Pharmacological Properties of Allium cepa, Preclinical and Clinical Evidences; A Review.

Onion or Allium cepa (A. cepa) is one of the most important condiment plants grown and consumed all over the world. This plant has various therapeutic effects attributed to its constituents, such as quercetin, thiosulphinates and phenolic acids. In the present article, various pharmacological and therapeutic effects of A. cepa were reviewed. Different online databases using keywords such as onion, A. cepa, therapeutic effects, and pharmacological effects until the end of December 2019 were searched for this purpose. Onion has been suggested to be effective in treating a broad range of disorders, including asthma, inflammatory disorders, dysentery, wounds, scars, keloids and pain. In addition, different studies have demonstrated that onion possesses numerous pharmacological properties, including anti-cancer, anti-diabetic and anti-platelet properties as well as the effect on bone, cardiovascular, gastrointestinal, nervous, respiratory, and urogenital systems effects such as anti-osteoporosis, anti-hypertensive, antispasmodic, anti-diarrheal, neuro-protective, anti-asthmatic and diuretic effects. The present review provides detailed the various pharmacological properties of onion and its constituents and possible underlying mechanisms. The results of multiple studies suggested the therapeutic effect of onion on a wide range of disorders.

Effects of Allium cepa and Its Constituents on Respiratory and Allergic Disorders: A Comprehensive Review of Experimental and Clinical Evidence.

The health benefits of Allium cepa (A. cepa) have been proclaimed for centuries. Various pharmacological and therapeutic effects on respiratory, allergic, and immunologic disorders are shown by A. cepa and its constituents. Flavonoids such as quercetin and kaempferol, alk(en)yl cysteine sulfoxides including S-methyl cysteine sulfoxide and S-propyl cysteine sulfoxide, cycloalliin, thiosulfinates, and sulfides are the main compounds of the plant. A. cepa displays broad-spectrum pharmacological activities including antioxidant, anti-inflammatory, antihypertensive, and antidiabetic effects. Our objective in this review is to present the effects of A. cepa and its constituents on respiratory, allergic, and immunologic disorders. Different online databases were searched to find articles related to the effect of A. cepa extracts and its constituents on respiratory, allergic, and immunologic disorders until the end of December 2020 using keywords such as onion, A. cepa, constituents of A. cepa, therapeutic effects and pharmacological effects, and respiratory, allergic, and immunologic disorders. Extracts and constituents of A. cepa showed tracheal smooth muscle relaxant effects, indicating possible bronchodilator activities or relieving effects on obstructive respiratory diseases. In experimental animal models of different respiratory diseases, the preventive effect of various extracts and constituents of A. cepa was induced by their antioxidant, immunomodulatory, and anti-inflammatory effects. The preventive effects of the plant and its components on lung disorders induced by exposure to noxious agents as well as lung cancer, lung infection, and allergic and immunologic disorders were also indicated in the experimental and clinical studies. Therefore, this review may be considered a scientific basis for development of therapies using this plant, to improve respiratory, allergic, and immunologic disorders.

A review of anti-inflammatory, antioxidant, and immunomodulatory effects of Allium cepa and its main constituents.

CONTEXT: Allium cepa L. (Liliaceae), known as onion, is consumed throughout the world. Onion and its derivatives including saponins, aglycones, quercetin, cepaenes, flavonoids, organosulfurs, and phenolic compounds, showed various pharmacological properties and therapeutic effects. OBJECTIVE: Anti-inflammatory, antioxidant, and immunomodulatory effects of A. cepa and its main constituents, along with the underlying molecular mechanisms are presented. METHODS: Databases including, Web of Knowledge, Medline/PubMed, Scopus, and Google Scholar were checked for articles published between 1996 and the end of July 2020, using the key-words Allium cepa, quercetin, anti-inflammatory, antioxidant and immunomodulatory. RESULTS: A. cepa and its constituents mainly quercetin showed anti-inflammatory effects mediated via reduction of total and differential WBC counts, inhibition of chemotaxis of polymorphonuclear leukocytes, COX, and LOX pathways and prevented formation of leukotrienes and thromboxanes, prostaglandin E2 (PGE2) as onVCAM-1, NF-κB, MARK,d STAT-1, JNK, p38 and osteoclastogenesis. A. cepa and its derivatives showed antioxidant effect by decreasing lipid peroxidation, NAD(P)H, MDA, NO, LPO and eNOS but enhancing antioxidants such as SOD, CAT, GSH, GPx, GSPO, TrxR, SDH, GST and GR activities and thiol level. Immunomodulatory effects of the plant and quercetin was also shown by reduction of Th2 cytokines, IL-4, IL-5, and IL-13 as well as IL-6, IL-8, IL-10, IL-1ß and TNF-α and IgE levels, but increased CD4 cells, IFN-γ level and IFN-γ/IL4 ratio (Th1/Th2 balance). CONCLUSIONS: The effect of onion and its constituents on oxidative stress, inflammatory and immune system were shown indicating their therapeutic value in treatment of various diseases associated with oxidative stress, inflammation, and immune-dysregulation.

The Relaxant Effect of Plantago Major on Rat Tracheal Smooth Muscles and Its Possible Mechanisms.

This study was conducted to evaluate the possible mechanisms of the relaxant effects of hydroalcoholic extract of Plantago major (P. major) on tracheal smooth muscle (TSM) in rats. The effects of cumulative concentrations of P. major (5, 10, 20 and 40 mg/mL) and theophylline (0.2, 0.4, 0.6 and 0.8 mM) were evaluated on pre-contracted TSM with 10 µΜ methacholine or 60 mM KCl. To determine the possible mechanisms, the relaxant effect of the plant was also examined on incubated TSM with atropine, indomethacin, chlorpheniramine, glibenclamide, diltiazem, papaverine, and propranolol. The results indicated concentration-dependent relaxant effects for P. major in non-incubated TSM contracted by methacholine or KCl. There was no statistically significant difference in the relaxant effects of P. major between non-incubated and incubated tissues with indomethacin, papaverine, and propranolol. However, the relaxant effects of P. major in incubated tissues with atropine (p<0.01 to p<0.001), chlorpheniramine (p<0.05 to p<0.001), glibenclamide (p<0.05), or diltiazem (p<0.01) were significantly lower than non-incubated TSM. P. major indicated relatively potent relaxant effects which were lower than those of theophylline. Muscarinic and histamine (H1) receptors inhibition, as well as calcium channel blocking and potassium channel opening effects are suggested to contribute to the TSM relaxant effect of the plant.

Histamine (H1) Receptors, Cyclooxygenase Pathway and Nitric Oxide Formation Involved in Rat Tracheal Smooth Muscle Relaxant Effect of Berberine.

In this study we aimed to examine the relaxant effect of berberine, a compound extracted from a variety of herbs, on rat tracheal smooth muscle (TSM) and its possible mechanism(s). Cumulative concentrations of berberine (20, 65, 200 and 600 µg/mL) were added on pre-contracted TSM by methacholine or KCl in non-incubated or incubated tissues with atropine, chlorpheniramine, propranolol, diltiazem, glibenclamide, indomethacin, L-NG-nitro arginine methyl ester (L-NAME) and papaverine. The relaxant effects of theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control and saline (1 mL) as negative control were also examined in non-incubated tissues. Berberine showed significant and concentration-dependent relaxant effects in non-incubated tissues contracted by KCl and methacholine (p<0.01 to p<0.001). There was no significant difference in the relaxant effects of berberine between non-incubated and incubated tissues with atropine, propranolol, diltiazem, glibenclamide, and papaverine. The relaxant effects of second concentrations of berberine in incubated tissues with L-NAME, its three lower concentration in incubated tissues with chlorpheniramine and its all concentrations in incubated tissues with indomethacin were significantly lower than non-incubated tissues (p<0.05 to p<0.001). The EC50 values of berberine in incubated tissues with chlorpheniramine was significantly higher than the non-incubated condition (p<0.05). Our findings reveal a relatively potent relaxant effect of berberine that is lower than the effect of theophylline. Proposed mechanisms for the relaxant effect of berberine are histamine (H1) receptor blockade, inhibition of cyclooxygenase pathways and/or nitric oxide formation.

Gastrointestinal effects of Nigella sativa and its main constituent, thymoquinone: a review.

Gastrointestinal (GI) diseases affect a large number of people all over the world. Uncontrolled acid secretion and occurrence of gastric ulcers are common disorders of GI tract which pose serious problems to human health. Many synthetic drugs have been used to treat GI disorders but a definite cure has not been discovered so far and the available medications cause several side effects. Nigella sativa (N. sativa) (Ranunculacea) has several therapeutic effects which are attributed to its constituents like nigellicine, nigellidine, thymoquinone, dithymoquinone, thymol and carvacrol. Several beneficial pharmacological properties of this plant such as anti-oxidant, anti-bacterial, anti-histaminic, anti-hypertensive, hypoglycemic, anti-fungal, anti-inflammatory, anti-cancer and immunomodulatory effects were reported and different therapeutic properties such as reliving bronchial asthma, jaundice, hydrophobia, paralysis, conjunctivitis, piles, skin diseases, anorexia, headache, dysentery, infections, obesity, back pain, hypertension and gastrointestinal problems, have been described for the seeds of N. sativa and its oil. The present review provides a detailed summery of scientific researches regarding gastrointestinal effect of N. sativa and its main constituent, thymoquinone.

Effect of bone marrow derived mesenchymal stem cells on lung pathology and inflammation in ovalbumin-induced asthma in mouse.

OBJECTIVES: Bone marrow-derived mesenchymal stem cells (BMSCs) have attracted significant interest to treat asthma and its complication. In this study, the effects of BMSCs on lung pathology and inflammation in an ovalbumin-induced asthma model in mouse were examined. MATERIALS AND METHODS: BALB/c mice were divided into three groups: control group (animals were not sensitized), asthma group (animals were sensitized by ovalbumin), asthma+BMSC group (animals were sensitized by ovalbumin and treated with BMSCs). BMSCs were isolated and characterized and then labeled with Bromodeoxyuridine (BrdU). After that the cells transferred into asthmatic mice. Histopathological changes of the airways, BMSCs migration and total and differential white blood cell (WBC) count in bronchoalveolar lavage (BAL) fluid were evaluated. RESULTS: A large number of BrdU-BMSCs were found in the lungs of mice treated with BMSCs. The histopathological changes, BAL total WBC counts and the percentage of neutrophils and eosinophils were increased in asthma group compared to the control group. Treatment with BMSCs significantly decreased airway pathological indices, inflammatory cell infiltration, and also goblet cell hyperplasia. CONCLUSION: The results of this study revealed that BMSCs therapy significantly suppressed the lung pathology and inflammation in the ovalbumin induced asthma model in mouse.

Animal Model of Asthma, Various Methods and Measured Parameters: A Methodological Review.

Asthma is a chronic inflammatory disease of the airway with extensive airway remodeling. The ethical issues associated with the studies in asthmatic patients, required development of animal model of asthma. Animal models of asthma can provide valuable information on several features of asthma pathogenesis and treatment. Although these models cannot carry out all clinical features, they are valuable to understand mechanisms of the disease and curative access. Related articles were searched in different databases from September 1994 to April 2016 using; animal model of asthma, animal sensitization, allergen-induced asthma in animals terms. Although there are several reviews on this topic, in the present article, induction of animal model of asthma in different animals, various methods used for this purpose, measured parameters and research purposes were reviewed, which will help investigators to use the appropriate animal, methods, and evaluating parameters depending on their study design. In this study various method used for induction of animal model of asthma in different animals and measured parameters were described, which will help investigators to use the appropriate animal, method and evaluating parameters depending on their study design.

Diagnosis of chronic obstructive pulmonary disease earlier than current Global Initiative for Obstructive Lung Disease guidelines using a feasible spirometry parameter (maximal-mid expiratory flow/forced vital capacity).

Some patients suffer from clinical symptoms of chronic obstructive pulmonary disease (COPD) but their pulmonary function tests are in the normal range (at risk group). The objective of this study was to discover a practical test to distinguish these patients from non-COPD subjects. A total of 77 subjects including 40 COPD patients, 37 subjects at risk for developing COPD, and 32 control subjects were entered in this study. The accuracy of maximal-mid expiratory flow (MMEF)/forced vital capacity (FVC) for the diagnosis of COPD in at risk patients and its capability to differentiate from early COPD and normal patients were evaluated. Body plethysmography was used for measurement of lung volume as the Global Initiative for Obstructive Lung Disease standard. MMEF/FVC in the at risk group of COPD (0.73±0.19) was significantly lower than the normal control group (0.9±0.24, respectively), and also, it was significantly higher than the COPD group (0.31±0.17). There was significant correlation between the MMEF/FVC and amount of smoking measured by pack year (r2=0.112, p=0.005) and stages of COPD (Spearman's ρ=0.82, p=0.0001). Early stage COPD (smoker subjects without spirometry derangement) can be diagnosed by MMEF/FVC. Using this tool we may be able to detect this highly preventable disease at an earlier stage.

Pulmonary function tests and work-related respiratory and allergic symptoms in Iranian bakers.

Bakers are frequently exposed to various irritant chemicals during work which can induce respiratory problems. In this study, pulmonary function tests and self-reported respiratory and allergic symptoms in bakers were compared with matched control subjects. The frequency of respiratory and allergic symptoms was evaluated in a sample of 58 Iranian bakers and 58 control subjects using a questionnaire. Pulmonary function tests (PFT) were also measured in all participants. All respiratory symptoms were significantly higher in bakers than control croup (p<0.05 to p<0.005). All allergic symptoms in bakers were also significantly greater than control group (p<0.05 to p<0.005). In addition, all respiratory (except sputum) and allergic (except urticaria) symptoms were significantly higher in bakers compared to rest period (p<0.05 to p<0.01) during work. Most PFT values except MEF25 were also significantly lower in bakers than control subjects (p<0.05 to p<0.001). These results showed that bakers have a higher frequency of work related respiratory symptoms and to a lesser extend allergic symptoms particularly during the work period. PFT values were also significantly reduced among bakers.