Comparative retinal histomorphometry and visual acuity of three bat species of the genus Artibeus (Phyllostomidae: Stenodermatinae) / Histomorfometria comparada da retina e acuidade visual de três espécies de morcegos do gênero Artibeus (Phyllostomidae: Stenodermatinae)

This study performed a histomorphometric analysis of the retina and estimated the visual acuity of three fruit-eating bats of the genus Artibeus, including Artibeus lituratus, Artibeus planirostris and Artibeus obscurus. In total, 13 animals were used for this study, in which the retinas were hemidisected, fixed, cut, and stained. The visual acuity was determined by the density of ganglion cells in the retina and the retinal layers were also measured from histological sections. The retinas of these bats are avascular, do not present tapetum lucidum in any quadrant, and have the 10 retinal layers common in mammals. Moreover, it was observed that the thickness of the retina in the central region was significantly higher in all measured parameters (p<0.001), except for the outer plexiform layer (OPL) which was significantly higher in the peripheral region (p<0.001). The retinas of the three species showed a horizontal visual streak with a higher concentration of retinal ganglion cells (RGCs) at the inferotemporal region. In addition, the species A. lituratus exhibited extras areas of high cell density in the retina. Thus, A. lituratus showed the highest visual acuity (1.92 cycles/degree), while A. planirostris showed a visual acuity of (1.77 cycles/degree) and A. obscurus exhibited the lowest visual acuity (1.50 cycles/degree). All these characteristics are related to the echolocation system and the eating habits of each species. Therefore, it can be concluded that bats of the genus Artibeus have a high visual acuity value compared to other echolocating bats and all these differences might be directly linked to the phylogeny of the genus.(AU)

Este estudo realizou uma análise histomorfométrica da retina e determinou os valores de acuidade visual de três espécies de morcegos do gênero Artibeus, incluindo Artibeus lituratus, Artibeus planirostris e Artibeus obscurus. Em total, 13 animais foram usados para esse estudo, no qual as retinas foram hemidissecadas, fixadas, cortadas e coradas. A acuidade visual foi determinada pela densidade de células ganglionares na retina e também foi realizado a mensuração das camadas retinianas a partir de cortes histológicos. As retinas dessas três espécies são avasculares, não apresentaram tapetum lucidum em nenhum quadrante e possuem as 10 camadas retinianas comum em mamíferos. Verificou-se também que a espessura da retina na região central foi significativamente maior em todos os parâmetros mensurados (p<0,001), com exceção da camada plexiforme externa (OPL) que foi significativamente maior na região periférica (p<0,001). As retinas das três espécies exibiram uma especialização retiniana em forma de faixa visual horizontal apresentando a maior concentração de células ganglionares na região inferotemporal. Além disso, a espécie A. lituratus exibiu áreas extras de alta densidade celular na retina. Assim, a espécie A. lituratus exibiu a maior acuidade visual (1,92 ciclos/grau), A. planirostris mostrou um valor intermediário entre essas duas espécies (1,77 ciclos/grau) e A. obscurus exibiu a menor acuidade visual (1,50 ciclos/grau). Todas estas características estão relacionadas aos padrões de ecolocalização e hábitos alimentares de cada espécie. Portanto, pode-se concluir que os morcegos do gênero Artibeus têm um alto valor de acuidade visual em comparação com outros morcegos ecolocalizadores e todas essas diferenças devem estar diretamente ligadas à filogenia do gênero.(AU)

Comparative retinal histomorphometry and visual acuity of three bat species of the genus Artibeus (Phyllostomidae: Stenodermatinae) / Histomorfometria comparada da retina e acuidade visual de três espécies de morcegos do gênero Artibeus (Phyllostomidae: Stenodermatinae)

This study performed a histomorphometric analysis of the retina and estimated the visual acuity of three fruit-eating bats of the genus Artibeus, including Artibeus lituratus, Artibeus planirostris and Artibeus obscurus. In total, 13 animals were used for this study, in which the retinas were hemidisected, fixed, cut, and stained. The visual acuity was determined by the density of ganglion cells in the retina and the retinal layers were also measured from histological sections. The retinas of these bats are avascular, do not present tapetum lucidum in any quadrant, and have the 10 retinal layers common in mammals. Moreover, it was observed that the thickness of the retina in the central region was significantly higher in all measured parameters (p<0.001), except for the outer plexiform layer (OPL) which was significantly higher in the peripheral region (p<0.001). The retinas of the three species showed a horizontal visual streak with a higher concentration of retinal ganglion cells (RGCs) at the inferotemporal region. In addition, the species A. lituratus exhibited extras areas of high cell density in the retina. Thus, A. lituratus showed the highest visual acuity (1.92 cycles/degree), while A. planirostris showed a visual acuity of (1.77 cycles/degree) and A. obscurus exhibited the lowest visual acuity (1.50 cycles/degree). All these characteristics are related to the echolocation system and the eating habits of each species. Therefore, it can be concluded that bats of the genus Artibeus have a high visual acuity value compared to other echolocating bats and all these differences might be directly linked to the phylogeny of the genus.(AU)

Este estudo realizou uma análise histomorfométrica da retina e determinou os valores de acuidade visual de três espécies de morcegos do gênero Artibeus, incluindo Artibeus lituratus, Artibeus planirostris e Artibeus obscurus. Em total, 13 animais foram usados para esse estudo, no qual as retinas foram hemidissecadas, fixadas, cortadas e coradas. A acuidade visual foi determinada pela densidade de células ganglionares na retina e também foi realizado a mensuração das camadas retinianas a partir de cortes histológicos. As retinas dessas três espécies são avasculares, não apresentaram tapetum lucidum em nenhum quadrante e possuem as 10 camadas retinianas comum em mamíferos. Verificou-se também que a espessura da retina na região central foi significativamente maior em todos os parâmetros mensurados (p<0,001), com exceção da camada plexiforme externa (OPL) que foi significativamente maior na região periférica (p<0,001). As retinas das três espécies exibiram uma especialização retiniana em forma de faixa visual horizontal apresentando a maior concentração de células ganglionares na região inferotemporal. Além disso, a espécie A. lituratus exibiu áreas extras de alta densidade celular na retina. Assim, a espécie A. lituratus exibiu a maior acuidade visual (1,92 ciclos/grau), A. planirostris mostrou um valor intermediário entre essas duas espécies (1,77 ciclos/grau) e A. obscurus exibiu a menor acuidade visual (1,50 ciclos/grau). Todas estas características estão relacionadas aos padrões de ecolocalização e hábitos alimentares de cada espécie. Portanto, pode-se concluir que os morcegos do gênero Artibeus têm um alto valor de acuidade visual em comparação com outros morcegos ecolocalizadores e todas essas diferenças devem estar diretamente ligadas à filogenia do gênero.(AU)

Evaluation of cytotoxicity and wound healing activity of Avicennia schaueriana in cream.

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.

Evaluation of embryotoxic and embryostatic effects of the aqueous extract of Rhizophora mangle and tannic acid on eggs and larvae of Aedes aegypti.

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 µg/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 (250µg/ml) there was significant stimulus in hatching, but in 500, 750 and 1000 µg/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 embryostatic effects.

Acute Toxicity and Cytotoxicity Effect of Ethanolic Extract of Spondias tuberosa Arruda Bark: Hematological, Biochemical and Histopathological Evaluation.

Spondias tuberosa Arruda, popularly named as umbu, is native from savanna-like vegetation and widely used for medicinal purposes, however, the toxicological profile is not available yet. This study evaluated the phytochemical profile and acute toxicity and citoxicity of Ethanolic Extract of Spondias tuberosa Arruda Bark (EEStb) in hematological, biochemical and histopathological parameters. Female Wistar rats were divided into: control (C) and animal treated single doses of 300mg/Kg (EEStb300) or 2.000mg/kg body weight (ESStb2.000) of the EEStb. After 24 hours and 14 days from gavage, the behavior, hematological, biochemical and histopathological parameters were assayed. Cytotoxicity effect was evaluated on HEp-2 cell lines. Neither EEStb300 nor EEStb2.000 produced mortality nor changes in body weight during the 14-days of observation, but EEStb2.000 reduced quietly the food and water intake as well as locomotor activity at first day. There were no changes in macroscopic, histopathological, biochemical and hematological parameters. EEStb in concentrations of 6.25- 50µg ml-1 on HEp-2 cell did not produce cytotoxic effect. These results suggest that EEStb did not cause acute toxicity and cytotoxic, suggesting a good safety rate for Spondias tuberosa Arruda.

Phytochemical Screening and Acute Toxicity of Aqueous Extract of Leaves of Conocarpus erectus Linnaeus in Swiss Albino Mice.

Mangroves represent areas of high biological productivity and it is a region rich in bioactive substances used in medicine production. Conocarpus erectus (Combretaceae) known as button mangrove is one of the species found in mangroves and it is used in folk medicine in the treatment of anemia, catarrh, conjunctivitis, diabetes, diarrhea, fever, gonorrhea, headache, hemorrhage, orchitis, rash, bumps and syphilis. The present study aimed to investigate the acute toxicity of aqueous extract of leaves of C. erectus in Swiss albino mice. The plant material was collected in Vila Velha mangroves, located in Itamaracá (PE). The material was subjected to a phytochemical screening where extractive protocols to identify majority molecules present in leaves were used. The evaluation of acute toxicity of aqueous extract of C. erectus followed the model of Acute Toxicity Class based on OECD 423 Guideline, 2001. The majority molecules were identified: flavonoids, tannins and saponins. The LD50 was estimated at 2,000 mg/kg bw. Therefore, the aqueous extract showed low acute toxicity classified in category 5.