Brazilian Red Propolis Accelerates Gastric Healing and Reduces Gastric Submucosal Layer Inflammation in Ultrasound-Monitored Rats.

Propolis has been used for the treatment of gastric disturbances in folk medicine, nevertheless, the gastric healing effects of Brazilian red propolis have not been unveiled. This study aimed to assess the gastric healing effect of the hydroalcoholic extract of red propolis (HERP) in the acetic acid-induced ulcer model. Rats under acetic acid-induced-ulcer were treated with HERP (100 mg/kg, p.o.) twice a day for seven days. Histological changes, oxidative stress, and inflammatory parameters were analyzed in the gastric tissue. Moreover, the gastric wall thickness was measured by ultrasound. The in vitro cytotoxicity of HERP and cellular migration of fibroblasts were evaluated. The treatment with HERP promoted gastric healing, reducing gastric wall thickness, macroscopic lesion area, and histopathological damages compared to the vehicle. Moreover, HERP reduced oxidative stress and inflammation in the gastric tissue but did not change mucin or collagen levels. HERP did not show signs of toxicity either in vivo or in vitro. HERP displayed a healing effect in vivo by reducing oxidative stress and inflammation. These data contribute to validating the popular use of this product in the treatment of gastric disorders and advance scientific knowledge in the search for new drugs for the management of gastric ulcers.

Phloroglucinol derivatives from Hypericum species trigger mitochondrial dysfunction in Leishmania amazonensis.

Bioactive molecules isolated from plants are promising sources for the development of new therapies against leishmaniasis. We investigated the leishmanicidal activity of cariphenone A (1), isouliginosin B (2) and uliginosin B (3) isolated from Hypericum species. Promastigotes and amastigotes of Leishmania amazonensis were incubated with compounds 1-3 at concentrations 1-100 µm for 48 h. The anti-promastigote effect of compounds was also tested in combinations. The cytotoxicity against macrophages and human erythrocytes were determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method and hemolysis assay, respectively. The compounds 1-3 showed high leishmanicidal activity against promastigotes, IC50 values of 10.5, 17.5 and 11.3 µm, respectively. Synergistic interactions were found to the associations of compounds 1 and 2 [Σ fractional inhibitory concentration (FIC) = 0.41], and 2 and 3 (ΣFIC = 0.28) on promastigotes. All Hypericum compounds induced mitochondrial hyperpolarization and reactive oxygen species production in promastigotes. The compounds showed low cytotoxicity toward mammalian cells, high selectivity index and killed intracellular amastigotes probably mediated by oxidative stress. These results indicate that these compounds are promising candidates for the development of drugs against leishmaniasis.