Effects of different extracts of Dendrobium officinale on rats with chronic pharyngitis induced by pepper water combined with ammonia / 中国中药杂志

Dendrobium officinale can serve as Chinese medicinal material effective in nourishing yin, clearing heat, and producing fluid, and is used to treat throat diseases, but its active substances and mechanism are not clear. To clarify the active fraction and underlying mechanism of D. officinale against chronic pharyngitis(CP), the present study induced a CP model in rats by pepper water combined with low-concentration ammonia, and crude polysaccharides of D. officinale(DOP), non-polysaccharides of D. officinale(DON), and total extract of D. officinale(DOT)(0.33 g·kg~(-1), calculated according to the crude drug) were administered by gavage for six weeks. The changes in oral secretions and pharyngeal conditions of rats with CP were observed and rated. The hematological indicators were determined by an automatic hematology analyzer. The serum levels of pro-inflammatory factors, such as tumor necrosis factor-alpha(TNF-α), interleukin 1β(IL-1β), and interleukin 6(IL-6), and T-lymphocyte cytokines, including interferon γ(IFN-γ), interleukin 4(IL-4), interleukin 17(IL-17), and transforming growth factor β1(TGF-β1) were detected by the enzyme-linked immunosorbent assay(ELISA). The proportions of CD3~+, CD4~+, and CD8~+cells in peripheral blood T lymphocyte subsets were determined by the flow cytometry. The histomorphological changes of the pharynx were observed by hematoxylin-eosin(HE) staining. The protein expression of nuclear factor-κB P65(NF-κB P65), cyclooxygenase-2(COX-2), F4/80, and monocyte chemoattractant protein-1(MCP-1) in the pharynx were detected by immunohistochemistry and Western blot. The results showed that DOP and DON could significantly relieve pharyngeal lesions, reduce white blood cells(WBC) and lymphocytes(LYMP), decrease the levels of pro-inflammatory factors TNF-α, IL-6, and IL-1β, and inhibit the protein expression of NF-κB P65, COX-2, F4/80, and MCP-1 in the pharynx. DOP was superior in reducing oral secretions and serum IL-17 level and inferior in increasing CD4~+/CD8~+ratio to DON. It is suggested that both polysaccharides and non-polysaccharides of D. officinale have anti-PC effects and the anti-inflammatory mechanism may be related to the regulation of T lymphocyte distribution and inhibition of the inflammatory signaling pathways mediated by NF-κB P65. The anti-inflammatory effect of DOP may be related to the regulation of Th17/Treg balance, while that of DON may be related to the regulation of the Th/Tc ratio.

Effect of Dendrobii officinalis superfine powder on overeating greasy-induced metabolic hypertension in rats / 中国中药杂志

Dendrobii officinalis, with a definite effect of nourishing Yin and clearing heat, has been a folk habit for drinking after being mixed with water. Because its superfine powder has the advantages of high dissolution and convenient drinking, we observed the effect of D. officinalis superfine powder on metabolic hypertension model rats and its possible mechanism in this experiment, which can be used as a reference for its clinical application for hypertension. The overeating greasy-induced metabolic hypertension model was established with high-fat, high-sugar and high-purine diet. These rats were orally administered with 400 mg·kg~(-1) and 200 mg·kg~(-1) of D. officinalis superfine powder for 20 consecutive weeks. During this period, blood pressure, blood lipid, blood glucose, insulin and other related indexes of glucose and lipid metabolism were monitored; the levels of lipopolysaccharide(LPS), C-reactive protein(CRP), interleukin 6(IL-6) and other inflammatory mediators were measured; the levels of nitric oxide(NO) and endothelin-1(ET-1) were detected, and the histomorphological and ultrastructural changes of aorta were observed. In addition, the expression of LPS/TLR4 pathway-related molecules in aorta was determined. The results showed that long-term administration of D. officinalis superfine powder significantly reduced the levels of systolic blood pressure(SBP), diastolic blood pressure(DBP) and mean arterial pressure(MBP) in metabolic hypertension model rats, decreased the levels of total cholesterol(TC), triglyceride(TG), low density lipoprotein cholesterol(LDL-c), glucose(Glu), and insulin(INS) levels in blood, increased the contents of high density lipoprotein cholesterol(HDL-c),decreased the LPS, CRP, IL-6 and ET-1 levels in blood and increased NO content. Furthermore, it improved the abnormality of aortic histomorphology and endothelial ultrastructure, and inhibited the protein expression of TLR4, myeloid differentiation factor(MyD88), IL-6, interleukin-1 β(IL-1β), and tumor necrosis factor-α(TNF-α) as well as mRNA expression of TNF-α and IL-1β in aorta. In conclusion, D. officinalis superfine powder may improve the abnormal function and structure of blood vessels by inhibiting the activation of LPS/TLR4 pathway, thus playing a role against metabolic hypertension.