Marcos Sobral

Leishmanicidal, trypanocidal, and cytotoxic activities of endophytic fungi associated with bioactive plants in Brazil

One hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive Brazilian plant species Ageratum myriadenia, Palicourea tetraphylla, Piptadenia adiantoides, and Trixis vauthieri. All fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. The crude extracts were tested in bioassay panels using Leishmania amazonensis, Trypanosoma cruzi, the enzyme trypanothione reductase (TryR) from Trypanosoma cruzi, and three human cancer cell lines. Thirty-three extracts (27.2%) exhibited at least one biological activity. Seventeen extracts (14%) were cytotoxic against one or more human cancer cell line with the IC50 values ranged of >0.2 to 25 µg/mL. Twenty-four extracts (19.8%) inhibited the activity of TryR, and three showed ability to inhibit the growth of T. cruzi above 60% and their IC50 values ranged among 1 to 10 µg/mL. Eleven extracts (9%) were able to inhibit the growth of L. amazonensis and showed with IC50 values ranged among 4.6 to 24.4 µg/mL. The endophytic fungi were identified as belonging to the genera Alternaria, Arthrinium, Cochliobolus, Colletotrichum, Penicillium, Fusarium, and Gibberella. An interesting result was obtained for the bioactive isolates UFMGCB 508, 537, 899 and 903, which were related to fungi associated with medicinal plants native to Asia, Australia, Africa, and Polynesia. These results indicate that bioactive plants living in Brazilian ecosystems are a potential host of endophytic fungi able to produce bioactive prototype molecules for drug development against neglected tropical diseases.

Essential oil composition of fruit colour varieties of Eugenia brasiliensis Lam.

Eugenia brasiliensis Lam. is a variable species concerning fruit colour, with three recognized varieties. However, the definition of varieties is not easy for Myrtaceae species and not widely accepted. Two fruit colour varieties (purple and yellow) of E. brasiliensis had their essential oil composition analysed in order to give support to the existence of varieties for this species. Although, the major components in the leaf oil are the same monoterpenes for both varieties, α-pinene, β-pinene and 1,8-cineol, the purple fruit variety accumulates more oxygenated sesquiterpenes (33.9%) than the one with yellow fruits (3.8%). The major differences occurred in purple fruits that present as major components caryophyllene oxide (22.2%) and α-cadinol (10.4%), not found in the leaf oil, and the yellow fruit oil presented a similar composition as observed for the leaves. These fruit colour varieties of E. brasilensis can be considered as two distinct chemotypes, since the sesquiterpene pathway is more operant in the purple variety than in the yellow one, in which monoterpenes are mainly accumulated.

Biological Activities and Essential Oil Composition of Leaves of Blepharocalyx salicifolius

Infusions obtained from dried and fresh leaves of Blepharocalyx salicifolius were assessed in antibacterial (with S. aureus and E. coli), antiinflammatory, antinociceptive, antispasmodic and intestinal transit models. All samples analyzed showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. The highest activity was observed with the dried leaves against E. coli. An infusion from fresh leaves inhibited the stimulating action of acetylcholine on intestinal musculature (average inhibition 45%). Other biological assays gave no significant results with doses up to 300 and 600 mg/kg for dried and fresh material, respectively. The essential oil obtained from fresh leaves by hydrodistillation (0.9%) was analyzed by GC and GC/MS, where 42 components were identified. The main components were 1,8-cineole (25.2%), linalool (20.4%) and ß-caryophyllene (22.9%).

Anti-inflammatory activity of essential oil from leaves of Myrciaria tenella and Calycorectes sellowianus.

The GC-MS analysis revealed that the leaf essential oils of Myrciaria tenella (DC.) Berg and Calycorectes sellowianus O. Berg (Myrtaceae) were composed of 34 and 37 compounds, respectively. The main constituents of M. tenella oil were β-caryophyllene (25.1%), and spathulenol (9.7%), while for C. sellowianus were guaiol (13.1%) and β-caryophyllene (8.6%). The anti-inflammatory effect of both essential oils was investigated in vitro and in vivo. Both oils reduced significantly (p < 0.005) the treated neutrophils chemotaxis with 93% and 91% inhibition for M. tenella and C. sellowianus, respectively. However, in the systemic treatment with the essential oils (50u2009mg/kg p.o.) only the M. tenella oil was able to significantly reduce the carrageenan-induced paw edema with a similar effect to that observed for indomethacin (10u2009mg/kg), the positive control.

Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedelianaO. Berg, Myrtaceae

The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.

Four New Myrtaceae from Eastern Brazil

ABSTRACT Myrcia clavija Sobral, Myrciaria pilosa Sobral & Couto, Plinia longiacuminata Sobral, and Plinia subavenia Sobral are newly described and illustrated. Myrcia clavija, from montane forests of Minas Gerais, is related to M. hexasticha Kiaerskou, from which it differs by its 6-verticillate leaves, persistent bracteoles, and aristate calyx lobes. Myrciaria pilosa, from rocky fields of Bahia and forests of Minas Gerais, is close to M. floribunda (H. West ex Willdenow) O. Berg, differing by the pubescence of its leaves and flowers. Plinia longiacuminata and P. subavenia were collected from rainforests in coastal Bahia and Espírito Santo; the former is close to P. edulis (Vellozo) Sobral, differing from it by glabrous twigs and smaller leaves, and the latter is close to P. involucrata (O. Berg) McVaugh, from which it is distinguished by the glabrescence of leaves and fruits and by blades with the midvein adaxially sulcate. Comments on the conservation status of the species are also provided.

Leishmanicidal activities of the extract from Blepharocalyx salicifolius (Kunth) O. Berg, Myrtaceae

Crude ethanolic extracts from Blepharocalyx salicifolius (Kunth) O. Berg, Myrtaceae, was fractioned by Gel Permeation Chromatography, using SephadexTM LH-20 gel.Sixteen fractions were obtained and were supplied to cytotoxicity in vitro assay against Leishmania (L.) amazonensis amastigota cells. It was observed eight cytotoxic fractions against Leishmania (L.) amazonensis amastigota cells at range of 19 to 29 μg.mL-1. Two of them were not citotoxic against human peripheral blood mononuclear cell, with a great potential to isolation of more selective leishmanicidal substances.

Myrcia inconspicua (Myrtaceae), a New Species from Espírito Santo, Brazil

ABSTRACT Myrcia inconspicua L. Kollmann & Sobral, a new species from montane forests of the Brazilian state of Espírito Santo, is described and illustrated. The species is characterized by solitary, axillary flowers, an uncommon feature in the genus, and by its shrubby habit and dense red-brown indument of branches and leaves. It is tentatively related to Myrcia anomala Cambessèdes, a subshrub from southern and central Brazil that occasionally bears solitary flowers.

A New Name and Three New Combinations in Brazilian Myrtaceae

ABSTRACT Four nomenclatural arrangements are proposed in Brazilian Myrtaceae: in Myrcia, one new name (M. neorostrata for Aulomyrcia rostrata) and two new combinations (M. densa for Calyptranthes densa and M. tenuifolia for Aulomyrcia tenuifolia), and one new combination in Myrciaria, M. glazioviana, based on Eugenia cabelludo var. glazioviana.

Antinociceptive and anti-inflammatory effects of the essential oil of Eugenia candolleana DC., Myrtaceae, on mice

Eugenia candolleana DC. (Myrtaceae), conhecida popularmente como murta ou murtinha, e uma especie vegetal sem estudos quimicos e farmacologicos descritos na literatura, distribuida no Nordeste brasileiro, principalmente, na Zona da Mata. Na medicina popular do Estado de Sergipe e utilizada no tratamento de disturbios febris e da dor. O presente estudo buscou avaliar as possiveis atividades antinociceptiva e antiinflamatoria do oleo essencial extraido das folhas de E. candolleana DC (OEEc) em roedores. A administracao intraperitoneal (i.p.) do OEEc (25, 50 e 100 mg/kg) reduziu significativamente o numero de contorcoes no teste das contorcoes abdominais e a duracao da lambida da pata na segunda fase do teste da formalina (p < 0,001). Entretanto, a administracao do OEEc nao alterou o tempo de reacao no teste da placa quente. No experimento de peritonite induzido por carragenina, o OEEc reduziu de forma significativa (p < 0,01) a migracao de leucocitos para a cavidade peritoneal. Os resultados obtidos sugerem que o OEEc possui acao antinociceptiva, provavelmente mediado por mecanismos perifericos, e acao antiinflamatoria.