Long COVID-19 gastrointestinal related disorders and traditional Chinese medicine: A network target-based approach.

The significant number of individuals impacted by the pandemic makes prolonged symptoms after COVID-19 a matter of considerable concern. These are numerous and affect multiple organ systems. According to the World Health Organization (WHO), prolonged gastrointestinal issues are a crucial part of post-COVID-19 syndrome. The resulting disruption of homeostasis underscores the need for a therapeutic approach based on compounds that can simultaneously affect more than one target/node. The present review aimed to check for nutraceuticals possessing multiple molecular mechanisms helpful in relieving Long COVID-19-specific gastrointestinal symptoms. Specific plants used in Keywords Chinese Medicine (TCM) expected to be included in the WHO Global Medical Compendium were selected based on the following criteria: (1) they are widely used in the Western world as natural remedies and complementary medicine adjuvants; (2) their import and trade are regulated by specific laws that ensure quality and safety (3) have the potential to be beneficial in alleviating intestinal issues associated with Long COVID-19. Searches were performed in PubMed, Elsevier, Google Scholar, Scopus, Science Direct, and ResearchGate up to 2023. Cinnamomum cassia, Glycyrrhiza uralensis, Magnolia officinalis, Poria cocos, Salvia miltiorrhiza, Scutellaria baicalensis, and Zingiber officinalis were identified as the most promising for their potential impact on inflammation and oxidative stress. Based on the molecular mechanisms of the phytocomplexes and isolated compounds of the considered plants, their clinical use may lead to benefits in gastrointestinal diseases associated with Long COVID-19, thanks to a multiorgan and multitarget approach.

Magnolia officinalis L. bark extract and respiratory diseases: From traditional Chinese medicine to western medicine via network target.

The understanding of the use of Magnolia officinalis L. (Magnoliaceae) as a possible dietary supplement for supporting the treatment of airway pathologies might be of clinical interest. Two commercially available bark extracts (M. officinalis extract [MOE]) were characterized by quantitation in honokiol and magnolol content by means of high-performance liquid chromatography with UV detection. MOE effects, as well as those of the reference compounds per se, on some targets connected to airway pathologies (antibacterial- and lung and trachea relaxing- activities) were investigated. Results showed that MOE possessed interesting antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pneumoniae. This was accompanied by a spasmolytic and antispasmodic activity, possibly owing to its ability to concurrently modulate different targets such as H1 -, ß2 - and muscarinic receptors and l-type calcium channels involved in bronchodilation. All these effects were directly related to the MOE content in honokiol and magnolol. In conclusion, the properties of MOE highlighted here strongly encourage its application as dietary supplement in the treatment of airway diseases.

hERG stereoselective modulation by mexiletine-derived ureas: Molecular docking study, synthesis, and biological evaluation.

Long QT syndrome (LQTS) is a disorder of cardiac electrophysiology resulting in life-threatening arrhythmias; nowadays, only a few drugs are available for the management of LQTS. Focusing our attention on LQT2, one of the most common subtypes of LQTS caused by mutations in the human ether-à-go-go-related gene (hERG), in the present work, the stereoselectivity of the recently discovered mexiletine-derived urea 8 was investigated on the hERG potassium channel. According to preliminary in silico predictions, in vitro studies revealed a stereoselective behavior, with the meso form showing the greatest hERG opening activity. In addition, functional studies on guinea pig isolated left atria, aorta, and ileum demonstrated that 8 does not present any cardiac or intestinal liability in our ex vivo studies. Due to its overall profile, (R,S)-8 paves the way for the design and development of a new series of compounds potentially useful in the treatment of both congenital and drug-induced forms of LQTS.

Tannins-Based Extracts: Effects on Gut Chicken Spontaneous Contractility.

The impossibility of using drugs for the health of farm animals leads to the search for alternative strategies with two purposes: to maintain animal health and safeguard human health. In this perspective, tannins have shown great promises. These phytocomplexes obtained from natural matrices with multiple health properties may be used as a feed supplement in chicken farms. In this work, we studied two tannin-based extracts (from Castanea sativa Mill. wood and from Schinopsis balansae Engl. Quebracho Colorado hardwood) with different chemical compositions on the spontaneous contractility on the isolated intestinal tissues of healthy chicken. The results showed that the chemical composition of the two phytocomplexes influenced the spontaneous intestinal contractility in different ways by regulating the tone and consequent progression of the food bolus. The chemical analysis of the two extracts revealed that Castanea sativa Mill. wood mainly contains hydrolysable tannins, while Schinopsis balansae Engl. hardwood mainly contains condensed tannins. The two phytocomplexes showed different effects towards gastrointestinal smooth muscle contractility, with Castanea sativa Mill. wood providing a better activity profile than Schinopsis balansae Engl. hardwood.

Further Quinolizidine Derivatives as Antiarrhythmic Agents- 3.

Fourteen quinolizidine derivatives, structurally related to the alkaloids lupinine and cytisine and previously studied for other pharmacological purposes, were presently tested for antiarrhythmic, and other cardiovascular effects on isolated guinea pig heart tissues in comparison to well-established reference drugs. According to their structures, the tested compounds are assembled into three subsets: (a) N-(quinolizidinyl-alkyl)-benzamides; (b) 2-(benzotriazol-2-yl)methyl-1-(quinolizidinyl)alkyl-benzimidazoles; (c) N-substituted cytisines. All compounds but two displayed antiarrhythmic activity that was potent for compounds 4, 1, 6, and 5 (in ascending order). The last compound (N-(3,4,5-trimethoxybenzoyl)aminohomolupinane) was outstanding, exhibiting a nanomolar potency (EC50 = 0.017 µM) for the increase in the threshold of ac-arrhythmia. The tested compounds shared strong negative inotropic activity; however, this does not compromise the value of their antiarrhythmic action. On the other hand, only moderate or modest negative chronotropic and vasorelaxant activities were commonly observed. Compound 5, which has high antiarrhythmic potency, a favorable cardiovascular profile, and is devoid of antihypertensive activity in spontaneously hypertensive rats, represents a lead worthy of further investigation.

Nutraceuticals, a Bridge Between Past and Future: Focus on Mushrooms Biological Activities and Myco-Chemistry.

BACKGROUND: Mushrooms are consumed worldwide due to their high nutritional and nutraceutical values. In addition to the presence of various vitamins, low-fat, and proteins, they are also an important source of trace elements, dietary fibers, and bioactive compounds. Their potential therapeutic properties are due to their multiple biological effects, such as antimicrobial, antiviral, antioxidant, anticancer, immune-modulating, cardioprotective, and antidiabetic properties. The global market of mushroom farming is anticipated to witness remarkable progress for its potential application in health products, profitable production and a rising demand for the healthy foods across the globe. The Asia Pacific marketplace seems to represent the major market of mushrooms, due to the higher per capita consumption of culinary and medical purposes. OBJECTIVE: Mushrooms have generally low calories, low levels of cholesterol, fats, gluten and sodium. Several biological effects of mushroom are due to the presence of phenolic components, polysaccharides, terpenoids, terphenyl-related compounds, and many other lower molecular weight molecules. This review aims at describing the chemical characterization of several mushrooms species and their biological effects. CONCLUSION: The current review describes different secondary metabolites found in several mushrooms and mushrooms extracts, and the molecular mechanisms underlying the biological activities. Also the antimicrobial activities of mushrooms, mushrooms extracts and isolated compounds from mushrooms were described. The description of these activities, related to the presence of specific classes of secondary metabolites and isolated compounds, may lead to the identification of mycomplexes and mushrooms compounds that may be further studied for their potential application in nutraceutical products.

A potential host and virus targeting tool against COVID-19: Chemical characterization, antiviral, cytoprotective, antioxidant, respiratory smooth muscle relaxant effects of Paulownia tomentosa Steud.

COronaVIrus Disease 2019 (COVID-19) is a newly emerging infectious disease that spread across the world, caused by the novel coronavirus Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). Despite the advancements in science that led to the creation of the vaccine, there is still an urgent need for new antiviral drugs effective against SARS-CoV-2. This study aimed to investigate the antiviral effect of Paulownia tomentosa Steud extract against SARS-CoV-2 and to evaluate its antioxidant properties, including respiratory smooth muscle relaxant effects. Our results showed that P. tomentosa extract can inhibit viral replication by directly interacting with both the 3-chymotrypsin-like protease and spike protein. In addition, the phyto complex does not reduce lung epithelial cell viability and exerts a protective action in those cells damaged by tert-butyl hydroperoxide , a toxic agent able to alter cells' functions via increased oxidative stress. These data suggest the potential role of P. tomentosa extract in COVID-19 treatment, since this extract is able to act both as an antiviral and a cytoprotective agent in vitro.

Favourable involvement of α2A-adrenoreceptor antagonism in the I2-imidazoline binding sites-mediated morphine analgesia enhancement.

Aim of the present study was to obtain novel α(2)-adrenoreceptor (α(2)-AR) antagonists, possibly endowed with subtype-selectivity. Therefore, inspired by the non subtype-selective α(2)-AR antagonist idazoxan, we designed 1,4-dioxane derivatives bearing an aromatic area in position 5 or 6 and the imidazoline nucleus in position 2. Among the novel molecules 1-6, compound 2, with a trans stereochemical relationship between 5-phenyl and 2-imidazoline groups, was able to antagonize the sole α(2A)-subtype. Moreover, 2 showed an affinity at I(2)-imidazoline binding sites (I(2)-IBS) comparable to that at α(2A)-AR. In in vivo studies 2 strongly increased morphine analgesia. This interesting behaviour appeared to be induced by the favourable involvement of α(2A)-AR antagonism in the I(2)-IBS-mediated morphine analgesia enhancement.

Effects of Brugmansia arborea Extract and Its Secondary Metabolites on Morphine Tolerance and Dependence in Mice.

The aim of the present study was to investigate, in vivo, the effect of a Brugmansia arborea extract (BRU), chromatographic fractions (FA and FNA), and isolated alkaloids on the expression and the acquisition of morphine tolerance and dependence. Substances were acutely (for expression) or repeatedly (for acquisition) administered in mice treated with morphine twice daily for 5 or 6 days, in order to make them tolerant or dependent. Morphine tolerance was assessed using the tail-flick test at 1st and 5th days. Morphine dependence was evaluated through the manifestation of withdrawal symptoms induced by naloxone injection at 6th day. Results showed that BRU significantly reduced the expression of morphine tolerance, while it was ineffective to modulate its acquisition. Chromatographic fractions and pure alkaloids failed to reduce morphine tolerance. Conversely BRU, FA, and pure alkaloids administrations significantly attenuated both development and expression of morphine dependence. These data suggest that Brugmansia arborea Lagerh might have human therapeutic potential for treatment of opioid addiction.

Polyphenols from Olive-Mill Wastewater and Biological Activity: Focus on Irritable Bowel Syndrome.

Waste represents a cost for companies, in particular for agro-food companies, which can become a resource as a secondary material. In this work, we examine three products of olive-oil waste water, named MOMAST® (Plus30, PW25, and HY100). Based on the chemical composition, obtained with different methods, we hypothesized a possible application as food supplements in irritable bowel syndrome (IBS). We therefore studied MOMASTs on some targets linked to this pathology: antioxidant action and spontaneous and induced intestinal contractility of the ileum and colon. Plus30, which showed a more promising biological of activity also for its oleuropein content, was characterized by an interesting action against some microorganisms. The results highlighted the ability of Plus30 to modulate spontaneous and induced contractility, to exert a good antioxidant action, and to significantly act on various microorganisms. These effects are synergistic in the presence of antibiotics. In conclusion, we can confirm that Plus30 could be a great candidate as a food supplement in patients with IBS.

Olea europea L. Leaves and Hibiscus sabdariffa L. Petals Extracts: Herbal Mix from Cardiovascular Network Target to Gut Motility Dysfunction Application.

It is well known that diet and nutrition play a critical role in the etiopathogenesis of many disorders. On the other hand, nutrients or bioactive compounds can specifically target and control various aspects of the mechanism underlying the pathology itself, and, in this context, diseases related to intestinal motility disorders stand out. The Herbal Mix (HM) consisting of Olea europea L. leaf (OEE) and Hibiscus sabdariffa L. (HSE) extracts (13:2) has been proven to be a promising nutraceutical option for many diseases, but its potential in inflammatory-driven gastrointestinal disorders is still unexplored. In this study, HM effects on guinea-pig ileum and colon contractility (induced or spontaneous) and on human iNOS activity, as well as on human colorectal adenocarcinoma Caco-2 cells, were studied. Results showed that the HM can control the ileum and colon contractility without blocking the progression of the food bolus, can selectively inhibit iNOS and possesses a strong pro-apoptotic activity towards Caco-2 cells. In conclusion, the present results suggest that, in some diseases, such as those related to motility disorders, an appropriate nutritional approach can be accompanied by a correct use of nutraceuticals that could help not only in ameliorating the symptoms but also in preventing more severe, cancer-related conditions.

Hibiscus Flower and Olive Leaf Extracts Activate Apoptosis in SH-SY5Y Cells.

Compounds of natural origin may constitute an interesting tool for the treatment of neuroblastoma, the most prevalent extracranial solid tumor in children. PRES is a commercially available food supplement, composed of a 13:2 (w/w) extracts mix of Olea europaea L. leaves (OE) and Hibiscus sabdariffa L. flowers (HS). Its potential towards neuroblastoma is still unexplored and was thus investigated in human neuroblastoma SH-SY5Y cells. PRES decreased the viability of cells in a concentration-dependent fashion (24 h IC50 247.2 ± 31.8 µg/mL). Cytotoxicity was accompanied by an increase in early and late apoptotic cells (AV-PI assay) and sub G0/G1 cells (cell cycle analysis), ROS formation, reduction in mitochondrial membrane potential, and caspases activities. The ROS scavenger N-acetyl-L-cysteine reverted the cytotoxic effects of PRES, suggesting a key role played by ROS in PRES-mediated SH-SY5Y cell death. Finally, the effects of OE and HS extracts were singularly tested and compared to those of the corresponding mixture. OE- or HS-mediated cytotoxicity was always significantly lower than that caused by PRES, suggesting a synergic effect. In conclusion, the present findings highlight the potential of PRES for the treatment of neuroblastoma and offers the basis for a further characterization of the mechanisms underlying its effects.

Acacia catechu Willd. Extract Protects Neuronal Cells from Oxidative Stress-Induced Damage.

Oxidative stress (OS) and the resulting reactive oxygen species (ROS) generation and inflammation play a pivotal role in the neuronal loss occurring during the onset of neurodegenerative diseases. Therefore, promising future drugs that would prevent or slow down the progression of neurodegeneration should possess potent radical-scavenging activity. Acacia catechu Willd. heartwood extract (AC), already characterized for its high catechin content, is endowed with antioxidant properties. The aim of the present study was to assess AC neuroprotection in both human neuroblastoma SH-SY5Y cells and rat brain slices treated with hydrogen peroxide. In SH-SY5Y cells, AC prevented a decrease in viability, as well as an increase in sub-diploid-, DAPI positive cells, reduced ROS formation, and recovered the mitochondrial potential and caspase-3 activation. AC related neuroprotective effects also occurred in rat brain slices as a reversal prevention in the expression of the main proteins involved in apoptosis and signalling pathways related to calcium homeostasis following OS-mediated injury. Additionally, unbiased quantitative mass spectrometry allowed for assessing that AC partially prevented the hydrogen peroxide-induced altered proteome, including proteins belonging to the synaptic vesicle fusion apparatus. In conclusion, the present results suggest the possibility of AC as a nutraceutical useful in preventing neurodegenerative diseases.

Thymus vulgaris L. Essential Oil Solid Formulation: Chemical Profile and Spasmolytic and Antimicrobial Effects.

A new Thymus vulgaris L. solid essential oil (SEO) formulation composed of liquid EO linked to solid excipients has been chemically analysed and evaluated for its intestinal spasmolytic and antispastic effects in ex vivo ileum and colon of guinea pig and compared with liquid EO and excipients. Liquid EO and solid linked EO were analysed by original capillary electrochromatography coupled to diode array detection (CEC-DAD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodologies. The main bioactive constituents are thymol and carvacrol, with minor constituents for a total of 12 selected analysed compounds. Liquid EO was the most effective in decreasing basal contractility in ileum and colon; excipients addiction permitted normal contractility pattern in solid linked EO SEO. In ileum and colon, the Thymus vulgaris L. solid formulation exerted the relaxant activity on K+-depolarized intestinal smooth muscle as well as liquid EO. The solid essential oil exhibits antimicrobial activity against different strains (Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli, Salmonella Thyphimurium, Candida albicans) similarly to liquid oil, with activity against pathogen, but not commensal strains (Bifidobacterium Breve, Lactobacillus Fermentum) in intestinal homeostasis. Therefore, Thymus vulgaris L. solid essential oil formulation can be proposed as a possible spasmolytic and antispastic tool in medicine.

Rhodiola rosea L. extract reduces stress- and CRF-induced anorexia in rats.

Rhodiola rosea L. is one of the most popular adaptogen and anti-stress plants in European and Asiatic traditional medicine. Its pharmacological properties appear to depend on its ability to modulate the activation of several components of the complex stress-response system. Exposure to both physical and psychological stress reduces feeding in rodents. The aim of this work was thus to determine whether in rats an hydroalcoholic R. rosea extract standardized in 3% rosavin and 1% salidroside (RHO) reverses hypophagia induced by (1) physical stress due to 60 min immobilization; (2) intracerebroventricular injection of corticotrophin-releasing factor (CRF, 0.2 microg/rat), the major mediator of stress responses in mammals; (3) intraperitoneal injection of Escherichia coli Lipopolysaccharide (LPS, 100 microg/kg); (4) intraperitoneal administration of fluoxetine (FLU, 8 mg/kg). The effect of the same doses of the plant extract was also tested in freely-feeding and in 20 h food-deprived rats. RHO was administered acutely by gavage to male Wistar rats 1 h before the experiments. The results show that at 15 and 20 mg/kg, RHO reversed the anorectic effects induced both by immobilization and by intracerebroventricular CRF injection. Moreover, at the same doses, RHO failed to reduce the anorectic effect induced both by LPS and FLU, and did not modify food intake in both freely-feeding and food-deprived rats. These findings strongly demonstrated that RHO is able selectively to attenuate stress-induced anorexia, providing functional evidence of claimed adaptogen and anti-stress properties of Rhodiola rosea L.

Effect of the cannabinoid CB1 receptor antagonist SR-141716A on ethanol self-administration and ethanol-seeking behaviour in rats.

RATIONALE: It has been suggested that endocannabinoid mechanisms are involved in the control of ethanol consumption. OBJECTIVES: The aims of the present study were (1) to evaluate the role of the endocannabinoid system in the control of operant ethanol self-administration and in the reinstatement of ethanol seeking, when induced by stress or conditioned stimuli and (2) to offer new insights on the specificity of such a role. METHODS: Rats were administered intraperitoneally with the selective cannabinoid CB1 receptor antagonist, SR-141716A, 30 min before operant self-administration or reinstatement sessions. Two schedules of reinforcement, the fixed-ratio 1 (FR1) and the progressive ratio (PR), were used to study 10% (w/v) alcohol and 5.0% sucrose self-administration. NaCl (2% w/v) intake in sodium-depleted rats was studied only under the FR1 program. RESULTS: Treatment with SR-141716A (0.3-3.0 mg/kg) significantly attenuated FR1 alcohol self-administration and lowered the break point for ethanol under PR. SR-141716A also markedly inhibited the reinstatement of alcohol seeking elicited by presentation of cues predictive of drug availability. Conversely, the cannabinoid antagonist did not prevent the reinstatement of alcohol seeking induced by foot-shock stress. Lever pressing for sucrose under FR1 and PR schedules was also significantly decreased by SR-141716A treatment, whereas the drug modestly and only at the highest dose decreased 2% NaCl self-administration. CONCLUSIONS: Results emphasize that endocannabinoid mechanisms play a major role in the control of ethanol self-administration and in the reinstatement of conditioned ethanol seeking. However, these effects extend to the control of operant behaviours motivated by natural rewards (i.e. sucrose). On the other hand, SR-141716A only weakly reduces NaCl self-administration in sodium-depleted rats, in which salt intake is largely controlled by homeostatic mechanisms. Overall, these observations demonstrate that the inhibition of operant behaviour following blockade of CB1 receptors by SR-141716A is linked to a reduction of reward-related responding and is not related to drug-induced motor deficits.

Involvement of I2-imidazoline binding sites in positive and negative morphine analgesia modulatory effects.

Some studies, suggesting the involvement of I(2)-imidazoline binding sites (I(2)-IBS) in morphine analgesia modulation, prompted us to examine on mice antinociceptive assays the effect produced by 1 (phenyzoline), that in view of its high I(2)-IBS affinity and high I(2)-IBS selectivity with regard to I(1)-IBS, alpha(2)-adrenoreceptors and mu-opioid receptors might be considered the first interesting I(2)-IBS ligand. The study was also applied to its ortho phenyl derivative 2 (diphenyzoline), designed and prepared in order to produce a possible modification of the biological profile of 1. Diphenyzoline (2) retains a significant I(2)-IBS selectivity with regard to I(1)-IBS, alpha(2)-adrenoreceptors and mu-opioid receptors. Moreover, by the functional assays 1 and 2 proved inactive at all alpha(2)-adrenoreceptors subtypes up to 10(-3) M. As expected, phenyzoline and diphenyzoline, which are structurally related, highlighted an interesting "positive" or "negative", respectively, morphine analgesia modulatory effect. In fact, 1 (s.c. 10 mg/kg) enhanced morphine analgesia (60% and 40% in mouse tail-flick and mouse hot-plate, respectively), while 2 (s.c. 10 mg/kg) decreased it (-41% and -20%, respectively). The ability to decrease morphine analgesia had never been observed before in I(2)-IBS ligands. These effects were not affected by i.p. treatment of animals with yohimbine (a selective alpha(2)-adrenoreceptor antagonist, 0.625 mg/kg) or efaroxan (an I(1)-IBS/alpha(2)-adrenoreceptor antagonist, 1.0 mg/kg). In contrast, they were completely reversed by i.p. treatment of animals with idazoxan (an I(2)-IBS/alpha(2)-adrenoreceptor antagonist, 2 mg/kg). Moreover, compound 2, in mouse tail-flick test, was able to potentiate by 23% the naloxone-induced decrease of morphine analgesia. Therefore, the results of this study indicate the crucial involvement of I(2)-IBS in the morphine analgesia modulatory effects of 1 and 2.

Combined Interactions with I1-, I2-Imidazoline Binding Sites and α2-Adrenoceptors To Manage Opioid Addiction.

Tolerance and dependence associated with chronic opioid exposure result from molecular, cellular, and neural network adaptations. Such adaptations concern opioid and nonopioid systems, including α2-adrenoceptors (α2-ARs) and I1- and I2-imidazoline binding sites (IBS). Agmatine, one of the hypothesized endogenous ligands of IBS, targeting several systems including α2-ARs and IBS, proved to be able to regulate opioid-induced analgesia and to attenuate the development of tolerance and dependence. Interested in the complex pharmacological profile of agmatine and considering the nature of its targets, we evaluated two series of imidazolines, rationally designed to simultaneously interact with I1-/I2-IBS or I1-/I2-IBS/α2-ARs. The compounds showing the highest affinities for I1-/I2-IBS or I1-/I2-IBS/α2-ARs have been selected for their in vivo evaluation on opiate withdrawal syndrome. Interestingly, 9, displaying I1-/I2-IBS/α2-ARs interaction profile, appears more effective in reducing expression and acquisition of morphine dependence and, therefore, might be considered a promising tool in managing opioid addiction.

Reduction of ethanol intake by chronic treatment with Hypericum perforatum, alone or combined with naltrexone in rats.

Acute treatment with extracts of Hypericum perforatum, the common plant usually called St. John's Wort, reduces voluntary ethanol intake in Marchigian Sardinian alcohol-preferring (msP) rats and acts synergistically with opioid receptor antagonists to further attenuate ethanol consumption. The present study evaluated the effect of chronic (once a day for 12 days) intragastric administration of a CO2 Hypericum perforatum extract (HPCO2), given alone or combined with naltrexone (NTX), on ethanol intake offered 2h/day in msP rats. Chronic treatment with HPCO2 markedly reduced ethanol intake at the dose of 125, but not at 7 mg/kg; the effect of 125 mg/kg was observed since the first day of treatment and remained constant across the 12 days. The same dose of HPCO2 slightly reduced the simultaneous intake of food only on day 3 and day 11 of treatment. Treated rats promptly recovered baseline ethanol intake when treatment did not precede access to ethanol (on day 8) or after the end of treatment (day 13 and day 14), suggesting that HPCO2 administrations did not induce conditioned aversion to alcohol. Chronic intraperitoneal treatment with NTX reduced ethanol intake at 3, but not at 0.5mg/kg. The synergistic effect on ethanol intake of HPCO2 and NTX was evident also in conditions of chronic treatment. HPCO2, 7 mg/kg, and NTX, 0.5mg/kg, evoked a pronounced and statistically significant reduction of ethanol intake, while being inactive. The effect on ethanol intake of the combined treatment remained stable over the 12 days of treatment; food intake was slightly reduced only on day 3 and on day 7 in response to 125 mg/kg of HPCO2 combined with NTX 0.5mg/kg, but no difference in body weight between controls and treated rats was observed at the end of treatment. Following 12-day treatment with 125 mg/kg of HPCO2, no difference was observed in the responsivity of msP rats to the effect on ethanol intake of several doses of the extract. In conclusion, the present results provide evidence for a selective and pronounced effect of HPCO2, alone or combined with naltrexone, on ethanol intake in conditions of chronic treatment, without development of tolerance. These findings further support the view that clinical trials for extracts of Hypericum perforatum in the treatment of alcoholism should be considered.

Rhodiola rosea L. extract and its active compound salidroside antagonized both induction and reinstatement of nicotine place preference in mice.

RATIONALE: Conventional pharmacological treatments for drug addiction aim to reduce three most important aspects: withdrawal syndrome, craving, and relapse. Pharmacological treatments currently available for the treatment of tobacco smoking are able to alleviate withdrawal symptoms but are not sufficiently effective in reducing craving and rarely effective to prevent relapse. Rhodiola rosea L., a well-known traditional oriental medicine with anxiolytic, antidepressive, antistress, and adaptogenic properties, has been recently shown to be effective in the prevention and treatment of nicotine-withdrawal symptoms. OBJECTIVES: The present study used the conditioned place preference (CPP) model to systematically investigate, in mice, the effects of a R. rosea L. extract (RHO) and its active compound salidroside (SDS), on the reinforcing properties of nicotine and their efficacy in the vulnerability to reinstatement. METHODS: To study the effects on the rewarding properties of nicotine, RHO (10, 15, and 20 mg/kg) and SDS (0.2 mg/kg) were tested both in the acquisition and expression of CPP induced by nicotine injection (0.5 mg/kg). Moreover, the efficacy of RHO and SDS in preventing relapse induced by nicotine priming (0.1 mg/kg, s.c.) and by restraint stress was also evaluated. RESULTS: Results showed the ability of RHO and salidroside to significantly reduce the rewarding properties of nicotine at all doses tested. RHO and SDS also suppressed both priming- and stress-induced reinstatement of CPP. CONCLUSIONS: The present study showed the positive effects of R. rosea L. in reducing rewarding properties and preventing relapse to nicotine and evidenced the important role of salidroside in the effects of the extract.