Diterpenes as lead molecules against neglected tropical diseases.

Nowadays, neglected tropical diseases (NTDs) are reported to be present everywhere. Poor and developing areas in the world have received great attention to NTDs. Drug resistance, safety profile, and various challenges stimulate the search for alternative medications. Plant-based drugs are viewed with great interest, as they are believed to be devoid of side effects. Diterpenes, a family of essential oils, have showed attractive biological effects. A systematic review of the literature was carried out to summarize available evidences of diterpenes against NTDs. For this, databases were searched using specific search terms. Among the 2338 collected reports, a total of 181 articles were included in this review. Of them, 148 dealt with investigations using single organisms, and 33 used multiple organisms. No mechanisms of action were reported in the case of 164 reports. A total of 93.92% were related to nonclinical studies, and 4.42% and 1.66% dealt with preclinical and clinical studies, respectively. The review displays that many diterpenes are effective upon Chagas disease, chikungunya, echinococcosis, dengue, leishmaniasis, leprosy, lymphatic filariasis, malaria, schistosomiasis, and tuberculosis. Indeed, diterpenes are amazing drug candidates against NTDs. Copyright © 2016 John Wiley & Sons, Ltd.

Trypanocidal and cytotoxic activities of essential oils from medicinal plants of Northeast of Brazil.

Chagas disease, caused by Trypanosoma cruzi, is an important cause of mortality and morbidity in Latin America. There are no vaccines available, the chemotherapy used to treat this illness has serious side effects and its efficacy on the chronic phase of disease is still a matter of debate. In a search for alternative treatment for Chagas disease, essential oils extracted from traditional medicinal plants Lippia sidoides, Lippia origanoides, Chenopodium ambrosioides, Ocimum gratissimum, Justicia pectorales and Vitex agnus-castus were investigated in vitro for trypanocidal and cytotoxic activities. Essential Oils were extracted by hydrodistillation and submitted to chemical analysis by gas chromatography/mass spectrometry. The concentration of essential oils necessary to inhibit 50% of the epimastigotes or amastigotes growth (IC(50)) and to kill 50% of trypomastigote forms (LC(50)) was estimated. The most prevalent chemical constituents of these essential oils were monoterpenes and sesquiterpenes. All essential oils tested demonstrated an inhibitory effect on the parasite growth and survival. L. sidoides and L. origanoides essential oils were the most effective against trypomastigote and amastigote forms respectively. No significant cytotoxic effects were observed in mouse peritoneal macrophages incubated with essential oils which were more selective against the parasites than mammalian cells. Taken together, our results point towards the use of these essential oils as potential chemotherapeutic agent against T. cruzi.

Volatile compounds and palynological analysis from pollen pots of stingless bees from the mid-north region of Brazil

ABSTRACT Samburá is the botanical pollen nectar agglutinated by salivary secretions of bees. Stingless bee pollen samples were collected in three periods of the year in Monsenhor Gil town, PI, Brazil, for extraction of volatile constituents by different techniques, analyzed by gas chromatography-mass spectrometry (GC-MS) and the palynological analysis used to identify the dominant pollen. Among the volatile compounds identified, kaur-16-ene, methyl and ethyl hexadecanoate, methyl linoleate and heneicosane were identified more frequently in the studied parameters: period of sample collection and extraction techniques used. The palynological analysis identified the pollen of Mimosa caesalpiniifolia Benth. as the dominant pollen in all samples studied.

In vitro antileishmanial activity and cytotoxicity of essential oil from Lippia sidoides Cham.

Leishmaniasis is a widespread tropical infection caused by different species of Leishmania protozoa. There is no vaccine available for Leishmania infections and conventional treatments are very toxic to the patients. Therefore, antileishmanial drugs are urgently needed. In this study we have analyzed the effects of essential oils from Lippia sidoides (LSEO) and its major compound thymol on the growth, viability and ultrastructure of Leishmania amazonensis. The essential oil and thymol showed significant activity against promastigote forms of L. amazonensis, with IC(50)/48 h of 44.38 and 19.47 µg/mL respectively. However, thymol showed toxicity against peritoneal macrophages and low selectivity against the promastigotes when compared with the crude LSEO. On the other hand, no cytotoxic effect was observed in macrophages treated with the crude essential oil. Incubation of L. amazonensis-infected macrophages with LSEO showed a marked reduction in amastigote survival within the macrophages. Significant morphological alterations as accumulation of large lipid droplets in the cytoplasm, disrupted membrane and wrinkled cells were usually seen in treated parasites. The LSEO's activity against both promastigote and the amstigote forms of L. amazonensis, together with its low toxicity to mammalian cells, point to LSEO as a promising agent for the treatment of cutaneous leishmaniasis.

Fenóis totais, atividade antioxidante e constituintes químicos de extratos de Anacardium occidentale L., Anacardiaceae / Total phenolics, antioxidant activity and chemical constituents from extracts of Anacardium occidentale L., Anacardiaceae

O presente artigo relata o isolamento e identificação do palmitato, oleato e linoleato de sitosterila, sitosterol, estigmasterol, 3-O-β-D-galactopiranosídeo do sitosterol, 3-O-β-Dgalactopiranosídeo do estigmasterol, 3-O-β-D-glicopiranosídeo do sitosterol e uma mistura de ácidos anacárdicos (monoeno e dieno) do extrato etanólico de cascas do caule de Anacardium occidentale L., Anacardiaceae, bem como do sitosterol, estigmasterol, lupeol, β-amirina, catequina e epicatequina do extrato etanólico do tegumento da castanha de caju in natura. Os extratos EtOH da casca e do tegumento foram avaliados quanto ao conteúdo de fenóis totais e atividade antioxidante. O extrato etanólico das cascas do caule apresentou maior conteúdo de compostos fenólicos e percentual de atividade antioxidante.

This paper describes the isolation and identification of a mixture of sitosteryl ester derivatives of fatty acids (palmitic, oleic and linoleic), sitosterol, stigmasterol, sitosterol-3-O-β-galactopyranoside, stigmasterol-3-O-β-galactopyranoside, sitosterol-3-O-β-glucopyranoside and a mixture of anacardic acids (monoene and diene) from stem bark of Anacardium occidentale L., Anacardiaceae, as well as sitosterol, stigmasterol, lupeol, β-amyrin, catechin and epicatechin from in natura cashew nut testa. Ethanol extracts from stem bark and testa were analyzed for antioxidant activity and total phenol content. The ethanol extract from stem bark exhibited the maximum of antioxidant activity and phenol content.