Study on the anti-inflammatory effect of stachyose by inhibiting TLR4/NF-κB signalling pathway in vitro and in vivo.

This study aimed to explore the anti-inflammatory effect of stachyose, a tetrasaccharide extracted from Stachys sieboldii Miq. A lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages model and a dextran sodium sulfate (DSS)-induced ulcerative colitis BALB/C mice model was used to assess the anti-inflammatory effect of stachyose both in vitro and in vivo. The levels of nitric oxide (NO) and cytokines (interleukin-1ß, interleukin-6 and tumour necrosis factor-α) were detected using enzyme-linked immunosorbent assay methods; moreover, haematoxylin-eosin staining was used to observe changes in intestinal morphology of mice. In addition, the possible mechanisms were explored by reverse transcription-polymerase chain reaction and western blot. Results showed that stachyose and four other oligosaccharides (galacto-oligosaccharides, xylo-oligosaccharides, inulin and resistant dextrin) inhibited NO secretion and the production of pro-inflammatory cytokines in LPS-stimulated RAW264.7 macrophages in a dose-dependent manner, whereas stachyose was most effective in vitro. In mice, different doses of stachyose significantly alleviated the symptoms of DSS-induced ulcerative colitis and stachyose also significantly inhibited the production of inflammatory cytokines and myeloperoxidase in vivo. In addition, our findings illustrated that stachyose inhibited expression of toll-like receptor 4 (TLR4) and suppressed the phosphorylation of nuclear factor (NF)-κB p65 both in vitro and in vivo. Taken together, results demonstrated that stachyose exerted anti-inflammatory effect through inhibition of the TLR4/NF-κB signalling pathway.

Apigenin acts as a partial agonist action at estrogen receptors in vivo.

The flavone apigenin is widely distributed in vegetables and fruits and has a variety of pharmacological effects. However, there is no definitive scientific evidence that apigenin could act as a phytoestrogen and exert exerting estrogenic or antiestrogenic efficacy in vivo. Therefore, this study was established an ovariectomy (OVX) and estrogenized mouse model to evaluate the effects of apigenin on reproductive target tissues. Our data demonstrated that apigenin could exert a double-directional adjusting estrogenic effect in vivo. Specifically, treatment with apigenin reversed the weight changes caused by abnormal estrogen levels and altered the status of vaginal epithelial cells via the estrogen receptors. In addition, we found that apigenin exhibited a significant estrogenic activity, as indicated by the reversal of uterine atrophy. Apigenin treatment could also regulate the target tissue coefficient changes and estrogen disorders caused by excessive estrogen. Importantly, the administration of apigenin could upregulated the estrogen receptor (ER) α and ER ß expression as a partial agonist. Our results demonstrate that apigenin has a double directional adjusting function in different physiological environments.

Apigenin Attenuates the Allergic Reactions by Competitively Binding to ER With Estradiol.

Apigenin (API) is a natural phytoestrogen with properties including anti-inflammatory and other abilities. This study aims to 1) systematically validate that excessive estrogen exacerbates allergic reactions; 2) explore the anti-allergic effects and mechanisms of API. We conduct a survey of college students, indicating that of the 505 effective results, 70 individuals were self-reported allergic and 74.1% of them were women, which proved the gender difference in allergic reactions. BALB/c mice are grouped into the negative control group (N-Ctrl), the OVA-sensitized group (P-Ctrl), the estrogenized OVA-sensitized group (E2), and three treatment groups administrating different dose of API (E2 + API/L/M/H). In vivo data indicated that API treatment significantly inhibited the enhancement of estradiol on clinical symptoms. Moreover, we found that high doses of API inhibited Th2 type humoral response and mast cell degranulation levels in vivo and in vitro. Additionally, medium, and high doses of API significantly reduced the potentiation of estradiol on ER expression, attenuated the transmission of estrogen/ER signaling, thereby inhibiting the phosphorylation of ERK1/2 and JNK1/2/3 in the MAPK. Besides, we found that API competitively bound to ER with estradiol, and showed a weak selectivity to ERß. Overall, we identified API can be beneficial in allergic disease.

Apigenin Inhibits Histamine-Induced Cervical Cancer Tumor Growth by Regulating Estrogen Receptor Expression.

Apigenin is a natural flavone with anti-inflammatory and antioxidant properties and antitumor abilities against several types of cancers. Previous studies have found that the antitumor effects of apigenin may be due to its similar chemical structure to 17ß-estradiol (E2), a main kind of estrogen in women. However, the precise mechanism underlying the antitumor effects of apigenin in cervical cancer remains unknown. On the other hand, there is increasing evidence that describes a histamine role in cancer cell proliferation. In this study, we examined whether apigenin can attenuate the effects of histamine on tumors by regulating the expression level of estrogen receptors (ERs) to inhibit cervical cancer growth. Our in vitro data indicates that apigenin inhibited cell proliferation in a dose-dependent manner in human cervical cancer cells (HeLa), while histamine shows the opposite effects. After that, the xenograft model was established to explore the antitumor effects of apigenin in vivo, the results show that apigenin inhibited cervical tumor growth by reversing the abnormal ER signal in tumor tissue which was caused by histamine. We also demonstrate that apigenin inhibited cell proliferation via suppressing the PI3K/Akt/mTOR signaling pathway. Collectively, our results suggest that apigenin may inhibit tumor growth through the ER-mediated PI3K/Akt/mTOR pathway and that it can also attenuate the effects of histamine on tumors.

Inhibition effect of blunting Notch signaling on food allergy through improving TH1/TH2 balance in mice.

BACKGROUND: Notch signaling regulates proliferation, differentiation, and function of dendritic cells, T cells, and mast cells, as well as many other immune cells, which act as important parts in food allergy, Notch signaling may play an important role in food allergy. OBJECTIVE: To investigate the role of Notch signaling in IgE-mediated food allergy. METHODS: An ovalbumin-induced food allergy mouse model was built (cholera toxin as adjuvant) and Notch signaling was blunted by FLI-06 and MW167, which inhibited Notch receptor-expressing phase and the γ-secretase-affecting phase, respectively. Then food allergy indicators, including levels of serum antibodies, cytokines, and degranulation, were examined. Meanwhile, clinical features, such as vascular permeability changes, intestinal permeability changes, body temperature changes, and symptoms, were also observed. RESULTS: After blunting Notch signaling, the levels of serum ovalbumin specific IgE and IgG1 were decreased significantly, suggesting that blunting Notch signaling inhibited antibody responses. The levels of TH1 cytokines (interferon-γ) were increased significantly, whereas the levels of TH2 cytokines (interleukin-4, -5, and -13) were decreased significantly, suggesting TH2 polarization was suppressed after blunting Notch signaling. The expression of T-bet was significantly increased, whereas the expression of Gata-3 was significantly reduced in both messenger RNA and protein levels, indicating TH2 polarization was inhibited and TH1 polarization was enhanced after blunting Notch signaling. Moreover, allergic clinical features of mice were alleviated after blunting Notch signaling. CONCLUSION: Food allergy was inhibited by blunting Notch signaling through suppressing TH2 polarization, enhancing TH1 cell differentiation and promoting TH1/TH2 balance in mice. Notch signaling plays a key role in IgE-mediated food allergy.