João Ernesto de Carvalho

Antiulcerogenic activity of crude hydroalcoholic extract of Rosmarinus officinalis L.

Rosmarinus officinalis L. crude hydroalcoholic (70%) extract was evaluated for antiulcerogenic activity employing different experimental models. The crude hydroalcoholic extract (CHE) decreased the ulcerative lesion index produced by indomethacin, ethanol and reserpine in rats. No antisecretory activity was observed on pyloric ligation model. The previous administration of L-NAME, a NO-synthase inhibitor, did not reduce the antiulcerogenic activity of CHE in ethanol induced ulcer model, suggesting that the pharmacological mechanism has no relationship with nitric oxide (NO). Whereas when the animal groups were treated with indomethacin, using the same experimental model, CHE did not reduce the antiulcerogenic activity, suggesting that the pharmacological mechanism has no relationship with prostaglandins. The previous treatment with N-ethymaleimide, a thiol blocker, including mucosal nonprotein sulfhydryl groups, reduced the anitulcerogenic activity of CHE on ethanol induced ulcer model. This result suggests that the crude hydroalcoholic extract of R. officinalis L. has active substances that increase the mucosal nonprotein sulfhydryl groups content. In another hypothesis, the pharmacological mechanism could be attributed to the activity of antioxidant compounds found in the crude hydroalcoholic extract which can react with N-ethylmaleimide.

Synthesis and antitumoral activity of novel 3-(2-substituted-1,3,4-oxadiazol-5-yl) and 3-(5-substituted-1,2,4-triazol-3-yl) β-carboline derivatives

Several novel 1-substituted-phenyl beta-carbolines bearing the 2-substituted-1,3,4-oxadiazol-5-yl and 5-substituted-1,2,4-triazol-3-yl groups at C-3 were synthesized and evaluated for their in vitro anticancer activity. The assay results pointed thirteen compounds with growth inhibition effect (GI(50)<100 microM) for all eight different types of human cancer cell lines tested. The beta-carbolines 7a and 7h, bearing the 3-(2-metylthio-1,3,4-oxadiazol-5-yl) group, displayed high selectivity and potent anticancer activity against ovarian cell line with GI(50) values lying in the nanomolar concentration range (GI(50)=10 nM for both compounds). The 1-(N,N-dimethylaminophenyl)-3-(5-thioxo-1,2,4-triazol-3-yl) beta-carboline (8g) was the most active compound, showing particular effectiveness on lung (GI(50)=0.06 microM), ovarian and renal cell lines. The potent anticancer activity presented for synthesized compounds 7a, 7h, and 8g, together with their easiness of synthesis, makes these compounds promising anticancer agents.

Evaluation of wound healing properties of Arrabidaea chica Verlot extract.

ETHNOPHARMACOLOGICAL RELEVANCE Arrabidaea chica Verlot. (Bignoniaceae), popularly known as Crajiru, has been traditionally used as wound healing agent. AIM OF THE STUDY Investigate in vitro and in vivo healing properties of Arrabidaea chica leaves extract (AC). MATERIALS AND METHODS AC was evaluated in vitro in fibroblast growth stimulation (0.25-250 microg/mL) and collagen production stimulation (250 microg/mL) assays. Allantoin (0.25-250 microg/mL) and vitamin C (25 microg/mL) were used as controls respectively. DPPH and Folin-Ciocalteau assays were used for antioxidant evaluation, using trolox (0.25-250 microg/mL) as reference antioxidant. To study wound healing properties in rats, AC (100mg/mL, 200 microL/wound/day) was topically administered during 10 days and wound area was evaluated every day. Allantoin (100mg/mL, 200 microL/wound/day) was used as standard drug. After treatment, wound sites were removed for histopathological analysis and total collagen determination. RESULTS AC stimulated fibroblast growth in a concentration dependent way (EC50=30 microg/mL), increased in vitro collagen production and demonstrated moderate antioxidant capacity. In vivo, AC reduced wound size in 96%, whereas saline group showed only 36% wound healing. CONCLUSION AC efficiency seems to involve fibroblast growing stimulus and collagen synthesis both in vitro and in vivo, beyond moderate scavenging activity, corroborating Crajiru folk use.

Evaluation of Antiproliferative, Anti-Type 2 Diabetes, and Antihypertension Potentials of Ellagitannins from Strawberries (Fragaria × ananassa Duch.) Using In Vitro Models

Strawberries represent the main source of ellagic acid derivatives in the Brazilian diet, corresponding to more than 50% of all phenolic compounds found in the fruit. There is a particular interest in the determination of the ellagic acid content in fruits because of possible chemopreventive benefits. In the present study, the potential health benefits of purified ellagitannins from strawberries were evaluated in relation to the antiproliferative activity and in vitro inhibition of α-amylase, α-glucosidase, and angiotensin I-converting enzyme (ACE) relevant for potential management of hyperglycemia and hypertension. Therefore, a comparison among ellagic acid, purified ellagitannins, and a strawberry extract was done to evaluate the possible synergistic effects of phenolics. In relation to the antiproliferative activity, it was observed that ellagic acid had the highest percentage inhibition of cell proliferation. The strawberry extract had lower efficacy in inhibiting the cell proliferation, indicating that in the case of this fruit there is no synergism. Purified ellagitannins had high α-amylase and ACE inhibitory activities. However, these compounds had low α-glucosidase inhibitory activity. These results suggested that the ellagitannins and ellagic acid have good potential for the management of hyperglycemia and hypertension linked to type 2 diabetes. However, further studies with animal and human models are needed to advance the in vitro assay-based biochemical rationale from this study.

Evaluation of the antiulcerogenic activity of friedelan-3β-ol and friedelin isolated from Maytenus ilicifolia (Celastraceae)

An easy methodology for triterpene isolation is shown. Evaluation in rats for antiulcer activity of friedelan-3beta-ol 1 and friedelin 2. The two triterpenes isolated from the leaves of Maytenus ilicifolia, did not decrease gastric ulcers when tested on indometacine induced ulcer model in rats.

Anti-Inflammatory Activity of Chitooligosaccharides in Vivo

All the reports to date on the anti-inflammatory activity of chitooligosaccharides (COS) are mostly based on in vitro methods. In this work, the anti-inflammatory activity of two COS mixtures is characterized in vivo (using balb/c mice), following the carrageenan-induced paw edema method. This is a widely accepted animal model of acute inflammation to evaluate the anti-inflammatory effect of drugs. Our data suggest that COS possess anti-inflammatory activity, which is dependent on dose and, at higher doses, also on the molecular weight. A single dose of 500 mg/kg b.w. weight may be suitable to treat acute inflammation cases; however, further studies are needed to ascertain the effect upon longer inflammation periods as well as studies upon the bioavailability of these compounds.

Central properties of the essential oil and the crude ethanol extract from aerial parts of Artemisia annua L.

The present study evaluated the central activity of the essential oil and the ethanolic extract from Artemisia annua L. in animals as a part of a psychopharmacological screening of this plant. The extract was prepared with fresh leaves in ethanol (AEE) and the essential oil (AEO) was obtained by hidrodestilation. The ED(50) and the LD(50) obtained for the essential oil were 470mg/kg (correlation coefficient r=0.97333 and linear regression y=-26.52x+0.158) and 790mg/kg, and for the extract, 450mg/kg (correlation coefficient r=0.99266 and linear regression y=-27.34+0.156) and more than 2g/kg, respectively. The doses increased the latency time to convulsions induced by picrotoxin and pilocarpine but prevented the onset of pentylenotetrazol and strychnine induced seizures. In addition to, the products have caused marked inhibition in the Rota-rod assay. According to the results, the AEO has a high acute toxicity and a possible cholinergic action, and the AEE showed a possible central activity as dopaminergic and cholinergic agents, and did not present a significant acute toxicity. These differences should be due to chemical substances present in each product. These products had no significant effect as an anticonvulsant, while exhibited a strong depressant activity on the CNS.

Antioxidative and in vitro antiproliferative activity of Arctium lappa root extracts.

BackgroundArctium lappa, known as burdock, is widely used in popular medicine for hypertension, gout, hepatitis and other inflammatory disorders. Pharmacological studies indicated that burdock roots have hepatoprotective, anti-inflammatory, free radical scavenging and antiproliferative activities. The aim of this study was to evaluate total phenolic content, radical scavenging activity by DPPH and in vitro antiproliferative activity of different A. lappa root extracts.MethodsHot and room temperature dichloromethanic, ethanolic and aqueous extracts; hydroethanolic and total aqueous extract of A. lappa roots were investigated regarding radical scavenging activity by DPPH, total phenolic content by Folin-Ciocalteau method and antiproliferative in vitro activity was evaluated in human cancer cell lines. The hydroethanolic extract analyzed by high-resolution electrospray ionization mass spectroscopy.ResultsHigher radical scavenging activity was found for the hydroethanolic extract. The higher phenolic contents were found for the dichloromethane, obtained both by Soxhlet and maceration extraction and hydroethanolic extracts. The HRESI-MS demonstrated the presence of arctigenin, quercetin, chlorogenic acid and caffeic acid compounds, which were identified by comparison with previous data. The dichloromethane extracts were the only extracts that exhibited activity against cancer cell lines, especially for K562, MCF-7 and 786-0 cell lines.ConclusionsThe hydroethanolic extracts exhibited the strongest free radical scavenging activity, while the highest phenolic content was observed in Soxhlet extraction. Moreover, the dichloromethanic extracts showed selective antiproliferative activity against K562, MCF-7 and 786-0 human cancer cell lines.

Antimicrobial and antiproliferative activities of stingless bee Melipona scutellaris geopropolis

BackgroundGeopropolis is a type of propolis containing resin, wax, and soil, collected by threatened stingless bee species native to tropical countries and used in folk medicine. However, studies concerning the biological activity and chemical composition of geopropolis are scarce. In this study, we evaluated the antimicrobial and antiproliferative activity of the ethanolic extract of geopropolis (EEGP) collected by Melipona scutellaris and its bioactive fraction against important clinical microorganisms as well as their in vitro cytotoxicity and chemical profile.MethodsThe antimicrobial activity of EEGP and fractions was examined by determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against six bacteria strains as well as their ability to inhibit Streptococcus mutans biofilm adherence. Total growth inhibition (TGI) was chosen to assay the antiproliferative activity of EEGP and its bioactive fraction against normal and cancer cell lines. The chemical composition of M. scutellaris geopropolis was identified by reversed-phase high-performance liquid chromatography and gas chromatography–mass spectrometry.ResultsEEGP significantly inhibited the growth of Staphylococcus aureus strains and S. mutans at low concentrations, and its hexane fraction (HF) presented the highest antibacterial activity. Also, both EEGP and HF inhibited S. mutans biofilm adherence (p < 0.05) and showed selectivity against human cancer cell lines, although only HF demonstrated selectivity at low concentrations. The chemical analyses performed suggest the absence of flavonoids and the presence of benzophenones as geopropolis major compounds.ConclusionsThe empirical use of this unique type of geopropolis by folk medicine practitioners was confirmed in the present study, since it showed antimicrobial and antiproliferative potential against the cancer cell lines studied. It is possible that the major compounds found in this type of geopropolis are responsible for its properties.

Antispermatogenic effect of Achillea millefolium L. in mice

The effect of an ethanolic extract (200 mg/kg/day, intraperitoneally, for 20 days) and a hydroalcoholic extract (300 mg/kg/day, orally, for 30 days) of Achillea millefolium L. (yarrow) flowers on the spermatogenesis of Swiss mice was studied by evaluating morphologic characteristics with the light and electron microscopes. The alterations observed were exfoliation of immature germ cells, germ cell necrosis, and seminiferous tubule vacuolization. Animals treated with the extracts had an increased number of metaphases in the germ epithelium that might be due to cytotoxic substances or substances stimulating cell proliferation.