In vitro antileishmanial and antitrypanosomal activity of compounds isolated from the roots of Zanthoxylum tingoassuiba

Abstract Five coumarins (5,7,8-trimethoxycoumarin (1), sabandin (2), cubreuva lactone (3), 5,7-dimethoxycoumarin (5) and braylin (6)), seven furoquinoline alkaloids (isopimpinelin (4), pteleine (7), maculine (8), skimianine (10), robustine (11), y-fagarine (12) and dictamine (13) and the furofuran type lignin syringaresinol (9)) have been identified for the first time in the roots of Zanthoxylum tingoassuiba A. St.-Hil., Rutaceae. Pure compounds 1, 6, 9, 12 were tested against Leishmania amazonensis parasites and epimastigotes forms of Trypanosoma cruzi. All the tested products displayed an antiparasitic activity similar to that of the positive controls (benznidazole and amphotericin B). Compound 9 was the most active against both parasites with IC50 values of 11.98 µM and 7.55 µM against L. amazonensis and T. cruzi, respectively.

In vitro antibacterial effects of Zanthoxylum tingoassuiba root bark extracts and two of its alkaloids against multiresistant Staphylococcus aureus

ABSTRACT The emergence of multiresistant strains of bacteria reinforces the need to search for new compounds able to combat resistant organisms. Medicinal plants are a great resource of bioactive substances, providing the possibility of obtaining molecules with potential antimicrobial activity. The aim of the present study is the evaluation of the antibacterial activity of extracts and alkaloids isolated from the root bark of Zanthoxylum tingoassuiba A. St.-Hil., Rutaceae, against four resistant clinical isolates and Staphylococcus aureus ATCC 25923. The dichloromethane and methanol extracts were fractionated by chromatography on silica gel, leading to the isolation of dihydrocheleryhtrine and N-methylcanadine, identified by Nuclear Magnetic Resonance spectroscopy. The antibacterial activity of the extracts and isolated compounds was evaluated by the disc diffusion method and the minimum inhibitory concentration was determined. The dichloromethane extract was the most active against all the tested strains and the two pure alkaloids were more active than the extracts. The anti-MRSA activity of the two benzophenanthridine alkaloids is demonstrated for the first time in this study. These compounds appear as potential leads for the development of new anti-MRSA compounds and could be responsible for the antibacterial activity, justifying the ethnobotanical use of Z. tingoassuiba and other species for the treatment of various infectious diseases.

Autophagy protects against neural cell death induced by piperidine alkaloids present in Prosopis juliflora (Mesquite)

ABSTRACT Prosopis juliflora is a shrub that has been used to feed animals and humans. However, a synergistic action of piperidine alkaloids has been suggested to be responsible for neurotoxic damage observed in animals. We investigated the involvement of programmed cell death (PCD) and autophagy on the mechanism of cell death induced by a total extract (TAE) of alkaloids and fraction (F32) from P. juliflora leaves composed majoritary of juliprosopine in a model of neuron/glial cell co-culture. We saw that TAE (30 µg/mL) and F32 (7.5 µg/mL) induced reduction in ATP levels and changes in mitochondrial membrane potential at 12 h exposure. Moreover, TAE and F32 induced caspase-9 activation, nuclear condensation and neuronal death at 16 h exposure. After 4 h, they induced autophagy characterized by decreases of P62 protein level, increase of LC3II expression and increase in number of GFP-LC3 cells. Interestingly, we demonstrated that inhibition of autophagy by bafilomycin and vinblastine increased the cell death induced by TAE and autophagy induced by serum deprivation and rapamycin reduced cell death induced by F32 at 24 h. These results indicate that the mechanism neural cell death induced by these alkaloids involves PCD via caspase-9 activation and autophagy, which seems to be an important protective mechanism.

Extraction with supercritical fluid and comparison of chemical composition from adults and young leaves of Zanthoxylum tingoassuiba

Plants differ in metabolism during their life cycle. In species used as phytotherapics, these changes determine the quality and effectiveness of the product. The aim of this study to evaluate the differences of chemical extracts obtained with supercritical CO2 from young and adult leaves of Zanthoxylum tingoassuiba St.-Hil., Rutaceae, a species used in the folk medicine in Brazil. The chemical composition of the extracts was elucidated by spectroscopic analysis and comparison with literature data. The results showed difference in the composition of the leaves from Z. tingoassuiba and allowed the determination of parameters for the extraction of α-bisabolol and furanocoumarins in this vegetal matrix.

Antinociceptive effects of Abarema cochliacarpos (B.A. Gomes) Barneby & J.W.Grimes (Mimosaceae) / Efeito antinociceptivo de Abarema cochliacarpos (B.A. Gomes) Barneby & J.W.Grimes (Mimosaceae)

In this study, we investigated the analgesic activity of crude aqueous and methanol extracts obtained from Abarema cochliacarpos bark in mice, and analyzed its phytochemical profile. All the extracts exhibited analgesic properties against the writhing test in mice, but the aqueous and methanol extracts were more active, and more potent than two known analgesic and anti-inflammatory drugs used as reference. They were also active against the capsaicin-model, but inactive when evaluated in the hot-plate test. Phytochemical studies revealed the presence of saponins, catechins, tannins, phenols and anthraquinones.

No presente trabalho foram avaliados a atividade antinociceptiva e o perfil fitoquímico dos extratos aquosos e metanólico produzidos com a casca do caule de Abarema cochliacarpos, uma espécie de Mata Atlântica com diversas indicações populares. Todos os extratos apresentaram atividade analgésica quando avaliados pelo teste das contorções abdominais induzidas pelo ácido acético via intraperitonial, apresentando respostas superiores às drogas usadas como referência, bem como no modelo da dor induzida por capsaicina. A avaliação fitoquímica demonstrou a presença de saponinas, catequinas, taninos, fenóis e antraquinonas.