Avicennia schaueriana Stapf is an endemic mangrove species widely used by traditional Brazilian communities as a folk remedy for the treatment of rheumatism, ulcers, and skin wounds. The aim of the present study was to evaluate the gastroprotective potential of the ethyl acetate extract from the leaves of A. schaueriana (As-AcOEt). Ultra-performance liquid chromatography coupled with diode-array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS/MS) was performed to identify chemical constituents of the ethyl acetate extract from the leaves ofA. schaueriana. Total phenols, flavonoids and tannins were determined and antioxidant activity was evaluated using the DPPH and ABTS methods. The acute toxicity of As-AcOEt and gastroprotective activity on HCl/ethanol-induced gastric ulcers were assessed and mechanisms of action involving the role of nitric oxide, sulfhydryl compounds, and prostaglandins were investigated. Terpenes, flavonoids and tannins were detected in the extract. As-AcOEt exhibited antioxidant activity, with an EC₅₀ of 42.2 ± 4.4 μg/mL (DPPH) and 73.2% inhibition of ABTS radicals. UPLC-DAD-QTOF-MS/MS analysis identified gallic acid, gallic acid derivative, ellagic acid, myricetin pentoside, myricetin deoxyhexose, quercetin pentoside, quercetin deoxyhexose, and other compounds. Gallic acid was isolated in this species for the first time. During the acute toxicity test, no deaths or changes occurred in the variables evaluated. In the ethanol-induced ulcer model, As-AcOEt reduced the ulcerative lesion index, with 50, 100 and 200 mg/kg achieving 83.8, 88.5 and 86.9% inhibition, respectively. MPO levels decreased and the gastric mucosa of the animals treated with the extract was preserved. Pre-treatment with N-omega-nitro-l-arginine methyl ester (L-NAME; NO blocker) or carbenoxolone (CBXN; NP-SH blocker) reversed the gastroprotective effect of As-AcOEt, but this effect was not reversed with the previous administration of indomethacin. The present findings reveal that the extract from the leaves ofA. schaueriana has gastroprotective effects, suggesting the involvement of nitric oxide and nonprotein sulfhydryl compounds, but not prostaglandin. Therefore, the use of A. schaueriana in Brazilian folk medicine for the treatment of gastric disorders has a scientific basis.

Avicennia schaueriana is found in Brazilian mangrove coast. The cytotoxicity in vitro of the Aqueous Extract of Leaves of Avicennia schaueriana (AELAs) and the healing activity of the plant in cream on mice skin wounds were evaluated in this study. The cytotoxic evaluation was performed on Vero cells. The healing activity was evaluated on mice treated during 5, 10 and 15 days with cream at 5%, solution of sodium chloride at 0.9% and dexpanthenol in cream at 5%. The extract did not show cytotoxicity, but showed mitogenic activity (100μg/ml). In morphometric analysis, the percentage of wound contraction after 10 days was higher in dexpanthenol group (93.41%). In 15 days, the lowest percentage of contraction was observed in the dexpanthenol group (94.41%) and the highest in the AELAs cream group (98.50%). In histomorphometry the dexpanthenol showed the lowest length of re-epithelialization in 10 days. In 15 days, the AELAs cream group showed 100% of re-epithelialization. The number of fibroblasts found in AELAs cream group was higher than the saline solution in 10 days. In 15 days, AELAs cream group maintained a higher amount of fibroblasts when compared to the others. A. schaueriana did not show cytotoxicity. Furthermore, topical application of AELAs cream decreased the wound area, stimulated the re-epithelialization and increased the number of fibroblasts. The species A. schaueriana could become a topical treatment in tissue repair process.

Rhizophora mangle is an abundant plant in mangroves and tannic acid is a polyphenol produced by the secondary metabolism of plants. The aim of the study was to evaluate the embryotoxic and embriostatic effects of the aqueous extract of R. mangle and synthetic tannic acid on eggs and larvae of Aedes aegypti. A. aegypti eggs were exposed in duplicate at concentrations of 250, 500, 750 and 1000 mu g/mL of extract and tannic acid for a period of 14 days. Mineral water was used as a negative control. The eggs were observed and counted in a stereomicroscope (1.2x). In all extract concentrations there was stimulation in hatching in relation to the control, but only in concentration of 750 mg/mL it was statistically significant. In tannic acid (250 mu g/ml) there was significant stimulus in hatching, but in 500, 750 and 1000 mu g/mL there was significant inhibition. All concentrations of aqueous extract and tannic acid on larvae showed embryotoxic and embryostatic effects when compared to the control. The aqueous extract of R. mangle showed effect on hatching of A. aegypti eggs and synthetic tannic acid showed embryotoxic and embryostatic effects. On larvae, both the aqueous extract as tannic acid showed embryotoxic and embiyostatic effects.

Aqueous extract ofIndigofera suffruticosaleaves obtained by infusion was used to evaluate the oviposition, its effect on development of eggs and larvae, and morphological changes in larvae ofAedes aegypti. The bioassays were carried out with aqueous extract in different concentrations on eggs, larvae, and female mosquitoes, and the morphological changes were observed in midgut of larvae. The extract showed repellent activity onA. aegyptimosquitoes, reducing significantly the egg laying by females with control substrate (343 (185–406)) compared with the treated substrate (88 (13–210)). No eclosion ofA. aegyptieggs at different concentrations studied was observed. The controleclodedin 35%. At concentration of 250 μg/mL, 93.3% of larvae remained in the second instar of development and at concentrations of 500, 750, and 1000 μg/mL the inhibitory effect was lower with percentages of 20%, 53.3%, and 46.6%, respectively. Morphological changes like disruption on the peritrophic envelope (PE), discontinued underlying epithelium, increased gut lumen, and segments with hypertrophic aspects were observed in anterior region of medium midgut of larvae ofA. aegypti. The results showed repellent activity, specific embryotoxicity, and general growth retardation inA. aegyptiby medium containing aqueous extract ofI. suffruticosaleaves.