Shikonin Controls the Differentiation of CD4+CD25+ Regulatory T Cells by Inhibiting AKT/mTOR Pathway

Shikonin-loaded PLGA nanoparticles: A promising strategy for psoriasis treatment

Psoriasis is an inflammation-based skin illness marked by aggravated proliferation of epidermal cells. Shikonin is a natural naphthoquinone obtained from Arnebiae radix. It exerts anti-inflammatory and immunosuppressive effects. However, the poor water solubility and low bioavailability of shikonin limit its application. In this study, shikosin-loaded PLGA nanoparticle hydrogel was prepared and used to deliver the drug to the epidermis of psoriasis mice through local administration. The results demonstrated that shikosin-loaded PLGA nanoparticles inhibited HaCaT cell multiplication, increased drug uptake, and induced apoptosis of HaCaT cells. Results from Western blotting assays indicated that shikosin down-regulated the protein expressions of p65 and p-p65. Furthermore, shikonin mitigated psoriasis and decreased the concentrations of inflammation-inducing cytokines, i.e., IL17A, IL-17F, IL-22, IL-1β, and TNF-α. Taken together, these results suggest that shikonin-PLGA nanoparticles loaded in hydrogel system possess promising therapeutic potential for psoriasis.

Pharmacological Effects of Shikonin and Its Potential in Skin Repair: A Review

Currently, skin injuries have a serious impact on people's lives and socio-economic stress. Shikonin, a naphthoquinone compound derived from the root of the traditional Chinese medicine Shikonin, has favorable biological activities such as anti-inflammatory, antibacterial, immunomodulatory, anticancer, and wound-healing-promoting pharmacological activities. It has been reported that Shikonin can be used for repairing skin diseases due to its wide range of pharmacological effects. Moreover, the antimicrobial activity of Shikonin can play a great role in food and can also reduce the number of pathogenic bacteria in food. This paper summarizes the research on the pharmacological effects of Shikonin in recent years, as well as research on the mechanism of action of Shikonin in the treatment of certain skin diseases, to provide certain theoretical references for the clinical application of Shikonin, and also to provides research ideas for the investigation of the mechanism of action of Shikonin in other skin diseases.

Recent advances in shikonin for the treatment of immune-related diseases: Anti-inflammatory and immunomodulatory mechanisms

Shikonin, the primary active compound found in the rhizome of the traditional Chinese medicinal herb known as "ZiCao", exhibits a diverse range of pharmacological effects. This drug has a wide range of uses, including as an anti-inflammatory, antioxidant, and anti-cancer agent. It is also effective in promoting wound healing and treating autoimmune diseases such as multiple sclerosis, diabetes, asthma, systemic lupus erythematosus, inflammatory bowel disease, psoriasis, and rheumatoid arthritis. Although shikonin has a wide range of applications, its mechanisms are still not fully understood. This review article provides a comprehensive overview of the recent advancements in the use of shikonin for the treatment of immune-related diseases. The article also delves into the anti-inflammatory and immunoregulatory mechanisms of shikonin and offers insights into the inflammation and immunopathogenesis of related diseases. Overall, this article serves as a valuable resource for researchers and clinicians working in this field. These findings not only provide significant new information on the effects and mechanisms of shikonin but also establish a foundation for the development of clinical applications in treating autoimmune diseases.

Pyruvate kinase M2 mediates IL-17 signaling in keratinocytes driving psoriatic skin inflammation

Psoriasis is an inflammatory skin disease characterized by keratinocyte proliferation and inflammatory cell infiltration induced by IL-17. However, the molecular mechanism through which IL-17 signaling in keratinocytes triggers skin inflammation remains not fully understood. Pyruvate kinase M2 (PKM2), a glycolytic enzyme, has been shown to have non-metabolic functions. Here, we report that PKM2 mediates IL-17A signaling in keratinocytes triggering skin psoriatic inflammation. We find high expression of PKM2 in the epidermis of psoriatic patients and mice undergoing psoriasis models. Specific depletion of PKM2 in keratinocytes attenuates the development of experimental psoriasis by reducing the production of pro-inflammatory mediators. Mechanistically, PKM2 forms a complex with Act1 and TRAF6 regulating NF-κB transcriptional signaling downstream of the IL-17 receptor. As IL-17 also induces PKM2 expression in keratinocytes, our findings reveal a sustained signaling circuit critical for the psoriasis-driving effects of IL-17A, suggesting that PKM2 is a potential therapeutic target for psoriasis.

Remodeling tumor microenvironment with natural products to overcome drug resistance

With cancer incidence rates continuing to increase and occurrence of resistance in drug treatment, there is a pressing demand to find safer and more effective anticancer strategy for cancer patients. Natural products, have the advantage of low toxicity and multiple action targets, are always used in the treatment of cancer prevention in early stage and cancer supplement in late stage. Tumor microenvironment is necessary for cancer cells to survive and progression, and immune activation is a vital means for the tumor microenvironment to eliminate cancer cells. A number of studies have found that various natural products could target and regulate immune cells such as T cells, macrophages, mast cells as well as inflammatory cytokines in the tumor microenvironment. Natural products tuning the tumor microenvironment via various mechanisms to activate the immune response have immeasurable potential for cancer immunotherapy. In this review, it highlights the research findings related to natural products regulating immune responses against cancer, especially reveals the possibility of utilizing natural products to remodel the tumor microenvironment to overcome drug resistance.

Naphthoquinones and derivatives as potential anticancer agents: An updated review

One of the leading global causes of death is cancer; even though several treatment methods have improved survival rates, the incidence and fatality rates remain high. Naphthoquinones are a type of quinone that is found in nature and has vital biological roles. These chemicals have anticancer (antineoplastic), analgesic, anti-inflammatory, antimalarial, antifungal, antiviral, antitrypanosomal, antischistosomal, leishmanicidal, and anti-ulcerative effects. Direct addition of a substituent group to the 1,4-naphthoquinone ring can alter the naphthoquinone's oxidation/reduction and acid/base characteristics, and the activity can be altered. Because of their pharmacological properties, such as anticancer activity and probable therapeutic application, naphthoquinones have greatly interested the scientific community. Some chemicals having a quinone ring in malignant cells have been found to have antiproliferative effects. Naphthoquinones' deadly impact is connected with the inhibition of electron transporters, the uncoupling of oxidative phosphorylation, the creation of ROS, and the formation of protein adducts, notably with -SH enzyme groups. This review article aims to discuss naphthoquinones and their derivatives, which act against cancer and their future perspectives. This review covers several studies highlighting the potent anticancer properties of naphthoquinones. Further, various proposed mechanisms of anticancer actions of naphthoquinones have been summarized in this review.

Shikonin impairs T lymphocyte proliferation and thymopoiesis while it may increase myeloid-derived suppressor cells to alleviate immune responses

Shikonin (SHK) has multifaceted physiological functions, including antitumor, anti-inflammatory, and antimicrobial effects. Recently, SHK has been shown to affect immune responses; however, its detailed immune modulatory function in vivo remains unclear. In this study, we demonstrated that SHK not only inhibited T cell proliferation in vitro, but also intensively inhibited thymopoiesis and eliminated CD4/CD8 double-positive thymic progenitor cells in vivo. Treatment of mice with SHK resulted in immune profile alterations, which promoted myelosis in the bone marrow and increased inhibitory immune cells in central immune organs. A decrease in T cells and B cells was observed in the spleen. Using a murine allogenic skin transplantation model, we revealed that short-term treatment of recipients with SHK significantly inhibited skin graft rejection, in which the levels of myeloid-derived suppressor cells (MDSC) were markedly increased. Taken together, our study suggests that SHK can efficiently eliminate proliferating T cells and inhibit thymopoiesis while promoting the generation of MDSC, indicating its potential role in alleviating immune responses in allogeneic organ/cell transplantation.

The immunoregulatory effects of natural products on psoriasis via its action on Th17 cells versus regulatory T cells balance

Psoriasis is an incurable, chronic inflammatory disease, which brings a substantial burden on individuals and society. Currently, the treatment of psoriasis has entered the era of biologics, but its highly targeting of inflammatory mediators may enable the immune response to circumvent the blockade, leading to disease recurrence, or other clinical and immunological characteristics. Therefore, the discovery of new therapies that have the ability of multidirectional regulation on immunity and maintain the dynamic balance of immunity in psoriasis, may be the key to the treatment of the disease. Natural products extracted from herbal medicines have synergistic effects to alleviate psoriasis and its comorbidities because of their structural diversity and multiple active mechanisms. To date, the characteristics of natural products regulating T helper 17 (Th17) cells/regulatory T (Treg) cells balance in the treatment of psoriasis have attracted more and more attention from basic and clinical studies. In this review, we systematically introduced the natural products regulating the balance of Th17/Treg and their specific mechanism of action, finding Datura metel L, Grape seed proanthocyanidin extract (GSPE), Thymol, Kaempferol, Aloperine, Abietic acid (AA), Isogarcinol, Luteolin reduced the frequency and function of Th17 cells and simultaneously increased that of Treg cells. It is expected that our work can provide a reference for clinicians in drug use.

Evidence and Potential Mechanism of Action of Lithospermum erythrorhizon and Its Active Components for Psoriasis

Background: Traditional Chinese medicine is effective in the treatment of psoriasis and can significantly reduce skin inflammation and psoriatic lesions with minimal side effects. Shikonin (SHI) and β,β-dimethylacryloyl alkannin (DMA), the main active components of Lithospermum erythrorhizon, have strong anti-inflammatory effects. This systematic review aimed to evaluate the efficacy and safety of Lithospermum erythrorhizon and its main active components and to elucidate the potential mechanisms of their action in psoriasis treatment.

Methods: PubMed, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Chinese Scientific Journals, Wan Fang, and Chinese Biomedicine databases were systematically searched for articles published between 1 January 1970, and 31 February 2021. We included clinical and preclinical studies that examined the effects of Lithospermum erythrorhizon and its active components on psoriasis. All data were analyzed using RevMan 5.3 software. The Cochrane and SYRCLE’s risk-of-bias tools were used to assess the quality of all studies.

Results: Eleven clinical trials including 1024 participants and 23 preclinical studies were assessed. Meta-analysis showed that when treating patients with psoriasis, the Chinese herbal medicine (CHM) formulas with Lithospermum erythrorhizon as the sovereign herb can significantly improve psoriatic dermatitis, which can significantly reduce the psoriasis area and severity index (PASI) score (mean difference [MD] = -2.00, 95% confidence interval [CI] [-3.19, -0.80], p = 0.001; I² = 85%). The incidence rates of diarrhea (risk ratio = 0.21, 95% CI [0.06, 0.81], p = 0.02) were higher in the CHM formulas group than in the control group, whereas other adverse events were not significantly different between the two groups (p > 0.05). We evaluated the PASI score of mice on day 7 and found that SHI and DMA also alleviated psoriatic lesions (MD = -3.36, 95% CI [-4.67, -2.05], p < 0.00001, I² = 94%). Furthermore, the epidermal thickness decreased more after SHI or DMA treatment than in the control group (MD = -34.42, 95%CI [-41.25, -27.59], p < 0.00001, I² = 93%). Based on preclinical studies, we also summarized and mapped the mechanisms of SHI and DMA in the treatment of psoriasis.

Conclusion: Available findings demonstrated that Lithospermum erythrorhizon combined with other conventional treatments is useful in treating psoriasis. Preclinical evidence has shown that the active components of Lithospermum erythrorhizon exhibit a potential anti-inflammatory effect, promote keratinocyte apoptosis, inhibit keratinocyte proliferation and angiogenesis, and block the cell cycle. In summary, our findings suggest that Lithospermum erythrorhizon and its active components can be used to treat psoriasis.

Shikonin combined with methotrexate regulate macrophage polarization to treat psoriasis

This study aimed to investigate whether shikonin combined with methotrexate could inhibit psoriasis progression by regulating the polarization of macrophages through in vivo and in vitro experiments. Imiquimod was administrated to the exposed skin of BALB/c mice, and shikonin and methotrexate suspension were also given by gavage. The erythema, scales and thickness were scored for mice lesions in each group, and the total score was obtained by adding the above three scores, and calculated as psoriasis area and severity index (PASI) score. The skin lesion tissue from mice was isolated and used for hematoxylin-eosin staining and immunohistochemistry assay. Drug-containing serum was prepared and administrated into mouse macrophage RAW264.7 cells, followed by simulation of LPS. The levels of tumor necrosis factor-α (TNF-α), Interleukin (IL)-1β, and IL-6 in cell supernatant were assessed using ELISA Kits and real-time PCR. In imiquimod-induced psoriasis mice, shikonin combined with methotrexate exerted protective effects by reducing erythema and PASI scores, decreasing backer score and epidermal thickness, and particularly regulating macrophage polarization. In LPS-stimulated RAW264.7 cells, shikonin combined with methotrexate regulated M1/M2 polarization and altered the levels of M1 markers. Shikonin combined with methotrexate inhibit psoriasis progression by regulating the polarization of macrophages, which may be useful in the treatment of psoriasis.

Therapeutic Effects of Shikonin on Skin Diseases: A Review

Shikonin is one of the primary active components extracted from the dried root ofZicao (Lithospermum erythrorhizon, Onosma paniculata, or Arnebia euchroma), a traditional Chinese herbal medicine. Shikonin is known to not only exert anti-proliferative, anti-inflammatory, and anti-angiogenic activities, but also play a crucial role in triggering the production of reactive oxygen species, suppressing the release of exosomes, and inducing apoptosis. Increasing evidence suggests that shikonin has a protective effect against skin diseases, including psoriasis, melanoma, and hypertrophic scars. In order to evaluate the application potential of shikonin in the treatment of skin diseases, this review is the first of its kind to provide comprehensive and up-to-date information regarding the uses of shikonin and its derivatives on skin diseases and its underlying mechanisms. In this review, we have focused on the signaling pathways and cellular targets involved in the anti-dermatosis effects of shikonin to bridge the gaps in the literature, thereby providing scientific support for the research and development of new drugs from a traditional medicinal plant.

Design, synthesis and anticancer activity of naphthoquinone derivatives

Basis on molecular docking and pharmacophore analysis of naphthoquinone moiety, a total of 23 compounds were designed and synthesised. With the help of reverse targets searching, anti-cancer activity was preliminarily evaluated, most of them are effective against some tumour cells, especially compound 12: 1-(5,8-dihydroxy-1,4-dioxo-1,4-dihydronaphthalen-2-yl)-4-methylpent-3-en-1-yl-4-oxo-4-((4-phenoxyphenyl)amino) butanoate whose IC₅₀ against SGC-7901 was 4.1 ± 2.6 μM. Meanwhile the anticancer mechanism of compound 12 had been investigated by AnnexinV/PI staining, immunofluorescence, Western blot assay and molecular docking. The results indicated that this compound might induce cell apoptosis and cell autophagy through regulating the PI3K signal pathway.

Circulating CD14+HLA-DR-/low Myeloid-Derived Suppressor Cells as Potential Biomarkers for the Identification of Psoriasis TCM Blood-Heat Syndrome and Blood-Stasis Syndrome

Psoriasis is a chronic autoimmune disease. Identification of the biomarkers responsible for Traditional Chinese Medicine (TCM) syndromes of psoriasis can help researchers recognize the different aspects of psoriasis and find novel therapeutic targets for the treatment of psoriasis. The current study investigated the levels of circulating Mo-MDSCs and Mo-MDSC-associated immune factors in the peripheral blood of psoriasis patients with different TCM syndromes. We found that the frequency of Mo-MDSCs (CD14⁺HLA-DR^−/low cells) among CD14⁺ cells from plaque psoriasis patients with blood-stasis (BS) syndrome was significantly increased when compared with healthy controls (p < 0.001) and blood-heat (BH) syndrome group (p < 0.001), respectively. However, serum IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, IFN-γ, iNOS, Arg-1, and NO concentration showed no statistically significant difference between healthy controls and psoriasis patients as well as no significant difference between the BH and BS syndrome groups. Compared with healthy controls, the mRNA expression of Arg-1, TNF-α, ROR-γ, and PD-L1 was increased, while the mRNA expression of PD-1 and IL-10 was decreased in PBMCs from psoriasis patients. Moreover, the mRNA expression of TNF-α and FOXP3 in PBMCs showed a pronounced statistical difference between the psoriatic BH syndrome group and the BS syndrome group. Therefore, we provide evidence that the percentage of CD14⁺HLA-DR^−/low MDSC/ CD14⁺ cells and TNF-α and Foxp3 mRNA expression levels in PBMCs are potential biomarkers for distinguishing TCM BH syndrome and BS syndrome.