Resumo em Inglês:

Plants have been used for thousands of years to flavor and conserve food, to treat health disorders and to prevent diseases including epidemics. The knowledge of their healing properties has been transmitted over the centuries within and among human communities. Active compounds produced during secondary vegetal metabolism are usually responsible for the biological properties of some plant species used throughout the globe for various purposes, including treatment of infectious diseases. Currently, data on the antimicrobial activity of numerous plants, so far considered empirical, have been scientifically confirmed, concomitantly with the increasing number of reports on pathogenic microorganisms resistant to antimicrobials. Products derived from plants may potentially control microbial growth in diverse situations and in the specific case of disease treatment, numerous studies have aimed to describe the chemical composition of these plant antimicrobials and the mechanisms involved in microbial growth inhibition, either separately or associated with conventional antimicrobials. Thus, in the present work, medicinal plants with emphasis on their antimicrobial properties are reviewed.

Resumo em Inglês:

Canine visceral leishmaniasis (CVL) is endemic in numerous Brazilian regions. The greatest difficulty in controlling the disease is the diagnostic limitation. In the present study, the most common tests employed for visceral leishmaniasis diagnosis were compared: immunofluorescence antibody test (IFAT), immunoenzymatic assay (ELISA), direct parasitological examination and polymerase chain reaction (PCR). Samples of lymph node aspirates and blood were collected from 100 dogs that lived in an endemic area (Bauru city, São Paulo state) and from 100 negative controls from a non-endemic area (Botucatu city, São Paulo state). Specificity of both IFAT and PCR was 100% whereas ELISA was 99%. Sensitivities were 97.77, 93.33 and 91.11% respectively for IFAT, ELISA and PCR.

Resumo em Inglês:

Specimens of the pufferfish Arothron hispidus collected at Parangipettai, on the southeast coast of India, were subjected to bacterial isolation and identification. Three species were identified, namely Bacillus sp., Kytococcus sedentarius and Cellulomonas fimi. Partially-purified microbial filtrates exhibited hemolytic activity on chicken and human erythrocytes of O, B and AB blood groups, with maximum activity of 32 HU. The microbial filtrates also presented ATPase, Mg2+-ATPase, Na+K+-ATPase and AchE enzymatic activities of positive neuromodulation in Kytococcus sedentarius with 1300, 300.1, 1549.98 and 140.55%, in Cellulomonas fimi with 620, 300, 10 and 128.42%, and in Bacillus species with 40, 200, 849.98 and 158.69%, respectively. Toxicity symptoms were observed when the bacterial filtrate was intraperitoneally injected into mice. The bacterial filtrate caused adverse effects on viability of the mouse muscle cell line (L929) and leukemia cell line (P388). Maximum level of inhibition was observed on the growth of L929 cell line. Bacillus lentimorbus inhibited the cell line from 84.03 to 94.43% whereas Bacillus species inhibited the growth in a range between 77.25 and 86.16% at the lowest dilution.

Resumo em Inglês:

The hydroalcoholic extract of Casearia gossypiosperma Briquet (Flacourtiaceae) was standardized for the first time through quality control procedures including pharmacognostic methods, fingerprint chromatograms, defined amounts of marker substances and physicochemical characteristics. The pharmacological activity of C. gossypiosperma (Cg) hydroalcoholic extract was assayed by a traditional in vitro test, which involved irreversible neuromuscular blockade induced by Bothrops jararacussu (Bjssu) venom (60 µg/mL) in mouse phrenic nerve-diaphragm preparations. Bjssu venom blocked muscle activity for 26 (± 2.0) minutes (n = 6). Cg extract (0.1 mg/mL) induced changes on the baseline muscle activity without impairing the muscle function and inhibited 87.6% (± 1.8) (n = 6) of the Bjssu venom-induced blockade. Both flavonoids (0.624 g%) and polyphenols (4.63 g%) from the extract were spectrophotometrically quantified. Therefore, the present study confirms the antibothropic activity of Cg extract, supporting the ethnomedical use of Casearia sp. in the treatment of snakebite victims.

Resumo em Inglês:

The most reliable determination of severity and prognosis in chronic viral hepatitis is the histological staging of the disease, which comprises an invasive procedure and is often not well accepted by patients. The search for alternative non-invasive methods is mandatory especially in follow-ups after initial assessment by biopsy. The aim of this study was to evaluate the role of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in patients under interferon alpha therapy whether responsive or non-responsive to therapy. Thirty chronic hepatitis C patients (CHC) under combined therapy of interferon-α with ribavirin, whether responsive or non-responsive, were included in the study as well as ten healthy controls. Serum VCAM-1 and ICAM-1 levels were calculated using commercial enzyme linked immunosorbent assay (ELISA) kits. Before the therapy, sICAM-1 and sVCAM-1 levels were significantly higher among CHC patients (96.9 ± 39.74 and 679.4 ± 218.98 ng/mL, respectively) than in the control group (14.3 ± 4.32 and 108.9 ± 49.21 ng/mL, respectively), (p < 0.05 for both). They were higher among non-responsive than in responsive patients. Comparisons in soluble ICAM-1 (sICAM-1) levels of responsive persons during treatment revealed a statistically significant increase at baseline (81.27 ± 25.797) versus its value after one month (52.33 ± 12.76), p < 0.05 and after three months (49.67 ± 14.42), p < 0.05. However, no statistically significant difference was detected between one and three-month sICAM-1 levels post-therapy commencement (p = 0.055). Also, no statistically significant difference was detected between sVCAM-1 levels at baseline (521.47 ± 137.29) versus three months after therapy initiation (517.53 ± 130.6), p = 0.854. The occurrence of a significant decrease in sICAM-1 level as early as one month after therapy in responsive patients only allows us to conclude that sICAM-1 could be used as an early marker in CHC patients under interferon therapy to predict prognosis and guide the treatment, whereas sVCAM-1 does not present any difference between the studied groups.

Resumo em Inglês:

The present study aimed to investigate the effects of Mesobuthus tamulus gangeticus Pocock (Buthidae) venom on albino mice (NIH strain). Whole venom was obtained by electrical stimulation and its toxicity was determined in albino mice by subcutaneous envenomation. The venom LD50 was 2.5 mg kg-1 of mouse body weight. Toxic effects on different biochemical and enzymatic parameters in blood serum and other tissues of albino mice were determined after experimental envenomation with sublethal doses of M. tamulus gangeticus venom. Increased levels of glucose, uric acid and cholesterol, as well as decreased serum total proteins, were observed at 2 and 4 hours after the envenomation. In the liver and muscles, glycogen content dropped after venom injection. Moreover, M. tamulus gangeticus venom elevated the enzymatic activity of acid phosphatase (ACP), lactic dehydrogenase (LDH) and alanine aminotransferase (ALT) in the serum of albino mice. In conclusion, M. tamulus gangeticus can be considered a lethal scorpion species.

Resumo em Inglês:

Hepatitis C virus (HCV) patients commonly have low platelet counts; however, the exact role of HCV infection in thrombocytopenia is unknown. This work aimed to study the serum levels of interleukins (IL) 10 and 12 in patients with mild and moderate thrombocytopenia associated with chronic hepatitis C infection. Our study included 15 patients with chronic HCV infection and newly diagnosed isolated autoimmune thrombocytopenia (Group I) and 15 patients with chronic HCV infection and normal platelet count as controls (Group II). All patients were examined for personal history and clinical aspects, complete blood count, bone marrow aspiration, liver function tests, HCV antibody assay by ELISA and polymerase chain reaction (PCR), abdominal ultrasound, Helicobacter pylori stool antigen test, evaluation of serum levels of IL-10, IL-12 and platelet specific antibodies. Our results revealed that eight patients from Group l had mild thrombocytopenia and seven patients had moderate thrombocytopenia. Serum IL-10 level was significantly elevated (t = 9.301, p < 0.001) while serum IL-12 showed a significant decrease (t = 6.502, p < 0.001) in Group I compared to the control group. No correlation was detected between platelet counts and the serum levels of either IL-10 [r = 0.454, p = 0.089 (Group I), r = 0.038, p = 0.89 (Group II)] or IL-12 [r = 0.497, p = 0.06 (Group I), r = 0.499, p = 0.058 (Group II)]. However, in Group I, a significant correlation was present only between moderate thrombocytopenia and serum levels of either IL-10 (r = 0.794, p = 0.033) or IL-12 (r = 0.967, p = 0.001), while no correlation was detected between these interleukin parameters and mild thrombocytopenia (r = 0.311 and p = 0.453 for IL-10 and r = -0.08 and p = 0.851 for IL-12). Based on our data, we may conclude that interleukins 10 and 12 are involved in low platelet levels.

Resumo em Inglês:

The damaging effects of neuwiedase, a non-hemorrhagic snake venom metalloproteinase from P-I class, on gastrocnemius muscle are studied herein. Following neuwiedase injection, ultrastructural alterations were detected early showing disarrangement of skeletal muscle fibers (characterized by discontinuity of Z lines), mitochondrial swelling, and disruption of plasma membrane and basal lamina. Degradation of skeletal muscle and the appearance of an amorphous substance, primarily composed of cellular debris, were noted after 24 hours. The presence of neuwiedase at the injection site (detected by immunocytochemistry) revealed highly specific labeling of myofibril components of damaged myocytes. In addition, proteolysis of muscle proteins assayed through myofibrils extracted from gastrocnemius muscle indicated that neuwiedase provoked degradation of myofibrils, especially myosin. These results suggest that skeletal muscle damage, induced by neuwiedase, is probably due to its proteolytic action on myofibrils, which are responsible for the maintenance of the cellular architecture.

Resumo em Inglês:

The prominent myotoxic effects induced by Bothrops jararacussu crude venom are due, in part, to its polycationic myotoxins, BthTX-I and BthTX-II. Both myotoxins have a phospholipase A2 structure: BthTX-II is an active enzyme Asp-49 PLA2, while BthTX-I is a Lys-49 PLA2 devoid of enzymatic activity. In this study, the effect of low-level laser therapy (LLLT), 685 nm laser at a dose of 4.2 J/cm2 on edema formation, leukocyte influx and myonecrosis caused by BthTX-I and BthTX-II, isolated from Bothrops jararacussu snake venom, was analyzed. BthTX-I and BthTX-II caused a significant edema formation, a prominent leukocyte infiltrate composed predominantly by neutrophils and myonecrosis in envenomed gastrocnemius muscle. LLLT significantly reduced the edema formation, neutrophil accumulation and myonecrosis induced by both myotoxins 24 hours after the injection. LLLT reduced the myonecrosis caused by BthTX-I and BthTX-II, respectively, by 60 and 43%; the edema formation, by 41 and 60.7%; and the leukocyte influx, by 57.5 and 51.6%. In conclusion, LLLT significantly reduced the effect of these snake toxins on the inflammatory response and myonecrosis. These results suggest that LLLT should be considered a potential therapeutic approach for treatment of local effects of Bothrops species venom.

Resumo em Inglês:

The basic knowledge on neoplasms is increasing quickly; however, few advances have been achieved in clinical therapy against tumors. For this reason, the development of alternative drugs is relevant in the attempt to improve prognosis and to increase patients' survival. Snake venoms are natural sources of bioactive substances with therapeutic potential. The objective of this work was to identify and characterize the antitumoral effect of Crotalus durissus terrificus venom (CV) and its polypeptide, crotoxin, on benign and malignant tumors, respectively, pituitary adenoma and glioblastoma. The results demonstrated that CV possess a powerful antitumoral effect on benign (pituitary adenoma) and malignant (glioblastoma multiforme) tumors with IC50 values of 0.96 ± 0.11 µg/mL and 2.15 ± 0.2 µg/mL, respectively. This antitumoral effect is cell-cycle-specific and dependent on extracellular calcium, an important factor for crotoxin phospholipase A2 activity. The CV antitumoral effect can be ascribed, at least partially, to the polypeptide crotoxin that also induced brain tumor cell death. In spite of the known CV nephrotoxicity and neurotoxicity, acute treatment with its antitumoral dose established in vitro was not found to be toxic to the analyzed animals. These results indicate the biotechnological potential of CV as a source of pharmaceutical templates for cancer therapy.

Resumo em Inglês:

Snake venom proteins from the C-type lectin family have very distinct biological activities despite their highly conserved primary structure, which is homologous to the carbohydrate recognition region of true C-type lectins. We purified a lectin-like protein (BmLec) from Bothrops moojeni venom and investigated its effect on platelet aggregation, insulin secretion, antibacterial activity, and isolated kidney cells. The BmLec was purified using two chromatographic steps: affinity chromatography and reverse phase high performance liquid chromatography (HPLC). BmLec showed a dose-dependent platelet aggregation and significantly decreased the bacterial growth rate in approximately 15%. During scanning electron microscopy, the profile of Xanthomonas axonopodis pv. passiflorae treated with lectin disclosed a high vesiculation and membrane rupture. BmLec induced a strong and significant increase in insulin secretion at 2.8 and 16.7 mM glucose concentrations, and this effect was seen in the presence of EGTA in both experiments. BmLec (10 µg/mL) increased the perfusion pressure, renal vascular resistance and urinary flow. The glomerular filtration rate and percentages of sodium, potassium and chloride tubular transport were reduced at 60 minutes of perfusion. Renal alterations caused by BmLec were completely inhibited by indomethacin in all evaluated parameters. In conclusion, the C-type lectin isolated from Bothrops moojeni affected platelet aggregation, insulin secretion, antibacterial activity and isolated kidney function.

Resumo em Inglês:

Mesobuthus gibbosus (Brullé, 1832) scorpions were collected from the Mugla province in the Aegean region of Turkey and housed in individual boxes. After extraction, the venom composition was analyzed using gel electrophoresis (SDS-PAGE). Interestingly, all scorpion venom samples contained only one protein band (~68 kDa) in common. Two protein bands (30 and 98 kDa) were common in six venom samples and were absent in the other venoms. Furthermore, two different protein bands (28 and 45 kDa) were detected in seven venom samples. This study proposes possible variations in the composition of individual scorpion venom samples collected from the same geographic region, based on the electrophoretic profile. Additional studies will be necessary in order to assess these variations further and to identify the proteins corresponding to the bands.

Resumo em Inglês:

Types C and D strains of Clostridium botulinum are commonly related to avian and mammalian botulism. Although there are numerous vaccine recommendations, little research has been conducted to indicate the real effectiveness of vaccine timing or the ideal immunization protocol for young beef calves. Four commercially available vaccines, two bivalent (Clostridium botulinum types C and D; vaccines 1 and 2) and two polyvalent (all Clostridium spp. including Clostridium botulinum types C and D; vaccines 3 and 4), that are currently used in Brazilian herds, were tested in order to verify the maternal immune response. One hundred cows, divided into four vaccinated groups and one unvaccinated group, were given a two-dose subcutaneous immunization, at day zero, followed by a second dose given at 42 days post-vaccination, which corresponded to 40 days before birth. Serum samples (n = 75) were collected only from healthy neonatal calves at 0, 7, 45 and 90 days post-calving (DPC) and subjected to indirect ELISA using the purified C and D holotoxins as capture antigens. The serological profile showed that all vaccines were able to induce a satisfactory neonatal immune response to both holotoxins at 7 DPC. However, at 45 and 90 DPC, a significant reduction (p < 0.05) was observed in the antibody level against C and D holotoxins in all tested vaccines. Neonatal immunization in calves is compromised by significant levels of maternal antibodies so that the necessity of planning a calf vaccination program involves assessment of disease risks at the production site. Finally, our findings represent the first demonstration of maternal immunity transferred to neonatal beef calves, including immunity levels after vaccination against Clostridium botulinum toxoids C and D.

Resumo em Inglês:

Pore-forming cytolysins of 19 kDa from sea anemones present a remarkable cytolytic property. In the present work, a purified 19-kDa cytolysin was obtained from the sea anemone Heteractis magnifica. The purification steps involved ammonium sulfate precipitation and subsequently desalting by dialysis against 10 mM sodium phosphate buffer (pH 7.4), followed by anion exchange chromatography in DEAE-Sepharose® column (GE Healthcare, Sweden) and gel filtration chromatography using Sephadex® G-50 matrix (GE Healthcare, Sweden). The active fractions from the gel filtration chromatography were pooled and rechromatographed in the same column. The final active fraction showed a prominent protein band of molecular mass of 19 kDa when analyzed by SDS-PAGE.

Resumo em Inglês:

Snakebites are endemic in some parts of Thailand, being associated with several complications. Ocular disturbances are uncommon, except in cases of corneal or conjunctival injury, when the eye is directly exposed to the snake venom. The present study presents a case of combined ophthalmic artery occlusion and transient central retinal artery occlusion with macular ischemia after a Russell's viper bite.