Protective effect of myricetin, apigenin, and hesperidin pretreatments on cyclophosphamide-induced immunosuppression

Phytochemistry, pharmacological properties and pharmacokinetics of Citri Reticulatae Pericarpium: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Citri Reticulatae Pericarpium (CRP), known as Chen Pi in China, is the most commonly used medicine for regulating qi. As a traditional medicine, CRP has been extensively used in the clinical treatment of nausea, vomiting, cough and phlegm for thousands of years. It is mainly distributed in Guangdong, Sichuan, Fujian and Zhejiang in China. Due to its high frequency of use, many scholars have conducted a lot of research on it and the related chemical constituents it contains. In this review, the research progress on phytochemistry, pharmacology, pharmacokinetics and toxicology of CRP are summarized.

AIM OF THE REVIEW

The review aims to sort out the methods of extraction and purification, pharmacological activities and mechanisms of action, pharmacokinetics and toxicology of the chemical constituents in CRP, in order to elaborate the future research directions and challenges for the study of CRP and related chemical constituents.

MATERIALS AND METHODS

Valid and comprehensive relevant information was collected from China National Knowledge Infrastructure, Web of Science, PubMed and so on.

RESULTS

CRP contains a variety of compounds, of which terpenes, flavonoids and alkaloids are the main components, and they are also the primary bioactive components that play a pharmacological role. Flavonoids and terpenes are extracted and purified by aqueous and alcoholic extraction methods, assisted by ultrasonic and microwave extraction, in order to achieve higher yields with less resources. Pharmacological studies have shown that CRP possesses a variety of highly active chemical components and a wide range of pharmacological activities, including anti-tumor, anti-inflammatory, immunomodulatory, hepatoprotective, therapeutic for cardiovascular-related disorders, antioxidant, antibacterial, and neuroprotective effects.

CONCLUSIONS

There is a diversity in the chemical compositions of CRP, which have multiple biological activities and promising applications. However, the pharmacological activities of CRP are mainly dependent on the action of its chemical components, but the relationship between the structure of chemical components and the biological effects has not been thoroughly investigated, and therefore, the structure-activity relationship is an issue that needs to be elucidated urgently. In addition, the pharmacokinetic studies of the relevant components can be further deepened and the correlation studies between pharmacological effects and syndromes of TCM can be expanded to ensure the effectiveness and rationality of CRP for human use.

Immunomodulatory Mechanisms of Tea Leaf Polysaccharide in Mice with Cyclophosphamide-Induced Immunosuppression Based on Gut Flora and Metabolomics

Tea polysaccharides (TPSs) are receiving increasing attention because of their diverse pharmacological and biological activities. Here, we explored the immunoregulatory mechanisms of TPSs from fresh tea leaves in a mouse model of cyclophosphamide (CTX)-induced immunosuppression in terms of gut microbiota and metabolites. We observed that TPSs significantly increased the body weight and alleviated CTX-induced thymus atrophy in the immunosuppressed mice; they also increased the plasma levels of immunoglobulins A and M, interleukin (IL) 1β, IL-6, inducible nitric oxide synthase, and tumor necrosis factor α. Furthermore, we conducted 16S rDNA sequencing of cecal contents, resulting in the acquisition of 5008 high-quality bacterial 16S rDNA gene reads from the sequencing of mouse fecal samples. By analyzing the data, we found that TPSs regulated the gut microbiota structure and diversity and alleviated the CTX-induced dysregulation of gut microbiota. The colonic contents of mice were subjected to analysis using the UPLC-Q-TOF/MS/MS technique for the purpose of untargeted metabolomics. In the course of our metabolite identification analysis, we identified a total of 2685 metabolites in positive ion mode and 1655 metabolites in negative ion mode. The analysis of these metabolites indicated that TPSs improved CTX-induced metabolic disorders by regulating the levels of metabolites related to tryptophan, arginine, and proline metabolism. In conclusion, TPSs can alleviate CTX-induced immunosuppression by regulating the structural composition of gut microbiota, indicating the applicability of TPSs as novel innate immune modulators in health foods or medicines.

Protective Role of Myricetin and Fisetin Against Nephrotoxicity Caused by Lead Acetate Exposure through Up-regulation of Nrf2/HO-1 Signalling Pathway

The effect of various flavonoids against oxidative stress and inflammation caused by lead exposure has been investigated. However, the protective effects of myricetin (MYC) and fisetin (FST), which are known to have potent antioxidant properties, against nephrotoxicity caused by exposure to lead acetate (LA), the water-soluble form of lead, have not been investigated. Our study investigated the protective role of these flavonoids against LA intoxication-induced nephrotoxicity. In our study, 42 male rats were used. The rats were randomly selected and divided into 6 groups. These groups were: control, LA (100 g/kg), LA + MYC (100 mg/kg), LA + MYC (200 mg/kg), LA + FST (100 mg/kg) and LA + FST (200 mg/kg). All chemicals were administered daily by gavage for 28 days. According to the experimental protocol, the animals were sacrificed and their kidney tissues were isolated. Serum biochemical parameters, histological examinations, levels of several trace elements, oxidative stress and inflammatory parameters at both biochemical and molecular levels in kidney tissues were examined. After LA administration, tissue lead levels increased and zinc levels decreased. This situation was reversed by MYC and FST treatment. Oxidative stress and inflammatory response were increased in the kidney tissue of LA-treated rats and renal function was impaired. It was observed that both doses of MYC and high dose of FST could prevent nephrotoxicity. Oral administration of both doses of MYC and high dose FST ameliorated the changes in biochemical, oxidative and inflammatory parameters. Restoration of normal renal tissue architecture was also demonstrated by histological studies. MYC and FST were found to have promising biological activity against LA-induced nephrotoxicity, acting by attenuating inflammation and oxidative stress and improving antioxidant status.

In Vitro Antitumor and Antioxidant Capacity as well as Ameliorative Effects of Fermented Kefir on Cyclophosphamide-Induced Toxicity on Cardiac and Hepatic Tissues in Rats

Fermented prebiotic and probiotic products with kefir are very important to slow down and prevent the growth of tumors and to treat cancer by stimulating the immune response against tumor cells. Cyclophosphamide (CPx) is widely preferred in cancer treatment but its effectiveness in high doses is restricted because of its side effects. The aim of this study was to investigate the protective effects of kefir against CPx-induced heart and liver toxicity. In an experiment, 42 Wistar albino rats were divided into six treatment groups: the control (Group 1), the group receiving 150 mg/kg CPx (Group 2), the groups receiving 5 and 10 mg/kg kefir (Groups 3 and 4) and the groups receiving 5 and 10 mg/kg kefir + CPx (Group 5 and 6). Fermented kefirs obtained on different days by traditional methods were mixed and given by gavage for 12 days, while a single dose of CPx was administered intraperitoneally (i.p.) on the 12th day of the experiment. It was observed that alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatinine kinase-MB (CK-MB), ischemia modified albumin (IMA) and Troponin I values, which indicate oxidative stress, increased in the CPx-administered group, and this level approached that of the control in the CPx + kefir groups. Likewise, as a result of the kefir, the rats' CPx-induced histopathological symptoms were reduced, and their heart and liver tissue were significantly improved. In conclusion, it was observed that kefir had a cytoprotective effect against CPx-induced oxidative stress, hepatotoxicity and cardiotoxicity, bringing their biochemical parameters closer to those of the control by suppressing oxidative stress and reducing tissue damage.

Protective effects of carvacrol on lipid profiles, oxidative stress, hypertension, and cardiac dysfunction - A comprehensive review

Cardiovascular diseases (CVDs) are a class of illnesses that affect the heart or blood vessels, leading to the most common causes of death worldwide. In 2017, CVD caused approximately 17.8 million deaths that were increased approximately to 20.5 million deaths in 2021, globally. Also, nearly 80% of worldwide CVD deaths occur in some countries. Some herbs and their constituents due to their several pharmacological activities have been used for medicinal purposes. Carvacrol is a phenolic mono-terpenoid found in the oils of aromatic herbs with several biological properties. The possible therapeutic effects of carvacrol on lipid profiles, oxidative stress, hypertension, and cardiac dysfunction were summarized in the current study. The data from this review article were obtained by searching the terms including; "Carvacrol", "Hypertension", Hypotensive, "Cardiac dysfunction", "Ischemia", "Lipid profile", and Oxidative stress in several web databases such as Web of Sciences, PubMed Central, and Google Scholar, until November 2023. The results of the reviewed studies revealed that carvacrol inhibits acetylcholinesterase (AchE) activity and alters lipid profiles, reducing heart rate as well as systolic and diastolic blood pressure (BP). Carvacrol also decreased the proinflammatory cytokine (IL-1β), while increasing secretion of anti-inflammatory cytokine (IL-10). Moreover, carvacrol improved oxidative stress and mitigated the number of apoptotic cells. The pharmacological effects of carvacrol on CVD might be through its antioxidative, anti-inflammatory, and antiapoptotic effects. The mentioned therapeutic effects of carvacrol on lipid profile, hypertension, and cardiac dysfunction indicate the possible remedy effect of carvacrol for the treatment of CVD.

Immunopotentiating effects of herb-partitioned moxibustion on the spleens of cyclophosphamide-induced immunosuppressed rats

BACKGROUND

To investigate the effec of the herb-partitioned moxibustion on T-lymphocyte activity in immunosuppressed rats through differential modulation of the immune checkpoint molecules CD28 and CTLA-4.

METHODS

Forty-eight Sprague‒Dawley rats were randomly divided into the normal group (NG), the cyclophosphamide model group (CTX), the herb-partitioned moxibustion group (HPM), the CD28 inhibitor + herb-partitioned moxibustion group (aCD28 + HPM), the CTLA-4 inhibitor + herb-partitioned moxibustion group (aCTLA-4 + HPM), and the levamisole group (LEV) (8 rats per group). The immunosuppression model was prepared using cyclophosphamide. HPM treatments was performed via herb-partitioned moxibustion at 4 acupoints, Zhongwan (CV12), Shenque (CV8), Guanyuan (CV4), and Zusanli (ST36). Subsequently, the moxa floss was made into a conical moxa cone, which was then placed on the herbal cake and ignited. Five consecutive moxibustion strokes were performed daily for 10 consecutive days. In addition to the same moxibustion, each rat in the aCD28 + HPM group was injected intraperitoneally with 0.5 mg/kg of CD28 inhibitor per rat on the first day of treatment, and 100 μL of CTLA-4 inhibitor was injected into the aCTLA-4 + HPM group on Days 1, 4, and 7. For the positive control, levamisole (LEV) was administered by gavage at a dose of 2 mg/kg once daily for 10 days.

RESULTS

Compared with those in CTX model rats, the WBC counts in the HPM and other groups were significantly higher. The immobility time of EPM in the HPM group was significantly lower than that of the CTX group. The HE stainin results also showed that after treatment, the the marginal zone area of the spleen tissue in the HPM increased, the number of lymphatic sheath lymphocytes around the small central artery of the spleen increased, and the amount of red pulp containing a small amount of pigmentation was partially reduced. Compared with those in the CTX group, the serum levels of CD28, CTLA-4, B7-1, and B7-2 were significantly lower, and the levels of α-MSH, TrkB, and BDNF were significantly greater in the HPM group. The results of the flow cytometry assay showed a significant increase in the number of CD8 + T lymphocytes after treatment with HPM or other agents compared to that in the CTX group. The immunofluorescence results showed that the levels of CD28 and CTLA-4 lower in spleen tissues than in control tissues, and the binding ability of CD28 to B7-1 and B7-2 was weakened after treatment with HPM and other treatments compared with CTX rats, PCR for CD28, CTLA-4 and B7-1 showed similar results.

CONCLUSION

In the immunosuppressive rat model induced by cyclophosphamide, HPM upregulated the expression of α-MSH, TrkB, and BDNF, and downregulated the expression of CD28 and CTLA-4, thereby enhancing the activity of CD8+ T lymphocytes, restoring spleen function, improving the immunosuppressive state, restoring immune function, and effectively alleviating depressive symptoms.

Efficacy of coenzyme Q10 and curcumin on antioxidant enzyme activity and hippocampal alteration following exposure to cyclophosphamide in male rat

Coenzyme Q10 (KQ10) and curcumin (KUR) supplements are extensively used for their potential antioxidant, anticancer, and antiapoptotic properties. The present study investigated the neuroprotective potential of KQ10 and KUR against the side effect of cyclophosphamide (SF) (150 mg/kg) on the hippocampus of male Wistar albino rats. Forty-nine 10-12 weeks old rats were randomly divided into seven groups: control, olive oil (OL), SF, KQ10, KUR, SF+KQ10, and SF+KUR. Our biochemical finding showed a significant decrease in superoxide dismutase (SOD) level in the SF group compared to the control group (p < 0.05). There was also a significant reduction in the total number of the hippocampal pyramidal neurons in the CA1, CA2, and CA1-3 regions in the SF group compared to the control group (p < 0.05). In the SF+KQ10 group, we found a significant increase in serum SOD level and the total number of the hippocampal pyramidal neurons in the CA1, CA2, and CA1-3 regions compared to the SF group (p < 0.05). Immunohistochemical and histopathological examination exhibited noteworthy findings in the hippocampus tissues. Our findings showed that KQ10 administration significantly mitigated the hippocampal alteration caused by SF through enhancing antioxidant enzyme activity and reducing apoptosis. However, we found no protective activity of KUR on the hippocampus tissue, which may be due to its weak antioxidative activity.

Resources for Human Health from the Plant Kingdom: The Potential Role of the Flavonoid Apigenin in Cancer Counteraction

Apigenin is one of the most widespread flavonoids in the plant kingdom. For centuries, apigenin-containing plant preparations have been used in traditional medicines to treat diseases that have an inflammatory and/or degenerative component. In the 1980s, apigenin was proposed to interfere with the process of carcinogenesis. Since then, more and more evidence has demonstrated its anticancer efficacy, both in vitro and in vivo. Apigenin has been shown to target signaling pathways involved in the development and progression of cancer, such as PI3K/Akt/mTOR, MAPK/ERK, JAK/STAT, NF-κB, and Wnt/β-catenin pathways, and to modulate different hallmarks of cancer, such as cell proliferation, metastasis, apoptosis, invasion, and cell migration. Furthermore, apigenin modulates PD1/PD-L1 expression in cancer/T killer cells and regulates the percentage of T killer and T regulatory cells. Recently, apigenin has been studied for its synergic and additive effects when combined with chemotherapy, minimizing the side effects. Unfortunately, its low bioavailability and high permeability limit its therapeutic applications. Based on micro- and nanoformulations that enhance the physical stability and drug-loading capacity of apigenin and increase the bioavailability of apigenin, novel drug-delivery systems have been investigated to improve its solubility.

An outlook on the target-based molecular mechanism of phytoconstituents as immunomodulators

The immune system is one of the essential defense mechanisms. Immune system inadequacy increases the risk of infections and cancer diseases, whereas over-activation of the immune system causes allergies or autoimmune disorders. Immunomodulators have been used in the treatment of immune-related diseases. There is growing interest in using herbal medicines as multicomponent agents to modulate the complex immune system in immune-related diseases. Many therapeutic phytochemicals showed immunomodulatory effects by various mechanisms. This mechanism includes stimulation of lymphoid cell, phagocytosis, macrophage, and cellular immune function enhancement. In addition increased antigen-specific immunoglobulin production, total white cell count, and inhibition of TNF-α, IFN-γ, NF-kB, IL-2, IL-6, IL-1β, and other cytokines that influenced the immune system. This review aims to overview, widely investigated plant-derived phytoconstituents by targeting cells to modulate cellular and humoral immunity in in vivo and in vitro. However, further high-quality research is needed to confirm the clinical efficacy of plant-based immunomodulators.

Apigenin inhibits macrophage pyroptosis through regulation of oxidative stress and the NF-κB pathway and ameliorates atherosclerosis

Pyroptosis plays an important role in inflammatory diseases such as viral hepatitis and atherosclerosis. Apigenin exhibits various bioactivities, particularly anti-inflammation, but its effect on pyroptosis remains unclear. The aim of this study is to investigate the effect of apigenin on pyroptosis and explore its potential against inflammatory diseases. THP-1 macrophages treated by lipopolysaccharides/adenosine 5'-triphosphate were used as the in vitro pyroptosis model. Western blot was used to detect the expression of NLRP3 inflammasome components and key regulators. Immunofluorescence was used to observe ROS production and intracellular location of p65. The potential of apigenin against inflammatory diseases was evaluated using atherosclerotic mice. Plaque progression was observed by pathological staining. Immunofluorescence was used to observe the expression of NLRP3 inflammasome components in plaques. The results showed that apigenin inhibited NLRP3 inflammasome activation. Apigenin reduced ROS overproduction and inhibited p65 nuclear translocation. Additionally, apigenin decreased the expression of NLRP3 inflammasome components in the plaque. Plaque progression was inhibited by apigenin. In conclusion, apigenin exhibited a preventive effect on macrophage pyroptosis by reducing oxidative stress and inhibiting the NF-κB pathway. Apigenin may alleviate atherosclerosis at least partially by inhibiting macrophage pyroptosis. These findings suggest apigenin to be a promising therapeutic agent for inflammatory diseases.

Ganoderic acid C2 exerts the pharmacological effects against cyclophosphamide-induced immunosuppression: a study involving molecular docking and experimental validation

Triterpenoids, as the main active ingredient of Ganoderma lucidum fermented extract, exert multiple pharmacological activities, including immunomodulatory properties. Our study aimed to reveal the pharmacological effects and potential mechanisms of Ganoderic acid C2 (GAC) against cyclophosphamide (CY)-associated immunosuppression. Target genes were collected from several public databases, including the DisGeNET, Comparative Toxicogenomics Database, GeneCards, and PharmMapper. STRING database was used to construct the protein-protein interaction of network. Subsequently, molecular docking was carried out to visualize the protein-GAC interactions. Experimental validations, including ELISA and qRT-PCR were performed to confirm the pharmacological activities of GAC on CY-induced immunosuppression model. A total of 56 GAC-related targets were identified to be closely associated with CY-induced immunosuppression. Enrichment analyses results revealed that these targets were mainly involved in immune and inflammatory response-related pathways. STAT3 and TNF were identified as the core targets of GAC. Molecular docking indicated that GAC combined well with STAT3 and TNF protein. In addition, animal experiments indicated that GAC improved immunity as well as STAT3 and TNF genes expression in CY-induced immunosuppression, which further verified the prediction through bioinformatics analysis and molecular docking. We successfully revealed the potential therapeutics mechanisms underlying the effect of GAC against CY-induced immunosuppression based on the combination of bioinformatics analysis, molecular docking, and animal experiments. Our findings lay a theoretical foundation for the in-depth development and utilization of Ganoderma lucidum fermentation product in the future, and also provide theoretical guidance for the development of innovative drugs that assist in improving immunity.

Aronia melanocarpa Flavonol Extract-Antiradical and Immunomodulating Activities Analysis

The study of Aronia melanocarpa's (A. melanocarpa) biological activity is focused on obtaining the crude extract and separation of the flavonol compounds. The extraction and fractionation of A. melanocarpa fruits, followed by quantitative analysis, were accomplished using high-performance liquid chromatography and Darco G-60 filtering. This approach enabled the quantification of flavonoids within each fraction. The antioxidative, immunomodulating activities and cytotoxicity with respect to the lymphoblast cell line RPMI-1788 were studied. The flavonol extract of A. melanocarpa has been shown to have a high capacity to neutralize free DPPH and AAPH radicals in vitro. It also caused an accelerated 'respiratory burst' formation of neutrophils and an increase in the metabolic reserves of cells in rats exposed to cyclophosphamide. The reference solution (an equivalent quercetin-rutin blend) contributed to a decrease in lipid peroxidation, intensifying phagocytosis processes. The studied compounds demonstrated their low influence on the leukocyte blood profile in animals.

Insights into the pharmacological and therapeutic effects of apigenin in liver injuries and diseases

Background

Liver diseases are a spectrum of diseases that include hepatic steatosis, nonalcoholic fatty liver disease, hepatitis, liver fibrosis, cirrhosis, and hepatic cancer. These diseases not only severely decrease the quality of life for patients, but also cause financial burden. Although apigenin (APG) has recently become the primary treatment for liver injuries and diseases (LIADs), there has been no systematic review of its use.

Purpose

To review the existing literature and put forward novel strategies for future APG research on LIADs.

Methods

A search was conducted in PubMed, Science Direct, Research Gate, Web of Science, VIP, Wanfang, and CNKI, and 809 articles were obtained. After applying inclusion and exclusion criteria, 135 articles were included.

Results

APG is promising in treating LIADs via various mechanisms arising from its anti-inflammation, anti-proliferation, anti-infection, anti-oxidation, and anti-cancer properties.

Conclusion

This review summarizes the evidence supporting the use of APG as a treatment for LIADs and provides an insight into the intestinal microbiota, which may have important implications in its future clinical use.

Dietary myricetin assuages atrazine-mediated hypothalamic-pituitary-testicular axis dysfunction in rats

Atrazine (ATZ) exposure is associated with reproductive dysfunction in both animals and humans. Myricetin, a flavonoid compound, is well documented for its numerous pharmacological activities. However, the impact of myricetin on the atrazine-mediated dysfunctional hypothalamic-pituitary-testicular axis is not known. This study investigated the role of myricetin on the atrazine-induced alterations in the male reproductive axis in rats orally gavaged with ATZ alone (50 mg/kg) or co-treated with ATZ + myricetin (MYR) at 5, 10, and 20 mg/kg for 30 consecutive days. Myricetin assuaged ATZ-induced reductions in intra-testicular testosterone, serum follicle-stimulating hormone, luteinizing hormone, and testosterone, coupled with decreases in alkaline phosphatase, acid phosphatase, lactate dehydrogenase, and glucose-6-phosphate dehydrogenase activities. Also, MYR treatment improved epididymal sperm count and motility and decreased sperm defects in ATZ-treated rats. Testicular sperm number, daily sperm production, and sperm viability remained unchanged in all treatment groups. Administration of MYR abated ATZ-mediated depletion in antioxidant status, an increase in myeloperoxidase activity, nitric oxide, hydrogen peroxide, malondialdehyde levels, and reactive oxygen and nitrogen species, as well as the histological lesions in the hypothalamus, epididymis, and testes of treated animals. All in all, MYR mitigated atrazine-mediated functional changes in the reproductive axis via anti-inflammatory and antioxidant mechanisms in atrazine-exposed rats. Dietary intake of MYR could be a worthy chemoprotective approach against reproductive dysfunction related to ATZ exposure.

Protective effects of hesperidin in cyclophosphamide-induced parotid toxicity in rats

Cyclophosphamide (CYP) is an alkylating agent that is used on a wide range as a treatment of malignancies and autoimmune diseases. Previous studies have shown the promising role of hesperidin (HSP) as an antioxidant agent against various models of toxic agents. The protective effect of the HSP against CYP-induced parotid damage was evaluated in this study. Forty rats (180-200 g) were divided into four equal groups: Group I (received normal saline), Group II (HSP-treated at a dose of 100 mg/kg/day for 7 consecutive days), Group III (CYP-treated at a dose of 200 mg/kg single intraperitoneal injection on the 7th day of the experiment), Group IV (CYP + HSP); HSP-treated at a dose of 100 mg/kg/day for 7 consecutive days and CYP (200 mg/kg) single intraperitoneal injection on the 7th day of the experiment. Afterwards, the oxidative stress and inflammatory markers, the histopathological and immunohistochemical alterations of the parotid tissues in the studied groups were evaluated. CYP intoxication induced a significant parotid tissue injury represented by the elevation in the values of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and decrease in the catalase activity and glutathione peroxidase (GPx). Histologically, extensive histopathological alterations e.g., widely spaced serous acini with irregular shapes and congested blood vessels as well as downregulated ki-67 and alpha-smooth muscle actin (α-SMA) immunoexpression were induced by CYP. HSP administration markedly improved the biochemical and the histopathological studies. We can conclude that HSP elicited protective effects against the CYP-induced parotid toxicity.

Gold Nanoparticles Coated with SH-PEG-NH2 and Loaded with Ziyuglycoside I for Promoting Autophagy in Hematopoietic Stem Cells

Introduction

Radiotherapy and chemotherapy are the fundamental causes of myelosuppression in cancer patients, which usually induce a serious hematopoietic system toxicity, causing the hemocytes and immunity decline of patients. Ziyuglycoside I (ZgI), an active ingredient isolated from traditional Chinese medicine Sanguisorba officinalis L, has been demonstrated to increase the leucocytes and protect hematopoietic stem cells, which is related to its promotion of autophagy in hematopoietic stem cells.

Methods

In the present study, we formulated the SH-PEG-NH₂-coated gold nanoparticles loading ZgI (ZgI-AuNPs) with a enhanced autophagy promotion in hematopoietic stem cells. ZgI-AuNPs were prepared by HAuCl₄-sodium citrate reduction method, and the synthesis of ZgI-AuNPs was validated by XRD, FT-IR, DSC, and TEM findings. Furthermore, the drug loading rate and the release of ZgI were evaluated, and the ZgI-AuNPs' effects on autophagy and immunofluorescence staining for LC3B were tested. Finally, the effect of ZgI-AuNPs on the autophagy and hematopoietic ability of HSCs in vivo was also carried out.

Results

The prepared ZgI-AuNPs have an irregular cubic crystal structure by TEM observation, and the average particle size was 340 ± 16.5 nm determined by DLS. The XRD, FT-IR and DSC detection showed that the ZgI had been well loaded in AuNPs, and the AuNPs can load the ZgI at a content of 160.63 ± 1.35 μg·mg^-1. Meanwhile, the AuNPs can reduce the drug release rate of ZgI. Importantly, the ZgI-AuNPs enhanced autophagy of HSCs both in vitro and in vivo. At the same time, the gold nanoparticles enhance the hematopoietic effect of ZgI on mice HSCs.

Conclusion

Our research suggests that SH-PEG-NH₂-coated gold nanoparticles loading ZgI has potential application in myelosuppression therapy.

Flavonoids regulate tumor-associated macrophages - From structure-activity relationship to clinical potential (Review)

In recent years, the strategy for tumor therapy has changed from focusing on the direct killing effect of different types of therapeutic agents on cancer cells to the new mainstream of multi-mode and -pathway combined interventions in the microenvironment of the developing tumor. Flavonoids, with unique tricyclic structures, have diverse and extensive immunomodulatory and anti-cancer activities in the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most abundant immunosuppressive cells in the TME. The regulation of macrophages to fight cancer is a promising immunotherapeutic strategy. This study covers the most comprehensive cognition of flavonoids in regulating TAMs so far. Far more than a simple list of studies, we try to dig out evidence of crosstalk at the molecular level between flavonoids and TAMs from literature, in order to discuss the most relevant chemical structure and its possible relationship with the multimodal pharmacological activity, as well as systematically build a structure-activity relationship between flavonoids and TAMs. Additionally, we point out the advantages of the macro-control of flavonoids in the TME and discuss the potential clinical implications as well as areas for future research of flavonoids in regulating TAMs. These results will provide hopeful directions for the research of antitumor drugs, while providing new ideas for the pharmaceutical industry to develop more effective forms of flavonoids.

Effects of Fucoidan Isolated From Laminaria japonica on Immune Response and Gut Microbiota in Cyclophosphamide-Treated Mice

The effects of Laminaria japonica fucoidan (LF) on immune regulation and intestinal microflora in cyclophosphamide (CTX)-treated mice were investigated in this work. Results indicated that LF significantly enhanced the spleen and thymus indices, promoted spleen lymphocyte and peritoneal macrophages proliferation, and increased the immune-related cytokines production in serum. Moreover, LF could regulate intestinal flora composition, increasing the abundance of Lactobacillaceae and Alistipes, and inhibiting Erysipelotrichia, Turicibacter, Romboutsia, Peptostreptococcaceae, and Faecalibaculum. These results were positively correlated with immune characteristics. Overall, LF could be useful as a new potential strategy to mitigate CTX immunosuppression and intestinal microbiota disorders.

The Effects of Immunosuppression on the Lung Microbiome and Metabolites in Rats

Immunosuppressed patients are more likely to suffer from pneumonia, especially Streptococcus and Enterobacter pneumonia. Studies have demonstrated the existence of a complex and dynamic microbiota on the surface of human respiratory epithelial cells, both in healthy and diseased states. However, it is not clear whether the pneumonia in immunosuppressed patients is caused by inhaled oropharyngeal pathogens or abnormal proliferation of pulmonary proteobacteria. In this study, immunosuppressed model was made by intraperitoneal injection of cyclophosphamide and oropharyngeal saliva aspiration was simulated by oral and pharyngeal tracheal instillation of sterilized phosphate buffered saline (PBS). Furthermore, the effects of immunosuppression on the lung microbial community and its metabolism were investigated using 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS) metabolomics analysis. The 16S rRNA gene sequencing results showed that immunosuppression alone did not change the composition of pulmonary bacteria. Moreover, although the bacteria brought by sterilized PBS from oropharynx to lower respiratory tract changed the composition of the microflora in healthy and immunosuppressed rats, the change in the latter was more obvious. Metabolomic analysis revealed that the levels of pulmonary metabolites were disturbed in the immunosuppressed rats. The altered lung microbiota, including Streptococcaceae and Enterobacteriaceae, showed significant positive correlations with pulmonary metabolites. Our study suggested that the source of the pathogens of pneumonia in immunosuppressed rats was via inhalation and explored the relationship between lung microbiome and metabolites in immunosuppressed rats. Our results provide the basis for the development of prevention and treatment strategies for pneumonia.

Myricetin: A comprehensive review on its biological potentials

Myricetin is a critical nutritive component of diet providing immunological protection and beneficial for maintaining good health. It is found in fruits, vegetables, tea, and wine. The families Myricaceae, Polygonaceae, Primulaceae, Pinaceae, and Anacardiaceae are the richest sources of myricetin. Different researchers explored the therapeutic potential of this valuable constituent such as anticancer, antidiabetic, antiobesity, cardiovascular protection, osteoporosis protection, anti-inflammatory, and hepatoprotective. In addition to these, the compound has been tested for cancer and diabetic mellitus during clinical trials. Health benefits of myricetin are related to its impact on different cell processes, such as apoptosis, glycolysis, cell cycle, energy balance, lipid level, serum protein concentrations, and osteoclastogenesis. This review explored the potential health benefits of myricetin with a specific emphasis on its mechanism of action, considering the most updated and novel findings in the field.