Anti-Inflammatory and Antimicrobial Volatile Oils: Fennel and Cumin Inhibit Neutrophilic Inflammation via Regulating Calcium and MAPKs

Abstract

Neutrophilic inflammatory diseases, such as chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), or psoriasis, exert a huge burden on the global health system due to the lack of safe and effective treatments. Volatile oils from terrestrial plants showed impressive therapeutic effects against disorders of the skin, digestive system, lungs, liver, metabolism, and nervous system. However, their effect on the immune system and neutrophil function is still elusive. Fennel, cumin, marjoram, lavender, caraway, and anise are the common nutraceuticals that are widely used in the Mediterranean diet. The volatile oils of these herbs were screened for various biological activities, including anti-inflammatory, anti-allergic, antimicrobial, and antiviral effects. Several oils showed anti-inflammatory and antimicrobial potential. Fennel (Foeniculum vulgare) and cumin (Cuminum cyminum) fruits' volatile oils significantly suppressed the activation of human neutrophils, including respiratory burst and the degranulation induced by formyl peptide receptor agonists fMLF/CB and MMK1 in the human neutrophils (IC50, 3.8–17.2 µg/ml). The cytotoxic effect and free-radical scavenging effects (ABTS, DPPH) of these oils did not account for the observed effects. Both fennel and cumin volatile oils significantly shortened calcium influx recovery time and inhibited phosphorylation of mitogen-activated protein kinases (p38, JNK, and ERK) expression. The gas chromatography–mass spectrometry analysis of these oils revealed the presence of estragole and cuminaldehyde as the major components of fennel and cumin volatile oils, respectively. Our findings suggested that cumin and fennel, common in the Mediterranean diet, hold the potential to be applied for the treatment of neutrophilic inflammatory diseases.

The effect of a fennel seed extract on the STAT signaling and intestinal barrier function

“…The treatment shown here with fennel seed extract is in line with these IBD treatment modalities as all three target the JAK/STAT pathway to critically reduce inflammatory signaling in the intestines. The active ingredients of fennel seed have been reported to have anti-inflammatory effects and protective effects against injury in different studies [57,64,65]. Due to its beneficial effect, different forms of fennel are included in specific diets to improve the symptoms of IBD [10,66,67].…”

“…Since the STAT1 phosphorylation is reduced back to control level with fennel treatment when compared with the active inflammatory state, it is possible that active ingredients of fennel seed extract may inhibit the kinase activity of JAK to prevent STAT 1 phosphorylation. Volatile oils from fennel have been reported to inhibit neutrophilic inflammation through modulating phosphorylation of MAPK pathway [57]. Thus fennel seed extract may act similarly on the JAK/STAT pathway.…”

Role of Inflammation, Oxidative Stress, and Mitochondrial Changes in Premenstrual Psychosomatic Behavioral Symptoms with Anti-Inflammatory, Antioxidant Herbs, and Nutritional Supplements

“…Fascinatingly, fennel inhibiting protein kinase (PKA) inhibitor H89 partly restores the superoxide anion generation, along with the inhibitory effect on calcium influx recovery time, and indicates a role of the cAMP/PKA pathway in the anti-inflammatory effects of fennel. Fennel estragole exhibited anti-inflammatory effects in vitro by suppressing Nrf-2 and NF-lB pathways and in vivo (30 mg/kg) reduction of paw edema and leukocyte emigration in the peritoneal fluid [ 111 ]. The mechanism of action of Allium sativum is immuno-regulation and modulation of secretion of cytokines with therapeutic effects for metabolic syndrome such as antihypertensive, antidiabetic, and hypolipidemic properties.…”

Combination Strategies of Different Antimicrobials: An Efficient and Alternative Tool for Pathogen Inactivation

“…The chemical composition of EOs is highly complex, with the main components being flavonoids, flavones, flavonols, phenols, polyphenols, tannins, alkaloids, quinones, coumarins, terpenoids, polypeptides, and lectins [ 22 ]. These compounds show potential pharmacological activities such as hepatoprotective, anti-inflammatory, antioxidant, anticancer, antiseptic, insecticidal, anti-parasitic, anti-allergic, antiviral, and antimicrobial properties [ 74 ]. Essential-oil-based products are in high demand in aromatherapy; as flavor-enhancers in food, beverages, cosmetics, perfumes, soaps, plastics, and resins; and in the pharmaceutical industries [ 75 ].…”