Anti-Allergic Activities of Smilax glabra Rhizome Extracts and Its Isolated Compounds.

BACKGROUND: The rhizomes of Smilax glabra (SG) has long been used in Traditional Chinese and Thai herbal medicine to treat a variety of infectious diseases and immunological disorders. OBJECTIVE: To investigate the in vitro anti-allergic activities of crude extracts andpure isolated flavonoid compounds from SG by determination of inhibitory effect on antigen-induced release of ß-hexosaminidasefrom RBL-2H3 cells. MATERIAL AND METHOD: The in vitro inhibitory effects ofcrude aqueous and organic extracts on ß-hexosaminidase release in RBL-2H3 cells were evaluated as an in vitro indication ofpossible anti-allergic activity. Bioassay-guided fractionation of extracts was used to isolate flavonoid compounds from the ethanolic extracts. RESULTS: The 95% and 50% ethanolic extracts of SG showed remarkably high anti-allergic activity, with IC50 values of 5.74 ± 2.44 and 23.54 ± 4.75 µg/ml, much higher activity than that for Ketotifen (IC50 58.90 µM). The water extract had negligible activity (IC50 > 100 µg/ml). The two isolated flavonols, Engeletin and Astilbin, showed weak anti-allergic activity, IC50 values 97.46 ± 2.04 and >100 µg/ml, respectively. CONCLUSION: The 95% and 50% ethanolic extracts of SG showed strong anti-allergic activity, but two flavonol constituents did not show any significant anti-allergic activity. These findings suggest that a combination of effects of various phytochemicals in crude extracts used in traditional medicine, are responsible for the purported anti-allergic activity of SG herbal preparations. The plethora of constituents in crude extracts, as yet unidentified, are likely to be acting synergistically to account for the strong observed anti-allergic in vitro activity.

[Preparation and identification of artificial antigen for rhein].

The Rhei Radix et Rhizoma was one of the most widely used traditional Chinese medicine for its special biological activities. The content of rhein, one of its major compounds, was an important standard for the quantity control of Rhei Radix et Rhizoma. The major method used for the detection of rhein was instrumental analysis like HPLC, but it was complex, time-consuming and cannot detect large samples at the same time. The enzyme-linked imunmosorbent assay (ELISA) was accurate, reliable, simple, low costs, and of a high-throughout. Recently, it was widely used for the determination of those small molecule compounds in some traditional Chinese medicinal plants. In this study, an artificial antigen were synthesized by the carbodiimide (CDI) method. Rhein-bovine (rhein-BSA) conju gate and rhein-ovalbumin (rhein-OVA) conjugate, were produced as the immunogen and coating antigen, respectively. The conjugate and the hapten number in the conjugate were determined by UV-Vis spectrophotometry (UV). The conjugation ratio of Rhein and BSA was about 4.0:1, rhein acid and OVA was 2.6 : 1, respectively. Rhein-BSA conjugate was used to immunize Bal b/c mice to produce antiserum. The antiserum titer of the Rhein were higher than 8000 detected by ELISA. The successfully synthesized conjugate antigen rhein-BSA implies its feasibility in the establishment of fast immunoassay for the rhein content determination.

Metabolic profiling of Zingiber zerumbet following Pythium myriotylum infection: investigations on the defensive role of the principal secondary metabolite, zerumbone.

Induced biosynthesis of bioactive secondary metabolites constitutes one of the mechanisms of plant basal innate immunity to fungal infection. Metabolic changes were studied in rhizomes of Zingiber zerumbet, a wild congener of ginger, after infection with soft rot-causative necrotrophic phytopathogen, Pythium myriotylum, by gas chromatography-mass spectrometry (GC-MS) analysis. Infection triggered a considerable alteration in the relative content of zerumbone and α-caryophyllene (humulene) with enhancement in zerumbone content (81.59%) and that of α-caryophyllene (11.91%) compared to 9.97 and 1.11%, respectively, in uninfected rhizomes. While zerumbone is the principal secondary metabolite in Z. zerumbet, α-caryophyllene is its immediate precursor. Principal component analysis (PCA) identified the correlations between metabolite changes in Z. zerumbet rhizomes and P. myriotylum infection. Radial diffusion assay with zerumbone indicated a concentration-dependent P. myriotylum growth inhibition with 93.75% inhibition observed at 700 µg and 50% maximal effective concentration (EC50) value of 206 µg. Scanning electron microscopy (SEM) analysis revealed that the mechanistic basis of zerumbone's antagonistic action on P. myriotylum growth involved the induction of aberrant morphology including severe hyphal deformities and membrane disruption. Results are discussed highlighting the critical role played by sesquiterpenoid zerumbone in affording resistance in Z. zerumbet and could expedite the development of appropriate strategies for biocontrol of Pythium spp., thus reducing the usage of broad-spectrum fungicides.

Inhibitory effects of steroidal timosaponins isolated from the rhizomes of Anemarrhena asphodeloides against passive cutaneous anaphylaxis reaction and pruritus.

To investigate the antiallergic effect of the rhizome of Anemarrhena asphodeloides (AA, family Liliaceae), which was found to inhibit the mouse passive cutaneous anaphylaxis (PCA) reaction induced by the antigen-immunoglobulin E (IgE) complex in preliminary experiments, main steroidal saponins, timosaponins AIII, BIII, and D, were isolated and their inhibitory effects against PCA reaction and scratching behaviors investigated in mice. Oral administration of three main steroidal sapogenins blocked the PCA reaction and scratching behaviors, timosaponin AIII was the most potent. However, intraperitoneal administration of timosaponin AIII showed weak inhibition. To understand its metabolism and antiallergic mechanism, timosaponin AIII was anaerobically incubated with human intestinal microflora to afford a main metabolite, sarsasapogenin. Intraperitoneal administration of sarsasapogenin inhibited allergic reaction more potently than timosaponin AIII. In addition, sarsasapogenin more potently inhibited degranulation and IL-4 protein expression of RBL-2H3 cells induced by IgE-antigen complex than timosaponin AIII. On the basis of these findings, antiallergic effect of AA may be due to those of its steroidal constituents, and that of timosaponin AIII may be activated by using intestinal microflora.

Aqueous extract of Rhodiola imbricata rhizome stimulates Toll-like receptor 4, granzyme-B and Th1 cytokines in vitro.

Rhodiola imbricata is a medicinal plant, native to mountainous regions of Asia, parts of Europe, and the Arctic. Traditionally it is recommended to help combat fatigue and restore energy. It exhibits anti-stress, anti-cancer, and immunostimulatory activities. However, the effect of Rhodiola on immunological responses largely remains unknown. In this study, we have investigated the effect of aqueous extract of R. imbricata rhizome (RAE), on Toll-like receptor-4 (TLR-4) and intracellular granzyme-B expression in mouse splenocytes. Furthermore, TH1/TH2 cytokine profile was analyzed in RAE-treated human peripheral blood mononuclear cells (PBMCs) using multiplex flowcytomix kit. Our findings suggest that RAE induces TLR-4 expression and intracellular granzyme-B in treated splenocytes while RAE stimulated IL-1beta, IL-6, and TNF-alpha in human PBMCs. The present study suggests that RAE stimulates the innate immune pathway and has potent immunostimulatory activity, which can be used in modulating the immune system of immunocompromised individuals.