Photobiomodulation exerts anti-inflammatory effects on the vascular and cellular phases of experimental inflammatory models.

Photobiomodulation therapy (PBMT) is a non-thermal therapeutic procedure widely used in clinical practice. It is considered an effective modality of treatment for the control of various inflammatory conditions with fewer adverse effects as compared to conventional therapy. However, despite the clinical effects, the mechanisms of action and dosimetric parameters of PBMT are not fully understood. This study was performed to describe the effects of two different doses of PBMT on experimental models of inflammation. Male Swiss mice were administered with 0.9% of saline or phlogistic agents (carrageenan, dextran, serotonin, histamine, or bradykinin) by intra-plantar injection and were treated with PBMT at a dose of 1 or 5 J/cm2; right after, the variation of the paw volume was made, and histopathological analysis and myeloperoxidase assay of the carrageenan-induced edematous paw tissues were performed. The action of PBMT on carrageenan-induced vascular permeability was further evaluated. Our results showed that PBMT (1 J/cm2) led to an improvement in paw edema induced by the phlogistic agents and further reduced the histological scores. Inhibition of neutrophil migration was observed following the administration of 1 and 5 J/cm2 of PBMT. However, only 1 J/cm2 of PBMT showed beneficial effects on carrageenan-induced edema. Laser at a dose of 1 J/cm2 showed cellular and vascular effects since it was able to reverse all the inflammatory parameters, and laser at a dose of 5 J/cm2 probably has only cellular effects in the presence of acute inflammation.

L-Glutamine and Physical Exercise Prevent Intestinal Inflammation and Oxidative Stress Without Improving Gastric Dysmotility in Rats with Ulcerative Colitis.

The aim of this study was to evaluate the effects of glutamine supplementation or exercise on gastric emptying and intestinal inflammation in rats with ulcerative colitis (UC). Strength exercise consisted of jump training 4 × 10 repetitions/5 days a week/8 weeks with progressive overload. Endurance exercise consisted of swimming without overload for a period of 1 h a day/5 days a week/8 weeks. Another group (sedentary) of animals was supplemented with L-glutamine (1 g/kg of body weight) orally for 8 weeks before induction of UC. Colitis was induced by intra-colonic administration of 1 mL of 4% acetic acid. We assessed gastric emptying, macroscopic and microscopic scoring, oxidative stress markers, and IL-1ß, IL-6, and (TNF-α) levels. The UC significantly increased (p < 0.05) the gastric emptying compared with the saline control group. We observed a significantly decrease (p < 0.05) in body weight gain in UC rats compared with the control groups. Both exercise interventions and L-glutamine supplementation significantly prevented (p < 0.05) weight loss compared with the UC group. Strength and endurance exercises significantly prevented (p < 0.05) the increase of microscopic scores and oxidative stress (p < 0.05). L-glutamine supplementation in UC rats prevented hemorrhagic damage and improved oxidative stress markers (p < 0.05). Strength and endurance exercises and glutamine decreased the concentrations of inflammatory cytokines IL-1ß, IL-6, and TNF-α compared with the UC group (p < 0.05). Strength and endurance exercises and L-glutamine supplementation prevented intestinal inflammation and improved cytokines and oxidative stress levels without altering gastric dysmotility in rats with UC.

Sulfated polysaccharide from Gracilaria caudata reduces hypernociception and inflammatory response during arthritis in rodents.

Polysaccharide from marine alga Gracilaria caudata has potential health benefits, such as anti-inflammatory, gastroprotective and antidiarrheal effects. Here, we investigated the effect of a sulfated polysaccharide from G. caudata (SP-GC) on hypernociception and inflammatory response in arthritis models. The animals received SP-GC (3, 10 or 30 mg/kg) 1 h before tibio-tarsal injection of zymosan. Hypernociception, histopathology, edema, vascular permeability, myeloperoxidase (MPO) activity, cell influx, interleukin (IL)-1ß and nitric oxide (NO) levels were evaluated in acute phase. In another protocol, animals received SP-GC (30 mg/kg) 2 h post-complete Freund's adjuvant (CFA). Hypernociception, edema and arthritis index were determined in acute, sub-chronic and chronic phases. Rota-rod test measured the motor performance. SP-GC significantly reduced, in a dose-dependent manner, the zymosan-induced hypernociception with maximal effect at 30 mg/kg. The microscopic inflammation, joint edema, MPO activity, cell influx, IL-1ß and NO levels were also reduced by SP-GC. In the CFA-induced arthritis, SP-GC inhibits the hypernociception, edema and arthritic index in acute, sub-chronic and chronic phases. SP-GC did not alter the motor performance of animals. In conclusion, SP-GC exerts protective effect in models of arthritis due to the modulation of cell influx, IL-1ß and NO levels, culminating in the reduction of hypernociception and edema.

Antidiarrheal activity of farnesol in rodents: Pharmacological actions and molecular docking.

Diarrhea is a condition in which the individual has about three or more daily bowel movements, followed by changes in stool consistency. It is currently considered as one of the worst public health problems due to the number of cases and deaths involved and difficulty of treatment. Thus, the use of natural products is an alternative for new treatments. Among these possibilities is Farnesol (C15H26O), a sesquiterpene found in different herbal species that has known biological activities. The objective of this study was to evaluate the antidiarrheal activity of Farnesol (FOH). Initially, FOH activity was evaluated in models of diarrhea and enteropooling induced by castor oil and PGE2. To evaluate motility, the opioid and cholinergic pathways were studied. In addition, the effect of FOH was investigated in the secretion model in intestinal loops treated with cholera toxin. FOH was evaluated for the ability to absorb fluids in intestinal loops and interact with GM1 receptors using the ELISA method and molecular docking. The dose of 50 mg/kg of FOH showed the best results in all antidiarrheal activity tests with castor oil and PGE2, being considered as the standard dose, reducing motility by anticholinergic mechanisms. There was a reduction in fluid secretion when FOH interacted directly with GM1 receptors; cholera toxin and molecular docking showed strong interaction between farnesol and these targets. In view of the results presented, the antidiarrheal activity occurs through anticholinergic, anti-inflammatory and anti-secretory action, making farnesol a potential candidate for the development of a new drug to treat diarrheal diseases.

Cardiovascular Effect of Diosgenin in Ovariectomized Rats.

Diosgenin is a phytoestrogen and a constituent of Dioscorea. It has several biological effects, and some of them are anti-inflammatory, antidiabetic, antitumor, and vasodilatory. The present study investigated both the vasorelaxing and antioxidant mechanisms of diosgenin in isolated rat aortic rings. Female rats weighing 200-220 g were subjected to sham or OVX operations at 8 weeks of age. Ovariectomy was performed for menopause induction after anesthesia. Diosgenin (10-9 M-3 × 10-4 M) produced a concentration-dependent relaxation in aortic rings precontracted with phenylephrine (1 µM), exhibiting Emax value of 55.34% ± 7.7% (in endothelium-intact rings) and Emax value of 30.30% ± 5.7% (in endothelium-denuded rings). In the endothelium-intact rings, the vasorelaxing effect of diosgenin was reduced by NG-nitro-l-arginine methyl ester (L-NAME) (100 µM), atropine (1 µM), indomethacin (10 µM), 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ) (10 µM), 4-aminopyridine (1 mM), tetraethylammonium (3 mM), glibenclamide (10 µM), apamin (10 µM), and Tiron (1 µM). Diosgenin (10-5 M) inhibited the contractions induced by cumulative addition of phenylephrine (10-9-10-5 M). The 28-days treatment with diosgenin (50 mg/kg, v.o.) did not imply changes in the myeloperoxidase parameter, but increased significantly, levels of glutathione, superoxide dismutase, and nitric oxide, as well as reduced the concentration of malondialdehyde related to lipid peroxidation. Our results suggest that diosgenin induced relaxation in aortic rings via an endothelium-dependent pathway, which involves the EDRF, the opening of potassium channels and antioxidant action.

Inhibition of neutrophil migration and reduction of oxidative stress by ethyl p-coumarate in acute and chronic inflammatory models.

BACKGROUND: It is well known that medicinal plants and their products are relevant candidates for the treatment of inflammatory conditions. Ethyl p-coumarate is a phenylpropanoid that has similar structure to others anti-inflammatory and antioxidant substances. However, these activities have never been tested. PURPOSE: The aim of this study was to investigate the effect of ethyl p-coumarate on inflammatory and oxidative stress parameters. STUDY DESIGN: This is an experimental study to evaluate the anti-inflammatory and antioxidant activities of ethyl p-coumarate in acute and chronic models of inflammation. METHODS: The anti-inflammatory effect of ethyl p-coumarate was evaluated in Swiss mice by carrageenan-induced paw edema model (1%, 50 µl), followed by histological analysis, and edema induced by compound 48/80 (12 µg/paw), histamine (100  µg/paw), serotonin (100 µg/paw) and prostaglandin E2 (3 nmol/paw) in comparison to indomethacin treatment (10 mg/kg, p.o.). In addition, peritonitis was induced by carrageenan (500 µg/cavity) to neutrophil and total leukocytes counting, myeloperoxidase (MPO), interleukin 6 (IL-6) and 8 (IL-8), nitrite (NO2-), glutathione (GSH) and malondialdehyde (MDA) measurements. The arthritis model was induced with Freund's complete adjuvant (id. 0.1 ml) in female Wistar rats, with measurement of joint diameter and X-ray. Changes in gastric tissue of Swiss mice were analyzed in comparison to indomethacin (20  mg/kg, p.o.). RESULTS: After treatment with ethyl p-coumarate, the animals had no apparent toxic effects, and significantly inhibited paw edema induced by edematogenic agents, neutrophil (p < 0.001) and total leukocyte (p < 0.001) migration, MPO (p < 0.01), IL-6 (p < 0.05) and IL-8 (p < 0.5), MDA (p < 0.5), GSH (p < 0.5), NO2- (p < 0.001), joint thickness and bones changes. Furthermore, were not observed significant formation of gastric lesions. CONCLUSION: Taken together, these results suggest that ethyl p-coumarate exhibits anti-inflammatory activity through the inhibition of inflammatory mediators and leukocyte migration without causing gastric lesions.

Antidiarrheal activity of α-terpineol in mice.

Diarrhea is one of the leading causes of infant death in the world accounting for high child mortality rate. It is also present in different pathophysiologies related to several etiological agents. The aim of this study is to investigate the antidiarrheal effect of α -Terpineol (α-TPN) in different diarrhea models in rodents. The antidiarrheal effect of α-TPN in the treatment of acute diarrhea and enteropooling induced by castor oil or PGE2 in Swiss mice pretreated orally with saline (NaCl 0.9%), Loperamide (5 mg/kg) and α-TPN (6.25, 12.5, 25 and 50 mg/kg) was analyzed. Additionally, parameters of severity, total weight of faeces and post-treatment for 4 h were evaluated. Modulation of the opioid and cholinergic pathways was performed and intestinal transit model using activated charcoal as marker was also used. The effect of α-TPN on secretory diarrhea was investigated using the model of fluid secretion in intestinal loops isolated from cholera toxin-treated mice. α-TPN showed antidiarrheal effect (*p < 0.05), reducing the total stool amount (*55%, *48%, *44%, *24%) and diarrheal (*47%, *66%; *56%, 10%) respectively for the doses tested. All doses investigated in the enteropooling test presented significant changes (*46%, *78%, *66%, *41% respectively) in relation to the control. α-TPN through the muscarinic pathway reduced the gastrointestinal transit (*31%), besides inhibiting PGE2-induced diarrhea (*39%). α-TPN also reduced fluid formation and loss of Cl- ions, by interacting directly with GM1 receptors and cholera toxin, thus increasing the uptake of intestinal fluids. The results suggest an anti-diarrheal activity of α-TPN due to its anticholinergic action, ability to block PGE2 and GM1 receptors and interaction with cholera toxin in secretory diarrhea, making it a promising candidate drug for the treatment of diarrheal diseases.

Photobiomodulation reduces neutrophil migration and oxidative stress in mice with carrageenan-induced peritonitis.

The purpose of the study is to investigate the effects of two doses of photobiomodulation (PBM) on inflammatory parameters including cell migration and oxidative stress in carrageenan-induced peritonitis models. Twenty-eight mice were divided into four groups: saline; untreated carrageenan (Cg; inflammation induced); and PMB treatment groups L1 and L5 (inflammation induced with carrageenan followed by laser irradiation at 1 and 5 J/cm2, respectively). After 30 min of inducing inflammation, laser irradiation was administered every hour, for 4 h. Peritoneal fluid was collected for analyses. The total leukocyte number in the peritoneal fluid in L1 (4.33 ± 2.34) and L5 (4.95 ± 2.86) after PBM was lower than that in Cg (10.93 ± 5.15 cells/ml). The average differential count of neutrophils in the Cg was 9.46 ± 4.31 cells/ml, which was higher than that in L1 (3.7 ± 2.08) and L5 (4.94 ± 2.57). Myeloperoxidase activity was also lower in L1 (1.89 ± 0.43) and L5 (4.84 ± 2.62) than in Cg (22.92 ± 4.52 UMPO/ml). Malondialdehyde content was lower in L1 (137.5 ± 12.33) and L5 (169.6 ± 22.77) than in Cg (345.7 ± 65.67 nmol/ml). Glutathione peroxidase concentration was significantly higher in L1 (155.2 ± 12.43) and L5 (145.9 ± 9.585) than in Cg (79.75 ± 9.567 µ/ml). Nitrite concentration was lower in L1 (0.3317 µM ± 0.0669) and L5 (0.2429 µM ± 0.0232) than in Cg (0.8380 µM ± 0.01615). Laser irradiation at 1 and 5 J/cm2 reversed the inflammation (as indicated by neutrophil infiltration and oxidative stress).

Antidiarrheal activity of a novel sulfated polysaccharide from the red seaweed Gracilaria cervicornis.

ETHNOPHARMACOLOGICAL RELEVANCE: The use of marine seaweeds as a source of natural compounds with medicinal purposes is increasing in Western countries in the last decades, becoming an important alternative in the traditional medicine of many developing countries, where diarrhea still remains a severe public health problem, with high rates of mortality and morbidity. Sulfated polysaccharides (PLS) extracted from red seaweeds can exhibit therapeutic effects for the treatment of gastrointestinal disorders. Thus, the pharmacological properties of the PLS from Gracilaria cervicornis, an endemic seaweed found in the Brazilian northeast coast, was evaluated as an alternative natural medication for diarrhea. AIM OF THE STUDY: This study aimed to evaluate the antidiarrheal activity of sulfated polysaccharides (PLS) extracted from the red seaweed G. cervicornis in Swiss mice pre-treated with castor oil or cholera toxin. MATERIALS AND METHODS: The seaweed Gracilaria cervicornis was collected at Flecheiras beach (city of Trairí, State of Ceará, Brazil) and the PLS was obtained through enzymatic extraction and administered in mice (25-30 g) before diarrhea induction with castor oil or cholera toxin. For the evaluation of the total number of fecal output and diarrheal feces, the animals were placed in cages lined with adsorbent material. The evaluation of intestinal fluid accumulation (enteropooling) on castor oil-induced diarrhea in mice occurred by dissecting the small intestine and measuring its volume. The determination of Na+/K+-ATPase activity was measured in the small intestine supernatants by colorimetry, using commercial biochemistry kits. The gastrointestinal motility was evaluated utilizing an activated charcoal as a food tracer. The intestinal fluid secretion and chloride ion concentration were evaluated in intestinal closed loops in mice with cholera toxin-induced secretory diarrhea. The binding ability of PLS with GM1 and/or cholera toxin was evaluated by an Enzyme-Linked Immunosorbent Assay (ELISA). RESULTS: The G. cervicornis PLS showed antidiarrheal effects in both acute and secretory diarrhea, reducing the total number of fecal output, diarrheic stools, intestinal fluid accumulation, and increasing small intestine Na+/K+-ATPase activity on castor oil-induced diarrhea. However, the PLS did not affect gastrointestinal motility, indicating that this compound has a different action mechanism than loperamide. In secretory diarrhea, the PLS decreased intestinal fluid secretion and small intestine chloride excretion, binding with GM1 and/or cholera toxin and blocking their attachment to the enterocyte cell surface. CONCLUSIONS: In conclusion, PLS has a significant antidiarrheal effect in acute and secretory diarrhea. Further investigation is needed towards its use as a natural medicine to treat diarrhea.

Antidiarrheal effects of water-soluble proteins from Plumeria pudica latex in mice.

The water-soluble protein fraction obtained from Plumeria pudica (LPPp) latex has previously been demonstrated to have anti-inflammatory and antinociceptive effects. In the present study, LPPp was tested for activity against diarrhea induced by castor oil, prostaglandin E2 (PGE2) or cholera toxin. Different doses of LPPp (10, 20 or 40mg/kg) significantly inhibited the percentage of diarrheal stools (31.18%, 42.97% and 59.70%, respectively) induced by castor oil. This event was followed by significant reduction of both intestinal fluid accumulation (31.42%; LPPp 40mg/kg) and intestinal transit (68.4%; LPPp 40mg/kg). The pretreatment of animals with LPPp (40mg/kg) prevented glutathione and malondialdehyde alterations induced by castor oil. The effects of LPPp against diarrhea induced by castor oil were lost when the fraction was submitted to protein denaturing treatment with heat. LPPp (40mg/kg) also inhibited the average volume of intestinal fluid induced by PGE2 (inhibition of 46.0%). Furthermore, LPPp (40mg/kg) prevented intestinal fluid secretion accumulation (37.7%) and chloride ion concentration (50.2%) induced by cholera toxin. In parallel, colorimetric assays demonstrated that proteinases, chitinases and proteinase inhibitors were found in LPPp. Our data suggest that the antidiarrheal effect of LPPp is due to its protein content and is probably associated with its anti-inflammatory properties.

Anticonvulsant effects of acute treatment with cyane-carvone at repeated oral doses in epilepsy models.

Epilepsy affects about 40 million people worldwide. Many drugs block seizures, but have little effect in preventing or curing this disease. So the search for new drugs for epilepsy treatment using animal models prior to testing in humans is important. Increasingly pharmaceutical industries invest in the Re​search & Drug Development area to seek safe and effective new therapeutic alternatives to the currently available epilepsy treatment. In this perspective, natural compounds have been investigated in epilepsy models, particularly the monoterpenes obtained from medicinal plants. In our study we investigated the effects of cyane-carvone (CC), a synthetic substance prepared from natural a monoterpene, carvone, against pilocarpine- (PILO), pentylenetetrazole- (PTZ) and picrotoxine (PTX)-induced seizures in mice after acute treatment with repeated oral doses (CC 25, 50 and 75 mg/kg) for 14 days. CC in all doses tested showed increase in latency to first seizure, decrease in percentages of seizuring animals as well as reduction percentages of dead animals (p<0.05) in PILO, PTZ and PTX groups when compared with vehicle. However, these effects were not reversed by flumazenil, benzodiazepine (BZD) antagonist used to investigate the CC action mechanism. Our results suggest that acute treatment with CC at the doses tested can exert anticonvulsant effects in PILO, PTZ and PTX epilepsy models. In addition, our data suggest that CC could act in an allosteric site of GABAA, which would be different from the site in which BDZ acts, since flumazenil was not able to reverse any of CC effects on the modulation of seizure parameters related with epilepsy models investigated. New studies should be conducted to investigate CC effects in other neurotransmitter systems. Nevertheless, our study reinforces the hypothesis that CC could be used, after further research, as a new pharmaceutical formulation and a promising alternative for epilepsy treatment, since it showed anticonvulsant effects.

Anti-inflammatory effect of a sulphated polysaccharide fraction extracted from the red algae Hypnea musciformis via the suppression of neutrophil migration by the nitric oxide signalling pathway.

OBJECTIVES: The aim of this study was to evaluate the anti-inflammatory effect of a sulphated polysaccharide fraction (PLS) extracted from the alga Hypnea musciformis and investigate the possible involvement of the nitric oxide (NO) pathway in this effect. METHODS: The anti-inflammatory activity of PLS was evaluated using inflammatory agents (carrageenan and dextran) to induce paw oedema and peritonitis in Swiss mice. Samples of paw tissue and peritoneal fluid were removed to determine myeloperoxidase (MPO) activity, NO3 /NO2 levels, and interleukin-1ß (IL-1ß) level. The involvement of NO in the modulation of neutrophil migration in carrageenan-induced paw oedema or peritonitis was also investigated. KEY FINDINGS: Compared with vehicle-treated mice, mice pretreated with PLS (10 mg/kg) inhibited carrageenan-induced and dextran-induced oedema; it also inhibited total and differential peritoneal leucocyte counts in a model of peritonitis. These PLS effects were reversed by l-arginine treatment and recovered with the administration of a NO synthase blocker (aminoguanidine). Furthermore, PLS reduced the MPO activity, decreased IL-1ß levels, and increased NO3 /NO2 levels in the peritoneal cavity. CONCLUSIONS: PLS reduced the inflammatory response by modulating neutrophil migration, which appeared to be dependent on the NO pathway.

Antiinflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction extracted from the marine red algae Gracilaria caudata.

Many algal species contain relatively high concentrations of polysaccharide substances, a number of which have been shown to have anti-inflammatory and/or immunomodulatory activity. In this study, we evaluated the anti-inflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction (PLS) extracted from the algae Gracilaria caudata. The antiinflammatory activity of PLS was evaluated using several inflammatory agents (carrageenan, dextran, bradykinin, and histamine) to induce paw edema and peritonitis in Swiss mice. Samples of the paw tissue and peritoneal fluid were removed to determine myeloperoxidase (MPO) activity or TNF-α and IL-1ß levels, respectively. Mechanical hypernociception was induced by subcutaneous injection of carrageenan into the plantar surface of the paw. Pretreatment of mice by intraperitoneal administration of PLS (2.5, 5, and 10 mg/kg) significantly and dose-dependently reduced carrageenan-induced paw edema (p < 0.05) compared to vehicle-treated mice. Similarly, PLS 10 mg/kg effectively inhibited edema induced by dextran and histamine; however, edema induced by bradykinin was unaffected by PLS. PLS 10 mg/kg inhibited total and differential peritoneal leukocyte counts following carrageenan-induced peritonitis. Furthermore, PLS reduced carrageenan-increased MPO activity in paws and reduced cytokine levels in the peritoneal cavity. Finally PLS pretreatment also reduced hypernociception 3-4 h after carrageenan. We conclude that PLS reduces the inflammatory response and hypernociception in mice by reducing neutrophil migration and cytokines concentration.

Hydrogen peroxide pre-treatment induces salt-stress acclimation in maize plants.

The effect of exogenously applied H2O2 on salt stress acclimation was studied with regard to plant growth, lipid peroxidation, and activity of antioxidative enzymes in leaves and roots of a salt-sensitive maize genotype. Pre-treatment by addition of 1 microM H2O2 to the hydroponic solution for 2 days induced an increase in salt tolerance during subsequent exposure to salt stress. This was evidenced by plant growth, lipid peroxidation and antioxidative enzymes measurements. In both leaves and roots the variations in lipid peroxidation and antioxidative enzymes (superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase, and catalase) activities of both acclimated and unacclimated plants, suggest that differences in the antioxidative enzyme activities may, at least in part, explain the increased tolerance of acclimated plants to salt stress, and that H2O2 metabolism is involved as signal in the processes of maize salt acclimation.