Aqueous extracts of Ocimum basilicum L. (sweet basil) decrease platelet aggregation induced by ADP and thrombin in vitro and rats arterio--venous shunt thrombosis in vivo.
OBJECTIVE
To study the effects of aqueous extract of Ocimum basilicum L (OBL) on platelet aggregation and experimental thrombus.


METHODS
Platelet aggregation induced by ADP (5 muM) and thrombin (4 UI), and thrombus weight in an arteriovenous thrombosis (AVT) model were tested after 2 weeks treatment with 15, 75 and 375 mg/kg OBL orally in rats, compared to 8.8 mg/kg/day aspirin. AVT was also tested 2 h after 75 mg/kg OBL orally, after 3 and 7 days treatment, and one, three and seven days after the end of a two-week treatment. Analysis was done by ANOVA followed by protected t-tests (Tukey).


RESULTS
OBL (15, 75, 375 mg/Kg) dose-dependently inhibits platelet aggregation by ADP and thrombin, with 75 mg/kg/day having approximately the same effect as 8.8 mg/kg/day aspirin. ADP induced aggregation reached 45%, 28% and 18% for OBL, respectively, 15, 75, 375 mg/kg compared to 71% for control and 27% for aspirin (all p<0.01 except aspirin vs. OBL 75 mg/kg/day p=0.7). Thrombin-induced aggregation reached 33%, 22%, 21% for OBL, respectively, 15, 75, 375 mg/kg compared to 67% for control and 48% for aspirin (all p<0.01 except OBL 75 vs. OBL 375 mg/kg/day, p=1.0). Compared to a control thrombus weight of 48.1 mg (SD 4.9), thrombus weight was 29.4 (3.3), 19.0 (1.9) and 12.3 (1.7) after treatment for 2 weeks with 15, 75 and 375 mg/kg OBL, respectively, and 27.4 (5.3) after 8.8 mg/kg aspirin (all p<0.001 except aspirin vs. OBL 75 mg/kg/day p=1.0). Maximum effect of OBL was reached after one week's treatment. The effect subsided between 3 and 7 days.


CONCLUSIONS
OBL possesses an inhibitory effect on platelet aggregation induced by ADP and thrombin, that is dose-dependent and results in an anti-thrombotic effect in vivo which develops progressively over 7 days and disappears over 3-7 days. The active ingredient now needs to be characterized.
Department of Pharmacology, Xinjiang Medical University, Urumqi 830054, PR China.
Ibadet
I
Tohti
Maynur
M
Tursun
Anwar
A
Umar
Subat
S
Turdi
Horyat
H
Imin
Nicholas
N
Moore
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D008297:Male; D023421:Models, Animal; D018649:Ocimum basilicum; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013917:Thrombin / Q000494:pharmacology; D020246:Venous Thrombosis / Q000188:drug therapy* / Q000517:prevention & control
D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors; D000244:Adenosine Diphosphate; D013917:Thrombin