Development of new HPLC method for identification of metabolic degradation of N-pyrrolylhydrazide hydrazones with determined MAO- B activity in cellular cultures

In this research, a new rapid PR- HPLC method was developed for the determination of metabolites in isolated rat hapatocytes. The chromatographic parameters, including the stationary and mobile phases, outlet pressure, temperature and flow rate, were optimized. The method identified two initial from the synthesis molecules in higher concentration and one new unidentified structure as products of the hepatocytic processing of the evaluated analyte. The results identified as first step of metabolism the hydrolysis of the hydrazone group. Further investigations should be aimed into determining the next metabolic transformations, predicted by the in silico application of the web server SMARTCyp.

The role of K-channels in the formation of a nociceptive signal in the rat trigeminal nerve

The central problem of this work is to elucidate the mechanisms of pain in migraine and to establish the role of Kv channels in regulating the excitability of meningeal afferents of the trigeminal nerve that form a pain signal in migraine. The study was conducted on a preparation of an isolated rat skull. It was found that Kv-channel inhibitors 4-aminopyridine (100 microns and 1 mM) and tetraethylammonium (5mm) lead to an increase in the excitability of trigeminal nerve afferents, at the same time, this effect was partially removed by a nonsteroidal anti–inflammatory agent - naproxen, and was not sensitive to sumatriptan, a classic anti-migraine drug. Key words: migraine, K-channels, trigeminal nerve, 4-aminopyridine, tetraethylammonium, naproxen, sumatriptan.

Tadalafil in Increasing Doses: The Influence on Coronary Blood Flow and Oxidative Stress in Isolated Rat Hearts

<b><i>Introduction:</i></b> This study aimed to assess the influence of different doses of tadalafil on coronary flow and oxidative stress in isolated rat hearts. <b><i>Methods:</i></b> The hearts of male Wistar albino rats (<i>n</i> = 48) were retrogradely perfused according to the Langendorff technique at gradually increased constant perfusion pressure (CPP) (40–120 mm Hg). Coronary flow and oxidative stress markers: nitrite oxide (NO) outflow and superoxide anion production in coronary effluent were measured. The experiments were performed during control conditions and in the presence of tadalafil (10, 20, 50, and 200 nM) alone or with Nω-nitro-L-arginine monomethyl ester (L-NAME) (30 μM). <b><i>Results:</i></b> Tadalafil administration significantly increased coronary flow at all CPP values at all administered doses. Tadalafil led to an increase in the NO levels, but a statistically significant NO release increase was found only at the highest dose and highest CPP. Tadalafil did not significantly affect the release of O²⁻. After inhibiting the nitrite oxide synthase system by L-NAME, tadalafil-induced changes in cardiac flow and NO levels were reversed. L-NAME administration had no pronounced effect on the O²⁻ release. <b><i>Conclusion:</i></b> Tadalafil causes changes in the heart vasculature in a dose-dependent manner. It does not lead to a significant increase in the production of superoxide anion radicals.

High dilutions of homeopathic remedies induce relaxation of rat aorta precontracted with Noradrenalin

BACKGROUND Homeopathic potencies have been reported to produce alteration of contraction in isolated rat ileum in an organ bath. Potentized homeopathic drugs like Lycopus V and Aurum met are used for the treatment of hypertension. AIM The purpose of this study is to see whether Lycopus V 30 CH and Aurum met 30 CH could produce relaxation of isolated rat aorta in the organ bath. METHODS The aorta of rats were dissected out, placed in Krebs-Henseleit solution, cleared of connective tissue and endothelium and cut into 2-2.5 mm long rings. The rings were fixed in organ baths with the upper end connected by a string to an isometric transducer which was finally attached through a data acquisitation equipment to a computer. Aurum met 30 CH Lycopus V 30 CH, and their medium 90% ethanol were added separately to the bathing fluid containing the aorta rings which were precontracted with noradrenalin (NA). RESULTS Both the drugs produced significant relaxation of the aorta (p

Effect Of Fruit And Cork Extract Of Ficus Lacor Buch Ham On α/β -Glucosidase, α -Amylase, Lipase, Glucose Absorption And Uptake

Fruits of the plant Ficus Lacor Buch. Ham. were used traditionally for treatment of diabetes mellitus. The present study was undertaken to evaluate the antidiabetic potential of the plant using in vitro approach. Effect of Ficus Lacor Buch. Ham. was evaluated using α/β -glucosidase, α-amylase and lipase enzyme inhibition assay methods. The glucose absorption in intestine was evaluated using everted rat jejunum while glucose uptake was evaluated using isolated rat hemidiaphragm. Fruit and cork ethanolic extract was prepared by using soxhlation extraction method. In vitro assay of α-glucosidase showed that IC50 value of fruit extract was 83.03 µg/ml and cork extract 88.32 µg/ml when compared with control group acarbose. β-glucosidase enzyme was inhibited by fruit and cork extract of plant with IC50 value of fruit and cork extract 132.71 µg/ml and 171.93 µg/ml. The extracts further quantify α-amylase inhibitory activity of fruit (IC50 77.93 µg/ml) and cork (IC50 111.94 µg/ml) extract. Lipase inhibitory assay indicated the effect of plant extract on lipase enzyme was not prominent when compared to orlistat. Absorption of glucose through everted rat jejunum was reduced significantly (P ˂ 0.05) when compared with standard metformin. Effect of fruit and cork extract on rat hemidiaphragm exhibited significant (P ˂ 0.05) increase in glucose uptake when compared with standard metformin. Result suggests Ficus Lacor Buch. Ham. is effective in inhibiting carbohydrate metabolizing enzymes α/β –glucosidase and α-amylase while lipase enzyme was not affected. Fruit and cork extract of the plant was found to reduce significantly glucose absorption in everted rat jejunum. The significant increase in glucose uptake was observed in isolated rat diaphragm. The result reveals that Ficus Lacor Buch. Ham. acts by inhibiting carbohydrate metabolizing enzymes, reducing glucose absorption in intestine and increasing glucose uptake in hemidiaphragm

Potentilla reptans L. postconditioning protects reperfusion injury via the RISK/SAFE pathways in an isolated rat heart

Background Our previous study indicated that Potentilla reptans root has a preconditioning effect by its antioxidant and anti-apoptotic effects in an isolated rat heart ischemia/reperfusion (IR) model. In the present study, we investigated the post-conditioning cardio-protective effects of Potentilla reptans and its active substances. Methods The ethyl acetate fraction of P. reptans root (Et) was subjected to an IR model under 30 min of ischemia and 100 min of reperfusion. To investigate the postconditioning effect, Et was perfused for 15 min at the early phase of reperfusion. RISK/SAFE pathway inhibitors, 5HD and L-NAME, were applied individually 10 min before the ischemia, either alone or in combination with Et during the early reperfusion phase. The hemodynamic factors and ventricular arrhythmia were calculated during the reperfusion. Oxidative stress, apoptosis markers, GSK-3β and SGK1 proteins were assessed at the end of experiments. Results Et postconditioning (Etpost) significantly reduced the infarct size, arrhythmia score, ventricular fibrillation incidence, and enhanced the hemodynamic parameters by decreasing the MDA level and increasing expression of Nrf2, SOD and CAT activities. Meanwhile, Etpost increased the BCl-2/BAX ratio and decreased Caspase-3 expression. The cardioprotective effect of Etpost was abrogated by L-NAME, Wortmannin (a PI3K/Akt inhibitor), and AG490 (a JAK/STAT3 inhibitor). Finally, Etpost reduced the expression of GSK-3β and SGK1 proteins pertaining to the IR group. Conclusion P. reptans reveals the post-conditioning effects via the Nrf2 pathway, NO release, and the RISK/SAFE pathway. Also, Etpost decreased apoptotic indexes by inhibiting GSK-3β and SGK1 expressions. Hence, our data suggest that Etpost can be a suitable natural candidate to protect cardiomyocytes during reperfusion injury.

Ibogaine-Mediated ROS/Antioxidant Elevation in Isolated Rat Uterus Is β-Adrenergic Receptors and KATP Channels Mediated

Ibogaine effects are mediated by cellular receptors, ATP depletion followed by ROS production and antioxidant enzyme activity elevation in a dose and time dependent manner. Since the role of KATP channels and β-adrenoceptors in ROS cellular circuit was established here we explored their role in ibogaine pro-antioxidant effectiveness. Single dose of ibogaine (10 mg/L i.e., 28.8 μmol/L) was applied to isolated rat uterus (spontaneous and Ca2+-stimulated) and contractility and antioxidant enzymes activity were monitored during 4 h. Ibogaine increased amplitude and frequency of spontaneous active uteri immediately after addition that was prevented by propranolol (β1 and β2 adrenoceptors selective antagonists) and glibenclamide (KATP sensitive channels inhibitor; only frequency) pre-treatment. In Ca2+-stimulated uteri, ibogaine decreased both amplitude and frequency after 4 h. Pre-treatment with propranolol abolished ibogaine induced amplitude lowering, while glibenclamide had no effect. In both types of active uterus, ibogaine induced a decrease in SOD1 and an increase in CAT activity after 2 h. In Ca2+-stimulated uterus, there was also a decrease of SOD2 activity after 2 h. After 4 h, SOD1 activity returned to the baseline level, but GSH-Px activity increased. Pre-treatment with both propranolol and glibenclamide abolished observed changes of antioxidant enzymes activity suggesting that ibogaine pro-antioxidative effectiveness is β-adrenergic receptors and KATP channels mediated.