Phytochemical Characteristics and Anti-Inflammatory, Immunoregulatory, and Antioxidant Effects of Portulaca oleracea L.: A Comprehensive Review.

Portulaca oleracea L. (P. oleracea) or purslane is a plant from the Portulacaceae family, which is used as food and traditional medicine for various diseases. This review article provides comprehensive information on the antioxidant, immunomodulatory, and anti-inflammatory properties of P. oleracea and its constituents. The literature survey of the different databases until the end of June 2023 was explored based on the keywords including the "P. oleracea, purslane, anti-inflammatory, immunomodulatory, and antioxidant properties." The plant contains flavonoids, alkaloids, terpenoids, fatty acids, vitamins, minerals, and some other compounds. The results indicated that P. oleracea and its constituents showed anti-inflammatory and immunomodulatory properties through reduction of inflammatory mediators including interferon gama (IFN-γ), interleukin (IL)-10, IL-4, tumor necrosis factor-alpha (TNF-α), and nitric oxide. Improvement in cytokines' serum levels (IFN-γ, IL-10, and IL-4) and increased IgG and IgM serum levels, as well as reduction of IgE, phospholipase A2, and total protein were demonstrated for P. oleracea. The plant and its constituents also improved oxidative stress by reduction of oxidant and increase of antioxidant markers. P. oleracea could be considered as an effective remedy for various inflammatory and immune diseases.

The antihyperglycemic and hypolipidemic effects of Ribes khorassanicum hydro-ethanolic extract co-administration in type 2 diabetic patients: A randomized double blind placebo controlled trial.

Objective: The present randomized clinical trial assessed the antihyperglycemic and hypolipidemic effects of hydro-ethanolic extract of Ribes khorassanicum. Materials and Methods: Eighty type 2 diabetic patients were randomly allocated to placebo or intervention groups and respectively received placebo or extract capsules (700 mg, bid) beside their conventional medication for 3 months. Patients' blood pressure and blood levels of fasting blood glucose (FBS), glycosylated hemoglobin (HbA1c), 2 hr postprandial glucose (2hPPG), triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured at the beginning of the study and after 3 months of treatment. For determination of plant safety, liver enzymes (SGOT and SGPT) and kidney function (in terms of urea, creatinine, and microalbumin levels) were assessed and patients were asked to report adverse effects. Results: The R. khorasanicum hydro-ethanolic extract supplementation significantly decreased the levels of FBS, total cholesterol, triglyceride, and LDL-C in the extract group compared to the placebo group (p<0.05-p<0.01). However, 2hPPG, HbA1c, HDL-C, SGOT, SGPT, urea, creatinine, and urine microalbumin values were not significantly different between the placebo and the extract groups. No adverse effects were reported by the patients. Conclusion: Co-supplementation of diabetic patients with R. khorasanicum extract ameliorated hyperglycemia and hyperlipidemia without causing any adverse effects; therefore, the plant extract may be recommended as a complementary therapy to improve diabetes-induced metabolic disturbances.

A qualitative and quantitative comparison of Crocus sativus and Nigella sativa immunomodulatory effects.

The present article reviews and compares the immunomodulatory activities of Crocus sativus (C. sativus) and Nigella sativa (N. sativa) and their main bioactive compounds. Immunomodulatory effects of these plants, especially with respect to Th1 and Th2 cytokines, are discussed based on relevant articles, books, and conference papers published in English until the end of April 2020, that were retrieved from Web of Science, PubMed, Scopus and Google Scholar databases. C. sativus and its constituents increase immunoglobulin (Ig-)G, interleukin 2 (IL)-2, interferon gamma (IFN-γ), and IFN-γ/IL-4 ratio, but decreased IgM, IL-10 and IL-4 secretion. N. sativa extract and thymoquinone reduce the levels of IL-2, -4, -10, and -12, while enhance IFN-γ and serum IgG1 and 2a. The reviewed articles indicate that C. sativus and N. sativa and their constituents could be potentially considered promising treatments for disorders associated with immune-dysregulation such as asthma and cancer.

Experimental and clinical reports on anti-inflammatory, antioxidant, and immunomodulatory effects of Curcuma longa and curcumin, an updated and comprehensive review.

Curcuma longa (C. longa) or turmeric is a plant with a long history of use in traditional medicine, especially for treating inflammatory conditions C. longa and its main constituent, curcumin (CUR), showed various pharmacological effects such as antioxidant and anti-microbial properties. The updated knowledge of anti-inflammatory, antioxidant, and immunomodulatory effects of C. longa and CUR is provided in this review article. Pharmacological effects of C. longa, and CUR, including anti-inflammatory, antioxidant, and immunomodulatory properties, were searched using various databases and appropriate keywords until September 2020. Various studies showed anti-inflammatory effects of C. longa and CUR, including decreased white blood cell, neutrophil, and eosinophil numbers, and its protective effects on serum levels of inflammatory mediators such as phospholipase A2 and total protein in different inflammatory disorders. The antioxidant effects of C. longa and CUR were also reported in several studies. The plant extracts and CUR decreased malondialdehyde and nitric oxide levels but increased thiol, superoxide dismutase, and catalase levels in oxidative stress conditions. Treatment with C. longa and CUR also improved immunoglobulin E (Ig)E, pro-inflammatory cytokine interleukin 4 (IL)-4, transforming growth factor-beta, IL-17, interferon-gamma levels, and type 1/type 2 helper cells (Th1)/(Th2) ratio in conditions with disturbance in the immune system. Therefore C. longa and CUR showed anti-inflammatory, antioxidant, and immunomodulatory effects, indicating a potential therapeutic effect of the plant and its constituent, CUR, for treating of inflammatory, oxidative, and immune dysregulation disorders.

The effect of chronic supplementation of Nigella sativa on splenocytes response in rats following treadmill exercise.

Nigella sativa (N. sativa) was shown to recover fatigue and imbalanced immune system. Therefore, effect of chronic administration of N. sativa hydroethanolic extract on splenocytes response in sedentary and exercised animals, was evaluated. Male Wistar rats were randomly divided into non-treated (control sedentary (C), moderately trained (MT; Velocity 20 m/min, 30 min/day 8 weeks), and over-trained (OT; Velocity 25 m/min, 60 min/day 11 weeks)), and N. sativa-treated animals (Nisa, 200 mg/kg, orally) (control (Nisa-C), moderately trained (Nisa-MT) and over-trained (Nisa-OT)). Finally, cell viability and proliferation, as well as interleukin 4 (IL-4) and interferon-γ (IFN-γ) secretion in non-stimulated and concanavalin A (Con A)-stimulated splenocytes, were evaluated. In the absence of the mitogen, cell viability in Nisa-C and Nisa-OT, cell proliferation in Nisa-C and Nisa-MT, IFN-γ concentration in Nisa-MT and Nisa-OT and IFN-γ/IL-4 ratio in Nisa C, Nisa-MT and Nisa-OT were higher compared to non-treated groups; but, IL-4 level in Nisa-MT was lower than non-treated groups. In the presence of the mitogen, cell viability in Nisa-C and Nisa-OT, IL-4 concentration in Nisa-C and Nisa-OT groups, and IFN-γ concentration and IFN-γ/IL-4 ratio in Nisa-MT were higher, while IFN-γ/IL-4 ratio was lower in Nisa-C group compared to non-treated groups. Moreover, IFN-γ/IL-4 ratio in stimulated and non-stimulated splenocytes supernatant was higher in Nisa-MT compared to Nisa-C and Nisa-OT groups. N. sativa chronic administration may shift Th1/Th2 cytokines profile of splenocytes towards Th1, especially in over-trained and non-stimulated condition. Moderate exercise and N. sativa supplementation may improve disorders associated with elevated Th2 such as overtraining syndrome.

Protective effects of medicinal plant against diabetes induced cardiac disorder: A review.

ETHNOPHARMACOLOGY RELEVANCE: Nowadays, there is an increase in global tendency to use medicinal plants as preventive and therapeutic agents to manage diabetes and its long-term complications such as cardiovascular disorders owing to their availability and valuable traditional background. AIM OF STUDY: This review aims to introduce common medicinal plants, which have been demonstrated to have cardioprotective effects on diabetes and their mechanisms of action. MATERIALS AND METHODS: Online literature databases, including Web of Sciences, PubMed, Science Direct, Scopus and Google Scholar were searched without date limitation by May 2020. The following keywords (natural products or medicinal plants or herbal medicine or herb or extract) and (diabetes or antidiabetic or hyperglycemic) and (cardiomyopathy or heart or cardioprotective or cardiac or cardio) were used, and after excluding non-relevant articles, 81 original English articles were selected. RESULTS: The surveyed medicinal plants induced cardioprotective effects mostly through increasing antioxidant effects leading to attenuating ROS production as well as by inhibiting inflammatory signaling pathways and related cytokines. Moreover, they ameliorated the Na+/K + ATPase pump, the L-type Ca2+ channel current, and the intracellular ATP. They also reduced cardiac remodeling and myocardial cell apoptosis through degradation of caspase-3, Bax, P53 protein, enhancement of Bcl-2 protein expression as well as downregulation of TGFß1 and TNFα expression. In addition, the extracts improved cardiac function through increasing EF% and FS% as well as restoring hemodynamic parameters. CONCLUSIONS: The reviewed medicinal plants demonstrated cardioprotective manifestations in diabetes through intervention with mechanisms involved in the diabetic heart to restore cardiovascular complications.

The Stimulatory Effects of Medicinal Plants on ß2-adrenoceptors of Tracheal Smooth Muscle.

Medicinal plants have been identified and used as primary sources in prevention and treatment of pulmonary diseases (mainly obstructive pulmonary diseases) from ancient times due to various pharmacological activities. In this review, the stimulatory effects of extracts, some fractions and constituents of medicinal plants on ß2-adrenoceptors which could be used as possible therapeutic agents in the future were reviewed. Various databases including; Medline, PubMed, ScienceDirect, Scopus, and Google Scholar were searched using stimulatory effect, ß2-adrenoceptors, possible mechanism, tracheal smooth muscle (TSM), medicinal plants and their constituents as keywords from 1985 to 2017. All studied plants including; Nigella sativa, Rosa damascena, Thymus vulgaris, Carum copticom, Carum carvi, Zataria multiflora, Crocus sativus, Cuminum cyminum, Liomnia acidissima, Portulaca oleraceae, Satureja hortensis, Ephedra sinica and Achillea millefolium showed relaxant effect on tracheal smooth muscle with a stimulatory effect on ß2-adrenoceptors mechanism. The studied plants and their constituents could be of therapeutic value in clinical practice as a bronchodilatory drug by ß2-adrenoceptors stimulatory mechanism for treatment of obstructive pulmonary diseases.

Memory enhancing effect of Nigella Sativa hydro-alcoholic extract on lipopolysaccharide-induced memory impairment in rats.

In this study, the effects of Nigella Sativa (NS) hydro-alcoholic extract on lipopolysaccharide (LPS)-induced learning and memory impairments, hippocampal cytokine levels, and brain tissues oxidative damage were investigated in rats. The rats were grouped and treated: (1) control (saline), (2) LPS (1 mg/kg i.p.), and (3-5) 100, 200, or 400 mg/kg NS hydro-alcoholic extract 30 min before LPS injection. The treatment was started since 6 days before the behavioral experiments and continued during the behavioral tests (LPS injection 2 h before each behavioral experiment). Finally, the brains were removed for biochemical assessments. In Morris water maze (MWM) test, LPS increased the escape latency and traveled path compared to control group, whereas all doses of NS hydro-alcoholic extract decreased them compared to LPS group. In passive avoidance (PA) test, the latency to enter the dark compartment in LPS group was shorter than control group while in all treated groups it was longer than LPS group. LPS increased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), malondialdehyde (MDA), and nitric oxide (NO) metabolites, and decreased thiol content, superoxide dismutase (SOD), and catalase (CAT) in the hippocampal tissues compared to control group while NS hydro-alcoholic extract decreased MDA and NO metabolites and increased thiol content, SOD, and CAT compared to LPS group. Findings of the current study indicated that the hydro-alcoholic extract of NS improved the LPS-induced learning and memory impairments induced by LPS in rats by improving hippocampal cytokine levels and brain tissues oxidative damage.

The effects of medicinal plants on muscarinic receptors in various types of smooth muscle.

Pharmacological agents that can affect muscarinic receptors are commonly used to treat or manage various diseases. Medicinal plants have been used from ancient time to treat cardiovascular, gastrointestinal, respiratory, and urogenital disorders, which may related to their muscarinic receptors effects. Several pharmacological studies revealed the inhibitory or stimulatory effect of some herbal plants on muscarinic receptors. Medline, PubMed, Science Direct, Scopus, and Google Scholar as online database were searched from the beginning of 1983 to March 2018 using following keywords: muscarinic receptor, medicinal plant, herbal medicine, and smooth muscle, animal, human, in vivo, and in vitro. The original studies in English language were included. Based on the results of the reviewed articles, more than 70 medicinal plants extracts or constituents affected muscarinic receptors (stimulatory or inhibitory) of smooth muscles in cardiovascular, gastrointestinal, respiratory, and urogenital systems. Among them, there are some tropical plant and herbs that have been traditionally used as food additive. The therapeutic properties of these plants may be regarded in treatment of cardiovascular (hypertension and tachycardia); gastrointestinal (diarrhea, colitis, and constipation); and urological (overactive bladder, abortion, and preterm labor) diseases. However, more clinical trials are needed to use some of these medicinal plants in clinical target therapy.

Muscarinic receptors, nitric oxide formation and cyclooxygenase pathway involved in tracheal smooth muscle relaxant effect of hydro-ethanolic extract of Lavandula angustifolia flowers.

BACKGROUND: Lavandula angustifolia (L. angustifolia) Mill. (Common name Lavender) is used in traditional and folk medicines for the treatment of various diseases including respiratory disorders worldwide. The relaxant effect of the plant on the smooth muscle of some tissues was shown previously. The present study has investigated the role of different receptors and pathways in the relaxant effect of L. angustifolia on tracheal smooth muscle. METHODS: Cumulative concentrations of the hydro-ethanolic extract of L. angustifolia flowers (0.5, 1, 2 and 4 mg/ml) were added on pre-contracted tracheal smooth muscle by methacholine (10 µM) or KCl (60 mM) on non-preincubated or preincubated tissues with atropine, chlorpheniramine, propranolol, diltiazem, glibenclamide, indomethacin, ω-nitro-L-arginine methyl ester (L-NAME) and papaverine. The results compared with of theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control and saline (1 ml) as negative control. RESULTS: The extract showed concentration-dependent relaxant effects in non-preincubated tracheal smooth muscle contracted by KCl and methacholine (p < 0.05 to p < 0.001). The relaxant effect ofL. angustifolia was not significantly different between non-preincubated and preincubated tissues with chlorpheniramine, propranolol, diltiazem, glibenclamide, and papaverine. However, two higher concentrations of L. angustifolia in preincubated tissues with L-NAME (p < 0.01), indomethacin (p < 0.05 to p < 0.001) and atropine (p < 0.05) showed significantly lower relaxant effects than non-preincubated tissues. The EC50 values of L. angustifolia in tissues preincubated with indomethacin was significantly higher than non-preincubated trachea (p < 0.05). The effects of three first concentrations of the extract on KCl and methacholine-induced muscle contraction were significantly lower than those of theophylline (p < 0.05 to p < 0.001). CONCLUSIONS: These results indicated a relatively potent relaxant effect ofL. angustifolia that was lower than the effect of theophylline. The possible mechanisms of relaxant effect of this plant on tracheal smooth muscle are muscarinic receptors blockade, inhibition of cyclooxygenase pathways and/or involvement of nitric oxide production. Its clinical applications should be investigated in further studies.

Preclinical and clinical effects of Nigella sativa and its constituent, thymoquinone: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Nigella sativa (N. sativa) L. (Ranunculaceae), well known as black cumin, has been used as a herbal medicine that has a rich historical background. It has been traditionally and clinically used in the treatment of several diseases. Many reviews have investigated this valuable plant, but none of them focused on its clinical effects. Therefore, the aim of the present review is to provide a comprehensive report of clinical studies on N. sativa and some of its constituents. MATERIALS AND METHODS: Studies on the clinical effects of N. sativa and its main constituent, thymoquinone, which were published between 1979 and 2015, were searched using various databases. RESULTS AND DISCUSSION: During the last three decades, several in vivo and in vitro animal studies revealed the pharmacological properties of the plant, including its antioxidant, antibacterial, antiproliferative, proapoptotic, anti-inflammatory, and antiepileptic properties, and its effect on improvement in atherogenesis, endothelial dysfunction, glucose metabolism, lipid profile dysfunction, and prevention of hippocampus pyramidal cell loss. In clinical studies, antimicrobial, antioxidant, anti-inflammatory, antitumor, and antidiabetic properties as well as therapeutic effects on metabolic syndrome, and gastrointestinal, neuronal, cardiovascular, respiratory, urinary, and reproductive disorders were found in N. sativa and its constituents. CONCLUSION: Extensive basic and clinical studies on N. sativa seed powder, oil, extracts (aqueous, ethanolic, and methanolic), and thymoquinone showed valuable therapeutic effects on different disorders with a wide range of safe doses. However, there were some confounding factors in the reviewed clinical trials, and a few of them presented data about the phytochemical composition of the plant. Therefore, a more standard clinical trial with N. sativa supplementation is needed for the plant to be used as an inexpensive potential biological adjuvant therapy.

Immunomodulatory and cytotoxic effects of Nigella sativa and thymoquinone on rat splenocytes.

Three different concentrations of Nigella sativa (N. sativa) ethanolic extract, thymoquinone (TQ), dexamethasone, and saline were examined to see whether they had any effects on cell viability, proliferation, and interleukin 4 (IL-4) and interferon-γ (IFN-γ) secretion in non-stimulated, phytohemagglutinin (PHA) and concavaline A (Con A)-stimulated splenocytes. In PHA and Con A-stimulated splenocytes, cell viability and proliferation were increased and Con A shifted cytokine profile towards Th2 balance. Dexamethasone treatment showed a suppression in viability, IFNγ and IL-4 secretion in non-stimulated and stimulated splenocytes. Extract and TQ reduced the viability and inhibited the proliferation of stimulated and non-stimulated splenocytes concentration-dependently. Higher concentrations of N. sativa (1000 mg/ml) and TQ (5 and 10 mg/ml) reduced the secretion of IL-4 in stimulated cells. Two higher concentrations of N. sativa had decreased IFNγ secretion in both stimulated and non-stimulated cells. In non-stimulated cells, only the highest and in Con A-stimulated cells, all TQ concentrations had inhibited IFNγ secretion. The highest concentration of N. sativa increased IFNγ/IL-4 ratio in both stimulated and non-stimulated cells while higher concentrations of TQ only had the same effect on stimulated cells. N. sativa and TQ showed cytotoxic inhibitory effect on rat splenocytes and on Th1/Th2 cytokines concentration-dependently. Higher concentrations of extract and TQ increased cytokines balance in Th1/Th2.

Effect of Nigella sativa on immune response in treadmill exercised rat.

BACKGROUND: In the present study the effect of Nigella sativa (N. sativa) ethanolic extract on cytokine profile in control, moderate and overtrained heavy exercised rat was examined. METHODS: Male Wistar rats were randomly divided into control sedentary (C), moderate trained (MT), (V = 20 m/min, 30 min/day, 6 days a week, for 8 weeks), overtrained (OT) (V = 25 m/min, 60 min/day, 6 days a week, for 11 weeks), control sedentary + N. sativa (NC), moderate trained + N. sativa (NM) and overtrained + N. sativa (NO). Immediately and 24 h after the last bout of exercise blood samples were obtained. The serum concentrations of TNFα, IL-6, IL-10, IL-4 and IFNγ were measured by ELISA method. RESULTS: Immediately after exercise the following findings were observed; IL-6, IL-10 and TNFα concentration increased in OT and NC groups but Just IL-6 in MT groups compared with control (P< 0.05-P< 0.001). Serum level of IL-4 decreased in MT and NC (P< 0.05-P< 0.001) but IFNγ increased (P< 0.05) just in MT group vs control. In addition, circulatory levels of TNFα, IL-6, IL-10 and IL-4 were higher in OT and NM groups but the IFNγ concentration was lower in the OT group than the MT group (P< 0.05-P< 0.01). The IFN-γ/IL4 ratio was significantly increased in MT and NC (P< 0.05-P< 0.01) while it decreased in OT group. There were not statistical differences in TNFα, IL-6, and IFNγ levels between different time intervals after exercise in all groups. CONCLUSIONS: Chronic administration of N. sativa may change pro and anti-inflammatory cytokines profiles. Also it may act as a balancing factor on Th1/Th2 lymphocytes in different exercise loads and act as an inhibitory factor on Th2 phenotype in control animals.

The effect of hydroalcoholic extract of Cannabis Sativa on appetite hormone in rat.

BACKGROUND: Ghrelin is an orexigenic peptide which is secreted from stomach. Cannabis sativa is known as an orexigenic herb in Iranian traditional medicine. Little evidence is published about its effect on energy intake and its mechanism. In the current study, the possible effect of hydroalcoholic extract of C. sativa on appetite and ghrelin is evaluated. METHODS: Thirty male Wistar rats were randomly divided into five groups. Two control groups were selected, the first group received 0.5 mL water per day (vehicle group) and another group did not receive anything (control group). The other three groups were treated daily with 50, 100 or 150 mg/kg of C. sativa for 7 days, respectively. Daily energy intake of the rats was calculated for 10 days prior to the> intervention and for the 7 day intervention. To investigate changes in plasma ghrelin as a potential mechanism, an orexigenic dose (150 mg/kg) of C. sativa or distilled water (vehicle) was fed to two separate groups of six rats by gavage. Total ghrelin levels in plasma were measured for 3 h post-gavage. RESULTS: There was no significant difference in energy intake between control and vehicle groups. Treatment with 100 and 150 mg/kg of the extract significantly increased energy intake vs the other groups (p<0.05). Total ghrelin levels were significantly elevated in the C. sativa group vs vehicle 30 and 60 min post-gavage. CONCLUSIONS: This study showed that C. sativa had both positive and dose-related effects on appetite of rats. Future studies are warranted to evaluate the orexigenic effect of this plant in human.

The preventive effects of natural adjuvants, G2 and G2F on tracheal responsiveness and serum IL-4 and IFN-γ (th1/th2 balance) in sensitized guinea pigs.

OBJECTIVE: The effects of natural adjuvants on lung inflammation and tracheal responsiveness were examined in sensitized guinea pigs. METHODS: The responses of guinea pig tracheal chains and the serum levels of interleukin-4 and interferon-gamma were examined in control pigs and three other groups of guinea pigs: the sensitized group and two other sensitized groups treated with either adjuvant G2 or adjuvant G2F (n=7 for each group). Sensitization of the animals was achieved by injection and inhalation of ovalbumin. RESULTS: The results showed that sensitized animals had increased tracheal responsiveness and increased serum levels of interleukin-4 and interferon-gamma compared to controls (p<0.05 to p<0.001). Treatments with either G2 or G2F prevented the increase in tracheal responsiveness and serum interleukin-4 (p<0.01 to p<0.001). However, the serum levels of interferon-gamma and the interleukin-4-to-interferon-gamma ratio was increased in the treated groups (p<0.001 for all cases). CONCLUSIONS: These results indicate important preventive effects of two natural adjuvants, particularly G2, on the changes in tracheal responsiveness, serum cytokines and the interleukin-4-to-interferon-gamma ratio (T helper 1/T helper 2 balance) in sensitized guinea pigs.

The preventive effects of natural adjuvants, G2 and G2F on tracheal responsiveness and serum IL-4 and IFN-? (th1/th2 balance) in sensitized guinea pigs

OBJECTIVE: The effects of natural adjuvants on lung inflammation and tracheal responsiveness were examined in sensitized guinea pigs. METHODS: The responses of guinea pig tracheal chains and the serum levels of interleukin-4 and interferon-gamma were examined in control pigs and three other groups of guinea pigs: the sensitized group and two other sensitized groups treated with either adjuvant G2 or adjuvant G2F (n = 7 for each group). Sensitization of the animals was achieved by injection and inhalation of ovalbumin. RESULTS: The results showed that sensitized animals had increased tracheal responsiveness and increased serum levels of interleukin-4 and interferon-gamma compared to controls (p<0.05 to p<0.001). Treatments with either G2 or G2F prevented the increase in tracheal responsiveness and serum interleukin-4 (p<0.01 to p<0.001). However, the serum levels of interferon-gamma and the interleukin-4-to-interferon-gamma ratio was increased in the treated groups (p<0.001 for all cases). CONCLUSIONS: These results indicate important preventive effects of two natural adjuvants, particularly G2, on the changes in tracheal responsiveness, serum cytokines and the interleukin-4-to-interferon-gamma ratio (T helper 1/T helper 2 balance) in sensitized guinea pigs. .

Relaxant effects of asafoetida extract and its constituent umbelliprenin on guinea-pig tracheal smooth muscle.

OBJECTIVE: To investigate the relaxant effects of the asafoetida (Ferula Asafoetida Oleo-Gum-Resin) and its coumarin constituent umbelliprenin on tracheal chains of guinea pigs. METHODS: The relaxant effects of three cumulative concentrations of the aqueous extract (2, 5 and 10 mg/mL), umbelliprenin (0.04, 0.2 and 0.4 mg/mL), theophylline (0.05, 0.1 and 0.15 mg/mL) and saline were examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mmol/L KCl (group 1), and 10 µ mol/L methacholine (group 2). RESULTS: In group 1 all concentrations of theophylline and the highest concentration of the extract showed signififi cant relaxant effects compared with that of saline (P<0.01 for theophylline and P<0.05 for extract). In group 2, relaxant effects of all concentrations of theophylline, extract and two higher concentrations of umbelliprenin differed significantly compared with saline [P<0.01 for all cases except low concentration of umbelliprenin (0.04 mg/mL)]. There were no signififi cant differences between relaxant effects of the extract and theophylline in group 2. The relaxant effect of the extract in group 2 was signififi cantly greater than that of group 1 (P<0.01). The relaxant effect of the extract was significantly more potent than umbelliprenin in all groups (P<0.05 or P<0.01). CONCLUSION: These results showed a potent relaxant effect for the asafoetida extract on tracheal smooth muscle which is, at least, in part, due to its constituent umbelliprenin. A muscarinic receptor blockade was also suggested for the extract.

The effect of hydroalcoholic extract of Coriandrum sativum on rat appetite.

OBJECTIVE: Losing weight in consequence of appetite loss can be a sign of a serious underlying condition. Currently, the most widely prescribed medication for anorexia is cyproheptadine hydrochloride. However, the clinical use of cyproheptadine hydrochloride is limited by its side effects. In Iranian traditional medicine, Coriandrum sativum stimulates the appetite. Therefore, the effect of Coriandrum sativum (coriander) hydroalcoholic extract was investigated on food intake in rats. MATERIAL AND METHODS: Thirty male Wistar rats were randomly divided into five groups. Two control groups were used, one group received 0.5 ml water per day (vehicle group), and another group did not receive anything (control group). The other 3 groups were daily treated by 50, 100 or 150 mg/kg of coriander for 7 days, respectively. The daily amount of the food eaten by each rat was measured for 10 days. The amount of energy intake of each rat was also calculated for 7 days during the intervention. The difference in energy intake was calculated and compared between groups. RESULT: There was no significant change in energy intake between control and vehicle groups. The change in energy intake after treatment by 100 and 150 mg/kg of the extract was significantly higher than other groups (p=0.030 and p=0.007) CONCLUSION: This study indicated that coriander had positive effects on appetite of rats. Future studies are needed to evaluate the mechanisms of the effects of this plant on appetite.

Inhibitory effect of Zataria multiflora Boiss and carvacrol on histamine (H(1) ) receptors of guinea-pig tracheal chains.

The inhibitory effect of aqueous-ethanolic extract of Zataria multiflora Boiss (Labiatae) and carvacrol on histamine (H(1) ) receptors was examined on tracheal chains of guinea-pigs. The effects of three concentrations of aqueous-ethanolic extract, carvacrol, 10 nm chlorpheniramine, and saline on histamine (H(1) ) receptors were tested on three groups of guinea-pig tracheal chains as follows: incubated trachea with (i) indomethacin (n = 9), (ii) indomethacin, propranolol, and atropine (n = 7), and (iii) indomethacin and propranolol (n = 6). The EC(50) (effective concentration of histamine causing 50% of maximum response) obtained in the presence of chlorpheniramine for all concentrations of the extract and carvacrol in all three groups was significantly higher than that of saline (P < 0.001 for all cases). The EC(50) obtained in the presence of all concentrations of extract in groups 2 and 3 was lower than group 1 and in group 3 lower than group 2 (P < 0.01 to P < 0.001). However, EC(50) obtained in the presence of all concentrations of carvacrol in group 3 and two higher concentrations in group 2 was higher than that of group 1 (P < 0.01 to P < 0.001). There was no significant difference in the maximum response obtained in the presence of different concentrations of extract and carvacrol between three groups. There was a parallel rightward shift in concentration-response curves obtained in the presence of all concentrations of the extract and carvacrol in all three groups. These results indicated an inhibitory effect of Z. multiflora and its constituent carvacrol on histamine H(1) receptors.