Alcoholic monoterpenes found in essential oil of aromatic spices reduce allergic inflammation by the modulation of inflammatory cytokines

Chronic post-ischemic pain (CPIP) a model of complex regional pain syndrome (CRPS-I): Role of oxidative stress and inflammation

Complex regional pain syndrome (CRPS) presents as a persistent and distressing pain condition often stemming from limb trauma or ischemia, manifesting as either CRPS-I (without initial nerve injury) or CRPS-II (accompanied by nerve injury). Despite its prevalence and significant impact on functionality and emotional well-being, standard treatments for CRPS remain elusive. The multifaceted nature of CRPS complicates the identification of its underlying mechanisms. In efforts to elucidate these mechanisms, researchers have turned to animal models such as chronic post-ischemic pain (CPIP), which mirrors the symptoms of CRPS-I. Various mechanisms have been proposed to underlie the acute and chronic pain experienced in CRPS-I, including oxidative stress and inflammation. Traditional treatment approaches often involve antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids. However, these methods frequently fall short of providing adequate relief. Accordingly, there is a growing interest in exploring alternative treatments, such as antioxidant supplementation, anti-inflammatory agents, and non-pharmacological interventions. Future research directions should focus on optimizing treatment strategies and addressing remaining gaps in knowledge to improve patient outcomes. This review aims to delve into the pathophysiological mechanisms implicated in the CPIP model, specifically focusing on oxidative stress and inflammation, with the ultimate goal of proposing innovative therapeutic strategies for alleviating the symptoms of CRPS-I.

Molecular insights of Eucalyptol (1,8-Cineole) as an anti-arthritic agent: in vivo and in silico analysis of IL-17, IL-10, NF-κB, 5-LOX and COX-2

The monoterpene oxide, Eucalyptol (1,8-Cineole), a primary component of eucalyptus oil, has been evaluated pharmacologically for anti-inflammatory and analgesic activity. Current research aimed to evaluate Eucalyptol's anti-arthritic potential in a Complete Freund's adjuvant induced arthritis that resembles human rheumatoid arthritis. Polyarthritis developed after 0.1 mL CFA injection into the left hind footpad in rats. Oral administration of Eucalyptol at various doses (100, 200 and 400 mg/kg) significantly reduced paw edema, body weight loss, 5-LOX, PGE2 and Anti-CCP levels. Real-time PCR investigation showed significant downregulation of COX-2, TNF-α, NF-κB, IL-17, IL-6, IL-1β and upregulation of IL-4 and IL-10 in Eucalyptol treated groups. Hemoglobin and RBCs counts significantly increased post-treatment with Eucalyptol while ESR, CRP, WBCs and platelets count significantly decreased. Eucalyptol significantly increased Superoxide Dismutase, Catalase and Glutathione levels compared to CFA-induced arthritic control however, MDA significantly decreased post-treatment. Further, radiographic and histopathological examination of the ankle joints of rodents administered Eucalyptol revealed an improvement in the structure of the joints. Piroxicam was taken as standard. Furthermore, molecular docking findings supported the anti-arthritic efficacy of Eucalyptol exhibited high binding interaction against IL-17, TNF-α, IL-4, IL-10, iNOS NF-κB, 5-LOX, and COX-2. Eucalyptol has reduced the severity of CFA induced arthritis by promoting anti-inflammatory cytokines for example IL-4, IL-10 and by inhibiting pro-inflammatory cytokines such as 5-LOX, COX-2, IL-17, NF-κB, TNF-α, IL-6 and IL-1β. Therefore, Eucalyptol might be as a potential therapeutic agent because of its pronounced anti-oxidant and anti-arthritic activity.

Cang-ai volatile oil alleviates nasal inflammation via Th1/Th2 cell imbalance regulation in a rat model of ovalbumin-induced allergic rhinitis

We previously revealed that Cang-ai volatile oil (CAVO) regulates T-cell activity, enhancing the immune response in people with chronic respiratory diseases. However, the effects of CAVO on allergic rhinitis (AR) have not been investigated. Herein, we established an ovalbumin (OVA)-induced AR rat model to determine these effects. Sprague-Dawley (SD) rats were exposed to OVA for 3 weeks. CAVO or loratadine (positive control) was given orally once daily for 2 weeks to OVA-exposed rats. Behavior modeling nasal allergies was observed. Nasal mucosa, serum, and spleen samples of AR rats were analyzed. CAVO treatment significantly reduced the number of nose rubs and sneezes, and ameliorated several hallmarks of nasal mucosa tissue remodeling: inflammation, eosinophilic infiltration, goblet cell metaplasia, and mast cell hyperplasia. CAVO administration markedly upregulated expressions of interferon-γ, interleukin (IL)-2, and IL-12, and downregulated expressions of serum tumor necrosis factor-α, IL-4, IL-5, IL-6, IL-13, immunoglobulin-E, and histamine. CAVO therapy also increased production of IFN-γ and T-helper type 1 (Th1)-specific T-box transcription factor (T-bet) of the cluster of differentiation-4+ T-cells in splenic lymphocytes, and protein and mRNA expressions of T-bet in nasal mucosa. In contrast, levels of the Th2 cytokine IL-4 and Th2-specific transcription factor GATA binding protein-3 were suppressed by CAVO. These cumulative findings demonstrate that CAVO therapy can alleviate AR by regulating the balance between Th1 and Th2 cells.

Reprogramming of arachidonic acid metabolism using α-terpineol to alleviate asthma: insights from metabolomics

Asthma is a chronic inflammatory disorder in airways with typical pathologic features of airway inflammation and mucus hypersecretion. α-Terpineol is a monocyclic terpene found in many natural plants and foods. It has been reported to possess a wide range of pharmacological activities including anti-inflammatory and expectorant effects. However, the role of α-terpineol in asthma and its potential protective mechanism have not been well elucidated. This study is designed to investigate the pharmacological effect and mechanism of α-terpineol on asthmatic mice using the metabolomics platform. A murine model of asthma was established using ovalbumin (OVA) sensitization and then challenged for one week. The leukocyte count and inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), lung histopathology, inflammatory  infiltrate and mucus secretion were evaluated. An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based metabolomics study was performed on lung tissues and serum to explore endogenous small molecule metabolites affected by α-terpineol in asthmatic mice. After α-terpineol treatment, leukocyte count, inflammatory cytokines in the BALF, and peribronchial inflammation infiltration were significantly downregulated. Goblet cell hyperplasia and mucus secretion were attenuated, with the level of Muc5ac in BALF decreased. These results proved the protective effect of α-terpineol against airway inflammation, mucus hypersecretion and Th1/Th2 immune imbalance. To further investigate the underlying mechanisms of α-terpineol in asthma treatment, UPLC-MS/MS-based metabolomics analysis was performed. 26 and 15 identified significant differential metabolites were found in the lung tissues and serum of the control, model and α-terpineol groups, respectively. Based on the above differential metabolites, enrichment analysis showed that arachidonic acid (AA) metabolism was reprogrammed in both mouse lung tissues and serum. 5-Lipoxygenase (5-LOX) and cysteinyl leukotrienes (CysLTs) are the key enzyme and the end product of AA metabolism, respectively. In-depth studies have shown that pretreatment with α-terpineol can alleviate asthma by decreasing the AA level, downregulating the expression of 5-LOX and reducing the accumulation of CysLTs in mouse lung tissues. In summary, this study demonstrates that α-terpineol is a potential agent that can prevent asthma via regulating disordered AA metabolism.

Attenuation of CFA-induced chronic inflammation by a bicyclic monoterpene fenchone targeting inducible nitric oxide, prostaglandins, C-reactive protein and urea

Fenchone (a bicyclic monoterpene) is present in the essential oils of plant species like Foeniculum vulgare and Peumus boldus and is used to treat GIT disorders. Research reports have indicated its strong anti-inflammatory, antioxidant, and anti-nociceptive properties. The present study was designed to investigate fenchone's anti-arthritic effects in a rat model of chronic joint inflammation (Complete Freud's Adjuvant-mediated inflammation [CFA]). Molecular docking analysis revealed a high binding interaction of fenchone with inducible nitric oxide synthase (iNOS), Interleukin-17, Prostaglandin E Receptor EP4, and Cycloxygenase-2 (COX-2), indicating its anti-inflammatory efficacy using computational tests. Fenchone treatment at 100 mg/kg, 200 mg/kg, and 400 mg/kg significantly enhanced the tail-flick latency when compared with the solvent-treated group. Correspondingly, the raised mRNA values of iNOS, IL-17, IL-1β, IL-6, TNF-α, and COX-2 in solvent-treated group were significantly reduced following treatment with fenchone. Moreover, fenchone significantly lowered spleen and thymus indices, Nitric oxide (NO) and PGE2 values as compared to solvent-treated group. Hence, the results of the present study indicated that fenchone has a potent anti-inflammatory effect by inhibiting pro-inflammatory markers and thus may have therapeutic potential for chronic joint inflammation as well as chronic inflammatory disorders.

Pharmacologic effects approach of essential oils and their components on respiratory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Essential oils (EOs) are concentrated hydrophobic liquids with volatility and a unique aroma. Formed by aromatic plants as secondary metabolites, EOs have been used as traditional medicines to treat various health problems worldwide. Historical records show that herbs rich in EOs have been widely used to treat respiratory diseases in China, Europe, and many other regions.

AIM OF THE REVIEW

This review summarizes the traditional applications and modern pharmacological mechanisms of EOs derived from aromatic herbs and their active ingredients in respiratory diseases in preclinical and clinical trials through multitarget synergy.

MATERIALS AND METHODS

Information about EOs and respiratory diseases was collected from electronic databases, such as ScienceDirect, Web of Science, PubMed, Google Scholar, Baidu Scholar, and the China National Knowledge Infrastructure (CNKI).

RESULTS

This review presents the preventive and therapeutic effects of EOs on respiratory diseases, including chronic obstructive pulmonary disease, bronchial asthma, acute lung injury, pulmonary infection, and pulmonary fibrosis. The molecular mechanisms of EOs in treating different lung diseases are summarized, including anti-inflammation, anti-oxidation, mucolytic, and immune regulatory mechanisms.

CONCLUSIONS

EOs show potential as supplements or substitutes for treating lung diseases.

Evaluation of Rosa germplasm resources and analysis of floral fragrance components in R. rugosa

Rosa rugosa (Rosaceae) is an important functional plant used in food products, tea, and aromatherapy. Characteristics of R. rugosa varieties based on the biological traits and floral fragrant components were studied by applying an analytic hierarchy process, headspace solid-phase microextraction gas chromatography-mass spectrometry, and metabolomic analysis. The 77 Rosa accessions (comprising 27 R. rugosa varieties, 43 scented R. hybrida cultivars, and seven fragrant R. species) were grouped into nine classes based on 17 morphological characters and 16 targeted fragrant substances by cluster analysis. Three R. rugosa cultivars differing in fragrance type were selected for volatile metabolomics analysis at four stages of flower development. In total, 156 differential volatile organic compounds (VOC) were detected and the VOC content patterns were further investigated in two important metabolic pathways (the monoterpenoid biosynthetic pathway, and the phenylalanine, tyrosine, and tryptophan biosynthesis pathway). The results provide a foundation for efficient use of Rosa germplasm and insights into the utilization of R. rugosa as a functional flower.

Experimental and clinical evidence on the effect of carvacrol on respiratory, allergic, and immunologic disorders: A comprehensive review

Carvacrol (CAR) showed various pharmacological and therapeutic effects in different disorders. In the current article, the experimental and clinical effects of CAR on respiratory, allergic, and immunologic disorders are described. Various databases, including PubMed, Science Direct, and Scopus, were searched regarding the effects of CAR on respiratory and allergic disorders until the end of October 2021. CAR showed the relaxant effect, with various possible mechanisms suggesting the bronchodilatory effect in obstructive pulmonary diseases. The preventive effects of CAR on experimental animal models of respiratory diseases were shown through mechanisms such as antioxidant, immunomodulatory, and anti-inflammatory. CAR also showed therapeutic potential on lung cancer, lung infections, and allergic and immunologic disorders. Clinical studies also revealed therapeutic effects of CAR on asthma, sulfur-mustard-induced lug disorders, and some other allergic and immunologic diseases. Pharmacological and therapeutic effects of CAR indicate possible remedy effects of this agent in the treatment of respiratory, allergic, and immunologic diseases.

The effect of Zataria multiflora on respiratory allergic and immunologic disorders, experimental and clinical evidence: A comprehensive review

Zataria multiflora (Z. multiflora) is used in traditional and modern medicine for therapeutic objectives especially in respiratory disorders. Therefore, updated experimental and clinical studies on the effects of Z. multiflora on respiratory, allergic, and immunologic disorders are reviewed. Various electronic search engines including PubMed, Science Direct, Scopus, and Google Scholar were searched using appropriate keywords until the end of November 2021. Books, thesis-hard copies of some articles were also included. The effects of Z. multiflora on respiratory disorders including asthma, chronic obstructive pulmonary disease (COPD), lung infection, and lung cancer were shown. Extracts of Z. multiflora showed the relaxant effect with various mechanisms. The preventive effects of Z. multiflora were also demonstrated by mechanisms such as antioxidant, immunomodulatory, and antiinflammatory properties in the experimental animal models of different respiratory diseases. Carvacrol and thymol are probably responsible for the therapeutic effect of plant among 56 constituents of Z. multiflora. In addition, bronchodilatory and preventive effects of the plant and its constituents on asthma, COPD, lung disorders due to noxious agents and allergic and immunologic disorders were shown in the clinical studies. Therefore Z. multiflora and its constituents may be considered as a preventive and/or relieving therapy in various respiratory diseases.

Antidepressant-Like Effect of Terpineol in an Inflammatory Model of Depression: Involvement of the Cannabinoid System and D2 Dopamine Receptor

Depression has a multifactorial etiology that arises from environmental, psychological, genetic, and biological factors. Environmental stress and genetic factors acting through immunological and endocrine responses generate structural and functional changes in the brain, inducing neurogenesis and neurotransmission dysfunction. Terpineol, monoterpenoid alcohol, has shown immunomodulatory and neuroprotective effects, but there is no report about its antidepressant potential. Herein, we used a single lipopolysaccharide (LPS) injection to induce a depressive-like effect in the tail suspension test (TST) and the splash test (ST) for a preventive and therapeutic experimental schedule. Furthermore, we investigated the antidepressant-like mechanism of action of terpineol while using molecular and pharmacological approaches. Terpineol showed a coherent predicted binding mode mainly against CB1 and CB2 receptors and also against the D2 receptor during docking modeling analyses. The acute administration of terpineol produced the antidepressant-like effect, since it significantly reduced the immobility time in TST (100-200 mg/kg, p.o.) as compared to the control group. Moreover, terpineol showed an antidepressant-like effect in the preventive treatment that was blocked by a nonselective dopaminergic receptor antagonist (haloperidol), a selective dopamine D2 receptor antagonist (sulpiride), a selective CB1 cannabinoid receptor antagonist/inverse agonist (AM281), and a potent and selective CB2 cannabinoid receptor inverse agonist (AM630), but it was not blocked by a nonselective adenosine receptor antagonist (caffeine) or a β-adrenoceptor antagonist (propranolol). In summary, molecular docking suggests that CB1 and CB2 receptors are the most promising targets of terpineol action. Our data showed terpineol antidepressant-like modulation by CB1 and CB2 cannabinoid receptors and D2-dopaminergic receptors to further corroborate our molecular evidence.

Design, synthesis and pharmacological evaluation of CVIB, a codrug of carvacrol and ibuprofen as a novel anti-inflammatory agent

The search for new drugs with anti-inflammatory properties remains a challenge for modern medicine. Among the various strategies for drug discovery, deriving new chemical entities from known bioactive natural and/or synthetic compounds remains a promising approach. Here, we designed and synthesized CVIB, a codrug developed by association of carvacrol (a phenolic monoterpene) with ibuprofen (a non-steroidal anti-inflammatory drug). In silico pharmacokinetic and physicochemical properties evaluation indicated low aqueous solubility (LogP ≥5.0). Nevertheless, the hybrid presented excellent oral bioavailability, gastrointestinal tract absorption, and low toxicity. CVIB did not present cytotoxicity in peripheral blood mononuclear cells (PBMCs), and promoted a significant reduction in IL-2, IL-10, IL-17, and IFN-γ cytokine levels in vitro. The LD₅₀ was estimated to be approximately 5000 mg/kg. CVIB was stable and detectable in human plasma after 24 h. In vivo anti-inflammatory evaluations revealed that CVIB at 10 and 50 mg/kg i.p. caused a significant decrease in total leukocyte count (p < 0.01) and provoked a significant reduction in IL-1β (p < 0.01). CVIB at 10 mg/kg i.p. efficiently decreased inflammatory parameters better than the physical mixture (carvacrol + ibuprofen 10 mg/kg i.p.). The results suggest that the codrug approach is a good option for drug design and development, creating the possibility of combining NSAIDs with natural products in order to obtain new hybrid drugs may be useful for treatment of inflammatory diseases.

Natural products as a perspective for cancer pain management: A systematic review

BACKGROUND

Cancer is the leading cause of death in the world and one of the main symptoms affecting these individuals is chronic pain, which must be evaluated and treated in its various components. Several drugs are currently used, but beyond the high cost, they have harmful side effects to patients or are transitorily effective. Ergo, there is a need to look for new options for cancer pain relief. Natural products (NPs) present themselves as strong candidates for the development of new drugs for the treatment of chronic pain, such as cancer pain.

PURPOSE

This systematic review aimed to summarize current knowledge about the analgesic profile of NPs in cancer pain.

METHODS

The search included PubMed, Scopus and Web of Science (from inception to June 2018) sought to summarize the articles studying new proposals with NPs for the management of oncological pain. Two independent reviewers extracted data on study characteristics, methods and outcomes.

RESULTS

After an extensive survey, 21 articles were selected, which described the analgesic potential of 15 natural compounds to relieve cancer pain. After analyzing the data, it can be suggested that these NPs, which have targets in central and peripheral mechanisms, are interesting candidates for the treatment of cancer pain for addressing different pharmacological mechanisms (even innovative), but ensuring the safety of these compounds is still a challenge. Likewise, the cannabinoids compounds leave the front as the most promising compounds for direct applicability due to the clinical studies that have already been developed and the background already established about these effects on chronic pain.

CONCLUSION

Regarding these findings, it can be concluded that the variability of possible biological sites of action is strategic for new perspectives in the development of therapeutic proposals different from those available in the current market.