Topical Antiedematogenic Activity of the Essential Oil of Psidium brownianum Mart. (OEPB) in Murine Ear Edema Models.

Psidium brownianum Mart is reported in the literature by antinociceptive and antioxidant activities, indicating that this species' secondary metabolites might be used to control inflammatory processes. The present study aimed to characterize the topical antiedematogenic activity of the essential oil of Psidium brownianum Mart. (OEPB) in ear edema models by different inflammatory agents. Female Swiss mice (25-35 g) and Wistar albino rats (200-300 g) were used throughout tests (n=6/group) on acute or chronic edema models induced by single and multiple topical applications. The OEPB is administered topically pure or at a concentration of 100 or 200 mg/mL. The antiedematogenic mechanism of OEPB was analyzed by administering capsaicin, arachidonic acid, histamine, and phenol at the best effective dose (200 mg/mL). The results showed a significant reduction of edema-induced single (28.87 %) and multiple (50.13 %) applications of croton oil compared to the negative control group. Regarding potential mechanisms of action, OEPB (200 mg/mL) inhibited the development of edema triggered by capsaicin (29.95 %), arachidonic acid (22.66 %), phenol (23.35 %), and histamine (75.46 %), suggesting an interference with the histaminergic pathway. These results indicate that OEPB presents a topical antiedematogenic effect in acute and chronic murine models, possibly interfering with inflammatory pathways triggered by mediators such as histamine.

Spirulina platensis prevents oxidative stress and inflammation promoted by strength training in rats: dose-response relation study.

The purpose of this study was to evaluate the effects of Spirulina Platensis supplementation on selected blood markers of oxidative stress, muscle damage, inflammation, and performance in trained rats. Rats (250 g - 300 g) were submitted to a strength training program (eight weeks), divided into four groups: control (GT) (trained without supplementation), trained with daily-supplementation of 50 mg/kg (GT50), 150 mg/kg (GT150) and 500 mg/kg (GT500). Training consisted of a jump protocol in PVC-cylinder containing water, with increasing load over experimental weeks. We evaluated the markers of oxidative stress (malondialdehyde - MDA and antioxidant capacity) and inflammation (C-reactive protein) at the end of the training. Among groups submitted to strength training, concentration of C-reactive protein decreased after 8 weeks of intervention in the trained group and GT500. Strength training enhanced plasma MDA concentration of malondialdehyde with supplementation of S. platensis in GT150 and GT500. In plasma analysis, strength training enhanced the percentage of oxidation inhibition, with spirulina supplementation in rates of 150 and 500 mg/kg. Spirulina supplementation for 8 weeks (in a dose-effect manner) improved antioxidant capacity as well as attenuated exercise-induced increases in ROS and inflammation. As a practical application, the use as high doses did not cause a reduction in positive physiological adaptations to exercise training. Additional studies are necessary to test the application of Spirulina Platensis in other contexts, as collective sports (basketball, football, soccer).

Antinociceptive activity of the Psidium brownianum Mart ex DC. leaf essential oil in mice.

Chronic pain management has several adverse effects and research looking for new and effective pain management drugs posing lower undesirable effects is necessary. Given the above, the pharmacological investigation of medicinal plants significantly contributes to the dissemination of plant-derived therapeutics. The aim of this study was to evaluate the antinociceptive activity of the Psidium brownianum Mart ex DC. leaf essential oil (PBEO) and the participation of the opioid pathway in this effect in mice. Swiss Mus musculus male mice were tested using acute nociception models (acetic acid induced abdominal contortions, formalin, capsaicin and hot plate tests). The possible myorelaxant action of the PBEO was tested using the rotarod test. The essential oil reduced animal nociception in chemical and heat models, with this action being devoid of a myorelaxant effect. Naloxone (2 mg/kg, intraperitoneally - i.p.) partially antagonized the PBEO activity, possibly acting via opioid receptors. The results obtained provide evidence that the traditional Psidium brownianum use may be effective for pain treatment.

Supplementation with Spirulina platensis Modulates Aortic Vascular Reactivity through Nitric Oxide and Antioxidant Activity.

The possible mechanism is involved in the effects of Spirulina platensis on vascular reactivity. Animals were divided into sedentary group (SG) and sedentary groups supplemented with S. platensis at doses of 50 (SG50), 150 (SG150), and 500 mg/kg (SG500). To evaluate reactivity, cumulative concentration-response curves were constructed for phenylephrine and acetylcholine. To evaluate the involvement of the nitric oxide (NO) pathway, aorta tissue was preincubated with L-NAME and a new curve was then obtained for phenylephrine. Biochemical analyses were performed to evaluate nitrite levels, lipid peroxidation, and antioxidant activity. To contractile reactivity, only SG500 (pD2 = 5.6 ± 0.04 vs. 6.1 ± 0.06, 6.2 ± 0.02, and 6.2 ± 0.04) showed reduction in phenylephrine contractile potency. L-NAME caused a higher contractile response to phenylephrine in SG150 and SG500. To relaxation, curves for SG150 (pD2 = 7.0 ± 0.08 vs. 6.4 ± 0.06) and SG500 (pD2 = 7.3 ± 0.02 vs. 6.4 ± 0.06) were shifted to the left, more so in SG500. Nitrite was increased in SG150 and SG500. Lipid peroxidation was reduced, and oxidation inhibition was increased in all supplemented groups, indicating enhanced antioxidant activity. Chronic supplementation with S. platensis (150/500 mg/kg) caused a decrease in contractile response and increase in relaxation and nitrite levels, indicating greater NO production, due to decreased oxidative stress and increased antioxidant activity.