Anti-allergic effect of the flavonoid myricitrin from Myrica rubra leaf extracts in vitro and in vivo. Nat Prod Res

Department of Cooperative Medical Research, Collaboration Center, Shimane University, Izumo, Japan.
Natural product research (Impact Factor: 0.92). 02/2011; 25(4):374-80. DOI: 10.1080/14786411003774320
Source: PubMed


Flavonoids are ingested by the general population as anti-oxidant and anti-inflammatory agents. In this study, we investigated the effects of myricitrin, a flavonoid rich in Myrica rubra leaf, upon anti-inflammatory action. Myrica rubra leaf extracts inhibited pro-inflammatory TNFα production in a macrophage cell line, Raw264.7 cells. We observed that the serum IgE levels in the leaf extract-treated DO11.10, a mouse allergy model, were down-regulated. HPLC was performed to demonstrate that M. rubra leaf extracts contain a large amount of myricitrin. We observed an inhibitory effect of HPLC-purified myricitrin on TNFα production in Raw264.7 cells. Thus, myricitrin may be of potential interest in the management of inflammatory conditions.

1 Follower
17 Reads
  • Source
    • "Several natural extracts from plants such as polyphenols (Kojima et al., 2000), polysaccharides (Tian et al., 2012), flavonoids (Shimosaki et al., 2011) etc. are known to possess anti-allergic activity in addition to having low side effects and high safety to human health. Recently , marine source has attracted more and more attentions for the development of active compounds. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Natural polyphenol has been widely believed to be effective in allergy remission. Currently, most of the natural polyphenol products come from terrestrial sources such as tea, grape seeds among others, and few polyphenols have been developed from algae for their anti-allergic activity. The aim of the study was to screen some commercial seaweed for natural extracts with anti-allergic activity. Five algae including Laminaria japonica, Porphyra sp., Spirulina platensis, Chlorella pyrenoidosa and Scytosiphon sp. were extracted with ethanol, and the extracts were evaluated for total polyphenol contents and anti-allergic activity with the hyaluronidase inhibition assay. Results showed that the total polyphenol contents in the ethanol extracts ranged from 1.67% to 8.47%, while the highest was found in the extract from Scytosiphon sp. Hyaluronidase inhibition assay showed that the extracts from Scytosiphon sp. had the lowest IC50, 0.67 mg mL−1, while Chlorella pyrenoidosa extract had the highest IC50, 15.07 mg mL−1. The anti-allergic activity of Scytosiphon sp. extract was even higher than the typical anti-allergic drug Disodium Cromoglycate (DSCG) (IC50 = 1.13 mg mL−1), and was similar with natural polyphenol from Epigallocatechin gallate (EGCG) (IC50 = 0.56 mg mL−1). These results indicated that the ethanol extract of Scytosiphon sp. contains a high concentration of polyphenol with high anti-allergic activity. Potentially Scytosiphon sp. can be developed to a natural anti-allergic compound for allergy remission. © 2015, Science Press, Ocean University of China and Springer-Verlag Berlin Heidelberg.
    Journal of Ocean University of China 08/2015; 14(4):681-684. DOI:10.1007/s11802-015-2601-5 · 0.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies in young rats reported the impact of cocoa intake on healthy immune status and allow suggesting it may have a role in the prevention of some immune-mediated diseases. The aim of this study was to ascertain the effect of a cocoa diet in a model of allergy in young rats. Three-week-old Brown Norway rats were immunized by i.p. injection of ovalbumin (OVA) with alum as adjuvant and Bordetella pertussis toxin. During the next 4 weeks rats received either a cocoa diet (containing 0.2% polyphenols, w/w) or a standard diet. Animals fed a standard diet showed high concentrations of anti-OVA IgG1, IgG2a, IgG2b and high anti-OVA IgE titres, which is the antibody involved in allergic response. In contrast, animals fed a cocoa diet showed significantly lower concentrations of anti-OVA IgG1 and IgG2a antibodies. Interestingly, the cocoa diet prevented anti-OVA IgE synthesis and decreased total serum IgE concentration. Analysis of cytokine production in lymph node cells at the end of the study revealed that, in this compartment, the cocoa diet decreased the tumor necrosis factor (TNF)-α and the interleukin (IL)-10 secretion but not IL-4 production. In conclusion, a cocoa-enriched diet in young rats produces an immunomodulatory effect that prevents anti-allergen IgE synthesis, suggesting a potential role for cocoa flavonoids in the prevention or treatment of allergic diseases.
    Pharmacological Research 02/2012; 65(6):603-8. DOI:10.1016/j.phrs.2012.02.001 · 4.41 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: ETHNOPHARMACOLOGICAL RELEVANCE: Campomanesia species are used in folk medicine as anti-inflammatory, anti-rheumatic, anti-diarrheal and hypocholesterolemic. AIM OF THE STUDY: The present study investigated the in vivo anti-inflammatory and antinociceptive properties of ethyl acetate (AE) and aqueous (Aq) extracts from leaves of Campomanesia adamantium and in vitro anti-inflammatory activity of AE and its isolated flavonols, myricitrin and myricetin. MATERIALS AND METHODS: The antinociceptive activity of AE and Aq was evaluated using acetic acid-induced writhing and formalin methods. The in vivo anti-inflammatory effect of AE and Aq was evaluated using carrageenan-induced paw oedema in mice. AE, myricitrin and myricetin were evaluated for their abilities to modulate the production of NO, TNF-α and IL-10 in LPS/IFN-γ stimulated J774.A1 macrophages. RESULTS: It was found that orally administrated AE and Aq (125 and 250mg/kg) inhibited carrageenan-induced paw oedema in mice. AE (125 and 250mg/kg) and Aq (125mg/kg) reduced the time to licking at the second phase of formalin method in vivo in mice. AE (250mg/kg) and Aq (125mg/kg) also reduced the number of writhes. AE, myricitrin and myricetin inhibited NO (320µg/mL and 6.25-100µM, respectively) and TNF-α production by macrophages (320µg/mL for AE, 100µM for myricitrin and 25-100µM for myricetin). AE (160 and 320µg/mL), myricitrin (50 and 100µM) and myricetin (25-100µM) increased IL-10 production by macrophages. CONCLUSIONS: The ethyl acetate and aqueous extracts from C. adamantium showed antinociceptive and anti-inflammatory effects supporting the use of the plant in folk medicine. The results suggest that anti-edematogenic effect promoted by aqueous extract involves several anti-inflammatory mechanisms of action. The antinociceptive effect shown by aqueous extract can be due to the modulation of release of inflammatory mediators involved in nociception. The anti-inflammatory effects of AE and of its isolated flavonols may be attributed to inhibition of pro-inflammatory cytokines production, TNF-α and NO and to the increased of IL-10 production.
    Journal of ethnopharmacology 10/2012; 145(1). DOI:10.1016/j.jep.2012.10.037 · 3.00 Impact Factor
Show more