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In a previous study, we performed the chemical characterization of a polyvinyl alcohol (PVA) membrane supplemented with latex proteins (LP) displaying wound healing activity, and its efficacy as a delivery system was demonstrated. Here, we report on aspects of the mechanism underlying the performance of the PVA-latex protein biomembrane on wound healing. LP-PVA, but not PVA, induced more intense leukocyte (neutrophil) migration and mast cell degranulation during the inflammatory phase of the cicatricial process. Likewise, LP-PVA induced an increase in key markers and mediators of the inflammatory response (myeloperoxidase activity, nitric oxide, TNF, and IL-1β). These results demonstrated that LP-PVA significantly accelerates the early phase of the inflammatory process by upregulating cytokine release. This remarkable effect improves the subsequent phases of the healing process. The polyvinyl alcohol membrane was fully absorbed as an inert support while LP was shown to be active. It is therefore concluded that the LP-PVA is a suitable bioresource for biomedical engineering.

Myracrodruon urundeuva (Anacardiaceae) is the scientific designation of "aroeira-do-sertão", a tree well dispersed at the northeastern Brazil. The medicinal use of this plant is widespread throughout the rural population and the inner trunk bark decoction is used to treat cutaneous affections, urinary and respiratory diseases, and gynecological problems. "Aroeira-do-sertão" has been included in the list of native species under extinction threat. In order to find a sustainable source of the plant, seedlings have been cultivated. The purpose of this work was to investigate the chemical composition of the decoction from leaves of cultivated plants (aqueous extract from Myracrodruon urundeuva (AEMU)) and its anti-inflammatory activity on human neutrophils. The addition of AEMU on cells suspension inhibited significantly its activation/degranulation induced by phorbol myristate acetate. AEMU since at 50 µg mL-1 showed better pattern of inhibitions when related to indomethacin, nonselective cyclooxygenase inhibitor used as reference anti-inflammatory. The decoction fractionation was performed by high-speed counter-current chromatography (HSCCC) and semi-preparative highperformance liquid chromatography (HPLC) using a phenyl column as the stationary phase, allowing the isolation of 24 compounds. These results showed how the AEMU is rich in bioactive metabolites, which probably contribute for the anti-inflammatory effects of this plant extract, modulating the degranulation of human neutrophils, one of the pro-inflammatory mechanism of these cells.

Himatanthus drasticus (Apocynaceae), a laticifer plant, is popularly known as janaguba. This latex has been widely used in traditional folk medicine to treat diseases such cancer and ulcer. This study was performed to investigate the gastroprotective activity of proteins isolated from latex Himatanthus drasticus (HdPL) in gastric ulcer model. Experimental protocols were registered on the Institutional Ethics Committee under number 43/2011. Swiss male mice were treated with PrLP at doses 0.5; 5 and 50 mg/kg (i.v.; n=8). After 30 min they received 0.2 ml of absolute ethanol per oral, after 60 min, the animals were sacrificed, stomachs removed and analyzed the lesion index and dosage of GSH (reduced glutathione) and nitrite. To study the gastroprotective mechanism, its relations to capsaicin‐sensitive fibers, endogenous prostaglandins, nitric oxide, ATP‐sensitive potassium channels and cGMP were analyzed. HdPL gastroprotective effect was observed only at dose of 5mg/kg. HdPL also restored the GSH levels and nitrite in mucosa and only L‐NAME, Glibenclamide and ODQ were able to reverse the protective effect of PrLP. We can conclude that the HdLP has pharmacological activity with gastroprotetor effect in the gastric mucosa. This protection appears to be mediated in part by modulation of NO/cGMP/KATP pathway, which has been related to mucosal defense and maintenance of stomach's blood flow. Support: CNPQ ans CAPES.

Plumeria rubra (Apocynaceae) is frequently used in folk medicine for the treatment of gastrointestinal disorders, hepatitis, and tracheitis, among other infirmities. The aim of this study was to investigate the gastroprotective potential of a protein fraction isolated from the latex of Plumeria rubra (PrLP) against ethanol-induced gastric lesions and describe the underlying mechanisms. In a dose-dependent manner, the pretreatment with PrLP prevented ethanol-induced gastric lesions in mice after single intravenous administration. The gastroprotective mechanism of PrLP was associated with the involvement of prostaglandins and balance of oxidant/antioxidant factors. Secondarily, the NO/cGMP/KATP pathway and activation of capsaicin-sensitive primary afferents were also demonstrated as part of the mechanism. This study shows that proteins extracted from the latex of P. rubra prevent gastric lesions induced in experimental animals. Also, the results support the use of the plant in folk medicine.

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Background and aimsCalotropis procera is a tropical plant found worldwide and has been used in the traditional medicinal for the treatment of various diseases. This study aimed to evaluate the effects of protein fraction from Calotropis procera latex (LP) in the mechanical hypernociception (increase in the sensitivity of nociception).MethodsSwiss male mice were used. b) Mechanical hypernociception (MH) was evaluated using the electronic version of the Von Frey before and after the injection of carrageenan (300 μg/paw‐Cg) or LP (0.5, 5 and 50 mg/kg, iv, 30 min before Cg application) into the mice paw (1, 3 and 5 hours after Cg). c) After 3 h of Cg injection, subplantar tissue was collected for measurement of: myeloperoxidase activity (MPO); cytokines (TNF‐α and IL‐1β) and chemokine (KC) production; prostaglandin E2 (PGE2) production. d) ANOVA/Bonferroni was used as statistical tests. P<0.05 was accepted. e) Ethics Committee 61/11.ResultsLP 5 mg/kg reduced MH in 25%, 55% and 46% and LP 50 mg/kg in 39%, 64% and 60% in the 1st, 3rd and 5th hours. LP at 5 and 50 mg/kg decreased MPO concentration in 80% and 94% respectively. LP at 5mg/kg reduced the concentration of TNF‐ α, IL‐1β, KC and PGE2 at 71%, 81%, 72% and 72% respectively.ConclusionLP has antinociceptive properties in animal model of acute pain and this may be associated with the inhibition of neutrophil migration, cytokine and chemokine production. CAPES and CNPq.