Successful Pre-Clinical Management of Irinotecan-Debilitated Animals: A Protein- Based Accessory Phytomedicine.

BACKGROUND: Calotropis procera is a laticiferous plant (Apocynaceae) found in tropical regions all over the world. The ultrastructural characteristics of laticifers, their restricted distribution among different taxonomic groups, and in some species in each clade, as peptidases from latex, make them very attractive for biological analysis. OBJECTIVE: The study aims to investigate the effects of LP-PII-IAA (laticifer protein (LP) sub-fraction II (PII) of C. procera presenting an iodoacetamide-inhibited cysteine proteinase activity) on irinotecan-induced intestinal mucositis, a serious adverse effect of this medicine for the treatment of cancer. METHODS: LP-PII-IAA is composed of closely related isoforms (90%) of peptidases derived from catalysis and an osmotin protein (5%). Animals receiving co-administration of LP-PII-IAA presented a significant decrease in mortality, absence of diarrhea, histological preservation, and normalization of intestinal functions. RESULTS: Clinical homeostasis was accompanied by a reduction in MPO activity and declined levels of IL-1ß, IL-6 and KC, while the IL-10 level increased in LP-PII-IAA-treated animals. COX-2 and NF-kB immunostaining was reduced and the levels of oxidative markers (GSH, MDA) were normalized in animals that received LP-PII-IAA. CONCLUSION: We suggest that peptidases from the latex of Calotropis procera were instrumental in the suppression of the adverse clinical and physiological effects of irinotecan.

Anti-diarrheal therapeutic potential of diminazene aceturate stimulation of the ACE II/Ang-(1-7)/Mas receptor axis in mice: A trial study.

The angiotensin (Ang) II converting enzyme (ACE II) pathway has recently been shown to be associated with several beneficial effects on the body, especially on the cardiac system and gastrointestinal tract. ACE II is responsible for converting Ang II into the active peptide Ang-(1-7), which in turn binds to a metabotropic receptor, the Mas receptor (MasR). Recent studies have demonstrated that Diminazene Aceturate (DIZE), a trypanosomicide used in animals, activates the ACE II pathway. In this study, we aimed to evaluate the antidiarrheal effects promoted by the administration of DIZE to activate the ACE II/Ang-(1-7)/MasR axis in induced diarrhea mice models. The results show that activation of the ACE II pathway exerts antidiarrheal effects that reduce total diarrheal stools and enteropooling. In addition, it increases Na+/K+-ATPase activity and reduces gastrointestinal transit and thus inhibits contractions of intestinal smooth muscle; decreases transepithelial electrical resistance, epithelial permeability, PGE2-induced diarrhea, and proinflammatory cytokines; and increases anti-inflammatory cytokines. Enzyme-linked immunosorbent assay (ELISA) demonstrated that DIZE, when activating the ACE II/Ang-(1-7)/MasR axis, can still interact with GM1 receptors, which reduces cholera toxin-induced diarrhea. Therefore, activation of the ACE II/Ang-(1-7)/MasR axis can be an important pharmacological target for the treatment of diarrheal diseases.

Biopolymer Extracted from Anadenanthera colubrina (Red Angico Gum) Exerts Therapeutic Potential in Mice: Antidiarrheal Activity and Safety Assessment.

Anadenanthera colubrina var. cebil (Griseb.) Altschul (Fabaceae family), commonly known as the red angico tree, is a medicinal plant found throughout Brazil's semi-arid area. In this study, a chemical analysis was performed to investigate the antidiarrheal activity and safety profile of red angico gum (RAG), a biopolymer extracted from the trunk exudate of A. colubrina. Upon FT-IR spectroscopy, RAG showed bands in the regions of 1608 cm-1, 1368 cm-1, and 1029 cm-1, which relate to the vibration of O-H water molecules, deformation vibration of C-O bands, and vibration of the polysaccharide C-O band, respectively, all of which are relevant to glycosidic bonds. The peak molar mass of RAG was 1.89 × 105 g/mol, with the zeta potential indicating electronegativity. RAG demonstrated high yield and solubility with a low degree of impurity. Pre-treatment with RAG reduced the total diarrheal stool and enteropooling. RAG also enhanced Na+/K+-ATPase activity and reduced gastrointestinal transit, and thereby inhibited intestinal smooth muscle contractions. Enzyme-Linked Immunosorbent Assay (ELISA) demonstrated that RAG can interact with GM1 receptors and can also reduce E. coli-induced diarrhea in vivo. Moreover, RAG did not induce any signs of toxicity in mice. These results suggest that RAG is a possible candidate for the treatment of diarrheal diseases.

Inhibitory effects of a standardized extract of Justicia pectoralis in an experimental rat model of airway hyper-responsiveness.

OBJECTIVE: Justicia pectoralis is a plant useful for the treatment of respiratory diseases. Here, we studied the antiasthmatic properties of a standardized extract of J. pectoralis (Jp). METHODS: Ovalbumin (OVA)-sensitized rats were actively challenged with saline or OVA to study airway hyper-responsiveness after oral treatment with saline or Jp. The ability of Jp to inhibit hyper-reactivity was evaluated in isolated trachea mounted in isolated organ bath chamber. KEY FINDINGS: Using KCl or carbachol as contractile agents, tracheal rings of OVA-challenged rats contracted with higher magnitude than trachea of rats challenged with saline. Such hyper-responsive phenotype of OVA-challenged tissues decreased with Jp administration. In Ca+ -free medium, Jp or its major constituent coumarin inhibited preferentially the contractions induced by Ca2+ addition in tissues of OVA-challenged rats stimulated with KCl or acetylcholine. In tissues depleted of their internal Ca+ stores in the presence of thapsigargin, Jp inhibited the contraction induced by capacitative Ca2+ entry. By gavage, Jp abolished the increase caused by challenge with OVA on the levels of IL-1ß and TNF-α in the bronchoalveolar fluid and also impaired the changes in gene expression of canonical transient receptor proteins. CONCLUSIONS: Jp has antiasthmatic properties in an experimental model that reproduces tracheal hyper-reactivity.

The essential oil of Eucalyptus tereticornis, and its constituents alpha- and beta-pinene, potentiate acetylcholine-induced contractions in isolated rat trachea.

The effects of the essential oil of Eucalyptus tereticornis (EOET), especially the effects of its constituents alpha- and beta-pinene, were studied on rat trachea in vitro. In tracheal rings, EOET, alpha- or beta-pinene potentiated the contractions induced by acetylcholine (ACh). Contractions induced by K(+) (60mM) were also potentiated by alpha- and beta-pinene, but were reduced by EOET. Our findings show that EOET has myorelaxant effects on rat airways, but potentiates ACh-induced contractions. Monoterpenes alpha- and beta-pinene are involved in its potentiating actions, but are not responsible for its myorelaxant effects. A putative inhibition of the acetylcholinesterase enzyme is involved.

Antispasmodic effects of essential oil of Pterodon polygalaeflorus and its main constituent ß-caryophyllene on rat isolated ileum.

This study investigates the effects of essential oil of Pterodon polygalaeflorus (EOPP) and ß-caryophyllene (ß-CAR). EOPP and ß-CAR relaxed the basal tone of ileum smooth muscle in a concentration-dependent manner (IC(50) s = 394.35 ± 62.12 and 68.65 ± 9.51 µg/mL respectively), an effect that was unaltered by hexamethonium, L-nitroarginine methyl ester or indomethacin. Both EOPP and ß-CAR evoked a concentration-dependent relaxation of ileum pre-contracted with KCl with an IC(50) value of 107.78 ± 10.47 and 17.35 ± 0.75 µg/mL, respectively. EOPP and ß-CAR inhibited the contractions induced by acetylcholine (ACh) and by KCl. In ileal preparations, the CaCl(2) -induced contractions were reduced by EOPP (300 µg/mL) and ß-CAR (100 µg/mL). Furthermore, CaCl(2) -induced contractions were also reduced by EOPP (300 µg/mL) and ß-CAR (100 µg/mL) in ileal preparations pretreated with ACh under Ca(2+) -free condition and in the presence of verapamil. EOPP (100 and 300 µg/mL) and ß-CAR (30 and 100 µg/mL) reduced the ACh-induced contractions of isolated rat ileum under Ca(2+) -free conditions. In the presence of high KCl and Ca(2+) -free conditions, EOPP (300 µg/mL) and ß-CAR (100 µg/mL) reduced the contractions induced by barium. A similar effect was also observed with verapamil. It is concluded that (i) ß-CAR is an important constituent involved in the myorelaxant and antispasmodic effects induced by EOPP; (ii) the inhibitory effect on intestinal contractility is myogenic and seems mainly mediated through an intracellular mechanism. However, the ability of EOPP and ß-CAR to decrease Ca(2+) influx through cytoplasmic membrane could not be discounted.

Effects of 1,8-cineole on electrophysiological parameters of neurons of the rat superior cervical ganglion.

1. 1,8-Cineole is a non-toxic small terpenoid oxide believed to have medicinal properties in folk medicine. It has been shown to have various pharmacological effects, including blockade of the compound action potential (AP). In the present study, using intracellular recording techniques, we investigated the effects of 1,8-cineole on the electrophysiological parameters of neurons of the superior cervical ganglion (SCG) in rats. 2. 1,8-Cineole (0.1-6 mmol/L) showed reversible and concentration-dependent effects on various electrophysiological parameters. At 3 and 6 mmol/L, but not at 0.1 and 1 mmol/L, 1,8-cineole significantly diminished the input resistance (R(i)) and altered the resting potential (E(m)) to more positive values. At 6 mmol/L, 1,8-cineole completely blocked all APs within 2.7 +/- 0.6 min (n = 12). In neurons exposed to 3 and 1 mmol/L 1,8-cineole, the effects regarding excitability varied from complete AP blockade to minor inhibition of AP parameters. The depolarization of E(m) and the decrease in R(i) induced by 6 mmol/L 1,8-cineole were unaltered by 200 micromol/L niflumic acid, a well known blocker of Ca(2+)-activated Cl(-) currents. 3. Significant correlations (Pearson correlation test) were found between changes in E(m) and decreases in AP amplitude (r = -0.893; P < 0.00282) and maximum ascendant inclination (r = -0.799; P < 0.0173), but not for maximum descendant inclination (r = 0.598; P < 0.117). Application of current to restore the transmembrane potential equal to control E(m) values in the presence of 6 mmol/L 1,8-cineole resulted in the partial recovery of AP. 4. The present study shows that 1,8-cineole effectively blocks the excitability of SCG neurons, probably through various mechanisms, one of which acts indirectly via depolarization of the neuronal cytoplasmatic membrane.

Essential oil of Pterodon polygalaeflorus inhibits electromechanical coupling on rat isolated trachea.

The present work studied the effects of the essential oil of Pterodon polygalaeflorus (EOPP), a plant used to treat bronchitis and amigdalytis, on rat airway smooth muscle in vitro. In Ca(2+)-containing medium, EOPP (100-1300 microg/ml) inhibited preferentially high KCl- than 5-HT-induced muscle contractions in a concentration-dependent fashion, but did affect neither basal muscle tension nor ACh-induced contractions. In preparations maintained in either 60 mM K(+) or 10 microM ACh in Ca(2+)-free medium, EOPP (100, 600 and 1300 microg/ml) inhibited maximum contractile response induced by cumulative Ca(2+) addition (0.1-20 mM). Verapamil (10, 30 and 100 microg/ml), a Ca(2+) channel blocker, also inhibited Ca(2+)-induced concentration-effect curve in presence of ACh in Ca(2+)-free medium, whilst it was ineffective to decrease cholinergic contractions in Ca(2+)-containing medium. In presence of 150 mM K(+) in Ca(2+)-containing medium, EOPP (1300 microg/ml) did not reversed ACh-induced contractions. In contrast, under similar conditions, EOPP almost fully relaxed cholinergic contractions of tracheal smooth muscle in Ba(2+)-containing medium. In medium containing 10 mM tetraethylammonium and 2 mM Ba(2+) instead of Ca(2+), both EOPP (1300 microg/ml) and verapamil (approximately 5 microg/ml) significantly decreased ACh-induced contractions. Thus, in rat isolated trachea, EOPP induces inhibitor effects on contractions preferentially triggered by an electromechanical coupling mode.