The pVNS random frequency in the left ear for 10min had a longer lasting antihyperalgesic effect, superior to classical stimulation using alternating frequency and the FPR2/ALX receptor was involved in this effect. There was a reduction in the levels of pro-inflammatory cytokines and an increase in the immunocontent of AnxA1 and CD86 in mice paw. pVNS with a random frequency in the left ear for 10min showed to be optimal for inducing an antihyperalgesic effect. Thus, the random frequency was more effective than the alternating frequency. Therefore, pVNS may be an important adjunctive treatment for persistent inflammatory pain.

Comparison of Painful Response to Mechanical Stimulation of the Plantar and Dorsal Surface of Paw Following Chronic Constriction Injury-induced Neuropathic Pain

Mechanical and thermal stimuli were used to evaluate neuropathic pain-like behavior in animal models usually. Mechanical stimulation of paw plantar surface is commonly used to determine mechanical allodynia. In the present study, paw withdrawal response to plantar surface stimulation was compared with paw withdrawal response to dorsal surface stimulation. To this end, a total of 30 female Wistar rats (180-220 g), were assigned randomly to three groups as intact (without any manipulation), sham (incision of skin and muscles without nerve injury), and neuropathy (sciatic nerve lesion) with 10 in each group. To induction of neuropathy (chronic constriction injury), four movable ligations were established around the sciatic nerve using catgut chromic suture with a distance of one millimeter apart and then wound incision was closed. In the sham group, the incision site was closed without nerve ligation. Mechanical allodynia was examined by Von Frey filaments for four weeks. The findings indicated that the paw withdrawal threshold following dorsal surface stimulation was significantly reduced compared to the sham group at day 21 post-surgery. Moreover, paw withdrawal threshold following plantar surface stimulation significantly decreased compared to the sham group at day 21 post-surgery. The present results regarding the sham group showed that the paw withdrawal threshold after mechanical stimulation of the plantar surface was not significantly different from that of the dorsal surface paw. In addition, and there was no significant difference between the paw withdrawal response to plantar surface and dorsal one. In conclusion, paw withdrawal threshold to plantar surface mechanical stimulation was not significantly different from one in dorsal surface following neuropathic pain induced by chronic constriction injury.

An adolescent rat model of vincristine-induced peripheral neuropathy

Childhood acute lymphoblastic leukemia (ALL) is a significant clinical problem that can be effectively treated with vincristine, a vinca alkaloid-based chemotherapeutic agent. However, nearly all children receiving vincristine treatment develop vincristine-induced peripheral neuropathy (VIPN). The impact of adolescent vincristine treatment across the lifespan remains poorly understood. We, consequently, developed an adolescent rodent model of VIPN which can be utilized to study possible long term consequences of vincristine treatment in the developing rat. We also evaluated the therapeutic efficacy of voluntary exercise and potential impact of obesity as a genetic risk factor in this model on the development and maintenance of VIPN. Out of all the dosing regimens we evaluated, the most potent VIPN was produced by fifteen consecutive daily intraperitoneal (i.p.) vincristine injections at 100 µg/kg/day, throughout the critical period of adolescence from postnatal day 35 to 49. With this treatment, vincristine-treated animals developed hypersensitivity to mechanical and cold stimulation of the plantar hind paw surface, which outlasted the period of vincristine treatment and resolved within two weeks following the cessation of vincristine injection. By contrast, impairment in grip strength gain was delayed by vincristine treatment, emerging shortly following the termination of vincristine dosing, and persisted into early adulthood without diminishing. Interestingly, voluntary wheel running exercise prevented the development of vincristine-induced hypersensitivities to mechanical and cold stimulation. However, Zucker fa/fa obese animals did not exhibit higher risk of developing VIPN compared to lean rats. Our studies identify sensory and motor impairments produced by vincristine in adolescent animals and support the therapeutic efficacy of voluntary exercise for suppressing VIPN in developing rats.

Role of the NO-cGMP-K+ channels pathway in the peripheral antinociception induced by α-bisabolol

The aim of this study was to examine if the peripheral antinociception of α-bisabolol involves the participation of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) synthesis followed by K+ channel opening in the formalin test. Wistar rats were injected in the dorsal surface of the right hind paw with formalin (1%). Rats received a subcutaneous injection into the dorsal surface of the paw of vehicles or increasing doses of α-bisabolol (100-300 µg/paw). To determine whether the peripheral antinociception induced by α-bisabolol was mediated by either the opioid receptors or the NO-cGMP-K+ channels pathway, the effect of pretreatment (10 min before formalin injection) with the appropriate vehicles, naloxone, naltrexone, NG-nitro-l-arginine methyl ester (L-NAME), 1H-[1,2,4]-oxadiazolo[4,2-a]quinoxalin-1-one (ODQ), glibenclamide, glipizide, apamin, charybdotoxin, tetraethylammonium, or 4-aminopyridine on the antinociceptive effects induced by local peripheral α-bisabolol (300 µg/paw) were assessed. α-Bisabolol produced antinociception during both phases of the formalin test. α-Bisabolol antinociception was blocked by L-NAME, ODQ, and all the K+ channels blockers. The peripheral antinociceptive effect produced by α-bisabolol was not blocked by the opioid receptor inhibitors. α-Bisabolol was able to active the NO-cGMP-K+ channels pathway to produce its antinoceptive effect. The participation of opioid receptors in the peripheral local antinociception induced by α-bisabolol is excluded.

Participation of the opioid receptor - nitric oxide - cGMP - K+ channel pathway in the peripheral antinociceptive effect of nalbuphine and buprenorphine in rats.

The aim of this study was to examine if the peripheral antinociceptive effects of the opioid agonist/antagonist nalbuphine and buprenorphine involve the sequential participation of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) synthesis followed by K+ channel opening in the formalin test. Wistar rats (180-220 g) were injected in the dorsal surface of the right hind paw with formalin (1%). Rats received a subcutaneous (s.c.) injection into the dorsal surface of the paw of vehicles or increasing doses of nalbuphine (50-200 μg/paw) or buprenorphine (1-5 μg/paw) 20 min before formalin injection into the paw. Nalbuphine antinociception was reversed by the s.c. injection into the paw of the inhibitor of NO synthesis (NG-nitro-l-arginine methyl ester (L-NAME)), by the inhibitor of guanylyl cyclase (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ)), by the Kir6.1-2, ATP-sensitive K+ channel inhibitors (glibenclamide and glipizide), by the KCa2.1-3, small conductance Ca2+-activated K+ channel blocker (apamin), by the KCa1.1, large conductance Ca2+-activated K+ channel blocker (charybdotoxin), and by the KV, voltage-dependent K+ channel inhibitors (4-aminopyridine (4-AP) and tetraethylammonium chloride (TEA)). The antinociceptive effect produced by buprenorphine was blocked by the s.c. injection of 4-AP and TEA but not by L-NAME, ODQ, glibenclamide, glipizide, apamin, or charybdotoxin. The present results provide evidence for differences in peripheral mechanisms of action between these opioid drugs.

Involvement of serotonergic and opioidergic systems in the antinociceptive effect of ketamine-magnesium sulphate combination in formalin test in rats.

Ketamine and magnesium sulphate showed synergic interaction in the tail-immersion test and additive interaction in the rat formalin test. Aim of study was to evaluate the influence of serotonergic and opioidergic system of this combination in the formalin test in rats. Antinociceptive activity was assessed by the formalin test in male Wistar rats (200-250 g). Antagonists (naloxone and methysergide) were administrated 5 min before and magnesium sulphate 5 min after ketamine injection. Formalin (2.5%, 100 μL) was injected into the right hind paw surface (intraplantar) of rats 5 min after ketamine/magnesium combination. Data were recorded as the total time spent in pain related behavior after the injection of formalin or vehicle (0.9% NaCl). In the intermediate phase of the formalin test, methysergide at a dose of 0.2 mg/kg did not have any effect, but at doses of 0.5 and 1 mg/kg it had a pronociceptive effect. Methysergide (0.2, 0.5 and 1 mg/kg) inhibited the antinociceptive effect of ketamine-magnesium sulphate combination. In the intermediate phase, naloxone at a dose of 0.2 mg/kg did not have any effect, but at a dose of 3 mg/kg it produced a pronociceptive effect. Naloxone (0.2 and 3 mg/kg) antagonized the antinociceptive effect of the ketamine (5 mg/kg)-magnesium sulphate (5 mg/kg) combination. The results of the present study suggest that serotonergic and opioidergic systems are involved, at least in part, in the antinociceptive effect of the ketamine-magnesium sulphate combination in the model of inflammatory pain in rats.

Anti-inflammatory activity of a combined gel based on plant components in a model of adjuvant arthritis in rats

Topicality. According to WHO, more than 4 % of the population globe suffer from a variety of joint and spine disorders. In Ukraine, more than 34,500 patients with primary joint diseases are registered annually. Diseases of the musculoskeletal system have a chronic course that requires long-term treatment and puts increased demands on the effectiveness and safety of anti-inflammatory drugs. Therefore, the above justifies the feasibility and relevance of the search for new highly effective and safe domestic drugs.Aim. To make an experimental study of the pharmacological activity of a combined gel for the treatment of inflammatory joint disease if chronic inflammation – adjuvant arthritis in rats.Materials and methods. The subjects of the study were model samples of a combined gel with active pharmaceutical ingredients - white willow bark, common sage leaves dried extract and methyl salicylate. The anti-inflammatory properties of the new gel were studied using a model of adjuvant arthritis in rats (sensitization to the base of the tail by PAF at 0.1 ml/animal, and the introduction on the seventh day of a resolving dose by PAF 0.1 ml/animal under aponeurosis of the right hind limb subplantarly). Diclofenac sodium gel, 5 %, was used as the comparison drug. The test specimens were applied to the affected paw surface daily at a dose of 0.2 ml/animal. Indicators: volume of edema of animal paws (3, 7, 10, 14 and 21 days of experiment); leukocyte and FAN content in the blood and alkaline and acid phosphatase activity and serum CIK content (21 days).Results and discussion. According to the results of studies, against the background of chronic inflammation, the combined gel shows an efficiency comparing to the diclofenac sodium gel, 5 %, conceding to it only in its anti-exudative effect. However, a positive feature of the new gel, in contrast to the drug of comparison, is the ability to maintain the cellular level of non-specific animal immunity, which is significantly impaired under the condition of this pathology.Conclusions. The obtained experimental data substantiate the prospect of further pharmacological studies of the developed combination gel based on the active ingredients of white willow bark, sage medicinal leaves dried extract and methyl salicylate.

The Effects of Acute Neonatal Pain on Expression of Corticotropin-Releasing Hormone and Juvenile Anxiety in a Rodent Model.

Premature infants in the neonatal intensive care unit (NICU) may be subjected to numerous painful procedures without analgesics. One necessary, though acutely painful, procedure is the use of heel lances to monitor blood composition. The current study examined the acute effects of neonatal pain on maternal behavior as well as amygdalar and hypothalamic activation, and the long-term effects of neonatal pain on later-life anxiety-like behavior, using a rodent model. Neonatal manipulations consisted of either painful needle pricks or non-painful tactile stimulation in subjects’ left plantar paw surface which occurred four times daily during the first week of life [postnatal day (PND)1–PND7]. Additionally, maternal behaviors in manipulated litters were compared against undisturbed litters via scoring of videotaped interactions to examine the long-term effects of pain on dam-pup interactions. Select subjects underwent neonatal brain collection (PND6) and fluorescent in situ hybridization (FISH) for corticotropin-releasing hormone (CRH) and the immediate early gene c-fos. Other subjects were raised to juvenile age (PND24 and PND25) and underwent innate anxiety testing utilizing an elevated plus maze (EPM) protocol. FISH indicated that neonatal pain influenced amygdalar CRH and c-fos expression, predominately in males. No significant increase in c-fos or CRH expression was observed in the hypothalamus. Additionally, neonatal pain altered anxiety behaviors independent of sex, with neonatal pain subjects showing the highest frequency of exploratory behavior. Neonatal manipulations did not alter maternal behaviors. Overall, neonatal pain drives CRH expression and produces behavioral changes in anxiety that persist until the juvenile stage.

Evaluation of Antiarthritic Effect of Culinary-Medicinal Oyster Mushroom Pleurotus ostreatus cv. Florida (Agaricomycetes) on Complete Freund's Adjuvant Induced Arthritis in Rats.

The present study evaluates the antiarthritic effect of hydroethanolic extract of Pleurotus ostreatus cv. Florida, which was tested against adjuvant induced arthritis in rat models. Arthritis was induced by administration of complete Freund's adjuvant into the subplantar surface of left paw of rats. The extract was given orally at doses 200 mg/ kg and 400 mg/kg and piroxicam was administered intraperitonially (4 mg/kg). In vitro testing on parameters including antiproteinestrase, albumin denaturation and heat induce hemolysis was also carried out. There was significant decrease (p < 0.001) in proteinase activity and membrane stabilization in vivo studies on cv. Florida extract treated rats showed a significant (p < 0.001) decrease in paw volume, joint diameter, and spontaneous change in body weight recorded for 21 days. The treatment also resulted in an increase in rats' gripping activity compared with arthritic control rats. X-ray examinations showed a decrease in joint swelling. Histopathological examination of the extract treated group showed a significant decrease in joint space. There was also an increase in antibody levels. The antioxidant parameters showed a significant (p < 0.001) increase in superoxide dismutase and catalase enzymatic activities. Thus P. ostreatus cv. Florida extract demonstrates a potent antioxidant activity in a rat model. It is concluded that the P. ostreatus cv. Florida extract contains medicinally important constituents that show antiarthritic activity in rats.

Distributive differences of P2Xs between the forelimb and hind limb of adjuvant arthritis rats and intervention by Notopterygh rhizoma et radix

Context: Notopterygium incisum Ting ex H. T. Chang (Umbelliferae) (NI) specializes in treatment of upper limb rheumatoid arthritis (RA), but the exact mechanism is unclear. P2Xs are useful targets for inflammatory pain therapy. It led us to hypothesize that NI may preferentially act on particular P2Xs and these receptors may be unevenly distributed in the upper/lower limb.Objective: To investigate P2Xs distribution in the upper/lower limb and NI's targets in upper limb RA.Materials and methods: The SD rats were randomized into 11 groups of 10 animals each. Eight experimental groups were established by the injection of 0.1 mL FCA into the plantar surface of rat paw. Three control groups suffered the same volume of saline. The articular cavities were then taken on the seventh day to detect P2Xs expression. NI (3 g/kg) and prednisone (10 mg/kg) were respectively given by oral gavage once daily for 14 d. The swelling degree and P2Xs were evaluated individually.Results: In normal rats, the expressions of P2X3 and P2X6 in forelimb were markedly higher than that of in hind limb (P < 0.05). After induced by FCA, P2X1, P2X3, P2X4, P2X5 and P2X7 were increased significantly (P < 0.01). The biggest difference was P2X3. In NI treatment rats, swelling degree of the 7th/14th day in forelimb was 68.24%/38.89%, whereas that of in hind limb was 88.72%/79.92%. P2X3 mRNA and protein expression was significantly reduced as contrasted with the control group (P < 0.05).Conclusions: P2X3 receptor was predominantly expressed in the forelimb RA rat. NI relieved the FCA-induced RA by inhibiting upper limb’s P2X3 receptor.

Hesperidin, a plant flavonoid accelerated the cutaneous wound healing in streptozotocin-induced diabetic rats: Role of TGF-ß/Smads and Ang-1/Tie-2 signaling pathways.

Background: Delayed wound healing is a diverse, multifactorial, complex and inter-related complication of diabetes resulting in significant clinical morbidity. Hesperidin possesses potent antidiabetic and wound healing activity.Aim: To evaluate the potential of hesperidin against experimentally induced diabetes foot ulcers.Methods: Diabetes was induced experimentally by streptozotocin (STZ, 55 mg/kg, i.p.) in Sprague Dawley rats (180-220 g) and wounds were created on the dorsal surface of the hind paw of rats. Hesperidin (25, 50 and 100 mg/kg, p.o.) was administered for 21 days after wound stabilization. Various biochemical, molecular and histopathological parameters were evaluated in wound tissue.Results: STZ-induced decrease in body weight and increase in blood glucose, food, and water intake was significantly (p < 0.05) inhibited by hesperidin (50 and 100 mg/kg) treatment. It showed a significant increase (p < 0.05) in percent wound closure and serum insulin level. The STZ-induced decrease in SOD and GSH level, as well as elevated MDA and NO levels, were significantly (p < 0.05) attenuated by hesperidin (50 and 100 mg/kg) treatment. Intraperitoneal administration of STZ caused significant down-regulation in VEGF-c, Ang-1, Tie-2, TGF-β and Smad 2/3 mRNA expression in wound tissues whereas hesperidin (50 and 100 mg/kg) treatment showed significant up-regulation in these mRNA expressions. STZ-induced alteration in would architecture was also attenuated by hesperidin (50 and 100 mg/kg) treatment. Conclusion: Together, treatment with hesperidin accelerate angiogenesis and vasculogenesis via up-regulation of VEGF-c, Ang-1/Tie-2, TGF-β and Smad-2/3 mRNA expression to enhance wound healing in chronic diabetic foot ulcers.

Anti-inflammatory effect of an adhesive resin containing indomethacin-loaded nanocapsules

ObjectiveTo analyze the anti-inflammatory and analgesic effects of an adhesive resin containing indomethacin-loaded nanocapsules in rat model. DesignAdhesive resin disks with or without indomethacin-loaded nanocapsules were subcutaneously implanted into right hind paw of rats. A week after surgical procedure, 2% formalin solution was intradermally injected into plantar surface of paw. Nociceptive and inflammatory responses were evaluated by formalin test. Paw edema by pletismometer and mechanical hyperalgesia by von Frey test were performed on day 2, day 4, day 6, day 8, day 10 and day 12 after surgery. IL-6, IL-10, and lactate dehydrogenase (LDH) serum levels were determined by ELISA-sandwich test. ResultsGroup containing indomethacin-loaded nanocapsules (NC) presented lower edema in the right hind paw at 24h after formalin injection than those of the control group (CT) (P<0.01). NC group showed decrease in the nociceptive response in phase I (neurogenic pain) compared to CT group (NC − 66.86±22.83s X CT − 130.17±35.83s, P<0.001). NC group presented supporting higher intensity of stimulus on days 8 and 12 (24h and 72h after formalin injection) (P<0.01 and P<0.02 respectively). The IL-6 serum level was also significantly higher in the NC group than CT group (p<0.001). ConclusionsThese results indicate that an adhesive resin containing indomethacin-loaded nanocapsules has anti-inflammatory and nociceptive activities in a chemical model of acute inflammation. The present investigation confirms an adhesive resin with drug-loaded nanocapsules may be useful for improving therapeutic effect for adhesives to be used in deep cavities.

Trendelenburg-Like Gait, Instability and Altered Step Patterns in a Mouse Model for Limb Girdle Muscular Dystrophy 2i.

Limb-girdle muscular dystrophy type 2i (LGMD2i) affects thousands of lives with shortened life expectancy mainly due to cardiac and respiratory problems and difficulty with ambulation significantly compromising quality of life. Limited studies have noted impaired gait in patients and animal models of different muscular dystrophies, but not in animal models of LGMD2i. Our goal, therefore, was to quantify gait metrics in the fukutin-related protein P448L mutant (P448L) mouse, a recently developed model for LGMD2i. The Noldus CatWalk XT motion capture system was used to identify multiple gait impairments. An average galloping body speed of 35 cm/s for both P448L and C57BL/6 wild-type mice was maintained to ensure differences in gait were due only to strain physiology. Compared to wild-type mice, P448L mice reach maximum contact 10% faster and have 40% more paw surface area during stance. Additionally, force intensity at the time of maximum paw contact is roughly 2-fold higher in P448L mice. Paw swing time is reduced in P448L mice without changes in stride length as a faster swing speed compensates. Gait instability in P448L mice is indicated by 50% higher instances of 3 and 4 paw stance support and conversely, 2-fold fewer instances of single paw stance support and no instance of zero paw support. This leads to lower variation of normal step patterns used and a higher use of uncommon step patterns. Similar anomalies have also been noted in muscular dystrophy patients due to weakness in the hip abductor muscles, producing a Trendelenburg gait characterized by “waddling” and more pronounced shifts to the stance leg. Thus, gait of P448L mice replicates anomalies commonly seen in LGMD2i patients, which is not only potentially valuable for assessing drug efficacy in restoring movement biomechanics, but also for better understanding them.

Effect of Shatpuspadya Churna - a classical Ayurvedic formulation on formaldehyde and Complete Freund’s adjuvant (CFA) induced arthritis in rats

Shatpuspadya Churna has been traditionally used in the Ayurvedic system of medicine of India to treat rheumatoid arthritis (RA). We evaluated anti-arthritic activity of ethanol extract of Shatpuspadya Churna (SCE). Arthritis was induced in male rats of wistar strain by administration of formaldehyde (2%v/v) or Complete Freund’s Adjuvant (CFA) into sub-plantar surface of the left hind paw. SCE (135,270 and 540 mg/kg) was given by oral route. Joint swelling was measured in formaldehyde induced arthritis. In case of CFA induced arthritis, paw volume, body weight, haematological and histological parameters were measured. In CFA induced arthritic rats, significant (p < 001) reductions in haemoglobin (28.4 %), packed cell volume (30.5 %), HDL(45 %), and significant(p < 001) increases in WBC (28.0 %), platelet count (40.7 %), ESR (52.5 %), rheumatoid factor (274 %), total cholesterol(49.5 %), triglycerides(34.8 %), LDL (106.8 %) and VLDL (35 %) were observed. Treatment with SCE significantly (p < 0.001) reversed these changes in a dose dependent manner. Treatment with 540 mg/kg SCE significantly (p < 0.001) reversed/prevented the decline in Hb, PCV and HDL to only 7.9 %, 19.9 % and 9.8 % respectively. Similarly, the rise in values of various blood parameters was comparatively less in SCE treated arthritic group (540 mg/kg) than that observed in untreated arthritic rats. We noted only a marginal rise in the values of WBC (18.2 %), platelet count (26.5 %), ESR (40.15 %), RF (60.6 %), TC (25.4 %), TG (9.3 %), LDL (49.2 %) and VLDL (9.2 %). Histopathological studies of the ankles revealed significant improvements. The study clearly establishes the usefulness of Shatpuspadya Churna in the treatment of arthritis, lipid imbalance and anaemia associated with it.

Effects of repetitive noxious stimuli during neonatal period on pain sensitivity during adulthood in rats

Objective To evaluate the effects of repetitive noxious stimuli during the neonatal period on the pain sensitivity during adulthood in rats. Methods Twenty pathogen-free male neonatal Sprague-Dawley rats, weighing 6.2-6.8 g, were randomly divided into 2 groups (n=10 each) using a random number table: control group (group C) and repetitive noxious stimuli group (group RNS). In RNS group, neonatal rats sequentially received needle pricks into the dorsal surface of 4 paws at 6 h intervals with a 28 G needle per day during the first postnatal week. In group C, the animals received non-painful tactile stimuli with cotton tip rub. At the age of 10 weeks, complete Freund's adjuvant was injected into the plantar surface of the right hind paw to induce inflammatory pain. Before injection, and at 24 h and 7 days after injection (T0-2), the mechanical and thermal thresholds were measured, and alcohol preference test was performed for assessment of the behavior at T2. Results The mechanical threshold of the right paws was significantly lower at T1, 2 than that of the left paws in the two groups. Compared to group C, the mechanical threshold of the left and right paws at T0-2 and thermal threshold of the right paws at T1 were significantly decreased, and alcohol intake was increased in group RNS. Conclusion Repetitive noxious stimuli during the neonatal period can lead to increase in the pain sensitivity during adulthood in rats. Key words: Infant, newborn; Hyperalgesia; Pain; Adult

Weight bearing evaluation in inflammatory, neuropathic and cancer chronic pain in freely moving rats

Preclinical pain assessment remains a key step for the development of new and potent painkillers. Significant progress in pain evaluation has been achieved with the development of non-reflexive tools. Seeking efficient and clinically relevant devices for pain-related quality of life assessment, we evaluated a new Dynamic Weight Bearing (DWB) device based on pressure captors in three different preclinical chronic pain models. Inflammatory (CFA), neuropathic (CCI) and bone cancer pain (femoral tumor) models were evaluated in Sprague Dawley rats for mechanical allodynia using dynamic von Frey for pain-related behaviors and DWB for discomfort. We observed similar impairment patterns in all of the models for both von Frey (allodynia) and DWB (weight balance) during the complete observation period, starting at day 3 in CCI- and CFA-affected limbs and at day 14 in bone cancer-afflicted rats, indicating that the DWB could be a useful tool for supporting pain assessment. Interestingly, we demonstrated that the main compensation, when animals experienced pain, was seen in the forepaws, ranging from 46% to 69% of increased load compared to normal. Other pain-related coping behaviors were also measured, such as the time spent on each paw and the contact surface. Our results revealed that CFA, CCI and cancerous rats decreased the use of their ipsilateral hind paws by 30% and showed a 50% reduction in paw surface pressed against the floor. In conclusion, this new device improves methods for preclinical evaluation of discomfort and quality of life proxies and could be helpful in screening putative analgesics.