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

Abstract

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-1β 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.

Antioxidant Properties and Structure-Antioxidant Activity Relationship of Allium Species Leaves

“…Inflammation can also be defined as a reaction to defend the body in eliminating factors that can cause damage and the formation of homeostasis in the body. This causes increased blood flow due to the increased permeability of capillaries and white blood cells to the site of inflammation, resulting in inflammatory symptoms such as redness, swelling and pain [ 82 ]. Several previous studies reported that the Allium species has several bioactivities, one of which is anti-inflammatory [ 83 , 84 , 85 , 86 , 87 ].…”

Allium cepa: A Treasure of Bioactive Phytochemicals with Prospective Health Benefits

“…In addition, ointment extract gel reveals hypertrophic presternal scar defense [ 74 ]. It is often used in topical methods for care and mitigation of postoperative hypertrophic scars [ 3 , 4 ] and keloid surgery [ 75 ]. A. cepa -allantoinpentaglycan gel also cures hypertrophic skin skins [ 76 ] and enhances the aesthetic appearance of postoperative scars [ 77 ] and burning cells [ 78 ].…”

“…Studies demonstrate that onion extract is capable of removing hypertrophic wounds too [ 3 ]. Regular intake of onions lowers the risk of colorectal, lung, liver, brain, stomach, ovarian, prostate, and breast cancer [ 4 ]. The function of antiplatelets is significantly influenced by genotype, climate, and vegetable storage period.…”

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

“…Various pharmacological effects such as antidiabetic, antihyperglycemic, antiparasitic, antifungal, antimicrobial, antiplatelet, anti-inflammatory, antioxidant, and antispasmodic properties were reported for the extracts of A. cepa and its different constituents [28,31,42,[47][48][49][50][51][52]. e preventive effects of the extracts of A. cepa on the vascular and heart diseases [53], neurodegenerative and antidepressant disorders [8], and cataract formation as well as improving effects on kidney function were also reported [6,54].…”