Hancornia speciosa Gomes Latex Increases Bone Mineralization in Rats: A Preclinical Study.

Objective To evaluate the systemic effect of Hancornia speciosa latex on bone neoformation and mineralization in rats. Methods For that, the latex was first collected, and its composition was analyzed. A total of 30 male Wistar rats were used, which were simultaneously submitted to two surgical procedures: extraction of an incisor and creation of a defect with 2 mm in diameter in the parietal bone. The rats were divided into two groups: systemic control (SC) systemic latex (SX) which were administered, orally and daily, 1.5 mL of water or a solution containing 50% of water and 50% of latex by gavage, respectively. After 15 days of the treatment, the animals were euthanized and their samples were collected. Results The results were statistically analyzed, and the level of significance was set at 0.05. We showed that H. speciosa latex contained calcium. The oral and daily administration of the latex for 15 days increased the contents of calcium and phosphorus in the basal bone and newly-formed bone in the mandibular alveolus of rats. Conclusion The present was a pioneer study demonstrating the potential of H. speciosa latex in increasing bone mineralization. Our results may aid in the conception and development of a natural drug.

Hancornia speciosa Gomes Latex Increases Bone Mineralization in Rats: A Preclinical Study / Látex de Hancornia speciosa Gomes aumenta a mineralização óssea em ratos: Um estudo pré-clínico

Abstract Objective To evaluate the systemic effect of Hancornia speciosa latex on bone neoformation and mineralization in rats. Methods For that, the latex was first collected, and its composition was analyzed. A total of 30 male Wistar rats were used, which were simultaneously submitted to two surgical procedures: extraction of an incisor and creation of a defect with 2 mm in diameter in the parietal bone. The rats were divided into two groups: systemic control (SC) systemic latex (SX) which were administered, orally and daily, 1.5 mL of water or a solution containing 50% of water and 50% of latex by gavage, respectively. After 15 days of the treatment, the animals were euthanized and their samples were collected. Results The results were statistically analyzed, and the level of significance was set at 0.05. We showed that H. speciosa latex contained calcium. The oral and daily administration of the latex for 15 days increased the contents of calcium and phosphorus in the basal bone and newly-formed bone in the mandibular alveolus of rats. Conclusion The present was a pioneer study demonstrating the potential of H. speciosa latex in increasing bone mineralization. Our results may aid in the conception and development of a natural drug.

Resumo Objetivo Avaliar o efeito sistêmico do látex de Hancornia especiosa na neoformação óssea e mineralização em ratos. Métodos Para isso, primeiro o látex foi coletado, e sua composição foi analisada. No estudo, foram utilizados 30 ratos Wistar machos submetidos simultaneamente a dois procedimentos cirúrgicos: extração de incisivo e criação de um defeito de 2 mm de diâmetro no osso parietal. Os ratos foram divididos em dois grupos: controle sistêmico (CS) e látex sistêmico (XS), aos quais foi administrado, oral e diariamente, 1,5 mL de água ou uma solução contendo 50% de água e 50% de látex por gavagem, respectivamente. Após 15 dias do tratamento, os animais foram eutanizados, e suas amostras, coletadas. Resultados Os resultados foram analisados estatisticamente, e o nível de significância foi fixado em 0,05. Mostramos que o látex de H. speciosa continha cálcio. A administração oral e diária deste látex por 15 dias aumentou o conteúdo de cálcio e fósforo de osso basal e de osso recém-formado no alvéolo mandibular de ratos. Conclusão Este foi um estudo pioneiro, que demonstrou o potencial do látex de H. speciosa no aumento da mineralização óssea. Nossos resultados podem ajudar na concepção e no desenvolvimento de uma droga natural.

Initial inflammatory response after the pulpotomy of rat molars with MTA or ferric sulfate.

PURPOSE: To compare, both qualitatively and quantitatively, the inflammatory cells, vascular density and IL-6 immunolabeled cells present in the pulp after pulpotomy with white MTA versus 15.5% ferric sulfate (FS). METHODOLOGY: Forty-eight mandibular first molars from 24 Wistar rats were divided into MTA or FS groups and subdivided according to the period after pulpotomy procedure (24, 48 and 72 hours). Four teeth (sound and untreated) were used as controls. Histological sections were obtained and assessed through the descriptive analysis of morphological aspects of pulp tissue and the quantification of inflammatory cells, vascular density and interleukin-6 (IL-6) expression. Data were statistically analyzed (p<0.05). RESULTS: The number of inflammatory cells was similar in both groups, being predominantly localized at the cervical radicular third. In the MTA group, increased inflammation was observed at 48 hours. Vascular density was similar in both groups and over time, being predominant in the medium radicular third. No correlation was found between the number of inflammatory cells and the vascular density. Pulp tissue was more organized in MTA-treated teeth. In both groups, a weak to moderate IL-6 expression was detected in odontoblasts and inflammatory cells. Comparing both groups, there was a greater IL-6 expression in the cervical radicular third of teeth treated with MTA at 24 hours and in the medium and apical thirds at 72 hours, while in the FS group a greater IL-6 expression was found in the apical third at 24 hours. CONCLUSION: The MTA group presented better histological features and greater IL-6 expression than the FS group. However, no difference was observed between the groups regarding the inflammatory status and vascularization, suggesting the usefulness of FS as a low-cost alternative to MTA.

Initial inflammatory response after the pulpotomy of rat molars with MTA or ferric sulfate

Abstract Purpose To compare, both qualitatively and quantitatively, the inflammatory cells, vascular density and IL-6 immunolabeled cells present in the pulp after pulpotomy with white MTA versus 15.5% ferric sulfate (FS). Methodology Forty-eight mandibular first molars from 24 Wistar rats were divided into MTA or FS groups and subdivided according to the period after pulpotomy procedure (24, 48 and 72 hours). Four teeth (sound and untreated) were used as controls. Histological sections were obtained and assessed through the descriptive analysis of morphological aspects of pulp tissue and the quantification of inflammatory cells, vascular density and interleukin-6 (IL-6) expression. Data were statistically analyzed (p<0.05). Results The number of inflammatory cells was similar in both groups, being predominantly localized at the cervical radicular third. In the MTA group, increased inflammation was observed at 48 hours. Vascular density was similar in both groups and over time, being predominant in the medium radicular third. No correlation was found between the number of inflammatory cells and the vascular density. Pulp tissue was more organized in MTA-treated teeth. In both groups, a weak to moderate IL-6 expression was detected in odontoblasts and inflammatory cells. Comparing both groups, there was a greater IL-6 expression in the cervical radicular third of teeth treated with MTA at 24 hours and in the medium and apical thirds at 72 hours, while in the FS group a greater IL-6 expression was found in the apical third at 24 hours. Conclusion The MTA group presented better histological features and greater IL-6 expression than the FS group. However, no difference was observed between the groups regarding the inflammatory status and vascularization, suggesting the usefulness of FS as a low-cost alternative to MTA.

Muscle pain induced by static contraction in rats is modulated by peripheral inflammatory mechanisms.

Muscle pain is an important health issue and frequently related to static force exertion. The aim of this study is to evaluate whether peripheral inflammatory mechanisms are involved with static contraction-induced muscle pain in rats. To this end, we developed a model of muscle pain induced by static contraction performed by applying electrical pulses through electrodes inserted into muscle. We also evaluated the involvement of neutrophil migration, bradykinin, sympathetic amines and prostanoids. A single session of sustained static contraction of gastrocnemius muscle induced acute mechanical muscle hyperalgesia without affecting locomotor activity and with no evidence of structural damage in muscle tissue. Static contraction increased levels of creatine kinase but not lactate dehydrogenase, and induced neutrophil migration. Dexamethasone (glucocorticoid anti-inflammatory agent), DALBK (bradykinin B1 antagonist), Atenolol (ß1 adrenoceptor antagonist), ICI 118,551 (ß2 adrenoceptor antagonist), indomethacin (cyclooxygenase inhibitor), and fucoidan (non-specific selectin inhibitor) all reduced static contraction-induced muscle hyperalgesia; however, the bradykinin B2 antagonist, bradyzide, did not have an effect on static contraction-induced muscle hyperalgesia. Furthermore, an increased hyperalgesic response was observed when the selective bradykinin B1 agonist des-Arg9-bradykinin was injected into the previously stimulated muscle. Together, these findings demonstrate that static contraction induced mechanical muscle hyperalgesia in gastrocnemius muscle of rats is modulated through peripheral inflammatory mechanisms that are dependent on neutrophil migration, bradykinin, sympathetic amines and prostanoids. Considering the clinical relevance of muscle pain, we propose the present model of static contraction-induced mechanical muscle hyperalgesia as a useful tool for the study of mechanisms underlying static contraction-induced muscle pain.

MT1-MMP expression in the odontogenic region of rat incisors undergoing interrupted eruption.

MT1-MMP (membrane type matrix metalloproteinase-1) has been considered an important membrane-type matrix metalloproteinase involved in the remodeling process in tissue and organ development, including the processes of the tooth and root growth and dental eruption. Therefore, the aims of this study were to evaluate MT1-MMP expression in the odontogenic region, as well as the eruption rate and morphology of the lower-left rat incisor, where the eruption process was interrupted for 14 days by a steel wire attached from the center of the incisor labial face and braced to the first molar. In the interrupted eruption group, the eruption rate was significantly reduced, producing drastic morphological alterations in the tooth germ and socket area. The MT1-MMP expression was widespread in the dental follicle, in both groups studied (normal and interrupted eruption groups); however a significant decrease in immunostaining was observed in the interrupted eruption group. Results indicate that MT1-MMP may have an important role in the process of dental eruption.

Influence of different decalcifying agents on EGF and EGFR immunostaining.

This study was designed to verify the influence of three demineralizing agents on EGF and EGFR immunostaining as well as on tissue morphology. We chose submandibular glands that are a source of EGF and its receptor and which could be analyzed using a control in which the decalcification step was not carried out. After sacrifice of adult male Wistar rats by perfusion fixation, the submandibular glands and mandibles were excised and placed together in each of the following solutions: (a) 5% nitric acid in 4% formaldehyde; (b) 4.13% EDTA pH 7.4; (c) 5% trichloroacetic acid. Mandibles served as a parameter for decalcification time in each demineralizing solution. A control group was performed with submandibular glands that were not placed in any demineralizing solution. After mandibles were completely decalcified, glands were processed by embedding in Paraplast® and immunohistochemical staining was made to detect EGF and EGFR. It was observed that decalcification did not produce noticeable differences in terms of EGF and EGFR immunoreactivity, but had an effect on the quality of the morphology and staining. Our results indicate there is no problem performing immunostaining of EGF and EGFR in tissues that require decalcification. 4.13% EDTA (pH 7.4) is the best choice for decalcification in cases that are not urgent.

Pulpite crônica hiperplásica: análise histológica ao microscópio de luz e microscópio eletrônico de transmissão / Chronic hyperplastic pulpitis: histological analysis in light microscope and transmission electron microscope

Este estudo analisou as características morfológicas de pólipos pulpares de adultos jovens ao microscópio de luz (ML) e ao microscópio eletrônico de transmissão (MET). Foram analisados 5 pólipos de primeiros molares, que foram removidos e fixados em glutaraldeído 2,5%. Após a fixação, cada pólipo foi dividido em duas metades, uma foi processada para inclusão em glicol metacrilato e a outra para inclusão em resina epóxica. Os cortes histológicos com 3 μm de espessura foram corados em azul de toluidina e analisados ao ML e os cortes com 80 nm foram contrastados em citrato de chumbo e acetato de uranila e analisados ao MET. Ao ML foi observado epitélio espesso não queratinizado com alguns mastócitos na camada basal. O conjuntivo apresentou infiltrado inflamatório crônico, com ninhos de plasmócitos e vasos neoformados. A análise ao MET mostrou células epiteliais da camada basal com núcleo ovóide, citoplasma com muitos ribossomas livres, mitocôndrias e poucos feixes de tonofilamentos. A lâmina basal apresentou-se nítida com muitos hemidesmossomas. Na camada espinhosa observou-se células grandes, núcleos com cromatina descondensada e nucléolos evidentes. No citoplasma foi observado muitos feixes de tonofilamentos, muitas mitocôndrias, ribossomas livres e muitos desmossomas. No conjuntivo observou-se macrófagos, mastócitos e plasmócitos na região adjacente ao epitélio. Nas regiões mais profundas predominavam fibroblastos entres feixes de fibrilas colágenas, vasos sangüíneos com células endoteliais proeminentes e pericitos associados. Os resultados confirmaram que o epitélio do pólipo pulpar apresenta características morfológicas semelhantes ao da mucosa oral humana. O conjuntivo mostrou características de inflamação crônica de intensidade variada.