Effect of traditional Uyghur medicine abnormal Savda Munziq extract on rabbit platelet aggregation in vitro and rat arteriovenous shunt thrombosis in vivo

OBJECTIVE

Abnormal Savda Munziq (ASMq) is a standard herbal preparation used in Uyghur traditional medicine to fight chronic diseases including cardiovascular, but its specific effects on thrombosis and platelet aggregation are unknown.

METHODS

Rabbit platelets were incubated with ASMq extract (10, 20, 40 µg/ml) for 15, 30, or 60 min, and aggregation was induced with ADP and collagen. In vivo, ASMq extract 2.97 g/kg, 5.94g/kg, 11.88 g/kg per os daily for 15 days were tested on thrombus wet weight in a rat model of arterio-venous bypass thrombosis. Plasma thromboxane B2 (TXB2) and 6-keto-PGF1a (6PG) were measured by radioimmunoassay. Aspirin (12 µg/ml and 5mg/kg) and saline were used as control in both experiments.

RESULTS

ASMq inhibited ADP and collagen-induced aggregation in vitro in a dose-dependent manner that increased over time, to a maximum of 6.4 ± 1.3% and 21.6 ± 4.0% for ADP and collagen, respectively, at one hour׳s incubation with the highest concentration, whereas the effects of aspirin (34.5 ± 2.2% and 41.9 ± 2.5%, respectively) were stable over time. In vivo, ASMq inhibited thrombus formation dose-dependently, by 70% at the highest dose, compared to 67% with aspirin. ASMq essentially did not change prostaglandin production, compared to the clear inhibition by aspirin.

CONCLUSION

Abnormal Savda Munziq extract inhibits dose-dependent platelet aggregation with ADP or collagen in vitro and thrombosis in vivo to values similar to those of aspirin, though unlike aspirin this effect does not seem mediated by an inhibition of cyclo-oxygenase.

Effect of Ocimum basilicum L. on cyclo-oxygenase isoforms and prostaglandins involved in thrombosis

ETHNOPHARMACOLOGICAL RELEVANCE

Ocimum basilicum L. (OBL) is a plant used in traditional Uyghur medicine for the treatment and prevention of cardiovascular disease. In previous studies we had found an antihypertensive and antithrombotic effect suggestive of an effect on prostaglandins, which we attempt to document here.

MATERIALS AND METHODS

6-keto-PGF1α, the metabolite of prostacyclin, and PGE2 were measured in the supernatant of human umbilical vein endothelial cells (HUVEC) and basal or LPS-stimulated mouse coeliac macrophage cultures exposed to OBL ethanol (OBL-E) extracts and petroleum ether, chloroform, ethylacetate and butanol (PE, C, EA, B) fractions. In addition, 6-keto-PGF1α and thromboxane B2 (TXB2) were measured in a rat model of thromboangiitis obliterans exposed or not to OBL.

RESULTS

Short-term exposure to OBL-E dose-dependently increased 6-keto-PGF1α from HUVEC, and long-term (24h) exposure decreased it. OBL-C and OBL-B increased 6-keto-PGF1α, whereas the other fractions tended to decrease it after 24h exposure. The extract and all fractions decreased basal and stimulated PGE2 production, but only OBL-EA and OBL-B reduced PGE2 in stimulated cultures to concentrations below the unstimulated values (P<0.05). In vivo OBL increased 6-keto-PGF1α and decreased TXB2.

CONCLUSION

OBL and its extracts increased 6-keto-PGF1α and reduced PGE2 and TXB2 production in a dose and time-related manner. This could indicate simultaneous inhibition of COX-2 and stimulation of endothelial COX-1. The butanol fraction seemed most promising in this respect.

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.

CONCLUSION

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.