Ethanol extracts of Saururus chinensis suppress ovalbumin-sensitization airway inflammation.
OBJECTIVE
The aerial part of Saururus chinensis has been used in folk medicine to treat several inflammatory diseases in China and Korea. Previously, our group reported that anti-asthmatic activity of an ethanol extract of Saururus chinensis (ESC) might occur, in part, via the inhibition of prostaglandin D(2) (PGD(2)) and leukotriene C(4) (LTC(4)) production, and degranulation reaction in vitro, as well as through the down-regulation of interleukin (IL)-4 and eotaxin mRNA expression in an in vivo ovalbumin-sensitization animal model. However, the effects of Saururus chinensis on eicosanoid generation, as well as Th2 cytokines and eotaxin production in an in vivo asthma model, have not been fully investigated. Moreover, it has not been determined whether ESC can ameliorate airway inflammation in vivo. In the present study, we investigated the therapeutic activity of Saururus chinensis on ovalbumin (OVA)-sensitized airway inflammation and its major phytochemical compositions.


METHODS
Asthma was induced in BALB/c mice by ovalbumin-sensitization and inhalation. ESC (10-100 mg/kg) or dexamethasone (5 mg/kg), a positive control, was administered 7 times orally every 12 h from one day before the first challenge to 1 h before the second challenge. The recruitment of inflammatory cells and hyperplasia of goblet cells were evaluated by H&E and PAS staining. Levels of Th2 cytokines, eotaxin, PGD(2) and LTC(4) were measured to evaluate the anti-inflammatory activity of ESC in OVA-sensitized mice. Contents of major components were analyzed by HPLC using a reversed-phase C18 column.


RESULTS
ESC (10 mg/kg) suppressed allergic airway inflammation by inhibition of the production of IL-4 (P<0.001), IL-5 (P<0.05), IL-13 (P<0.001), eotaxin (P<0.001), PGE(2) (P<0.001), LTC(4) (P<0.001) in lung extract and IgE level (P<0.001) in the serum. In addition, ESC (50 mg/kg) reduced the infiltration of inflammatory cells and hyperplasia of goblet cells in the lung tissues. The anti-inflammatory effect of ESC was comparable to that of the positive control drug, dexamethasone. Its major phytochemical composition includes manassantin A, B and sauchinone.


CONCLUSIONS
These results suggest that ESC decreased inflammation and mucus secretion in the OVA-induced bronchial asthma model, and its anti-asthmatic activity may occur in part via the inhibition of Th2 cytokines and eotaxin protein expression, as well as through prostaglandin E(2) (PGE(2)) and leukotriene C(4) (LTC(4)) generation. This effects may be attributed particularly to the presence of manassantin A, B and sauchinone major component evidenced by a HPLC analysis.
Quan
Zhejiu
Z
College of Pharmacy, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
Lee
Youn Ju
YJ
Yang
Ju Hye
JH
Lu
Yue
Y
Li
Ying
Y
Lee
Yeun-Kyung
YK
Jin
Meihua
M
Kim
Jong-Yeon
JY
Choi
Joon Hyuk
JH
Son
Jong Keun
JK
Chang
Hyeun Wook
HW
D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D002851:Chromatography, High Pressure Liquid; D016207:Cytokines / Q000097:blood / Q000276:immunology; D015232:Dinoprostone / Q000097:blood / Q000276:immunology; D004195:Disease Models, Animal; D000431:Ethanol / Q000737:chemistry; D005260:Female; D006965:Hyperplasia; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D017997:Leukotriene C4 / Q000097:blood / Q000276:immunology; D008168:Lung / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D055670:Medicine, Korean Traditional; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D020545:Respiratory Mucosa / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D032134:Saururaceae / Q000737:chemistry*
D016207:Cytokines; D010936:Plant Extracts; D017997:Leukotriene C4; D007073:Immunoglobulin E; D000431:Ethanol; D010047:Ovalbumin; D015232:Dinoprostone