The Essential Oil Derived from Perilla frutescens (L.) Britt. Attenuates Imiquimod–Induced Psoriasis-like Skin Lesions in BALB/c Mice

Green and efficient extraction of flavonoids from Perilla frutescens (L.) Britt. leaves based on natural deep eutectic solvents: Process optimization, component identification, and biological activity

In this study, an ultrasonic-assisted natural deep eutectic solvent (NaDES) was used to extract flavonoids from Perilla frutescens (L.) Britt. leaves. Of 10 tested NaDESs, that comprising D-(+)-glucose and glycerol exhibited the best total flavonoid extraction rate. Response surface methodology (RSM) was used for extraction modeling and optimization, and the total flavonoid content reached 87.48 ± 1.61 mg RE/g DW, which was a significant increase of 5.36% compared with that of 80% ethanol extraction. Morphological changes in P. frutescens leaves before and after extraction were analyzed by scanning electron microscopy (SEM), and the mechanism of NaDES formation was studied by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, 10 flavonoids were identified by UPLC-Q-TOF-MS. In addition, the NaDES extract had better biological activity according to five kinds of antioxidant capacity measurements, cyclooxygenase-2 (COX-2) and hyaluronidase (Hyal) inhibition experiments. Moreover, the stability test revealed that the total flavonoid loss rate of the NaDES extract after four weeks was 37.75% lower than that of the ethanol extract. These results indicate that the NaDES can effectively extract flavonoids from P. frutescens leaves and provide a reference for further applications in the food, medicine, health product and cosmetic industries.

Unlocking milk thistle's anti-psoriatic potential in mice: Targeting PI3K/AKT/mTOR and KEAP1/NRF2/NF-κB pathways to modulate inflammation and oxidative stress

Silybum marianum, known as milk thistle (MT), is traditionally used to manage liver diseases. This study aimed to investigate the role of MT extract topical application as a potential treatment for imiquimod (IMQ)-induced psoriatic lesions in mice with particular emphasis on phosphoinositol-3 Kinase (PI3K)/ protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) and Kelch-like ECH-associated protein 1 (KEAP1)/ nuclear factor erythroid-2-related factor (NRF2)/ nuclear factor-kappa B (NF-κB) molecular cascades involvement. To address this aim, forty male Swiss albino mice were subdivided into four groups (n = 10 mice/group): control, IMQ model, standard group where mice were treated topically with IMQ, then the anti-psoriatic mometasone cream, and MT extract-treated group where mice were treated topically with IMQ followed by MT extract. In most measured parameters, MT extract, rich in silymarin, exhibited potent anti-psoriatic activity comparable to the standard cortisone treatment. MT extract mitigated dorsal skin erythema, scaling, and epidermal thickening, reflected by lowering the Psoriasis Area Severity Index (PASI) score. Moreover, it alleviated IMQ-induced splenomegaly. Mechanistically, the PI3K/AKT/mTOR pathway was the main functional pathway behind such improvements, where it was significantly inhibited by MT extract application. This led to NRF2 activation via KEAP1 downregulation with subsequent anti-inflammatory effect proven by reducing NF-κB, interleukin (IL)-23, and IL-17A and antioxidant ability proven by boosting the antioxidant glutathione and heme oxygenase-1. Such improvements were confirmed by alleviating the histopathological alteration. Thus, MT extract could be a promising therapeutic agent for psoriasis treatment by inhibiting PI3K/AKT/mTOR cascade, along with NRF2 signaling activation.

Cang-ai volatile oil ameliorates imiquimod-induced psoriatic skin lesions by suppressing the ILC3s

ETHNOPHARMACOLOGICAL RELEVANCE

Cang-ai volatile oil (CAVO) is an aromatic Chinese medicine with potent antibacterial and immune regulatory properties. While CAVO has been used to treat upper respiratory tract infections, depression, otomycosis, and bacterial infections in the skin, its effect on psoriasis is unknown.

AIM OF THE STUDY

This study explores the effect and mechanism of CAVO in psoriasis intervention.

MATERIAL AND METHODS

The effect of CAVO on the expression of IL-6 and IL-1β was assessed in TNF-α-induced HaCaT cells using enzyme-linked immunosorbent assay (ELISA). Mice were given imiquimod (IMQ) and administered orally with different CAVO doses (0.03 and 0.06 g/kg) for 5 days. The levels of inflammatory cytokines related to group-3 innate lymphoid cells (ILC3s) in the skin were assessed using hematoxylin and eosin (H&E) staining, ELISA, and western blotting (WB). The frequency of ILC3s in mice splenocytes and skin cells was evaluated using flow cytometry.

RESULTS

The results demonstrated that CAVO decreased the expression of IL-6 and IL-1β in TNF-α- induced HaCaT cells. CAVO significantly reduced the severity of psoriatic symptoms in IMQ-induced mice. The expression of inflammatory cytokines in the skin, such as IL-1β, IL-6, IL-8, IL-22, IL-23, and IL-17 A were decreased, whereas IL-10 levels were increased. The mRNA expressions of TNF-α, IL-23 A, IL-23 R, IL-22, IL-17 A, and RORγt were down-regulated in skin tissues. CAVO also decreased the levels of NF-κB, STAT3, and JAK2 proteins.

CONCLUSIONS

CAVO potentially inhibits ILC3s activation to relieve IMQ-induced psoriasis in mice. These effects might be attributed to inhibiting the activation of NF-κB, STAT3, and JAK2 signaling pathways.

Multiplicative Effects of Essential Oils and Other Active Components on Skin Tissue and Skin Cancers

Naturally derived essential oils and their active components are known to possess various properties, ranging from anti-oxidant, anti-inflammatory, anti-bacterial, anti-fungal, and anti-cancer activities. Numerous types of essential oils and active components have been discovered, and their permissive roles have been addressed in various fields. In this comprehensive review, we focused on the roles of essential oils and active components in skin diseases and cancers as discovered over the past three decades. In particular, we opted to highlight the effectiveness of essential oils and their active components in developing strategies against various skin diseases and skin cancers and to describe the effects of the identified essential-oil-derived major components from physiological and pathological perspectives. Overall, this review provides a basis for the development of novel therapies for skin diseases and cancers, especially melanoma.

GC-MS analysis and the effect of topical application of essential oils of Pinus canariensis C.Sm., Cupressus lusitanica Mill. and Cupressus arizonica Greene aerial parts in Imiquimod-Induced Psoriasis in Mice

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, Coniferous plants, in particular Pinus and Cupressus species, have been used in the treatment of burns, skin infections, and immune-mediated inflammatory diseases such as psoriasis.

AIM OF THE STUDY

A comparative study between essential oils (EOs) extracted from aerial parts of three coniferous plants: Pinus canariensis C.Sm. (PC), Cupressus lusitanica Mill. (CL) and Cupressus arizonica Greene (CA), cultivated in Egypt, was designed to investigate their composition and their anti-psoriasis mechanism.

MATERIALS AND METHODS

The phytochemical profiles were confirmed using Gas Chromatography-Mass Spectrometry (GC-MS) method. In-vivo Imiquimod (IMQ)-induced psoriasis model was performed and EOs were applied topically and compared to mometasone cream as a standard subsequently histopathological analysis and inflammatory biomarkers were measured.

RESULTS

In GC-MS analysis, Monoterpene hydrocarbons, sesquiterpene hydrocarbons and oxygenated monoterpenes were the major detected classes in the three plants, except in Pinus canariensis essential oil, oxygenated monoterpenes were absent. A significant attenuation of imiquimod-induced psoriasis symptoms after topical application of P. canariensis C.Sm., and C. lusitanica Mill. essential oils were observed by reducing the psoriasis area severity index (PASI) score, alleviating histopathological alteration, restoring the spleen index, and decreasing serum levels of interleukins 23 and 17A. Indeed, the results of Pinus canariensis essential oil is comparable to mometasone and showed no significant difference from standard treatment. On the other hand, the topical application of C. arizonica essential oil failed to alleviate imiquimod-induced psoriasis symptoms as observed in the PSAI score, the histopathological investigation, and the spleen index.

CONCLUSION

The essential oils of P. canariensis C.Sm., and C. lusitanica Mill aerial parts could be promising candidates for psoriasis treatment and for further studies on inflammation-related skin diseases.

Mesosphaerum suaveolens Essential Oil Attenuates Inflammatory Response and Oxidative Stress in LPS-Stimulated RAW 264.7 Macrophages by Regulating NF-κB Signaling Pathway

Mesosphaerum suaveolens (L.) Kuntze (Syn. Hyptis suaveolens (L.) Poit.) is a wild essential-oil-bearing plant having multiple uses in traditional medicine, perfumery, food, agriculture, and pharmaceutical industries. The present paper is the first report on the in vitro anti-inflammatory effects of the leaf essential oil of M. suaveolens (MSLEO) and unravels its molecular mechanism in LPS-stimulated RAW 264.7 macrophage cells. GC-MS analysis of the essential oil (EO) isolated from the leaves by hydro-distillation led to the identification of 48 constituents, accounting for 90.55% of the total oil, and β-caryophyllene (16.17%), phyllocladene (11.85%), abietatriene (11.46%), and spathulenol (7.89%) were found to be the major components. MSLEO treatment had no effect on the viability of RAW 264.7 cells up to a concentration of 100 μg/mL, and the EO was responsible for a reduction in proinflammatory cytokines like IL-6, IL-1β, and TNF-α, a decrease in intracellular ROS production, and the restoration of oxidative damage by elevating the levels of endogenous antioxidative enzymes like CAT, SOD, GPx, and GSH. RT-qPCR analysis indicated that MSLEO reduced the mRNA expression levels of iNOS and COX-2 as compared to the LPS-induced group. In addition, a confocal microscopy analysis showed that MSLEO inhibited the translocation of NF-κB from the cytosol to the nucleus. The results of this experiment demonstrate that MSLEO possesses significant anti-inflammatory potential by preventing the activation of NF-κB, which, in turn, inhibits the downstream expression of other inflammatory mediators associated with the activation of the NF-κB pathway in LPS-induced RAW 264.7 cells. Thus, the leaf essential oil of M. suaveolens may prove to be a promising therapeutic agent for the treatment of inflammation, and targeting the NF-κB signaling pathway may be considered as an attractive approach for anti-inflammatory therapies.

In Vitro and In Vivo Anti-Psoriasis Activity of Ficus carica Fruit Extracts via JAK-STAT Modulation

Psoriasis, a chronic and autoimmune inflammatory disorder of the skin, has been often underdiagnosed and underestimated despite its prevalence and considerable negative effects on the quality of life. In this study, the anti-inflammatory activity of Ficus carica fruit extract (FFE) was investigated against LPS-stimulated RAW 264.7 cells. The in vitro results showed that FFE reduced the production of nitric oxide (NO) and iNOS expression. Moreover, FFE reduced the level of β-hexosaminidase released with histamine in allergic reactions. However, the MAPK and NFκB signaling molecules associated with the inflammatory response were not significantly regulated by FFE. In contrast, the phosphorylation of JAK1 and STAT3 in the JAK-STAT signaling pathway was dramatically reduced by FFE treatment. Psoriasis-like skin lesions were induced in BALB/c mice using imiquimod (IMQ) to test the feasibility of FFE as a treatment for psoriasis. The efficacy of FFE was evaluated based on phenotypic and histological features. FFE was effective in relieving the symptoms of psoriasis-like skin lesions, such as erythema, dryness, scales, and thick epidermis. Notably, STAT3 modulation was also contributable to the in vivo ameliorative activity of FFE. Taken together, FFE with anti-psoriasis activity in vitro and in vivo through the JAK-STAT modulation could be developed as a therapeutic agent against psoriasis.

Linalool: Monoterpene alcohol effectiveness in chronic synovitis through lowering Interleukin-17, spleen and thymus indices

Interleukin-17 has a positive role in the initial induction and late chronic phases of many inflammatory disorders like arthritis. This cytokine has a strong option for therapeutic targeting due to the fact that it was found in the inflamed joints of individual with rheumatoid arthritis (RA) and persuasive evidence from experimental arthritis models indicating its pro-inflammatory actions. IL-17 suppression lessened the asperity of arthritis. The present study aimed to assess the anti-arthritic potential of linalool in a model of chronic joint inflammation (CFA-mediated rheumatoid arthritis) in rats. Linalool markedly lowered spleen and thymus indices as opposed to arthritic control. The over-formation of IL-17, COX-2, TNF-α IL-1β, iNOS and IL-6 were markedly impaired in all linalool treated rats, but IL-10 was raised as compared to arthritic animals in Real time-PCR. There was reduction in associated parameters like paw volume, arthritic index, mobility score, and flexion pain score and a marked increase in stance score in CFA model as compared to the arthritic control group. Furthermore, there was improvement in body weight, hematological, tissue, and radiological parameters in the CFA-model. Molecular docking study exhibited strong binding interaction of linalool with IL-17, PGE-2, iNOS and COX-2, thus providing a good correlation among experimental and theoretical results. The current findings show that linalool reduces adjuvant arthritis by suppressing pro-inflammatory mediators, arthritic development, and spleen and thymus indices. Thus, linalool may be employed therapeutically to alleviate arthritis in humans.

Tea Tree Oil: Properties and the Therapeutic Approach to Acne-A Review

Acne vulgaris is an inflammatory dermatological pathology that affects mostly young people. However, it can also appear in adulthood, mainly in women. It has a high psychosocial impact, not only at the time of active lesions but also due to the consequences of lesions such as scarring and hyperpigmentation. Several factors are involved in the physiopathology of acne and the constant search for active ingredients is a reality, namely phytotherapeutic ingredients. Tea tree oil is an essential oil extracted from Melaleuca alternifolia (Maiden & Betch) Cheel with known antibacterial, anti-inflammatory, and antioxidant properties, making it a candidate for the treatment of acne. This review aims to describe the various properties of tea tree oil that make it a possible ingredient to use in the treatment of acne and to present several human studies that have evaluated the efficacy and safety of using tea tree oil in the treatment of acne. It can be concluded that tea tree oil has good antibacterial, anti-inflammatory, and antioxidant properties that result in a decrease in the number of inflammatory lesions, mainly papules, and pustules. However, given the diversity of study designs, it is not possible to draw concrete conclusions on the efficacy and safety of this oil in the treatment of acne.

The Effect of Light and Dark Treatment on the Production of Rosmarinic Acid and Biological Activities in Perilla frutescens Microgreens

This study aimed to investigate the effect of light [a long-day photoperiod (16 h light/8 h dark cycle)] and dark treatment on the production of rosmarinic acid in P. frutescens microgreens and to determine its antioxidant and antibacterial activities. Microgreens of P. frutescens were grown under light and dark conditions and harvested after 10, 15, 20, and 25 days of each treatment. Although dry weight values of microgreens gradually increased from 10 to 25 days of both treatments, the microgreens grown under light treatment possessed slightly higher levels of dry weight than those grown in the dark. Rosmarinic acid and total phenolic content (TPC) were also analyzed using high-performance liquid chromatography (HPLC) and Folin-Ciocalteu assay. The accumulation patterns of rosmarinic acid and TPC gradually increased and decreased, respectively, in P. frutescens microgreens grown in continuous darkness. The highest accumulation was observed in microgreens grown for 20 days. However, rosmarinic acid and TPC values were not significantly different in microgreens grown under light conditions. According to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition assay, the extracts of P. frutescens microgreens were confirmed to be strong antioxidants, and their ability to scavenge DPPH radicals was positively correlated with the total phenolic content in the microgreens after 10, 15, 20, and 25 days of both treatments. Considering the relatively higher values of dry weight, rosmarinic acid, TPC, and DPPH assay, P. frutescens microgreens after 20 days of darkness and 20 days of light treatment, respectively, were selected for screening antibacterial activity using nine pathogens. Both microgreen extracts showed strong antibacterial activity against pathogens. In particular, the extracts of microgreens grown for 20 days under light treatment showed higher antimicrobial effects. Therefore, the light treatments for 20 days, as well as the darkness treatment for 20 days, were the best conditions for P. frutescens microgreen production because of their high levels of dry weight, phenolics, and biological activities.

Molecular mechanism of the anti-inflammatory effects of plant essential oils: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Plant essential oils (PEOs) extracted from aromatic compounds of the plant contain complex mixtures of volatile and lipophilic bioactive compounds. In ancient Egypt, Arabia, Greece, and China, PEOs were traditional used in aromatherapy for various health disorders, including pain and inflammation.

AIM OF THE STUDY

In this review, we provide an overview of the anti-inflammatory effects of PEOs and the underlying mechanisms associated with anti-inflammatory effects using in vitro and in vivo models. Further, clinical trials associated with PEOs were explored.

MATERIALS AND METHODS

The literature search was performed using various web-based tools and databases like Google Scholar, Web of Science, PubMed, CNKI and SCOPUS. The keywords used for conducting the literature review were general terms like "essential oils" followed by (AND) the subject of interest like "in vitro and/or in vivo anti-inflammatory models," "inflammatory response," "inflammatory indicators," "pro-inflammatory cytokines," "signaling pathway," "anti-inflammatory mechanism," "toxicology and side effects" and "clinical trials." The articles selected were published between 2017 and 2022. The articles prior to 2017 were only considered if they were associated with molecular mechanisms or signaling pathways involved in the inflammatory responses.

RESULTS

In vitro and in vivo inflammation models have been used to study the anti-inflammatory effects of 48 PEOs. Studies have reported that PEOs targets and inhibit multiple dysregulated signaling pathways associated with inflammation, including Toll-like receptors, nuclear transcription factor-κ B, mitogen-activated protein kinases, Nod-like receptor family pyrin domain containing 3, and auxiliary pathways like the nuclear factor erythroid 2-related factor 2/antioxidant response element and Janus kinase/signal transducers and activators of transcription) signaling pathways.

CONCLUSION

PEOs extracted from different plant materials had varied qualitative and quantitative compositions of biologically active compounds. Different anti-inflammatory potentials and different molecular signal transduction have been attributed to PEOs-derived bioactive compounds with different chemical structures. The data on therapeutic efficacy and the long-term side effects of PEOs as an anti-inflammatory drug are still unknown due to the lack of clinical trials on PEOs. There is still insufficient evidence to draw conclusions on anti-inflammatory properties of PEOs without promising outcomes from clinical trials.