Anticomplementary principles of a Chinese multiherb remedy for the treatment and prevention of SARS.
OBJECTIVE
To elucidate the anticomplementary principles of a Chinese multiherb remedy used for the treatment and prevention of SARS, which contains five ingredients of Herba Houttuyniae, Flos Chrysanthemi Indici, Herba Artemisiae Scopariae, Herba Eupatorii and Fructus Tsaoko.


METHODS
The anticomplementary activity was evaluated from hemolytic assays through the classical pathway (CP) and the alternative pathway (AP) of complement system in vitro. Compounds were isolated using bioactivity-guided fractionation and tested in vitro for their complement-inhibiting properties on the CP and AP. HPLC-DAD-ESI-MS was used to assign the isolated compounds in the five ingredient herbs.


RESULTS
15 compounds, including chlorogenic acid (1), rutin (2), hyperoside (3), p-hydroxyacephenone (4), scopoletin (5), quercitrin (6) (3R,4R,6S)-3,6-dihydroxy-1-menthene (7), acaciin (8), scoparone (9), luteolin (10), quercetin (11), apigenin (12), acacetin (13), aristolactam (14), and apigenin-7,4'-dimethyl ether (15) were isolated and identified. Nine flavonoids (2, 3, 6, 8, 10-13, 15) were found to show inhibitory effects towards the CP and AP of complement system, luteolin (10) was the most potent with the CH50 and AP50 values of 0.19 and 0.17 mM. The bioactive flavonoids were mainly derived from Herba Houttuyniae, Flos Chrysanthemi Indici and Herba Artemisiae Scopariae.


CONCLUSIONS
A Chinese multiherb remedy used for the treatment and prevention of SARS has robust inhibitory effect on complement system through the CP and AP, and its anticomplementary activity could be attributed to the flavonoids present in some ingredient herbs. Luteolin could be a potential anticomplementary agent.
Zhang
Ting
T
Department of Pharmacognosy, School of Pharmacy, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
Chen
Daofeng
D
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D051056:Complement Inactivating Agents / Q000494:pharmacology*; D003170:Complement Pathway, Alternative / Q000187:drug effects; D003171:Complement Pathway, Classical / Q000187:drug effects; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004912:Erythrocytes / Q000187:drug effects; D006168:Guinea Pigs; D007202:Indicators and Reagents; D008968:Molecular Conformation; D010936:Plant Extracts / Q000494:pharmacology; D011817:Rabbits; D045169:Severe Acute Respiratory Syndrome / Q000188:drug therapy* / Q000517:prevention & control*; D012756:Sheep; D021241:Spectrometry, Mass, Electrospray Ionization
D051056:Complement Inactivating Agents; D004365:Drugs, Chinese Herbal; D007202:Indicators and Reagents; D010936:Plant Extracts