The cytotoxicity to leukemia cells and antiviral effects of Isatis indigotica extracts on pseudorabies virus.
OBJECTIVE
Isatis indigotica (I. indigotica), Cruciferae, has been used in Chinese medicine for anti-leukemia and anti-severe acute respiratory syndrome (SARS). The aim of this study was to evaluate the cytotoxicity of Isatis indigotica extracts on human leukemia cell line (HL-60) and the antiviral activity on swine pseudorabies virus (PrV) in in vitro assays.


METHODS
Extracts and derived fractions of Isatis indigotica were prepared from root (R) and leaf (L) using methanol (M), ethyl acetate (E) and distilled water (D). The cytotoxic effect of extracts on swine peripheral blood mononuclear cells (PBMCs) and HL-60 was assessed by MTT method. The cytopathic effect (CPE) reduction, plaque reduction and inhibition assays on viral replication, and virucidal activity were further conducted to investigate the anti-PrV activity.


RESULTS
Indirubin, one of the biological active compounds of Isatis indigotica, had the most significant cytotoxicity on HL-60 cells and inhibitory effect on PrV replication. Extracts from roots and leaves of Isatis indigotica also presented CPE inhibition either before or after infection of PrV on porcine kidney (PK-15) cells. Leaf extracts had better virucidal activity than roots, and ethyl acetate extracts exhibited the highest efficacy among extracts tested.


CONCLUSIONS
Isatis indigotica posses a valuable virucidal effect in disease control of pseudorabies virus infection in swine.
Hsuan
Shih-Ling
SL
Graduate Institute of Veterinary Pathobiology and Department of Veterinary Medicine, National Chung-Hsing University, 250, Kuo-Kuang Road, Taichung, 402, Taiwan, ROC.
Chang
Shih-Chieh
SC
Wang
Sheng-Yang
SY
Liao
Tien-Ling
TL
Jong
Ting-Ting
TT
Chien
Maw-Sheng
MS
Lee
Wei-Cheng
WC
Chen
Shih-Shiung
SS
Liao
Jiunn-Wang
JW
D000818:Animals; D003588:Cytopathogenic Effect, Viral; D004354:Drug Screening Assays, Antitumor; D018922:HL-60 Cells; D011558:Herpesvirus 1, Suid / Q000187:drug effects* / Q000472:pathogenicity / Q000502:physiology; D006801:Humans; D031219:Isatis / Q000737:chemistry*; D007938:Leukemia / Q000473:pathology*; D010936:Plant Extracts / Q000494:pharmacology*; D013552:Swine; D014779:Virus Replication
D010936:Plant Extracts