Effects of Kaurenoic Acid and Arginine on Random Skin Flap Oxidative Stress, Inflammation, and Cytokines in Rats.

BACKGROUND: Kaurenoic acid (KA), a diterpene extracted from copaíba oil-resin, is known to have potent antioxidant and anti-inflammatory properties. L-Arginine (LA) is an amino acid and a nitrogenous precursor for the synthesis of nitric oxide (NO). NO paper in wound healing has already been well documented. The aim of this study was to investigate the protective effects of LA and KA against ischemia reperfusion injury in a randomized skin flap model in rats. METHODS: A modified McFarlane flap model measuring 2.5 wide × 8 cm long was established in 36 anesthetized rats and evaluated within 3 groups: group control, group L-arginine, and group kaurenoic acid. Each group was subdivided into two subgroups (T1 and T2, n = 6 each). Samples were collected 24 h (T1)/48 h (T2) postoperatively for oxidative stress (glutathione), as non-protein thiols, malondialdehyde (MDA), NO2, inflammation [myeloperoxidase (MPO)], and cytokines TNF-α and IL-1ß assays. RESULTS: KA promoted a significant decrease of TNF-α and IL-1 expression and MPO activity at T1/T2 time points. NSGH levels increased significantly in KA-treated rats, while MDA levels decreased significantly in the same rats. Arginine promoted a significant decrease in MDA levels at the T1 time point and a significant increase in non-protein thiols concentrations at T1/T2 time points. NO2 concentration also decreased at the T1 time point. CONCLUSIONS: KA may attenuate the oxidative stress and the inflammation, thereby reducing tissue damage induced by ischemia/reperfusion in rats subjected to dorsal skin flaps. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266.

Anticonvulsant action of Calotropis procera latex proteins.

Calotropis procera (Ait.) R.Br. is a laticiferous plant belonging to the Apocynaceae family. C. procera latex proteins were evaluated with respect to anticonvulsant and sedative activity in mouse models of pentylenetetrazol (PTZ)-, pilocarpine-, and strychnine-induced convulsions or turning behavior and pentobarbital-induced sleep. In the strychnine- and pilocarpine-induced seizure models, C. procera latex proteins caused no significant alterations in latencies to convulsions and death, as compared with controls. In the PTZ-induced seizure model, administration of C. procera latex proteins in high doses (50 or 100mg/kg) and diazepam caused significant increases in latencies to convulsions and death. C. procera latex proteins (50 or 100mg/kg) and 2mg/kg diazepam caused a decrease in sleep latency and an increase in sleep time compared with the control group and groups treated with 5 or 10mg/kg. Our results suggest that C. procera latex proteins have a central nervous system-depressant activity as reflected in their potentiation of pentobarbital-induced sleeping time and their anticonvulsant action in the PTZ-induced seizure model.

Pain behavior to electroacupuncture in rabbit tooth pulp

Aim: The aim of this study was to verify the pain behavior to electroacupuncture (EACP) in rabbit tooth-pulp assay. Methods: Albino rabbits weighing 1.5-2.0 kg) were pretreated with saline or morphine (5mg/kg, e.v.) 10 min before the nociceptive test (NT). In another group, EACP (rectangular pulses, f1=2 Hz, f2=0.1 s, 3 mA) was applied in acupoints and sham points, before and during the NT. After 120 min, EACP was withdrawn and the nociceptive threshold was measured every 10 min until the initial nociceptive threshold was achieved. Results: EACP, using the Yintang, ST4 and ST5 acupoints, induced an increased in the nociceptive threshold and this effect persisted for up to 2 h, even after the removal of electric stimulation. Application of EACP at sham points did not show significant analgesic activity. The present results demonstrated that males presented a higher initial level of analgesia, but a poorer maintenance of analgesic effect after the EACP procedure, while females demonstrated a long lasting analgesic effect even after discontinuation of EACP. Conclusions: EACP presented an analgesic effect in a rabbit tooth pulp assay that was probably due to the release of endogenous opioids. The duration of this analgesic effect seems to be different for males and females.

Metabolism of tetraglycine in isolated non-filtering rat kidneys.

The purpose of this work was to study the metabolism of tetraglycine in the isolated non filtering rat kidney. Kidneys were perfused with Krebs-Henseleit solution containing 1 mM of tetraglycine. The determination of the peptidic residues and their components was done in an aminoacid microanalyzer. The results showed that tetraglycine was significantly oxidized to a maximal concentration of 0.12 mM at the end of 120 minutes (88%). The peptide was degraded to its constituents, diglycine and glycine. There was no elution of triglycine. The tetrapeptide produced glycine in increasing concentrations while diglycine as a metabolite was almost constant up to 80 minutes of perfusion. The hydrolysis of tetraglycine allowed us to believe that aminopeptidase, carboxypeptidase and dipeptidyl dipeptidase can be present in the contraluminal membranes of the rat kidney contributing to the handling of tetraglycine. Our results indicate newer pathways of the tetrapeptide metabolism.