PARTICIPATION OF Hi- AND H 3-RECEPTORS IN THE REGULATION OF GUINEA-PIG TRACHEAL TONE - INFLUENCE OF INDOMETHACIN

The tracheal tone is influenced by histaminergic receptors and by the epithelium derived relaxing factor (EpDRF) which contains metabolites of arachidonic acid. The aims of the present study were the following: 1) to investigate the role of Hi- and Нз-receptors in the tracheal tone regulation using as test substances histamine (H), the Hi-receptor antagonist mepyramine and the Нз-receptor agonist (R)a-methylhistamine [(R)a -MHA]; 2) to study the influence of the cyclooxygenase (COX) inhibitor indomethacin on the tracheal responsiveness to the examined substances. The experiments were carried out on isolated guinea-pig tracheal rings. Histamine at cumulative concentrations contracts the trachea. In the presence of mepyramine the concentration- response curves to H are shifted to the right that proves the concept of the Hi-receptor mediated tracheal contraction. In the presence of indomethacin the concentration-response curves to H are shifted to the left and the maximal contraction is significantly increased due to the inhibition of the COX pathway. (R)oc-MHA at concentrations up to lxlfH M leads to a slight tracheal contraction, which is probably Hi-receptor mediated as it is reduced in the presence of mepyramine. The ЗхКИ M concentration of (R)a-MHA relaxes the trachea probably due to its Нз-receptor agonistic activity. In the presence of indomethacin this relaxation is turned to a further contraction. After tracheal precontraction by H, (R)a-MHA concentration dependently relaxes the trachea. This spasmolytic effect is insignificantly influenced by mepyramine and is almost completely abolished in the presence of indomethacin, which shows that it is probably due to an increased production of metabolites of arachidonic acid

Study of Natural Aronia Melanocarpa Fruit Juice for Antibacterial and Antiviral Activity

Natural Aronia melanocarpa fruit juice (AMFJ) is rich in polyphenols most of which are anthocyanins. These compounds and other natural plant products are recently evaluated for their anti-infectious activity. The aim of the present study was to investigate the antibacterial and antiviral activity of AMFJ. AMFJ bacteriostatic activity on referent strains of S. aureus ATCC 25923, E. coli ATCC 25922 and P. aeruginosa ATCC 27853 was assessed by counting the number of colonies after 24h incubation at 37°C using the microbial number method. AMFJ was not bacteriostatic for P. aeruginosa. The microbial number for E. coli was 0 ,3 6xl02 CFU/ml AMFJ and for N. aureus 0,87x10s CFU/ml AMFJ. Gram-positive bacteria should mainly be used as a test for further investigation of the bacteriostatic activity of AMFJ. AMFJ antiviral activity directed to the reproduction in ovo of influenza virus type A (H3N2) was investigated. AMFJ inhibited the reproduction of influenza virus in its initial stages, most probably, due to the formation of complex compounds between the virion, on one hand, and the polyphenols, on the other hand, which influenced the adsorption of the influenza virus on the cell surface

EFFECT OF ISOTEOLINE IN ANIMAL MODELS PREDICTIVE OF ANTIDEPRESSANT ACTIVITY

Isoteoline, a compound of aporphine structure, was studied for antidepressant activity. Two animal models were used: the behavioral despair test and the clonidine-induced hypothermia. Isoteoline failed to alter the immobility time in rats subjected to forced swimming, but antagonized the immobility-reducing effect of desipramine, both after a single and multiple administration. In rats made hypothermic by i.p. injection of clonidine, Isoteoline did not antagonize the effect on rectal temperature, but rather accentuated it. The conclusion was made that Isoteoline was devoid of antidepressant activity. The results were analyzed in terms of previously demonstrated interactions of Isoteoline with subtypes of serotonergic receptors and were found to provide further evidence in support of these interactions

Influence of Fruit Juice From Aronia Melanocarpa on the Process of Lipid Peroxidation in a Model of Carbon Tetrachloride-Induced Hepatotoxicity in Rats

The fruit juice from Aronia melanocarpa (FJAM) is rich in anthocyanins. We studied the effect of FJAM on the process of lipid peroxidation in a model of carbon tetrachloride (CCI4)-induced hepatotoxicity in rats. Malondialdehyde (MDA) levels were measured in plasma and liver homogenate. CCU induced a significant elevation of MDA levels in the plasma (p<0,05) and in the homogenate (p<0,01) in comparison with distilled water-treated controls. FJAM applied alone did not significantly influence on the MDA levels. The pretreatment of the rats with FJAM before their treatment with CCI4 lead dose-dependently to MDA levels in the plasma and homogenate which did not differ in most animal groups from the controls and were significantly lower from those of the CCI4-treated rats

Antiproliferative Activity of Natural Flavonoid Fustin Isolated from the Heartwood of Cotinus Coggygria Scop. Against Breast and Colon Cancer Cell Lines

Background and objective: Cotinus coggygria Scop. is a valuable medicinal plant species with pronounced pharmacological potential due to its numerous biological activities. The herb is characterized by a high content of polyphenols among which is fustin. The anticancer activities of fustin, however, are extremely weakly studied. The aim of the present study was to investigate the in vitro antiproliferative potential of fustin isolated from the heartwood of C. coggygria against cell lines originating from two of the most common cancer types – breast (MDA-MB-231 and MCF7), and colon cancer (Colon 26). Materials and methods: Cell growth inhibitory properties of fustin were examined by MTT assay. Subsequently, phase-contrast and fl uorescence microscopy analysis as well as colonyforming assay were carried out on the most sensitive to the cytostatic action of the fustin cell line. Results: The obtained results showed that fustin reduced the proliferation of all studied cell lines. The highest cytostatic eff ect was registered towards breast cancer MDA-MB-231 cells with a half maximal inhibitory concentration (IC50) value of 56.02 μg/ ml followed by colon cancer cells with an IC50 of 78.07 μg/ml. MCF7 cell proliferation was least aff ected with a calculated IC50 of 187.8 μg/ml. Further investigations on breast cancer MDA-MB-231 cells indicated decreased density of cell monolayer and some morphological alterations, signifi cant attenuation in the number of viable cells, and diminished clonogenic ability of cells after fustin exposure. Conclusion: It could be concluded that fustin isolated from the heartwood of medicinal plant C. coggygria possesses marked antiproliferative properties against breast cancer cell line MDA-MB-231 which will be a subject of our more detailed future investigations

Effect of Aronia melanocarpa fruit juice on glucose tolerance, lipid metabolism, and obesity in a rat model of metabolic syndrome

Abstract Metabolic syndrome (MS) is a serious health condition. The purpose of this study was to investigate the effects of polyphenol-rich Aronia melanocarpa fruit juice (AMFJ) on glucose tolerance, triglyceride levels, and adipose tissue in rats with MS induced by high-fat high-fructose (HFHF) diet. Fifty rats were allocated in 5 groups: control, MS, MS+AMFJ2.5, MS+AMFJ5, and MS+AMFJ10. In the course of 10 weeks, the control group was on a regular rat diet while the other groups received HFHF diet. During the experiment, control and MS groups were treated daily orally with distilled water (10.0 mL kg−1) and the other three groups – with AMFJ at doses of 2.5, 5.0, and 10.0 mL kg−1, respectively. In MS rats, glucose intolerance, hypertriglyceridemia, visceral obesity, and increased adipocyte size were observed. In AMFJ-treated groups, the serum glucose and triglycerides, as well as visceral fat and adipocyte size decreased significantly and did not differ from those of the control group. AMFJ at doses 2.5 and 5.0 mL kg−1 showed an anti-apoptotic activity in adipocytes, while at the dose of 10 mL kg−1 a pro-apoptotic effect was detected. In conclusion, AMFJ could antagonise most of the negative consequences of HFHF diet on carbohydrate and lipid metabolism in a rat MS model

Ameliorative effects of the flavonoid fustin in a rat model of trinitrobenzensulfonic acid-induced colitis

Trinitrobenzene sulfonic acid (TNBS)-induced colitis is a widely used animal model that mimics the signs and symptoms of inflammatory bowel disease. Fustin is a flavonoid found in Cotinus coggygria. The aim of the present study was to investigate the effect of fustin isolated from Cotinus coggygria heartwood in a rat model of TNBS-induced colitis. In this experiment, 30 male Wistar rats were used, allocated to three groups: Control, TNBS and TNBS+F10. Colitis was induced by rectal application of TNBS. After the induction of colitis, fustin at a dose of 10 mg/kg was administered orally to TNBS+F10 group in the course of 8 days. Severity of colitis, oxidative stress and inflammation were assessed by macroscopic, histopathological, immunohistochemical and biochemical analyses. Rats from TNBS group demonstrated severe colonic damage. Fustin treatment ameliorated most of the macroscopic and some of the histopathological indices of colonic damage, and restored the activity of the endogenous antioxidant superoxide dismutase in tissue homogenate but did not affect the signs of inflammation measured by the activity of alkaline phosphatase in serum and tissue homogenate, as well as the expression of NF-kB in the colon. In conclusion, the ameliorative effects of fustin in the experimental TNBS-induced colitis might be the result of its antioxidant properties.International Conference: Kliment's Days 2023 - 60 years Faculty of Biology 09/11/2023 - 11/11/2023 Sofia, Bulgari

Effects of Aronia melanocarpa fruit juice on exploratory behaviour and locomotor activity in rats

The main bioactive substances in Aronia melanocarpa fruit juice (AMFJ) are polyphenols (flavonoids, procyanidins, and phenolic acids). A great number of polyphenols are able to traverse the blood-brain barrier. In recent years more attention is drawn to the ability of these substances to influence central nervous system functions. The aim of the present study was to investigate the effects of AMFJ on exploratory behaviour and locomotor activity in male Wistar rats. AMFJ was administered orally for 7, 14, 21, and 30 days at three increasing doses (2.5, 5, and 10 ml kg−1). The changes in exploratory behaviour and locomotor activity were recorded in an Opto Varimex apparatus. It was found that the low doses of AMFJ (2.5 and 5 ml kg−1) for all treatment periods did not significantly affect exploratory behaviour and locomotor activity of rats compared to the saline-treated controls. AMFJ at the highest dose of 10 ml kg−1 had no significant effect on exploration and locomotion for the treatment periods of 7 and 14 days, while for the periods of 21 and 30 days it significantly decreased the number of horizontal and vertical movements, which might be the result of a sedative effect. At all the doses and testing periods, AMFJ did not disturb the progressive decrease in motor behaviour, suggesting habituation