Correction to: α-Phellandrene attenuates tissular damage, oxidative stress, and TNF-α levels on acute model ifosfamide-induced hemorrhagic cystitis in mice

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α-Phellandrene attenuates tissular damage, oxidative stress, and TNF-α levels on acute model ifosfamide-induced hemorrhagic cystitis in mice

Hemorrhagic cystitis (HC) is the major dose-limiting adverse effect of the clinical use ifosfamide (IFOS). The incidence of this side effect can be as high as 75%. Mesna has been used to reduce the risk of HC, although 5% of patients who get IFOS treatment may still suffer from HC. In previous studies, our group demonstrated that α-phellandrene (α-PHE) possesses anti-inflammatory activity, which opens the door for its study in the attenuation of HC. The objective of this study was to investigate the potential uroprotective effect of the α-PHE in the mouse model of IFOS-induced HC. In order to analyze the reduction of the urothelial damage, the bladder wet weight, hemoglobin content, and the Evans blue dye extravasation from the bladder matrix were evaluated. To investigate the involvement of neutrophil migration and lipid peroxidation and involvement of enzymatic and endogenous non-enzymatic antioxidants, the tissue markers myeloperoxidase (MPO), malondialdehyde, nitrite/nitrate (NOx), superoxide dismutase (SOD), and reduced glutathione (GSH) were evaluated. TNF-α and IL-1β were measured by ELISA immunoassay technique. The results show that pretreatment with α-PHE significantly reduced urothelial damage that was accompanied by a decrease in the activity of MPO, MDA, and NOx levels and prevention of the depletion of SOD and GSH in bladder tissues. In the assessment of cytokines, α-PHE was able to significantly reduce TNF-α level. However, it does not affect the activities of IL-1β. These data confirm that α-PHE exerts potent anti-inflammatory properties and demonstrates that α-PHE represents a promising therapeutic option for this pathological condition.

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.

The hydrogen sulfide donor, Lawesson's reagent, prevents alendronate-induced gastric damage in rats

Our objective was to investigate the protective effect of Lawesson's reagent, an H2S donor, against alendronate (ALD)-induced gastric damage in rats. Rats were pretreated with saline or Lawesson's reagent (3, 9, or 27 µmol/kg, po) once daily for 4 days. After 30 min, gastric damage was induced by ALD (30 mg/kg) administration by gavage. On the last day of treatment, the animals were killed 4 h after ALD administration. Gastric lesions were measured using a computer planimetry program, and gastric corpus pieces were assayed for malondialdehyde (MDA), glutathione (GSH), proinflammatory cytokines [tumor necrosis factor (TNF)-α and interleukin (IL)-1β], and myeloperoxidase (MPO). Other groups were pretreated with glibenclamide (5 mg/kg, ip) or with glibenclamide (5 mg/kg, ip)+diazoxide (3 mg/kg, ip). After 1 h, 27 µmol/kg Lawesson's reagent was administered. After 30 min, 30 mg/kg ALD was administered. ALD caused gastric damage (63.35 ± 9.8 mm(2)); increased levels of TNF-α, IL-1β, and MDA (2311 ± 302.3 pg/mL, 901.9 ± 106.2 pg/mL, 121.1 ± 4.3 nmol/g, respectively); increased MPO activity (26.1 ± 3.8 U/mg); and reduced GSH levels (180.3 ± 21.9 µg/g). ALD also increased cystathionine-γ-lyase immunoreactivity in the gastric mucosa. Pretreatment with Lawesson's reagent (27 µmol/kg) attenuated ALD-mediated gastric damage (15.77 ± 5.3 mm(2)); reduced TNF-α, IL-1β, and MDA formation (1502 ± 150.2 pg/mL, 632.3 ± 43.4 pg/mL, 78.4 ± 7.6 nmol/g, respectively); lowered MPO activity (11.7 ± 2.8 U/mg); and increased the level of GSH in the gastric tissue (397.9 ± 40.2 µg/g). Glibenclamide alone reversed the gastric protective effect of Lawesson's reagent. However, glibenclamide plus diazoxide did not alter the effects of Lawesson's reagent. Our results suggest that Lawesson's reagent plays a protective role against ALD-induced gastric damage through mechanisms that depend at least in part on activation of ATP-sensitive potassium (KATP) channels.

Role of the NO/cGMP/K(ATP) pathway in the protective effects of sildenafil against ethanol-induced gastric damage in rats

BACKGROUND AND PURPOSE

Sildenafil is a selective inhibitor of cGMP-specific phosphodiesterase. Sildenafil, acting via NO-dependent mechanisms, prevents indomethacin-induced gastropathy. Activation of ATP-sensitive potassium channels (K(ATP)) is involved in gastric defence. Our objective was to evaluate the role of the NO/cGMP/K(ATP) pathway in the protective effects of sildenafil against ethanol-induced gastric damage.

EXPERIMENTAL APPROACH

Rats were treated with L-NAME (1 or 3 mg kg(-1), i.p.) or with L-arginine (200 mg kg(-1), i.p.) + L-NAME (3 mg kg(-1), i.p.), the guanylate cyclase inhibitor, ODQ (10 mg kg(-1), i.p.), glibenclamide (0.1, 0.3, 1 or 3 mg kg(-1), i.p.) or with glibenclamide (1 mg kg(-1), i.p.) + diazoxide (3 mg kg(-1), i.p.). After thirty minutes, the rats received sildenafil (1 mg kg(-1), by gavage), followed by intragastric instillation of absolute ethanol (4 ml kg(-1)) to induce gastric damage. One hour later, gastric damage (haemorrhagic or ulcerative lesions) was measured with a planimetry programme. Samples of stomach were also taken for histopathological assessment and for assays of tissue glutathione and haemoglobin.

KEY RESULTS

Sildenafil significantly reduced ethanol-induced gastric damage in rats. L-NAME alone, without L-arginine, significantly reversed the protection afforded by sildenafil. Inhibition of guanylate cyclase by ODQ completely abolished the gastric protective effect of sildenafil against ethanol-induced gastric damage. Glibenclamide alone reversed sildenafil's gastric protective effect. However, glibenclamide plus diazoxide did not alter the effects of sildenafil.

CONCLUSIONS

Sildenafil had a protective effect against ethanol-induced gastric damage through the activation of the NO/cGMP/K(ATP) pathway.