Antinociceptive and anti-inflammatory effects of octacosanol from the leaves of Sabicea grisea var. grisea in mice.

Sabicea species are used in the Amazon for treatment of fever and malaria, which suggests that its chemical constituents may have some effect on pain and inflammation. Phytochemical analysis of the hexane fraction obtained from the crude ethanol extract from Sabicea grisea var. grisea Cham. & Schltdl (Rubiaceae), an endemic plant in Brazil, resulted in the isolation of octacosanol. This study investigated the antinociceptive and anti-inflammatory effects of the octacosanol in different experimental models. The crude ethanolic extract and hexane fraction obtained from the leaves of S. grisea produced an inhibition of acetic acid-induced pain. Moreover, octacosanol isolated from the hexane fraction produced a significant inhibition of pain response elicited by acetic acid. Pre-treatment with yohimbine, an alpha 2-adrenergic receptor antagonist, notably reversed the antinociceptive activity induced by octacosanol in the abdominal constriction test. Furthermore, mice treated with octacosanol did not exhibit any behavioral alteration during the hot plate and rota-rod tests, indicating non-participation of the supraspinal components in the modulation of pain by octacosanol with no motor abnormality. In the formalin test, octacosanol did not inhibit the licking time in first phase (neurogenic pain), but significantly inhibited the licking time in second phase (inflammatory pain) of mice. The anti-inflammatory effect of octacosanol was evaluated using carrageenan-induced pleurisy. The octacosanol significantly reduced the total leukocyte count and neutrophils influx, as well as TNF-α levels in the carrageenan-induced pleurisy. This study revealed that the mechanism responsible for the antinociceptive and anti-inflammatory effects of the octacosanol appears to be partly associated with an inhibition of alpha 2-adrenergic transmission and an inhibition of pathways dependent on pro-inflammatory cytokines. Finally, these results demonstrated that the octacosanol from the leaves of S. grisea possesses antinociceptive and anti-inflammatory activities, which could be of relevance for the pharmacological control of pain and inflammatory processes.

Estudo fitoquímico e avaliação das atividades moluscicida e larvicida dos extratos da casca do caule e folha de Eugenia malaccensis L. (Myrtaceae) / Phytochemical studies of the extracts of stem bark and leaves of Eugenia malaccensis L. (Myrtaceae) and evaluation of their molluscicidal and larvicidal activities

Eugenia malaccensis L. (Syzygium malaccensis Merr.& Perry), denominada comumente de jambo vermelho, é uma espécie arbórea de ocorrência comum no Brasil e faz parte das plantas medicinais do Estado de Alagoas. Estudos químicos anteriores com E. malaccensis foram realizados com plantas coletadas na Ásia, Oceania e na América Central. Este trabalho descreve o estudo químico do extrato etanólico das folhas e cascas de um espécimem coletado no Estado de Alagoas, Brasil. Considerando-se a escassa literatura sobre o potencial moluscicida e larvicida dessa espécie, buscou-se testar estas atividades contra caramujos Biomphalaria glabrata Say, e frente às larvas do mosquito Aedes aegypti L. Os extratos etanólicos da casca do caule e das folhas foram inativos frente às larvas de Aedes aegypti na concentração de 500 μg/mL, porém, ativos contra Biomphalaria glabrata (CL50 = 42,53 e 41,90 mg/mL, respectivamente). O estudo químico levou ao isolamento e identificação de 5,7,3',4',5'-penta-hidroxi-flavonol (1), 5,7,3',5'-tetra-hidroxi-4'-metoxi-flavonol (2), ácido 3,4,5-tri-hidroxibenzóico (3) e ácido 3-acetil-urs-12-en-28-óico (4) das folhas e da casca do caule. O composto 4 é isolado pela primeira vez no gênero Eugenia. As estruturas desses compostos foram estabelecidas através de estudos no IV, de RMN ¹H e 13C e comparação com dados da literatura.

Eugenia malaccensis L. (Syzygium malaccensis Merr. & Perry), popularly known in Brazil as jambo vermelho, is a very common tree and one of the medicinal plants of Alagoas State, Brazil. Previous chemical studies with E. malaccensis have been carried out with native plants from Asia, Oceania, and Central America. This work describes the chemical study of E. malaccensis L., a specimen collected in Alagoas State. Considering that studies on the molluscicidal and larvicidal potential of E. malaccensis were not reported, this work aimed to test its molluscicidal activity against Biomphalaria glabrata snails and larvicidal activity against Aedes aegypti mosquitos. The ethanolic stem bark and leaf extracts were inactive towards Aedes aegypti larvae. The ethanolic stem bark and leaf extract were active against Biomphalaria glabrata with CL50 = 42.53 and 41.90 mg/mL, respectively. 5,7,3',4',5'-Penta-hydroxy-flavonol (1), 5,7,3',5'-tetra-hydroxy-4'-methoxy-flavonol (2), 3,4,5-tri-hydroxybenzoic acid (3) and 3-acetyl-urs-12-en-28-oic acid (4) were isolated and identified from the leaves and stem bark. The acid 3b-O-acetyl-urs-12-en-28-oic is for the first time isolated from the genus Eugenia. The structures of the compounds have been established by IR, ¹H and 13C NMR spectral analysis and by comparison with literature data.