Abstract Exopolysaccharides (EPS) produced by Klebsiella oxytoca are of environmental, pharmaceutical, and medicinal interest. However, studies about the anti-inflammatory activity of EPS produced by this microorganism still remain limited. The aim of this study was to produce, characterize, and evaluate the anti-inflammatory activity of EPS from K. oxytoca in a pleurisy model. Colorimetric analysis revealed that precipitated crude exopolysaccharides (KEPSC) and deproteinated exopolysaccharides (KEPS) present high levels of total carbohydrates (65.57% and 62.82%, respectively). Analyses of uronic acid (7.90% in KEPSC and 6.21% in KEPS) and pyruvic acid (3.01% in KEPSC and 1.68% in KEPS) confirm that the EPS are acidic. Gas chromatography-mass spectrometry analyses demonstrated that the EPS consisted of rhamnose (29.83%), glucose (11.21%), galactose (52.45%), and mannose (6.50%). The treatment of an experimental pleurisy model in rats through subcutaneous administration of 50, 100, 200, and 400 mg/kg of KEPS decreased both the volume of inflammatory exudate and the number of leukocytes recruited to the pleural cavity. The present data showed that EPS production by K. oxytoca using the method described is easy to perform and results in a good yield. In addition, we show that KEPS exhibit anti-inflammatory activity when administered subcutaneously in rats.

Chemical investigation of Guettarda viburnoides (leaves) led to the isolation of ursolic acid, uncaric acid, secoxyloganin, and grandifloroside, along with a mixture of quercetin-3-O-β-D-galactopyranoside and quercetin-3-O-β-D-glucopyranoside, and of β-sitosterol and stigmasterol. The structures of the isolated compounds were elucidated on the basis of their NMR data. The crude extract, ethyl acetate fraction, aqueous-methanol fraction, and grandifloroside showed significant DPPH free-radical scavenging activities with IC50 ranging from 18.92 to 26.47 µg mL-1. The topical administration of the crude extract and fractions markedly reduced the croton oil-induced mice ear edema in 67.0%-99.0%. Inhibition of tissue MPO activity was also observed, which demonstrated an anti-inflammatory effect of the G. viburnoides species.