Anti-inflammatory and antinociceptive activities of methanolic extract from red seaweed Dichotomaria obtusata

Abstract

The aim of the present work was to investigate the anti-inflammatory and antinociceptive effects of methanolic extract from D. obtusata using classic models in mice (croton oil-induced ear edema and acetic acid-induced writhing) and a phospholipase A 2 activity test. Qualitative analysis of the chemical composition of seaweed was also determined by extraction with solvents of increasing polarity and precipitation and color tests. Results of qualitative chemical study showed the presence of lactonic and phenolic compounds, reduced carbohydrates, other sugars, flavonoids, fatty compounds, triterpenes and steroids. The extract inhibited mouse ear edema in a dose-dependent manner with an efficacy higher than 90% and a mean effective dose of 4.87μg/ear, while intraperitoneal administration presented a moderate activity. The extract did not inhibit phospholipase A 2 activity. In the writhing test, the intraperitoneal administration of the extract showed a strong antinociceptive activity (80.2%), while the oral route showed a lower efficacy. In conclusion, this study demonstrated the anti-inflammatory and antinociceptive effects of methanol extract of D. obtusata in experimental models, suggesting its therapeutic potential in the treatment of peripheral painful and/or inflammatory pathologies. O objetivo do presente trabalho foi investigar os efeitos antiinflamatórios e antinociceptivos de um extrato metanólico de D. obtusata, utilizando modelos clássicos em ratos (teste do edema de orelha induzido por óleo de cróton e teste de contorções induzidas por ácido acético) e um teste de atividade de fosfolipase A 2 . A análise qualitativa da composição química das algas foi também determinada através de extração com solventes de polaridade crescente e testes de precipitação e cor. Os resultados do estudo de química qualitativa mostraram a presença de compostos lactônicos e fenólicos, hidratos de carbono reduzidos e outros açúcares, flavonoides, compostos graxos, triterpenos e esteroides. O extrato inibiu o edema de orelha dos ratos de um modo dependente da dose com eficácia superior a 90% e dose média efetiva de 4.87μg/orelha, enquanto a administração intraperitoneal apresentou atividade moderada. O extrato não inibiu a atividade da fosfolipase A 2 . No teste de contorção, a administração intraperitoneal do extrato mostrou forte atividade antinociceptiva (80,2%), enquanto a administração oral mostrou menor eficácia. Em conclusão, este estudo demonstrou os efeitos antiinflamatórios e antinociceptivos do extrato metanólico de D. obtusata em modelos experimentais, sugerindo seu potencial terapêutico no tratamento de patologias dolorosas periféricas e/ou inflamatórias. UnitermsUnitermos: Dichotomaria obtusata/farmacognosia. Dichotomaria obtusata/atividade antiinflamatória. Dichotomaria obtusata/atividade antinociceptiva. Teste do edema de orelha. Teste de contorções.

Current Trends on Seaweeds: Looking at Chemical Composition, Phytopharmacology, and Cosmetic Applications

“…An increasing number of studies have reported that bioactive compounds found in seaweeds could have possible anti-inflammatory activities. Different metabolites with anti-inflammatory properties were isolated from seaweeds such as phlorotannins, polyphenols, glycosterols, polysaccharides, and polyunsaturated fatty acids (PUFAs) [5,252]. Several mechanisms could be involved in these anti-inflammatory properties such as the inhibition of toll-like receptors, phospholipase A2, cyclooxygenase and nitrite formation; and the increase of anti-inflammatory cytokines including IL-6r and IL-10 [252,253].…”

The Potential of Seaweeds as a Source of Functional Ingredients of Prebiotic and Antioxidant Value

“…Several studies have demonstrated that some extracts and compounds from a wide variety of algae have potential anti-inflammatory compounds. For example, [66] studied the anti-inflamatory capacity of methanolic extracts obtained from red seaweed Dichotomaria obtusata . Other authors [65] reported the enhanced anti-inflamatory ability of brown kelp Laminaria japonica by fermentation with Bacillus subtilis .…”