Isolamento e identificação de metabólitos de polimetoxiflavonas na urina de ratos e sua avaliação sobre a proteína transferidora de triglicerídeo microssomal
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Data
2016-10-31
Autores
Gonçalves, Danielle Raquel [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
As polimetoxiflavonas (PMF) são uma subclasse do grupo dos flavonoides cítricos, as quais são conhecidas devido à ação antioxidante, anti-inflamatória, hipolipidêmica e anticâncer; além de elevada biodisponibilidade. Estudos recentes demonstram que os metabólitos gerados a partir das PMF são biologicamente ativos, e possuem efeitos benéficos superiores aos compostos originais. Objetivo: Este trabalho teve por objetivo, isolar e identificar metabólitos das PMF a partir da urina de ratos, e avaliar sua atividade biológica sobre a proteína transferidora de triglicerídeo microssomal (MTP) em células Huh7.5. Métodos: Trinta ratos Wistar adultos foram separados em 3 grupos (n = 10) e administrados com 200 mg/kg/dia de tangeretina (TAN), nobiletina (NOB) ou heptametoxiflavona (HMF), durante 15 dias. Os metabólitos foram extraídos da urina, isolados por cromatografia líquida preparativa, e identificados por cromatografia líquida de alta eficiência (HPLC-ESI-MS) acoplada ao detector de UV (PDA). A ação dos metabólitos sobre a atividade da MTP foi avaliada por método fluorométrico. Resultados: Foram isolados metabólitos glucuronídeos com m/z [M+H]+ 565 amu (unidade de massa atômica), 551 amu, 535 amu, 521 amu, 505 amu; além de metabólitos hidroxilados com m/z [M+H]+ 419 amu, 405 amu, 389 amu, 375 amu, 359 amu, 329 amu, 315 amu. Os metabólitos TAN-4'-glucuronídeo (TAN-G1), TAN-dihidroxi-glucuronídeo (TAN-G2), TAN-4'-monohidroxilada (TAN-OH1), TAN-monohidroxilada (TAN-OH2), NOB-glucuronídeo (NOB-G), NOB-monohidroxilada (NOB-OH), HMF- monohidroxilada (HMF-OH) foram identificados e avaliados in vitro. TAN-OH1 e NOB-OH reduziram a atividade da MTP, e o HMF-OH apresentou efeito superior quando comparado ao seu composto de origem. As PMF obtidas de extrato seco da caca de laranjas, administradas nos ratos, não apresentaram efeito sobre a MTP. Conclusão: Estes dados mostram métodos viáveis para o isolamento dos metabólitos da urina após administração oral das PMF; reforçam a hipótese de que são estes os responsáveis pelos benefícios biológicos observados à saúde a partir do consumo dietético das PMF, podendo contribuir, portanto, para a prevenção e tratamento de dislipidemias, uma vez que foram capazes de reduzir a atividade da MTP.
The polymethoxylated flavones (PMF) are a subclass of flavonoids citrus, which are known because of their antioxidant, anti-inflammatory, hypolipidemic and anticancer properties; besides the high bioavailability that they present. Recent studies show that the metabolites generated from the PMF are biologically active and have beneficial effects greater than the original compounds. Objective: This study aimed to isolate and identify metabolites of PMF from the urine of rats, and evaluate its biological activity upon microsomal triglyceride transfer protein (MTP) in Huh7.5 cells. Methods: Thirty adult male Wistar rats were separated into 3 groups (n = 10) and fed with 200 mg / kg / day with tangeretin (TAN), nobiletina (NOB) or heptametoxiflavona (HMF) for 15 days. The metabolites were extracted from urine, isolated by preparative liquid chromatography and identified by high-performance liquid chromatography (HPLC-ESI-MS) coupled with UV detector (PDA). The action of the metabolites on the MTP activity was evaluated by fluorometric method. Results: We isolated glucuronide metabolites with m / z [M + H] + 565 amu (atomic mass unit), 551 amu, 535 amu, 521 amu, 505 amu; addition to the hydroxilated metabolites with m / z [M + H] + 419 amu, 405 amu, 389 amu, 375 amu, 359 amu, 329 amu, 315 amu. The TAN-4'-glucuronide metabolites (TAN-G1), TAN-dihydroxy-glucuronide (TAN-G2), TAN-4'-monohidroxilada (TAN-OH1), TAN-monohydroxylada (TAN-OH2), NOB-glucuronide (NOB-G) NOB-monohydroxylada (NOB-OH), HMF- monohydroxylada (HMF-OH) have been identified and evaluated in in vitro assay. TAN-OH1 and NOB-OH reduced the MTP activity, and HMF-OH showed higher effect compared to its parent compound. PMF obtained from dry extract of orange peel, administered in rats, showed no effect on the MTP. Conclusion: These data show viable methods for isolation of the metabolites from urine after oral administration of PMF; they also reinforce the hypothesis that the metabolites are responsible for the biological benefits observed from dietary intake of PMF and thus, they can contribute to the prevention and treatment of dyslipidemias, since they were able to reduce the MTP activity.
The polymethoxylated flavones (PMF) are a subclass of flavonoids citrus, which are known because of their antioxidant, anti-inflammatory, hypolipidemic and anticancer properties; besides the high bioavailability that they present. Recent studies show that the metabolites generated from the PMF are biologically active and have beneficial effects greater than the original compounds. Objective: This study aimed to isolate and identify metabolites of PMF from the urine of rats, and evaluate its biological activity upon microsomal triglyceride transfer protein (MTP) in Huh7.5 cells. Methods: Thirty adult male Wistar rats were separated into 3 groups (n = 10) and fed with 200 mg / kg / day with tangeretin (TAN), nobiletina (NOB) or heptametoxiflavona (HMF) for 15 days. The metabolites were extracted from urine, isolated by preparative liquid chromatography and identified by high-performance liquid chromatography (HPLC-ESI-MS) coupled with UV detector (PDA). The action of the metabolites on the MTP activity was evaluated by fluorometric method. Results: We isolated glucuronide metabolites with m / z [M + H] + 565 amu (atomic mass unit), 551 amu, 535 amu, 521 amu, 505 amu; addition to the hydroxilated metabolites with m / z [M + H] + 419 amu, 405 amu, 389 amu, 375 amu, 359 amu, 329 amu, 315 amu. The TAN-4'-glucuronide metabolites (TAN-G1), TAN-dihydroxy-glucuronide (TAN-G2), TAN-4'-monohidroxilada (TAN-OH1), TAN-monohydroxylada (TAN-OH2), NOB-glucuronide (NOB-G) NOB-monohydroxylada (NOB-OH), HMF- monohydroxylada (HMF-OH) have been identified and evaluated in in vitro assay. TAN-OH1 and NOB-OH reduced the MTP activity, and HMF-OH showed higher effect compared to its parent compound. PMF obtained from dry extract of orange peel, administered in rats, showed no effect on the MTP. Conclusion: These data show viable methods for isolation of the metabolites from urine after oral administration of PMF; they also reinforce the hypothesis that the metabolites are responsible for the biological benefits observed from dietary intake of PMF and thus, they can contribute to the prevention and treatment of dyslipidemias, since they were able to reduce the MTP activity.
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Palavras-chave
Polimetoxiflavonas, Metabólitos das PMF, Cromatografia líquida, Atividade da MTP, Dislipidemias, Polymethoxylated flavones, PMF metabolites, Liquid chromatography, MTP activity, Dyslipidemias