Diclofenac and dexamethasone modulate the effect of cannabidiol on the rat colon motility ex vivo.

Introduction: Due to the growing interest in the use of cannabinoids in supportive therapies, they are increasingly used together with anti-inflammatory drugs. Cannabinoids inhibit gastrointestinal motility, while steroidal and nonsteroidal anti-inflammatory drugs influence motility in other ways. The aim of the research was to study the interactions between cannabidiol (CBD) and these two classes of anti-inflammatory drugs in the context of gastrointestinal motility. Dexamethasone (DEX) was selected as a steroidal drug and diclofenac (DCF) as a nonsteroidal counterpart. Material and Methods: The experiments were performed on isolated rat colon strips in isometric conditions. The contractile response to acetylcholine (ACh) (1 µM) was measured with no substance applied as a control value and was measured after application of CBD (80 µM), DEX (100 µM), DCF (100 µM), or a combination of these substances. Results: Cannabidiol strongly inhibited intestinal motility mediated by ACh application, DCF inhibited it non-significantly, while DEX intensified it. When CBD was co-administered with DEX, the combination inhibited intestinal motility non-significantly relative to the ACh-only control. Co-administration of CBD with DCF inhibited motility more than when these substances were administered separately. Conclusion: Inhibition of the intestinal response to ACh is likely due to the synergistic effect of CBD and endogenous cannabinoids. Dexamethasone lessened the inhibitory effect of CBD, likely because of diminished availability of the arachidonic acid necessary for endogenous cannabinoid synthesis. However, diclofenac may increase endogenous cannabinoid synthesis, because of the greater availability of arachidonic acid caused by DCF blocking the cyclooxygenation pathway.

Does Deoxynivalenol Affect Amoxicillin and Doxycycline Absorption in the Gastrointestinal Tract? Ex Vivo Study on Swine Jejunum Mucosa Explants.

The presence of deoxynivalenol (DON) in feed may increase intestinal barrier permeability. Disturbance of the intestinal barrier integrity may affect the absorption of antibiotics used in animals. Since the bioavailability of orally administered antibiotics significantly affects their efficacy and safety, it was decided to evaluate how DON influences the absorption of the most commonly used antibiotics in pigs, i.e., amoxicillin (AMX) and doxycycline (DOX). The studies were conducted using jejunal explants from adult pigs. Explants were incubated in Ussing chambers, in which a buffer containing DON (30 µg/mL), AMX (50 µg/mL), DOX (30 µg/mL), a combination of AMX + DON, or a combination of DOX + DON was used. Changes in transepithelial electrical resistance (TEER), the flux of transcellular and intracellular transport markers, and the flux of antibiotics across explants were measured. DON increased the permeability of small intestine explants, expressed by a reduction in TEER and an intensification of transcellular marker transport. DON did not affect AMX transport, but it accelerated DOX transport by approximately five times. The results suggest that DON inhibits the efflux transport of DOX to the intestinal lumen, and thus significantly changes its absorption from the gastrointestinal tract.

Phytogenic Compounds for Enhancing Intestinal Barrier Function in Poultry-A Review.

After the European Union ban of antibiotic growth promoters, works on different methods of improving gut health have intensified. The poultry industry is struggling with problems that were previously controlled by antibiotic growth promoters, therefore the search for optimal solutions continues. Simultaneously, there is also increasing social pressure to minimize the use of antibiotics and replace them with alternative feed additives. A variety of available alternatives is considered safe by consumers, among which phytogenics play a significant role. However, there are still some limitations that need to be considered. The most questionable are the issues related to bioavailability, metabolism of plant derivatives in birds, and the difficulty of standardizing commercial products. There is still a need for more evidence-based recommendations for the use of phytogenics in livestock. On the other hand, a positive influence of phytogenic compounds on the health of poultry has been previously described by many researchers and practical application of these compounds has auspicious perspectives in poultry production. Supplementation with phytogenic feed additives has been shown to protect birds from various environmental threats leading to impaired intestinal barrier function. Phytogenic feed additives have the potential to improve the overall structure of intestinal mucosa as well as gut barrier function on a molecular level. Recognition of the phytogenics' effect on the components of the intestinal barrier may enable the selection of the most suitable ones to alleviate negative effects of different agents. This review aims to summarize current knowledge of the influence of various phytogenic constituents on the intestinal barrier and health of poultry.

Evaluation of the effects of Bidens tripartita extracts and their main constituents on intestinal motility - An ex vivo study.

ETHNOPHARMACOLOGICAL RELEVANCE: Based on traditional medicine, infusions of Bidens species (Asteraceae) have been successfully used in the treatment of acute and chronic enteritis. Additionally, ethnopharmacological reports demonstrating the gastrointestinal, gastroprotective, anti-inflammatory, antiulcerogenic and immunomodulatory potency of Bidens tripartita Linn. (Asteraceae) and its constituents make the plant a particularly interesting herbal drug candidate for the supportive treatment of functional gastrointestinal and motility disorders. AIM OF THE STUDY: The study aimed to verify the effects of B. tripartita and its main flavonoid constituents on intestinal contractility patterns under ex vivo conditions. MATERIALS AND METHODS: The effects of B. tripartita preparations and their main flavonoids were identified using an alternative model of porcine isolated jejunum specimens. Using LC-ESI-MS, the effects of six different standardized extracts, aqueous (BT1), methanolic 50% (BT2), methanolic (BT3), diethyl ether (BT4), ethyl acetate (BT5) and butanol (BT6) (0.001-0.1 mg/mL), as well as three pure isolated flavonoids, luteolin (LUT), cynaroside (CYN) and flavanomarein (ION) (0.001-100 µM), were evaluated towards spontaneous and acetylcholine-induced motility. RESULTS AND CONCLUSION: s: The results showed the potent prokinetic effects of the B. tripartita extracts and their flavonoids on jejunum smooth muscle. The myocontractile effect was observed on both spontaneous and acetylcholine-induced contractility. There were no substantial differences in the magnitude of myocontractile effects between all six extracts with the exception of the butanol extract which seemed to have a slightly stronger prokinetic effect than the other extracts. The use of extracts at the highest tested concentrations provoked an approximately 1.5-fold increased reaction to acetylcholine compared to the control treatment. The myocontractile effect of the single flavonoids justifies the hypothesis that these secondary metabolites are responsible for the prokinetic activity of all the tested extracts. Among the tested flavonoids, CYN appeared to be the most potent ingredient of B. tripartita; the increase in the response to acetylcholine in the presence of this compound exceeded 250% of the control reaction. In view of the obtained results, the range of functional gastrointestinal disorders in which B. tripartita could be expected to bring benefits include the predominantly constipative phases of irritable bowel syndrome and dyspeptic complaints in which treatment protocols usually involve gastroprokinetics.

The impact of chlorophyllin on deoxynivalenol transport across jejunum mucosa explants obtained from adult pigs.

Regardless of the efforts put into preventing or reducing fungal growth, extensive mycotoxin contamination has been reported in animal feeds. In the case of pigs, one of the mycotoxins of major concern is deoxynivalenol (DON). The use of adsorbents as feed additives represents one of the strategies to control mycotoxins' contamination in feedstuff. Therefore, the aim of the study was to verify the ability of chlorophyllin (CHL) to reduce the absorption rate of DON in swine mucosa explants. Intestine was obtained from routinely slaughtered adult pigs. The mucosa explants were studied by means of Ussing chamber technique. The effect of DON (10 and 30 µg/ml) on mucosa viability and permeability and CHL (100 µg/ml) impact on DON (30 µg/ml) absorption was verified. The results revealed that mucosa explants isolated from adult animals remained unaffected for 90 min in the presence of DON in the lower concentration (10 µg/ml). Mycotoxin in the higher dose (30 µg/ml) increased mucosa permeability (decreased transepithelial electrical resistance value) and enhanced paracellular transport of lucifer yellow and mannitol but did not affect lactate dehydrogenase leakage. The introduction of CHL neither diminished the absorption rate of DON across swine mucosa explants nor prevented the toxic effects of DON on intestine. In conclusion, the results confirm the negative effect of DON on pig jejunum mucosa. However, the toxic effect of DON was observed only when it was used in relatively high doses. A promising adsorbent agent, CHL, failed to reduce the intensity of DON transport across intestine under in vitro conditions.

Modulations of bovine hepatic microsomal metabolism of benzimidazoles by secondary plant metabolites.

The study was aimed to estimate the effect of plant secondary metabolites present in ruminants diet and phytogenic feed additives on liver microsomal metabolism of albendazole and fenbendazole. The selected phytocompounds comprised of flavonoids (apigenin, quercetin) and saponins (hederagenin, medicagenic acid). The experiments were performed on liver microsomal fraction obtained from routinely slaughtered cows. The intensity of albendazole and fenbendazole metabolism in the presence of flavonoids and saponins was analyzed in equimolar concentration (100 µM). The obtained results revealed that both flavonoids and saponins intensify the metabolism of albendazole and fenbendazole in bovine microsomes. In the case of albendazole, apigenin and quercetin doubled the amount of degraded drug and the amount of produced albendazole sulfoxide. Additionally, both flavonoids increased the amount of produced albendazole sulfone. Saponins, hederagenin, and medicagenic acid intensified the degradation of albendazole (1.8-fold) and the production of albendazole sulfoxide (twofold). Medicagenic acid inhibited the production of albendazole sulfone. In the case of fenbendazole, the degradation of the drug and the production of oxfendazole were increased four and five times in the presence of saponins and flavonoids, respectively. The enhancement of benzimidazoles' metabolism caused by the studied plant metabolites could change pharmacokinetics and the efficacy of benzimidazoles' treatment in cattle.

The effect of pyriproxyfen on the motoric activity of rat intestine - In vitro study.

The application of pyriproxyfen (PPF) to drinking water and constant exposure of the whole population to this insecticide is an unprecedented action on a world scale and presents a new and serious challenge for toxicology. The aim of the study was to evaluate the potential effect of PPF on the intestine muscle activity. The experiments were performed on isolated duodenum and jejunum strips of rat, in isometric conditions. Doses of PPF in the range of 0.032-100 µM were used in the experiments. The obtained results indicate that PPF affected significantly the spontaneous activity of duodenum and jejunum strips, PPF caused the muscle relaxation when used in the concentration of 0.8 µM and higher. The reaction to acetylcholine (ACh) when PPF preceded or followed ACh application was also reduced. It is demonstrated that the reduction of the contraction caused by ACh was stronger when duodenum strips were preincubated in the presence of PPF solution than in case of ACh-precontracted strips. The first significant reaction of duodenal strips appeared in the presence of PPF in a dose of 0.16 µM and 0.8 µM when the insecticide application preceded and followed ACh treatment, respectively. Besides, the duodenum turned out to be much more susceptible to the tested insecticide than jejunum. Taking into account PPF kinetic data obtained in animals, the observed disturbances were caused by the insecticide used in relatively high concentrations. However, the full risk estimation requires the kinetic data obtained in human, especially from monitoring studies on general population after long-term exposure to PPF.

The effect of glyphosate-based herbicide Roundup and its co-formulant, POEA, on the motoric activity of rat intestine - In vitro study.

The study was aimed at evaluating the effect of Roundup, polyoxyethylene tallow amine (POEA) and mixture of glyphosate and POEA in different levels on the motoric activity of jejunum strips. The incubation in the Roundup solutions caused a significant, mostly miorelaxant, reversible reaction of smooth muscle; only in the highest tested dose which is equivalent to the agricultural concentration (1% corresponding to 1.7g glyphosate/L) there was an irreversible disturbance of the spontaneous contractility and reactivity. The incubation in POEA solutions in the range of low doses (0.256; 1.28; 6.4mg/L) resulted in a biphasic muscle reaction (relaxation and contraction); whereas in the range of high doses, i.e. 32; 160 and 800mg/L (agricultural spray concentrations) induced only a miorelaxant, irreversible response. The results indicate very high toxicity of POEA which exceeds the toxicity of the commercial formulations. Besides, it is postulated that glyphosate and POEA may display antagonistic interaction towards the motoric activity of gastrointestinal tract.

Antispasmodic effect of selected Citrus flavonoids on rat isolated jejunum specimens.

Citrus flavonoids are acknowledged for numerous pharmacological activities, including the myorelaxant effect on various smooth muscles. However, there is no data on their effect on jejunum contractility. Therefore, the aim of the study at hand was to evaluate the impact of hesperetin and diosmetin along with their glycosides on the motoric activity of intestine and to verify the possible mechanism of hesperetin-induced effect. The experiments were performed on rat isolated jejunum strips and were conducted under isometric conditions. Hesperetin and diosmetin, but not hesperidin and diosmin, dose-dependently (10-100µM) and reversibly inhibited acetylcholine (1µM) and KCl (80mM) induced contractile activity. The antispasmodic effect of hesperetin was partially blocked by 4-aminopyridine (100µM), glibenclamide (100µM) and NG-nitro-L-arginine methyl ester (L-NAME, 100µM). By contrast, apamin (0.1µM), tetraethylammonium (500µM) and methylene blue (10µM) did not affect the magnitude of hesperetin-induced myorelaxant effect. Indomethacin (10µM) increased the force of hesperetin-evoked reaction. In conclusion, hesperetin and diosmetin are potent myorelaxant agents. The antispasmodic effect of hesperetin is partially mediated by fast current low-voltage activated K+ channels, voltage-independent K+ channels and involves the nitric oxide pathway. Finally, hesperetin shows a synergistic effect with indomethacin towards jejunal KCl-precontracted smooth muscle.

Glyphosate affects the spontaneous motoric activity of intestine at very low doses - in vitro study.

Glyphosate is an active substance of the most popular herbicides worldwide. Its common use results from the belief that it affects exclusively plants. However, studies on glyphosate and its trade formulations reveal that it causes numerous morphological, physiological and biochemical disturbances in cells and organisms of animals, including mammals. Due to the fact that shortly after oral exposure glyphosate is detected in the highest amount in small intestine, the aim of this study was to evaluate the effect of this compound on the spontaneous motoric activity of intestine under in vitro conditions. The experiments were conducted on rat jejunum strips under isotonic conditions. The strips were incubated in buffered (pH 7.35) and non-buffered (pH 5.2) glyphosate solutions ranged from 0.003 to 1.7 g/L. The results indicate that glyphosate applied in buffered solution affects significantly the spontaneous motoric activity of rat isolated jejunum strips. The muscle response is biphasic (miorelaxation accompanied by contraction). The contraction is observed already at a dose of 0.003 g/L and the first significant biphasic reaction at a dose of 0.014 g/L. The incubation of jejunum strips with glyphosate in non-buffered solution (pH 5.2) results in a different reaction. The smooth muscle undergoes only persistent relaxation, which is stronger than the response to glyphosate solution in pH 7.35. Motility disturbances are also observed after glyphosate removal from the incubation solution. The gathered data suggests that glyphosate impairs gastrointestinal strips' motility at concentration that are noticed in human exposed to non-toxic doses of glyphosate.

Participation of extracellular calcium in α-hederin-induced contractions of rat isolated stomach strips.

ETHNOPHARMACOLOGICAL RELEVANCE: The dry extract of Hedera helix leaves, due to its secretolytic and antispasmodic effects, is commonly used to produce pharmaceuticals applied in case of cough and other respiratory symptoms. The results of some in vitro studies as well as the clinical signs of poisoning caused by Hedera helix suggest however strong contractile effect on smooth muscle. In order to clarify the impact of α-hederin (the main active agent of ivy extract) on smooth muscle, the origin of activated calcium involved in α-hederin-induced contraction of gastric smooth muscle preparations was studied. MATERIALS AND METHODS: The study was carried out on rat isolated stomach corpus and fundus strips, under isotonic conditions. The effect of α-hederin (100 µM) on smooth muscle preparations was measured before and after the treatment with verapamil during the incubation in modified Krebs-Henseleit solution (M K-HS). Besides, the effect of saponin was measured during the incubation of preparation in Ca2+-free modified Krebs-Henseleit solution or Ca2+-free EGTA-containing modified Krebs-Henseleit solution. RESULTS: The obtained results revealed that the application of verapamil significantly inhibited the reaction evoked by α-hederin. The incubation of stomach strips in calcium-free modified Krebs-Henseleit solution did not change the force of the observed contraction in comparison to the reaction of the preparations incubated in regular incubation solution (M K-HS). In contrary, the replacement of M K-HS by calcium-free chelator-containing solution inhibited totally the reaction to α-hederin. CONCLUSIONS: The results indicated that α-hederin-induced contraction results from the influx of calcium which is located in intercellular spaces or bound to the outside of the cell membrane. The Ca2+ influx occurs predominantly through voltage-dependent calcium channels of L-type.