Synergistic and Antibiofilm Effects of the Essential Oil from Croton conduplicatus (Euphorbiaceae) against Methicillin-Resistant Staphylococcus aureus.

Bacterial resistance refers to the ability of bacteria to resist the action of some antibiotics due to the development of adaptation and resistance mechanisms. It is a serious public health problem, especially for diseases caused by opportunistic bacteria. In this context, the search for new drugs, used alone or in combination, appears as an alternative for the treatment of microbial infections, and natural products, such as essential oils, are important in this process due to their structural diversity, which increases the probability for antimicrobial action. The objective of this study was to extract and identify the chemical components of the essential oil from Croton conduplicatus (EOCC), to evaluate the antimicrobial activity, to investigate the effect of the interaction between the EOCC and different antibiotics and to evaluate its antibiofilm potential. The EOCC was obtained by hydrodistillation. Based on chemical characterisation, 70 compounds were identified, with 1.8 cineole (13.15%), p-cymene (10.68%), caryophyllene (9.73%) and spathulenol (6.36%) being the major constituents. The minimum inhibitory concentration (MIC) values of EOCC were 256 and 512 µg mL-1 for methicillin-sensitive and -resistant Staphylococcus aureus strains (MSSA and MRSA), respectively. The combinations of EOCC with the antibiotics oxacillin and ampicillin were synergistic (OXA/EOCC and AMP/EOCC combined decreased the OXA MIC and AMP MIC to 0.5 and 0.25 for MSSA, respectively, and OXA/EOCC and AMP/EOCC combined decreased the OXA MIC and the AMP MIC to 1 and 0.5 for MRSA, respectively) and could modify the resistance profile of MSSA and MRSA strains. The results indicated that EOCC was also able to partially inhibit biofilm formation. Our study presents important information about the chemical composition of EOCC and its antimicrobial potential and provides a reference to determine the mechanisms of action of EOCC and its use in pharmaceutical formulations.

Antiproliferative, antileishmanial and antimicrobial studies on Cnidoscolus quercifolius Pohl (Euphorbiaceae).

Cnidoscolus quercifolius is an Euphorbiaceae endemic to the northeast region of Brazil, which is used in folk medicine as anti-inflammatory, analgesic and antibiotic. An ethanolic extract was prepared with the leaves from C. quercifolius, and also partitioned and chromatographed leading to the isolation of cyanoglucoside linamarin (1), cinnamic acid (2), as well as a mixture of steroids and terpenoids (3-6). Structural elucidation of the compounds was done by IR, MS and NMR analysis. For the cyanoglucoside (1) were also evaluated its antimicrobial and antileishmanial viabilities by plaque microdilution and MTT test, respectively. Both tests showed from moderate to zero activity against the organisms evaluated. In addition, the antiproliferative activity of compounds 1 and 5-6 were tested against tumor cells, which did not show statistically significant growth inhibition 50% (GI50). The obtained results suggested that further pharmacological studies should prove the folk medicinal uses.

Evaluation of adherence to pharmacological treatment

The adherence to therapy associated with the socio-demographic variables and the habits of patients with hypertension and/or diabetes mellitus were investigated in this study. The registration forms of 105 patients in the Hiperdia program in the municipality of Campina Grande-PB were used as a data collection instrument, applying the Morisky-Green test (MGT) and Batalla test (BT) to assess compliance treatment. For the MGT, there was a prevalence of non-adherent individuals (76.2%) and the type of predominant behavior was unintentional. The internal consistency of the responses obtained through the MGT presented good reliability, according to the value of 0.69 obtained by Cronbach's alpha. For the BT, there was a predominance of adherence (68.6%) and the alpha value was 0.80, showing a high reliability level. It was found that a diet lacking in salt is a strong impact variable for determining the adherence to the BT. Given the representativity of the tests, there is a need to amend the interferences that facilitate the low adherence to drug treatment. The results of this study can be used to construct strategies that will address these difficulties and optimize the adherence level and quality of life of patients.

Phytochemical study of Harrisia adscendens

ABSTRACT Harrisia adscendens (Gürke) Britton & Rose is a species of the family Cactaceae found in the northeastern semi-arid and popularly known as foxtail. In folk medicine, the roots of this species are used for the treatment of toothache and heartburn. The objective of this study was to perform the isolation and identification of the secondary metabolites obtained from the vegetal drug by chromatographic and spectroscopic techniques and to evaluate the antimicrobial activity of the extract. The qualitative phytochemical analysis of the extract showed suggestive results for the presence of alkaloids. Two compounds were isolated and identified: 2-methyl-9H-β-carboline-2-ion, a β-carboline alkaloid obtained for the first time as a natural product and 2',6'-dihydroxy-4'-methoxyacetophenone-2'-O-β-glucoside. In the antimicrobial tests, it was possible to observe activity against Pseudomonas aeruginosa. The results obtained by spectroscopic techniques allowed to characterize the phytochemical properties of the vegetal drug and may be useful in future studies for production of herbal medicines.

Isolation of Monoterpene Dihydrochalcones from Piper montealegreanum Yuncker (Piperaceae).

Four new compounds were isolated from the branches of Piper montealegreanum Yuncker, a shrub found in the Amazon rainforest, including two new dihydrochalcones named claricine (1) and maisine (2), a cinnamic acid derivative 3 and a phenylalkanoid 4, along with a porphyrin identified as the known compound phaeophytin a (5). The structures were established using spectroscopic experiments, including 1D and 2D NMR and HRESIMS experiments, performed on the two monoterpene dihydrochalcones and their monoacetyl derivatives. The structural diversity of these substances is very important for the Piper genus chemotaxonomy.

Antifungal potential of Sideroxylon obtusifolium and Syzygium cumini and their mode of action against Candida albicans.

Context The emergence of resistant pathogens and toxicity of antifungals have encouraged an active search for novel candidates to manage Candida biofilms. Objective In this study, the little known species Sideroxylon obtusifolium T.D. Penn (Sapotacea) and Syzygium cumini (L.) Skeels (Myrtaceae), from the Caatinga biome in Brazil were chemically characterized and explored for their antifungal potential against C. albicans. Materials and methods We determined the effects of hydroalcoholic extracts/fractions upon fungal growth (minimum inhibitory and fungicidal concentrations, MIC/MFC), biofilm morphology (scanning electron microscopy) and viability (confocal laser scanning microscopy), proposed their mode of action (sorbitol and ergosterol assays), and finally investigated their effects against macrophage and keratinocyte cells in a cell-based assay. Data were analysed using one-way analysis of variance with Tukey-Kramer post-test (α = 0.05). Results The n-butanol (Nb) fraction from S. obtusifolium and S. cumini extract (Sc) showed flavonoids (39.11 ± 6.62 mg/g) and saponins (820.35 ± 225.38 mg/g), respectively, in their chemical composition and demonstrated antifungal activity, with MICs of 62.5 and 125 µg/mL, respectively. Nb and Sc may complex with ergosterol as there was a 4-16-fold increase in MICs in the presence of exogenous ergosterol, leading to disrupted permeability of cell membrane. Deleterious effects were observed on morphology and viability of treated biofilms from concentrations as low as their MICs and higher. Sc was not toxic to macrophages and keratinocytes at these concentrations (p > 0.05), unlike Nb. Conclusions Nb and Sc demonstrated considerable antifungal activity and should be further investigated as potential alternative candidates to treat Candida biofilms.

Antinociceptive and anti-inflammatory effects of flavonoids PMT1 and PMT2 isolated from Piper montealegreanum Yuncker (Piperaceae) in mice.

In this study, we identified the antinociceptive and anti-inflammatory effects of two flavonoids (PMT1 and PMT2) from Piper montealegreanum. The antinociceptive effect was evaluated using the classical tests: acetic acid-induced writhing, formalin and hot plate test. PMT1 and PMT2 (0.1, 1, 30 and 100 µmol/kg, i.p.) reduced the writhings, with an ID50 of 0.58 and 0.44 µmol/kg, respectively. Moreover, these flavonoids (100 µmol/kg, i.p.) inhibited paw-licking time in the neurogenic phase of the formalin test, but only PMT2 was active in the inflammatory phase. However, PMT1 and PMT2 (100 µmol/kg, i.p.) did not increase the latency time of the animals in the hot plate. In order to evaluate the anti-inflammatory effect of these flavonoids, capsaicin-induced ear oedema was carried out. Both flavonoids (100 µmol/kg, i.p.) were active in this model. These results suggest that PMT1 and PMT2 have antinociceptive and anti-inflammatory activities.