Gastroprotective action of the ethanol extract of Leonurus sibiricus L. (Lamiaceae) in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Leonurus sibiricus L. (Lamiaceae) is a medicinal plant known in Brazil as "rubim" or "erva de macaé". It is used for various purposes, including stomach disorders. AIM OF THE STUDY: To evaluate the effect of the ethanol extract of the aerial parts of L. sibiricus (EELs) in models of gastric damage in mice. MATERIAL AND METHODS: The effect of EELs (50, 100 and 300 mg/kg, p.o., 1 h before induction) was tested on acidified ethanol (ACEt)-induced gastric ulcers. Additionally, we tested the effect of EELs (by intraduodenal administration) in the pylorus ligation (PL) model. RESULTS: Pretreatment with EELs, at 300 mg/kg, but not 50 and 100 mg/kg, reduced the relative area of gastric ulcers induced by ACEt (p < 0.01) and lipoperoxidation (p < 0.001), and increased the sulfhydryl content (p < 0.01) in the stomach in comparison with the vehicle group. Pretreatment with N-ethylmaleimide (a blocker of non-protein sulfhydryl groups, 10 mg/kg, i.p.) or glibenclamide (a KATP channel blocker, 10 mg/kg, i.p.) inhibited the gastroprotective response caused by EELs (300 mg/kg; p < 0.001), but there were no alterations due to pretreatments with inhibitors of the synthesis of prostaglandins (indomethacin, 10 mg/kg), nitric oxide (L-NAME, 70 mg/kg) or hydrogen sulfide (DL-propargylglycine, 10 mg/kg). Treatment with EELs (300 mg/kg) reduced mucus production (p < 0.001) and the volume of gastric secretion (p < 0.001) after PL without affecting gastric acidity or pH. CONCLUSIONS: These results provide evidence that EELs exerts gastroprotective action in mice, with the participation of oxidative stress and mediation of NP-SH, KATP channels and mucus production.

Reduced cutaneous inflammation associated with antioxidant action after topical application of the aqueous extract of Annona muricata leaves.

Annona muricata L. is used in folk medicine for treatment of diseases related to inflammatory and oxidative processes. This study investigated the effect of the aqueous extract of A. muricata leaves (AEAM) on TPA-induced ear inflammation and antioxidant capacity, both in vitro and in vivo. The in vitro antioxidant capacity of AEAM was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP) and lipoperoxidation assays. Cytotoxicity and reactive oxygen species (ROS) release were evaluated in the L929 fibroblasts. Swiss mice were submitted to TPA application and were topically treated with AEAM (0.3, 1 or 3 mg/ear). After 6 h, inflammatory and oxidative parameters were evaluated. Quercetin 3-glucoside, rutin, chlorogenic acid, catechin and gallic acid were identified in AEAM. It also presented antioxidant activity in all in vitro assays used. Incubation with AEAM did not cause cell cytotoxicity but reduced ROS release from fibroblasts. Compared with the control group, treatment with AEAM significantly reduced ear oedema and mieloperoxidase activity in inflamed ears, as well as histological parameters of inflammation. These results were associated with the reduction of total hydroperoxides and modulation of catalase, but not superoxide dismutase activity. These findings show the anti-inflammatory effect of AEAM is associated with antioxidant capacity.

Modulation of exercise-induced muscular damage and hyperalgesia by different 630 nm doses of light-emitting diode therapy (LEDT) in rats.

We compared the acute effects of different doses of 630 nm light-emitting diode therapy (LEDT) on skeletal muscle inflammation and hyperalgesia in rats submitted to exercise-induced muscle damage (EIMD). Wistar rats were divided into five experimental groups (n = 5-8/group): sedentary control (CON); exercise + passive recovery (PR); and exercise + LEDT (1.2 J/cm2, 1.8 J; 4.2 J/cm2, 6.3 J; 10.0 J/cm2, 15 J). After 100 min of swimming, the rats in the LEDT groups were exposed to phototherapy on the triceps surae muscle. For mechanical hyperalgesia evaluation, paw withdrawal threshold was assessed before and 24 h after swimming. Immediately after hyperalgesia tests, blood samples were collected to analyze creatine kinase (CK) activity and the soleus muscle was removed for histological and tumor necrosis factor (TNF)-α immunohistological analyses. In all LEDT groups, plasma CK activity was reduced to levels similar to those measured in the CON group. Paw withdrawal threshold decreased in the PR group (- 11.9 ± 1.9 g) when compared to the CON group (2.2 ± 1.5 g; p < 0.01) and it was attenuated in the group LEDT 4.2 J/cm2 (- 3.3 ± 2.4 g, p < 0.05). Less leukocyte infiltration and edema and fewer necrotic areas were found in histological sections of soleus muscle in LEDT (4.2 J/cm2) and LEDT (10.0 J/cm2) groups compared to the PR group. Also, LEDT (4.2 J/cm2) and LEDT (10.0 J/cm2) groups showed less immunostaining for TNF-α in macrophages or areas with necrosis of muscle fibers compared to the PR group. LEDT (4.2 J/cm2, 6.3 J)-reduced muscle inflammation and nociception in animals submitted to EIMD.