Antiedematogenic activity of the indole derivative N-salicyloyltryptamine in animal models

ABSTRACT The N-salicyloyltryptamine (NST) is an indole derivative compound analogue to the alkaloid N-benzoyltryptamine. In the present study, the antiedematogenic activity of NST was investigated in animal models. Firstly, the acute toxicity for NST was assessed according to the OECD Guideline no. 423. The potential NST-induced antiedematogenic activity was evaluated by carrageenan-induced paw edema in rats, as well as by dextran-, compound 48/80-, histamine-, serotonin-, capsaicine-, and prostaglandin E2-induced paw edema in mice. The effect of NST on compound 48/80-induced ex vivo mast cell degranulation on mice mesenteric bed was investigated. No death or alteration of behavioral parameters was observed after administration of NST (2000 mg/kg, i.p.) during the observation time of 14 days. The NST (100 and 200 mg/kg, i.p.) inhibited the carrageenan-induced edema from the 1st to the 5th hour (**p<0.01; ***p<0.001). The edematogenic activity induced by dextran, compound 48/80, histamine, serotonin, capsaicin, and prostaglandin E2 was inhibited by NST (100 mg/kg, i.p.) throughout the observation period (**p<0.01; ***p<0.001). The pretreatment with NST (50, 100 or 200 mg/kg, i.p) attenuates the compound 48/80-induced mast cell degranulation (**p<0.01; ***p<0.001). Thus, the inhibition of both mast cell degranulation and release of endogenous mediators are probably involved in the NST-induced antiedematogenic effect.

Anti-inflammatory activity and acute toxicity studies of hydroalcoholic extract of Herissantia tiubae

ABSTRACT Hydroalcoholic extract of aerial parts of Herissantia tiubae (K. Schum.) Brizicky, Malvaceae, was evaluated in experimental models of inflammation and toxicity. For toxicity assays, male and female Swiss mice were orally treated with hydroalcoholic extract of H. tiubae (2000 mg/kg) and analyzed by consumption of water and food, body weight, mortality and rates of major organ weights, as well as biochemical and hematological indexes. For anti-inflammatory effect, phlogistic agents such as carrageenan or acetic acid were used to evaluate paw edema, cell migration and cytokine production. It was also investigated the hydroalcoholic extract of H. tiubae in RAW 264.7 macrophage lineage by nitric oxide and cytokine productions. Swiss mice treated with hydroalcoholic extract of H. tiubae showed low toxicity and (50 or 100 mg/kg) was able to reduce significantly (p < 0.01, p < 0.001) polymorphonuclear cell migration, TNF-α and IL-1β production in the carrageenan-induced peritonitis. However the hydroalcoholic extract of H. tiubae (50, 100 or 200 mg/kg) did not reduce carrageenan-induced paw edema. Additionally, hydroalcoholic extract of H. tiubae did not present cytotoxicity at concentrations of 6.25, 12.5, 25 or 50 µg/ml but induced significantly decrease of NO, TNF-α and IL-6 production in macrophage lineage. This study suggests that hydroalcoholic extract of H. tiubae has anti-inflammatory activity by inhibiting cell migration mainly by decreasing the inflammatory cytokine levels at the inflamed site independently of the anti-edematogenic effect.

Natural products inhibitors of the angiotensin converting enzyme (ACE): a review between 1980 - 2000 / Produtos naturais inibidores da enzima conversora de angiotensina (ECA): uma revisão entre 1980 - 2000

Inhibition of Angiotensin Converting Enzyme (ACE) is a modern therapeutic target in the treatment of hypertension. Within the enzyme cascade of the renin-angiotensin system, ACE removes histidyl-leucine from angiotensin I to form the physiologically active octapeptide angiotensin II, one of the most potent known vasoconstrictors. Therefore, a rationale for treating hypertension would be to administer drugs or natural compounds which selectively inhibit ACE. The present work constitutes a review of the literature of plants and chemically defined molecules from natural sources with in vitro anti-hypertensive potential based on the inhibition of ACE. The review refers to 321 plants, the parts utilized, type of extract and whether they are active or not. It includes also the names of 158 compounds isolated from higher plants, marine sponges and algae, fungi and snake venom. Some aspects of recent research with natural products directed to produce anti-hypertensive drugs are discussed. In this review, 148 references were cited.

A inibição da Enzima Conversora da Angiotensina (ECA) é um alvo terapêutico moderno e eficaz no tratamento da hipertensão arterial. Na cascata enzimática que envolve o sistema renina-angiotensina, a ECA promove a remoção dos aminoácidos histidil-leucina da angiotensina I para formar o octapeptídio angiotensina II, a qual é fisiologicamente ativa em diversos sistemas, e considerado como um dos mais potentes vasoconstrictores endógenos conhecido. Portanto, uma racionalidade no tratamento da hipertensão seria administrar drogas ou compostos de origem natural que inibam seletivamente a ECA. O presente estudo constitui uma revisão da literatura sobre plantas e moléculas de origem natural com potencial anti-hipertensivo, baseado na inibição in vitro da ECA. A revisão referencia 321 plantas, partes usadas, tipo de extrato e se é ativo ou não. Inclui ainda o nome de 158 compostos isolados de plantas superiores, esponjas e algas marinhas, fungos e venenos de cobra. Alguns aspectos de pesquisa recente com produtos naturais direcionados à produção de drogas anti-hipertensivas também são discutidos. Nesta revisão 148 referências foram consultadas.