The potential role of amlodipine on experimentally induced bacterial rhinosinusitis / O papel potencial da amlodipina na rinossinusite bacteriana induzida experimentalmente

Abstract Introduction: Antibiotics are frequently used for the treatment of rhinosinusitis. Concerns have been raised regarding the adverse effects of antibiotics and growing resistance. The lack of development of new antibiotic compounds has increased the necessity for exploration of non-antibiotic compounds that have antibacterial activity. Amlodipine is a non-antibiotic compound with anti-inflammatory activity. Objective: In this study we aimed to investigate the potential role of amlodipine in the treatment of rhinosinusitis by evaluating its effects on tissue oxidative status, mucosal histology and inflammation. Methods: Fifteen adult albino guinea pigs were inoculated with Staphylococcus aureus and treated with saline, cefazolin sodium, or amlodipine for 7 days. The control group was composed by five healthy guinea pigs. Animals were sacrificed after the treatment. Histopathological changes were identified using Hematoxylin-Eosin staining. Inflammation was assessed by Polymorphonuclear Leukocyte infiltration density. Tissue levels of antioxidants (superoxide dismutase, glutathione) and an oxidative product (malondialdehyde) were determined. Results: In rhinosinusitis induced animals, amlodipine reduced loss of cilia, lamina propria edema and collagen deposition compared to placebo (saline) and although not superior to cefazolin, amlodipine decreased polymorphonuclear leukocyte infiltration. The superoxide dismutase activity and glutathione levels were reduced, whereas the malondialdehyde levels were increased significantly in all three-treatment groups compared to the control group. Amlodipine treated group showed significantly increased superoxide dismutase and glutathione levels and decreased malondialdehyde levels compared to all treatment groups. Conclusion: The non-antibiotic compound amlodipine may have a role in acute rhinosinusitis treatment through tissue protective, antioxidant and anti-inflammatory mechanisms.

Resumo Introdução: Antibióticos são frequentemente usados para o tratamento de rinossinusite. Questões têm sido levantadas sobre os efeitos adversos dos antibióticos e a resistência crescente. A falta de desenvolvimento de novos compostos antibióticos aumentou a necessidade da exploração de compostos não antibióticos que têm atividade antibacteriana. A amlodipina é um composto não antibiótico com atividade anti-inflamatória. Objetivo: O objetivo desse estudo foi investigar o papel potencial da amlodipina no tratamento da rinossinusite, avaliando seus efeitos sobre o estado oxidativo do tecido, histologia da mucosa e inflamação. Método: Quinze cobaias albinas adultas foram inoculadas com Staphylococcus aureus e tratadas com solução salina, cefazolina ou amlodipina durante sete dias. O grupo controle incluiu cinco cobaias saudáveis. Os animais foram sacrificados após o tratamento. Alterações histopatológicas foram identificadas com a coloração de hematoxilina-eosina. A inflamação foi avaliada pela densidade de infiltração de leucócitos polimorfonucleares. Foram determinados os níveis teciduais de antioxidantes (superóxido dismutase, glutationa) e um produto de oxidação (malondialdeído). Resultados: Em animais com rinossinusite induzida, a amlodipina reduziu a perda dos cílios, edema da lâmina própria e deposição de colágeno em comparação com o grupo placebo (solução salina) e embora não seja superior à cefazolina, a amlodipina diminuiu a infiltração de leucócitos polimorfonucleares. Os níveis de atividade da superóxido dismutase e glutationa foram reduzidos, enquanto os níveis de malondialdeído aumentaram significativamente nos três grupos de tratamento em comparação ao grupo controle. O grupo tratado com amlodipina apresentou aumento significante dos níveis de superóxido dismutase e glutationa e diminuição dos níveis de malondialdeído em comparação com todos os grupos de tratamento. Conclusão: O composto não antibiótico amlodipina pode ter um papel no tratamento da rinossinusite aguda através de mecanismos protetores de tecido, antioxidantes e anti-inflamatórios.

The potential role of amlodipine on experimentally induced bacterial rhinosinusitis.

INTRODUCTION: Antibiotics are frequently used for the treatment of rhinosinusitis. Concerns have been raised regarding the adverse effects of antibiotics and growing resistance. The lack of development of new antibiotic compounds has increased the necessity for exploration of non-antibiotic compounds that have antibacterial activity. Amlodipine is a non-antibiotic compound with anti-inflammatory activity. OBJECTIVE: In this study we aimed to investigate the potential role of amlodipine in the treatment of rhinosinusitis by evaluating its effects on tissue oxidative status, mucosal histology and inflammation. METHODS: Fifteen adult albino guinea pigs were inoculated with Staphylococcus aureus and treated with saline, cefazolin sodium, or amlodipine for 7 days. The control group was composed by five healthy guinea pigs. Animals were sacrificed after the treatment. Histopathological changes were identified using Hematoxylin-Eosin staining. Inflammation was assessed by Polymorphonuclear Leukocyte infiltration density. Tissue levels of antioxidants (superoxide dismutase, glutathione) and an oxidative product (malondialdehyde) were determined. RESULTS: In rhinosinusitis induced animals, amlodipine reduced loss of cilia, lamina propria edema and collagen deposition compared to placebo (saline) and although not superior to cefazolin, amlodipine decreased polymorphonuclear leukocyte infiltration. The superoxide dismutase activity and glutathione levels were reduced, whereas the malondialdehyde levels were increased significantly in all three-treatment groups compared to the control group. Amlodipine treated group showed significantly increased superoxide dismutase and glutathione levels and decreased malondialdehyde levels compared to all treatment groups. CONCLUSION: The non-antibiotic compound amlodipine may have a role in acute rhinosinusitis treatment through tissue protective, antioxidant and anti-inflammatory mechanisms.