Paulo S. Pereira

Brazilian Propolis: Correlation Between Chemical Composition and Antimicrobial Activity

The chemical composition of ethanol extracts from samples of Brazilian propolis (EEPs) determined by HPLC and their activity against Trypanosoma cruzi, Staphylococcus aureus, Streptococcus pneumoniae, Klebisiella pneumoniae, Candida albicans, Sporothrix schenckii and Paracoccidioides brasiliensis were determined. Based on the predominant botanical origin in the region of samples collection, the 10 extracts were separated into three groups: A (B. dracunculifolia + Auraucaria spp), B (B. dracunculifolia) and C (Araucaria spp). Analysis by the multiple regression of all the extracts together showed a positive correlation, higher concentrations leading to higher biological effect, of S. aureus with p-coumaric acid (PCUM) and 3-(4-hydroxy-3-(oxo-butenyl)-phenylacrylic acid (DHCA1) and of trypomastigotes of T. cruzi with 3,5-diprenyl-4-hydroxycinnamic acid derivative 4 (DHCA4) and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (DCBEN). When the same approach was employed for each group, due to the small number of observations, the statistical test gave unreliable results. However, an overall analysis revealed for group A an association of S. aureus with caffeic acid (CAF) and dicaffeoylquinic acid 3 (CAFQ3), of S. pneumoniae with CAFQ3 and monocaffeoylquinic acid 2 (CAFQ2) and of T. cruzi also with CAFQ3. For group B, a higher activity against S. pneumoniae was associated DCBEN and for T. cruzi with CAF. For group C no association was observed between the anitmicrobial effect and any component of the extracts. The present study reinforces the relevance of PCUM and derivatives, especially prenylated ones and also of caffeolyquinic acids, on the biological activity of Brazilian propolis.

Anti-inflammatory, analgesic and anti-oedematous effects of Lafoensia pacari extract and ellagic acid.

Lafoensia pacari St. Hil. (Lythraceae) is used in traditional medicine to treat inflammation. Previously, we demonstrated the anti‐inflammatory effect that the ethanolic extract of L. pacari has in Toxocara canis infection (a model of systemic eosinophilia). In this study, we tested the antiinflammatory activity of the same L. pacari extract in mice injected intraperitoneally with β‐glucan present in fraction 1 (F1) of the Histoplasma capsulatum cell wall (a model of acute eosinophilic inflammation). We also determined the anti‐oedematous, analgesic and anti‐pyretic effects of L. pacari extract in carrageenan‐induced paw oedema, acetic acid writhing and LPS‐induced fever, respectively. L. pacari extract significantly inhibited leucocyte recruitment into the peritoneal cavity induced by β‐glucan. In addition, the L. pacari extract presented significant analgesic, anti‐oedematous and anti‐pyretic effects. Bioassay‐guided fractionation of the L. pacari extract in the F1 model led us to identify ellagic acid. As did the extract, ellagic acid presented anti‐inflammatory, anti‐oedematous and analgesic effects. However, ellagic acid had no anti‐pyretic effect, suggesting that other compounds present in the plant stem are responsible for this effect. Nevertheless, our results demonstrate potential therapeutic effects of L. pacari extract and ellagic acid, providing new prospects for the development of drugs to treat pain, oedema and inflammation.

Inhibition of enzymatic and pharmacological activities of some snake venoms and toxins by Mandevilla velutina (Apocynaceae) aqueous extract

Phospholipases A(2) (PLA(2)) are multifunctional proteins which exhibit varied biological activities correlated to the structural diversities of the sub-classes. The crude aqueous extract from subterranean system of Mandevilla velutina, a plant found in Brazilian savanna, was assayed for its ability to inhibit biological activities of several snake venoms and isolated PLA(2)s. The extract induced total inhibition of the phospholipase activity of Crotalus durissus terrificus venom and only partial inhibition of Bothrops venoms. When assayed against purified toxins, the highest efficacy was detected against CB and crotoxin, while almost ineffective against PLA(2)s from the genus Bothrops. Although M. velutina crude extract significantly inhibited the myotoxic activity of C. d. terrificus venom and CB, it produced only partial inhibition of either Bothrops jararacussu venom or its main myotoxins BthTX-I (basic Lys49), BthTX-II (basic Asp49) and BthA-I-PLA(2) (acidic Asp49). The extract exhibited also full inhibition of hemorrhage caused by Bothrops alternatus, Bothrops moojeni and Bothrops pirajai snake venoms, but partial inhibition (90%) of that induced by B. jararacussu venom. The extract was ineffective to inhibit the fibrinogenolytic activity of B. moojeni, B. alternatus and B. pirajai crude venoms, while their caseinolytic activity was only partially inhibited. No inhibition of the anticoagulant activity, although partial reduction of the edema-inducing activity of C. d. terrificus and B. alternatus crude venoms, CB, PrTX-I, BthTX-I and crotoxin was observed. Besides extending survival of mice injected with lethal doses of C. d. terrificus and B. jararacussu venoms, M. velutina extract decreased to 50% the lethality of mice. Extracts of 18 month old micropropagated plants were able to partially neutralize the effect of the crude venoms and toxins.

In vitro evaluation of the cytotoxic and trypanocidal activities of Ampelozizyphus amazonicus (Rhamnaceae)

Ampelozizyphus amazonicus Ducke is a tree commonly found in the Amazon region and an extract of its stem bark is popularly used as an antimalarial and anti-inflammatory agent and as an antidote to snake venom. Ursolic acid; five lupane type triterpenes: betulin, betulinic acid, lupenone, 3beta-hydroxylup-20(29)-ene-27,28-dioic acid, and 2alpha,3beta-dihydroxylup-20(29)-ene-27,28-dioic acid, and three phytosteroids: stigmasterol, sitosterol and campesterol, have been isolated from stem extracts of A. amazonicus Ducke. Their structures were characterized by spectral data including COSY and HMQC. In an in vitro biological screening of the isolated compounds, 3beta-hydroxylup-20(29)-ene-27,28-dioic acid was cytotoxic against the SKBR-3 human adenocarcinoma cell line (1 to 10 mg/mL), while 2alpha,3beta-dihydroxylup-20(29)-ene-27,28-dioic acid exhibited cytotoxicity against both SKBR-3 human adenocarcinoma and C-8161 human melanoma tumor cell lines (>0.1 mg/mL). In the present study, different extracts and some fractions of this plant were also investigated for trypanocidal activity due to the presence of pentacyclic triterpenes. The triterpene classes are potent against Trypanosoma cruzi. The bioassays were carried out using blood collected from Swiss albino mice by cardiac puncture during the parasitemic peak (7th day) after infection with the Y strain of T. cruzi. The results obtained showed that A. amazonicus is a potential source of bioactive compounds since its extracts and fractions isolated from it exhibited in vitro parasite lysis against trypomastigote forms of T. cruzi at concentrations >100 microg/mL. Fractions containing mainly betulin, lupenone, 3beta-hydroxylup-20(29)-ene-27,28-dioic acid, and 2alpha,3beta-dihydroxylup-20(29)-ene-27,28-dioic acid showed more activity than crude extracts.

Chemical constituents from Tabernaemontana catharinensis root bark: a brief NMR review of indole alkaloids and in vitro cytotoxicity

13 C, and 1 H NMR data and MS. Spectral data of indole alkaloids were reviewed. An in vitro screening of the extracts and isolated compounds was carried out. Compounds ibogamine (5), 3-oxo-coronaridine (9) and 12-methoxy-4-methylvoachalotine (MMV) demonstrated effective cytotoxicity towards SKBR-3 breast adenocarcinoma and C-8161 human melanoma tumor cell lines.

The role of polar phytocomplexes on anticonvulsant effects of leaf extracts of Lippia alba (Mill.) N.E. Brown chemotypes

Objectives The purpose of the present work was to characterize the pharmacological profile of different L. alba chemotypes and to correlate the obtained data to the presence of chemical constituents detected by phytochemical analysis.

Cytotoxicity and genotoxicity of coronaridine from Tabernaemontana catharinensis A.DC in a human laryngeal epithelial carcinoma cell line (Hep-2)

Cancer has become a major public health problem worldwide and the number of deaths due to this disease is increasing almost exponentially. In the constant search for new treatments, natural products of plant origin have provided a variety of new compounds to be explored as antitumor agents. Tabernaemontana catharinensis is a medicinal plant that produces alkaloids with expressive antitumor activity, such as heyneanine, coronaridine and voacangine. The aim of present study was firstly to screen the cytotoxic activity of the indole alkaloids heyneanine, coronaridine and voacangine against HeLa (human cervix tumor), 3T3 (normal mouse embryo fibroblasts), Hep-2 (human laryngeal epithelial carcinoma) and B-16 (murine skin) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide); and secondly to analyze the apoptotic activity, cell membrane damage and genotoxicity of the compound that showed the best cytotoxic activity against the tumor cell lines tested. Coronaridine was the one that exhibited greater cytotoxic activity in the laryngeal carcinoma cell line Hep-2 (IC50 = 54.47 μg/mL) than the other alkaloids tested (voacangine IC50 = 159.33 g/mL, and heyneanine IC50 = 689.45 μg/mL). Coronaridine induced apoptosis in cell lines 3T3 and Hep-2, even at high concentrations. The evaluation of genotoxicity by comet assay showed further that coronaridine caused minimal DNA damage in the Hep-2 tumor cell line, and the LDH test showed that it did not affect the plasma membrane. These results suggest that further investigation of coronaridine as an antitumor agent has merit.

Anti-snake venom activities of extracts and fractions from callus cultures of Sapindus saponaria

Context: Sapindus saponaria L. (Sapindaceae) bark, root, and fruits are used as sedatives and to treat gastric ulcer and also demonstrate diuretic and expectorant effects. Objective: The anti-snake venom properties of callus of S. saponaria are investigated here for the first time. Materials and methods: In vitro cultivated callus of Sapindus saponaria were lyophilized, and the extracts were prepared with different solvents, before submitting to phytochemical studies and evaluation of the anti-ophidian activity. Crude extracts were fractionated by liquid–liquid partition and the fractions were monitored by thin layer chromatography (TLC). Subsequently, anti-ophidian activities were analyzed toward Bothrops jararacussu Lacerda (Viperidae), B. moojeni Hoge (Viperidae), B. alternates Duméril (Viperidea) and Crotalus durissus terrificus Lineu (Viperidae) venoms and isolated myotoxins and phospholipase A2 (PLA2). Results: Fractions A1, A2 and the extract in MeOH:H2O (9:1) significantly inhibited the toxic and pharmacological activities induced by snake venoms and toxins, when compared to other extracts and fractions. The lethal, clotting, phospholipase, edema-inducing, hemorrhagic and myotoxic activities were partially inhibited by the different extracts and fractions. TLC profiles of the crude extracts (B and C) and fractions (A1 and A2) showed β-sitosterol and stigmasterol as their main compounds. Stigmasterol exhibited inhibitory effects on enzymatic and myotoxic activities of PLA2. Discussion and conclusion: Sapindus saponaria extracts and fractions presented anti-ophidian activity and could be used as an adjuvant to serum therapy or for its supplementation, and in addition, as a rich source of potential inhibitors of enzymes involved in several pathophysiological human and animal diseases.

Comparative study of antibacterial and antifugal activity of callus culture and adult plants extracts from Alternanthera maritima (Amaranthaceae)

The aim of this study was to evaluate the antibacterial and antifungal activity of callus culture (two different hormonal combination culture medium) and adult plants (two collect) extracts from Alternanthera maritima (Amaranthaceae) investigating the maintenance of antimicrobial activity in vivo and in vitro. The antibacterial and antifungal activity was determined by the agar-well diffusion method against thirty strains of microorganisms including Gram-positive and Gram-negative bacteria, yeasts and dermatophytes. All the organic crude extracts studied were bioactive. Extracts of aerial parts and roots of adult plants collected during the same period of years of 1995 and 1998 (Restinga de Marica (RJ), collect 1 and 2) inhibited the growth of several microorganisms (bacteria, yeasts and dermatophytes) with inhibition halo between 6 and 20 mm. Plant cell callus culture extracts obtained from two culture conditions were also bioactive. Thus, the positive results suggest that the A. maritima extracts should be further studied to determine the bioactive chemical compounds as well as to understand the possible mechanisms of action and evaluate their toxicity looking toward a pharmaceutical employment.

The glycosylated flavonoids vitexin, isovitexin, and quercetrin isolated from Serjania erecta Radlk (Sapindaceae) leaves protect PC12 cells against amyloid-β25-35 peptide-induced toxicity

The Aβ peptide-mediated toxicity participates in the neuronal death that occurs in Alzheimers disease. The present study aims to isolate the major compounds of Serjania erecta Radlk leaves and assess whether these compounds protect PC12 cells from Aβ25-35 peptide-induced toxicity. We isolated three flavonoid glycosides with high purity: quercetrin, vitexin, and isovitexin. The Aβ25-35 peptide alone decreased the PC12 cell viability in a concentration-dependent manner, as evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. We selected the Aβ25-35 peptide concentration of 50xa0µM for the experiments. Treatment of PC12 cells with the flavonoids before exposure to the Aβ25-35 peptide increased cell viability, i.e., these compounds protected the cells against Aβ25-35 peptide-induced toxicity. Vitexin promoted higher protection levels than quercetrin and isovitexin, and reduced the lactate dehydrogenase release and NO production in Aβ25-35 peptide-treated PC12 cells. Therefore, the glycosylated flavonoids that exist in S.xa0erecta leaves, especially vitexin, protect PC12 cells from Aβ25-35 peptide-induced toxicity.