Tephrosia toxicaria†Pers. reduces temporomandibular joint inflammatory hypernociception: the involvement of the HO-1 pathway.

BACKGROUND: We investigated both the efficacy and the sub-chronic toxicity of Tephrosia toxicaria Pers. in the zymosan-induced temporomandibular joint (TMJ) inflammatory hypernociception in rats evaluating the possible role of heme oxygenase-1 (HO-1). METHODS: Rats were pretreated with T. toxicaria (0.2, 2.0 or 20 mg/kg) 60 min before the intra-articular injection of zymosan (2 mg, 40 µL) in the left TMJ. In another series of experiments, rats were treated with ZnPP-IX (3 mg/kg), a specific HO-1 inhibitor, before T. toxicaria (20 mg/kg). Von Frey test was used to evaluate inflammatory hypernociception (g) 4 h after zymosan injection. Six hours after zymosan injection, the synovial lavage was collected for total cell count and myeloperoxidase (MPO) activity, and joint tissue for histopathological analysis and immunohistochemistry for HO-1. To evaluate the sub-chronic toxicity, mice received T. toxicaria (20 mg/kg) or saline once a day for 14 days to analyse body mass, organ weight and biochemical parameters. RESULTS: T. toxicaria partially reversed the zymosan-induced head withdrawal threshold, the number of cells and the MPO activity. T. toxicaria reduced the inflammatory cell influx in the synovial membrane. TMJ immunohistochemical analyses treated with T. toxicaria showed increased HO-1 expression. These effects of T. toxicaria were not observed in the presence of ZnPP-IX. T. toxicaria treatment for 14 days did not show significant signs of toxicity when administrated to mice. CONCLUSIONS: T. toxicaria did not produce any signs of toxicity and effectively decreased zymosan-induced TMJ inflammatory hypernociception dependent, at least in part, upon the HO-1 pathway integrity.

Is the antithrombotic effect of sulfated galactans independent of serpin?

BACKGROUND: Sulfated galactans are polysaccharides with heterogeneous structures that frequently show anticoagulant activity. Their anticoagulant mechanisms are complex and distinct from those observed for heparin. Sulfated galactans act through a combination of effects involving serpin-dependent and serpin-independent mechanisms. Interestingly, these polymers can also induce blood coagulation due to activation of factor XII (FXII). OBJECTIVES: The structure of a complex sulfated galactan from the red alga Acanthophora muscoides was characterized by solution nuclear magnetic resonance. This polysaccharide and another previously characterized algal sulfated galactan from Botryocladia occidentalis were each used in in vitro and in vivo anticoagulant and antithrombotic assays to understand the possible structural determinants of their functional effects. RESULTS AND CONCLUSIONS: The serpin-dependent anticoagulant effects and FXII-related procoagulant effects of the sulfated galactans decreased in parallel with the molecular size. The serpin-independent anticoagulation also correlated with the chemical structure of the sulfated galactans. The sulfated galactan from A. muscoides, which showed mostly serpin-independent anticoagulant activity and reduced activation of FXII, drastically reduced arterial thrombus formation. However, the sulfated galactans produced opposite effects on venous thrombosis; this difference appears to result from the tenuous balance between the various effects on coagulation, including serpin-dependent and serpin-independent anticoagulation and FXIIa-dependent procoagulation. This study of novel sulfated polysaccharides with distinct effects on coagulation and thrombosis helps to establish the minimal structural-function relationship required for the development of antithrombotic drugs.

Low-dose combination of alendronate and atorvastatin reduces ligature-induced alveolar bone loss in rats.

BACKGROUND AND OBJECTIVE: Atorvastatin (ATV) has bone anabolic properties, and alendronate (ALD) is an important antiresorptive drug. This study aimed to evaluate the effects of the combination of ALD and ATV on ligature-induced alveolar bone loss in rats. MATERIAL AND METHODS: Periodontitis was induced by ligature in 78 Wistar rats. Groups of six rats prophylactically received 0.9% saline (SAL), ALD (0.01 or 0.25 mg/kg subcutaneously) or ATV (0.3 or 27 mg/kg by gavage). Then, groups of six rats received the combination of ALD+ATV (0.25 mg/kg + 27 mg/kg, 0.01 mg/kg + 0.3 mg/kg, 0.25 mg/kg + 0.3 mg/kg or 0.01 mg/kg + 27 mg/kg) prophylactically. An extra group of six rats received therapeutic SAL or a lower-dose combination of ALD+ATV (0.01 mg/kg + 0.3 mg/kg, respectively) therapeutically. Three extra groups of six rats each received SAL or a lower-dose combination of ALD+ATV (0.01 mg/kg + 0.3 mg/kg, respectively) prophylactically or therapeutically for histometric and immunohistochemical analyses. The rats were killed on day 11 after ligature placement, and the maxillae were removed and processed for macroscopic, histomorphometric and TRAP immunohistochemical analyses. Gingival samples were collected to evaluate myeloperoxidase (MPO) activity. Blood samples were collected to measure serum bone-specific alkaline phosphatase (BALP) and transaminase levels and for hematological studies. Rats were weighed daily. RESULTS: All combined therapies prevented alveolar bone loss when compared with SAL or low doses of monotherapy (ALD or ATV) (p < 0.05). The lower-dose combination of ALD+ATV (0.01 mg/kg + 0.3 mg/kg, respectively), administered either prophylactically (39.0%) or therapeutically (53.5%), prevented alveolar bone loss. Decreases in bone and cementum resorption, in leukocyte infiltration and in immunostaining for TRAP and MPO activity corroborated the morphometric findings. The lower-dose combination of ALD+ATV (0.01 mg/kg + 0.3 mg/kg, respectively) prevented BALP reduction (p < 0.05) and did not alter the level of serum transaminases. Moreover, the lower-dose combination of ALD+ATV (0.01 mg/kg + 0.3 mg/kg, respectively) also reduced neutrophilia and lymphomonocytosis and did not cause weight loss when compared with administration of SAL. CONCLUSION: The lower-dose combination of ALD+ATV (0.01 mg/kg + 0.3 mg/kg, respectively) demonstrated a protective effect on alveolar bone loss.

Differential activity of a lectin from Solieria filiformis against human pathogenic bacteria

A lectin isolated from the red alga Solieria filiformis was evaluated for its effect on the growth of 8 gram-negative and 3 gram-positive bacteria cultivated in liquid medium (three independent experiments/bacterium). The lectin (500 æg/mL) stimulated the growth of the gram-positive species Bacillus cereus and inhibited the growth of the gram-negative species Serratia marcescens, Salmonella typhi, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus sp, and Pseudomonas aeruginosa at 1000 æg/mL but the lectin (10-1000 æg/mL) had no effect on the growth of the gram-positive bacteria Staphylococcus aureus and B. subtilis, or on the gram-negative bacteria Escherichia coli and Salmonella typhimurium. The purified lectin significantly reduced the cell density of gram-negative bacteria, although no changes in growth phases (log, exponential and of decline) were observed. It is possible that the interaction of S. filiformis lectin with the cell surface receptors of gram-negative bacteria promotes alterations in the flow of nutrients, which would explain the bacteriostatic effect. Growth stimulation of the gram-positive bacterium B. cereus was more marked in the presence of the lectin at a concentration of 1000 æg/mL. The stimulation of the growth of B. cereus was not observed when the lectin was previously incubated with mannan (125 æg/mL), its hapten. Thus, we suggest the involvement of the binding site of the lectin in this effect. The present study reports the first data on the inhibition and stimulation of pathogenic bacterial cells by marine alga lectins.

Differential activity of a lectin from Solieria filiformis against human pathogenic bacteria.

A lectin isolated from the red alga Solieria filiformis was evaluated for its effect on the growth of 8 gram-negative and 3 gram-positive bacteria cultivated in liquid medium (three independent experiments/bacterium). The lectin (500 microg/mL) stimulated the growth of the gram-positive species Bacillus cereus and inhibited the growth of the gram-negative species Serratia marcescens, Salmonella typhi, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus sp, and Pseudomonas aeruginosa at 1000 microg/mL but the lectin (10-1000 microg/mL) had no effect on the growth of the gram-positive bacteria Staphylococcus aureus and B. subtilis, or on the gram-negative bacteria Escherichia coli and Salmonella typhimurium. The purified lectin significantly reduced the cell density of gram-negative bacteria, although no changes in growth phases (log, exponential and of decline) were observed. It is possible that the interaction of S. filiformis lectin with the cell surface receptors of gram-negative bacteria promotes alterations in the flow of nutrients, which would explain the bacteriostatic effect. Growth stimulation of the gram-positive bacterium B. cereus was more marked in the presence of the lectin at a concentration of 1000 microg/mL. The stimulation of the growth of B. cereus was not observed when the lectin was previously incubated with mannan (125 microg/mL), its hapten. Thus, we suggest the involvement of the binding site of the lectin in this effect. The present study reports the first data on the inhibition and stimulation of pathogenic bacterial cells by marine alga lectins.

Antinociceptive activity of sulfated carbohydrates from the red algae Bryothamnion seaforthii (Turner) Kütz. and B. triquetrum (S.G. Gmel.) M. Howe.

We report the antinociceptive activity, determined by the writhing, formalin and hot-plate tests in mice, of crude (F0/60), lectin and carbohydrate fractions isolated by ammonium sulfate precipitation (0 to 60%) from Bryothamnion seaforthii and B. triquetrum, species of red algae. Not only fraction F0/60 but also lectins from both species significantly inhibited acetic acid-induced abdominal contractions after intraperitoneal or oral administrations. In the formalin test, lectins (1 and 5 mg/kg, ip, and 5 to 20 mg/kg, po) inhibited the 1st and 2nd phases (5 and 20 min, respectively), but the effect occurred predominantly on the 2nd phase. The effects of the lectins were totally or partially reversed by naloxone (2 mg/kg, sc) in the 1st and 2nd phases, respectively. Experiments performed with lectins in the absence and presence of avidin (1 mg/kg, ip) and D-mannose (1 mg/kg, ip) showed that avidin did not interfere with the effect of B. seaforthii lectin but partially reversed the effect of B. triquetrum lectin. D-Mannose completely reversed the effects of both species. F0/60 fractions from both algae significantly increased the latency time in response to thermal stimuli, and naloxone reversed antinociception, indicating the involvement of the opioid system in both the peripheral and central effects of the fractions. In the writhing test, the carbohydrate fractions were the most active, inhibiting the contractions by 71 and 79% (B. triquetrum) and by 46 and 69% (B. seaforthii) at doses of 1 and 5 mg/kg, ip, respectively. Sulfated carbohydrate fractions of B. seaforthii and B. triquetrum, containing only about 5% protein as contaminants, are probably responsible for the antinociceptive effects of these red algae.

Antinociceptive activity of sulfated carbohydrates from the red algae Bryothamnion seaforthii (Turner) Kütz. and B. triquetrum (S.G. Gmel.) M. Howe

We report the antinociceptive activity, determined by the writhing, formalin and hot-plate tests in mice, of crude (F0/60), lectin and carbohydrate fractions isolated by ammonium sulfate precipitation (0 to 60 percent) from Bryothamnion seaforthii and B. triquetrum, species of red algae. Not only fraction F0/60 but also lectins from both species significantly inhibited acetic acid-induced abdominal contractions after intraperitoneal or oral administrations. In the formalin test, lectins (1 and 5 mg/kg, ip, and 5 to 20 mg/kg, po) inhibited the 1st and 2nd phases (5 and 20 min, respectively), but the effect occurred predominantly on the 2nd phase. The effects of the lectins were totally or partially reversed by naloxone (2 mg/kg, sc) in the 1st and 2nd phases, respectively. Experiments performed with lectins in the absence and presence of avidin (1 mg/kg, ip) and D-mannose (1 mg/kg, ip) showed that avidin did not interfere with the effect of B. seaforthii lectin but partially reversed the effect of B. triquetrum lectin. D-Mannose completely reversed the effects of both species. F0/60 fractions from both algae significantly increased the latency time in response to thermal stimuli, and naloxone reversed antinociception, indicating the involvement of the opioid system in both the peripheral and central effects of the fractions. In the writhing test, the carbohydrate fractions were the most active, inhibiting the contractions by 71 and 79 percent (B. triquetrum) and by 46 and 69 percent (B. seaforthii) at doses of 1 and 5 mg/kg, ip, respectively. Sulfated carbohydrate fractions of B. seaforthii and B. triquetrum, containing only about 5 percent protein as contaminants, are probably responsible for the antinociceptive effects of these red algae