The present invention relates to a bioactive extract and the extracting method, and especially a non-polysaccharide constituent of genus Dendrobium and extracting method thereof. The non-polysaccharide constituent could be applied to efficiently cure or suppress the occurrence of allergic diseases.
(Introduction)
Genus Dendrobium, a member of family Orchidaceae, distributing in tropical and subtropical area is usually applied as cut flowers and potted orchids for ornament. Including 15 species found in Taiwan, there are 1500 species in genus Dendrobium in the world. Either dry or fresh stem of genus Dendrobium is a precious Chinese herb named as Dendrobium spp. (Herbs Dendrobii) that is widely used in traditional therapies for bringing down a fever, ophthalmology diseases or nourishing purpose.
According to the previous studies, genus Dendrobium includes many substances, such as phenanthrenes, bibenzyls, fluorenones, sesquiterpenes and alkaloids, containing various bioactivities and medical applications. Recent studies also demonstrated the anti-inflammatory, antioxidant and anti-allergic activities in these compounds. Dendrobium tosaense MAKINO is one of the medical genus Dendrobium plant applied as functional health food in Taiwan. So far, it is feasible to largely culture the Dendrobium tosaense, which contains qurecetin for removing free radical, in the warm room by plant tissue culture. Furthermore, quercetin (3,5,7,3′,4′-pentahydroxyflavone) is a kind of flavone which widely exists in the vegetables and fruits. It is quite beneficial for human health due to the anti-oxidation activity. The chemical structure of the queretin is aglycones, which belongs to non-polysaccharide polyphenols.
Atopic dermatitis (AD) is an allergic disease, preferentially occurring in babyhood with unknown reason, with obvious features such as itch, eczematous lesions, xerosis and lichenification. In addition, this allergic disease also associates with other allergic diseases such as asthma, allergic rhinitis, urticaria and food allergy that are the general problems for human health in the world. The incidence of atopic dermatitis is about 10-20% in childhood with a growing trend. The causing mechanisms of atopic dermatitis include genetic factors, environment, skin barrier disorders and immune response that are under investigation.
Mast cell is the key effector in IgE inducing allergic diseases that is activated by the interaction between IgE and high-affinity IgE receptor, FcεRI, on the cell surface. After the activation, mast cell undergoes degranulation to secrete the bioactive substances such as platelet activating factor (PAF), histamine, leukotriene C4 and prostaglandin E2 (PGE2), which play important role in allergy. Atopic dermatitis is usually related to IgE mediated allergic mechanism induced by dust mite, ovalbumin, seafood and fungus. Most patients of atopic dermatitis bear excessive expression of cytokine and production of IgE. Among these cytokines aberrantly produced in atopic dermatitis patients, interleukin-4 (IL-4), interleukin-5 (IL-5) and interleukin-3 (IL-3) are produced by type-2 T helper cells (TH2 cells). In addition to the increase of TH2 cells and cytokines produced by TH2 cells, the production of IFN-γ and interleukin-12 (IL-12) are decreased in these patients. These studies suggest that the occurrence of atopic dermatitis is related to the differentiation of T helper cells. Thus, it is reasonable to cure atopic dermatitis by regulation of TH1/TH2 balance through suppressing TH2 cells related factors and enhancing TH1 cells related factors.
Base of the foregoing, one aspect of the invention is to provide a non-polysaccharide constituent extracted from genus Dendrobium plant, shown in
Another aspect of the invention is to provide a non-polysaccharide constituent of genus Dendrobium plant for positive regulation of the immune system in allergic disease patients.
In another aspect of the invention also provides a method of extracting a non-polysaccharide constituent from genus Dendrobium plant through the following steps:
Step A: taking a specific part of a genus Dendrobium plant.
Step B: incubating the specific part of genus Dendrobium taken in step A in an alcohol to obtain a first product.
Step C: extracting a non-polysaccharide constituent from the first product by using at least one low-polarity solvent.
Furthermore the step-A is to take the stem of dry genus Dendrobium plant; the alcohol of the step-B is methanol; and the step-C extracts the first product of step-B by two solvents with different polarity, including the following steps:
The non-polysaccharide constituent extracted by the provided method, shown in
The present invention discloses a non-polysaccharide constituent extracted from a genus Dendrobium plant as the effective component in the therapy of allergic diseases through positively regulating immune system in the patients. These allergic diseases, including atopic dermatitis, asthma and urticarial, are correlated with the increase of IgE, cytokine and TH2 cells. The present invention also provides a method of extracting the non-polysaccharide constituent from the stem of the genus Dendrobium plant, wherein the genus Dendrobium plant will be illustrated by Dendrobium tosaense in the examples mentioned below.
A fresh Dendrobium tosaense is dehydrated at room temperature or low-temperature and followed by grind for obtaining the powder for the further extraction with better quantitation purpose. The powder of Dendrobium tosaense is dissolved in the methanol to further extract the non-polysaccharide constituent by using two solvents with different polarity. The components in the non-polysaccharide constituent of Dendrobium tosaense, shown in
The present invention will further be illustrated by variable examples with reference made to the Figures, wherein:
The Dendrobium tosaense used in this extraction, identified by China Medical University and preserved in the Herbarium, College of Pharmacy, China Medical University (Sample ID: CMCDT0303), is cultured in the warm room by plant tissue culture. In addition, the internal transcribed spacer of Dendrobium tosaense genome (genebank registration number: HM590367) is used to identify the genotype.
According to
Thus, the non-polysaccharide constituent (stand for DtE in the further description) extracted by using ethyl acetate will be provided for the further examples.
BALB/c female mice with body weight 18˜22 gram are purchased from National Laboratory Animal Center. These mice are maintained in specific conditions including consistent temperature between 21° C. to 24° C., regular light cycle (12 hours for both light and dark phase), autoclaved feedstuff and distilled water for two weeks. These mice are used to generate the mouse model of allergy when they are 8 weeks old.
The mouse model of allergy is generated according to the previous study (Dia et al., 2002). 7% of 2,4,6-tintrochlorobenzene (TNCB) is dissolved in the acetone and olive oil mixture (4:1) and followed by adding 25 μg ovalbumin. This solution is applied at the local region of back skin to harvest the mice with allergic disease on the skin, such as atopic dermatitis, for the further experiments after 7 days.
The mouse model of allergy generated in example 3 is treated with DtE at 30 mg/kg, 100 mg/kg and 300 mg/kg dissolved in carboxymethyl cellulose (CMC) by oral feeding. The experimental group includes the allergic mice fed with sterile carboxymethyl cellulose at 10 ml/kg. In addition, the naive group includes the normal mice or allergic mice without DtE administration. The blood sample is collected for the immune or blood analysis on seventh day after DtE administration. In addition, the skin tissue is taken from the sacrificed mice as sample with fixation in 10% formalin for the further histopathology examination. Furthermore, the spleen of the sacrificed mice is taken for the culture of splenocyte with activation by mitogen (ConA, 5 μm/ml) for 24 to 72 hours. The supernatant of the culture is collected for analyzing the production of IL-4, IL-6 and IFN-γ by sandwich enzyme-linked immunosorbent assay (sandwich ELISA).
The paraffin embedded mouse skin samples are sectioned with appropriated thickness of 5 μm. After rehydration, the sections are stained with hematoxylin and washed by rinse in water for five minutes. Subsequently, excessive hematoxylin is removed by acid alcohol that contains 1% hydrochloric acid for 3 to 5 seconds, and followed by washing with water. The sections are further stained with eosin for five minutes and washed by flowing water until the nuclei turn blue. Sequentially dehydration of the sections is performed with 70%, 80%, 90% and 100% ethanol and followed by mounting for the histopathology observation. As the data shown in
According to
Because mast cell is the critical effector in the atopic dermatitis, master cell infiltration is further observed in the mouse skin. Deparaffinization, rehydration and staining with toluidine blue reagent (1% toluidine blue and 1% potassium aluminum sulfate) for 2˜3 minutes are performed with the descripted sections. After wash with distilled water and dehydration with ethanol, the histology is observed using the microscope and shown in
The sera with different dilutions (1:20 to 1:100 dilution) are loaded into the 96-wells plate coated with ovalbumin-specific antibodies (OVA) for incubation at 4° C. overnight. The 96-wells plate is washed and followed by the incubation with HRP-conjugated goat anti-mouse IgE and IgG1 secondary antibody for one hour. After the incubation, the plate is washed and followed by color reaction by SureBlue Reserve TMB Microwell Peroxidase Substrate. Result is measured by spectrophotometer at 450 nm, and shown in table 1.
The spleen taken from the sacrificed mice in example 4 is cultured with activation by ConA for 24˜72 hours. Following the activation, the supernatant is collected for the sandwich ELISA analysis to measure the production of cytokines such as IL-4, IL-6 and IFN-γ. In detail, the capture antibodies are incubated in the plate at 4° C. overnight and followed by washing with 0.05% Tween20 containing Dulbecco's modified phosphate buffered saline at room temperature for 60 minutes. Samples and standards are added into the wells and incubated at room temperature for 2 hours, and followed by wash to remove the non-specific binding. The detecting antibodies are added into the wells and incubated for 1 hour, and followed by washing. After the incubation with substrate solution TMB in dark, the enzyme activity is terminated by 2N sulfuric acid. The absorption is detected by spectrophotometer and shown in table 2.
The leukocytes in spleen and T cells in the lymph node nearby the wounded area are analyzed according to the cell type-specific antigens on the surface with fluorescence-conjugated monoclonal antibodies. 50 μl suspension containing 5×105 cells is taken for incubation with saturated concentration of fluorescein, phycoerythrin (PE) or PE-Cy5 conjugated monoclonal antibodies in the dark on ice for minutes. The stained cells are washed with 1% sodium azide containing DPBS buffer after the incubation. The cells are centrifuged at 300×g, 4° C. for 10 minutes and re-suspended in 200 μl analyzing buffer that is composed of 2% fetal bovine serum and 0.1% sodium azide in the DPBS. The monoclonal antibodies used in the analysis are listed in table 3.
Examination of the antigen expression on splenocyte in the spleen and lymphocyte in the lymph node nearby the wounded area in skin using flow cytometry. These results are summarized in table 4 and table 5
Table 4 shows the obvious reduction in cell number of Treg cells in spleen of the unfed allergic mice. In addition, although the cell number of B cells, TH cells and Tc cells are similar with unfed allergic mice, the cell number of Treg cells is resorted by DtE administration. These results suggest that DtE administration participates in suppression of allergic dermatoid through enhancing the immune-suppression. Furthermore, the TH2 cell is obviously reduced in the lymph node nearby the wounded area in the allergic mice with DtE administration. This result means that the polarization of TH2 cell plays critical role in local immune-regulation.
According to these results, the non-polysaccharide constituent extracted from genus Dendrobium could obviously suppresses the epidermal damage and mast cell degranulation, up-regulate IFN-γ production, suppress IL-4 production and inhibit the excessive production of IgE or IgG1. In detail, DtE administration creats the suppressive environment for the activation of TH2 cell through reducing the expression of IL4 and enhancing the expression of TH1 cell produced IFN-γ. The activation of TH2 cell is achieved by obviously increasing the palarization of TH2 and anti-ovalbumin IgE. In addition, the obvious increase of Treg cell in the spleen maintains the immunosuppression to obviously reduce the differentiated TH2 cell.
In summary, the non-polysaccharide constituent actually contains the pharmacological activity for positively regulating the allergic disease through control of the TH1/TH2 balance to reduce IgE production.
The above-mentioned specification is only for detailedly describing the examples of the invention and shall not be construed as a limitation of the scope of the invention Thus, t any modification or change without departing from the characteristics of the invention or any equivalent thereof shall be included in the scope of the invention defined in the following claims.
Number | Date | Country | Kind |
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100120579 | Jun 2011 | TW | national |