Purpose:To evaluate and characterize the wound healing process profile induced by allantoin incorporated in soft lotion oil/water emulsion using the planimetric and histological methods. Methods: Female Wistar rats (n=60) were randomly assigned to 3 experimental groups: (C) control group-without treatment; (E) group treated with soft lotion O/W emulsion excipients; (EA) group treated with soft lotion O/W emulsion containing allantoin 5%. The emulsions either containing or not allantoin were topically administered for 14 days and the wound area was evaluated by planimetry and by qualitative and quantitative histological analysis of open wound model. Results:The data which were obtained and analyzed innovate by demonstrating, qualitatively and quantitatively, by histological analysis, the profile of healing process induced by allantoin. The results suggest that the wound healing mechanism induced by allantoin occurs via the regulation of inflammatory response and stimulus to fibroblastic proliferation and extracellular matrix synthesis. Conclusion: This work show, for the first time, the histological wound healing profile induced by allantoin in rats and demonstrated that it is able to ameliorate and fasten the reestablishment of the normal skin. Key words: Wound Healing. Allantoin. Histology. Animal Experimentation. Rats. RESUMOObjetivo: Avaliar e caracterizar o perfil cicatricial induzido pela alantoína incorporada em uma emulsão óleo/água, sob os aspectos planimétrico e histológico. Métodos: Ratos Wistar fêmeas (n=60) foram agrupados aleatoriamente em três grupos experimentais grupo controle -sem tratamento (C); grupo tratado com emulsão pura (E); grupo tratado com emulsão contendo 5% de alantoína (EA). As emulsões contendo ou não alantoína foram administradas topicamente durante 14 dias e a área da ferida foi avaliada por planimetria e por análise histológica qualitativa e quantitativa em modelo de ferida aberta. Resultados: Na análise planimétrica não foi observado diferenças significativas entre os grupos experimentais. Os resultados da análise histológica sugerem que o mecanismo de cicatrização induzido pela alantoína ocorre via controle da resposta inflamatória e estímulos à proliferação fibroblástica e síntese de matrix extracelular de maneira mais intensa e rapidamente em relação aos grupos controles. Conclusão: Este trabalho mostra pela primeira vez o perfil histológico de cicatrização induzido pela alantoína em ratos, demonstrando ser capaz de melhorar e acelerar o processo de reconstituição da pele. Descritores: Cicatrização de Feridas. Alantoína. Histologia. Experimentação Animal. Ratos.
Abstract-The aim of this work was to evaluate the potential of liposomes as a tool for the sustained release of the short half-life peptides of the renin-angiotensin system in a specific site of the brain. Angiotensin (Ang)-(1-7) was selected for this study because of its known cardiovascular effects at the level of the rostral ventrolateral medulla (RVLM) and because of the considerable interests in elucidating its physiopathological role as a neuromodulator. Ang-(1-7)-containing liposomes (LAng) were microinjected unilaterally in the RVLM of Wistar rats, and the effects on blood pressure (MAP) and heart rate were evaluated by telemetry. Empty liposomes (Lemp) were used as control. LAng elicited a significant pressor effect during daytime and bradycardia during nighttime that lasted for 5 and 3 days, respectively. These cardiovascular effects resulted in a significant attenuation of the circadian variations of MAP and heart rate. In the case of MAP, a significant inversion of the circadian rhythm was observed on day 2 after LAng microinjection. None of these effects were observed following microinjection of Lemp. Using this novel technique, it was possible to establish, in chronic conditions, the pressor effect of Ang-(1-7) at the RVLM. Moreover, our data unmasks a new physiological role for Ang-(1-7) at the level of the RVLM: modulation of the circadian rhythms of MAP and heart rate. Key Words: liposomes Ⅲ angiotensin-(1-7) Ⅲ cardiovascular effects Ⅲ rostral ventrolateral medulla Ⅲ Blood pressure Ⅲ heart rate S everal recent studies indicate that peptides of the reninangiotensin system (RAS) may act as important neuromodulators, especially in the brain medullary areas related to the tonic and reflex control of arterial pressure. 1 Experimental evidence was obtained following site-specific microinjections of these peptides; however, because of their very short in vivo half-life, only their acute cardiovascular effects could be observed. 2-6 Therefore, information is still lacking on the long-term effects of these peptides, which should allow a better understanding of their physiopathological role. To address this question, injectable microreservoirs, which could act as sustained release systems in specific sites of the brain, have to be developed. Liposomes appear to be good candidates because of their biocompatibility and their recognized potential for the encapsulation and delivery of polypeptides in vivo. 7 Moreover, liposome encapsulation was previously shown to produce a marked prolongation of the peripheral effect of some vasoactive peptides, including angiotensin (Ang) II, 8 vasopressin, 9 and vasoactive intestinal peptide. 10 In this work, we evaluated the potential of liposomes for the sustained release of RAS peptides in a specific site of the brain. Ang-(1-7) was selected for this study because of its known cardiovascular effects at the level of the rostral ventrolateral medulla (RVLM) 2-5 and because of the considerable interests in its long-term physiopharmacological effects. 11 More specifically, ...
Livers were evaluated for hepatocytes histological alterations, peroxidase activity, and apoptosis. Increased proportions of swollen and apoptotic hepatocytes were observed in animals treated with Glu compared to animals treated with saline or MA. The peroxidase activity was also enhanced in the liver of animals that received Glu. Cotreatment with AA reduced the extent of histological changes, the apoptotic index, and the peroxidase activity to levels corresponding to the control group. Moreover, the association with AA did not affect the hepatic uptake of Sb and the ability of Glu to reduce the liver and spleen parasite loads in infected mice. In conclusion, our data supports the use of pentavalent antimonials with low residue of Sb(III) and the association of pentavalent antimonials with AA, as effective strategies to reduce side effects in antimonial therapy.
The Brazilian generic drugs policy was implemented in 1999 with the aim of stimulating competition in the market, improve the quality of drugs and improve the access of the population to drug treatment. The process of implementing this policy allowed the introduction and discussion of concepts that had never before been used in the context of drug registration in Brazil: bioavailability, bioequivalence, pharmaceutical equivalence, generic drugs, biopharmaceutical classification system, biowaiver. The present article provides definitions for these concepts in the context of Brazilian legislation as well as a historical and chronological description of the implementation of the generic drugs policy in Brazil, including a list of current generic drug legislation. This article contributes to the understanding of the Brazilian generic drugs policy and facilitates the search for information concerning the legal requirements for registration of drugs in Brazil.
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