Do ethnobotanical and laboratory data predict clinical safety and efficacy of anti-malarial plants?

Malaria Journal

Table 2 Laboratory efficacy score for in vitro antiplasmodial activity of crude extracts

IC₅₀ (μg/ml) (best**)	Score	Level of activity
Not tested	0	Needs to be tested (priority to be determined according to other criteria)
< 2.0	+10*	Very good
2.0 - 5.0	+5*	Good
		This is the concentration range that is generally considered as active in screening programmes for anti-malarial activity, warranting bioassay-guided fractionation.
5.1 - 10	+3*	Good to moderate
		This range may reasonably be considered for bioassay-guided fractionation.
11 - 25	+2	Weak
26 - 50	+1	Very weak
>100	-2	Inactive

** Aqueous extracts were prioritized but if these were not available, results from ethanolic extracts or methanolic extracts were used. Results from non-polar extracts such as dichloromethane and petroleum ether are too far removed from traditional preparations and were excluded.
*Add +1 if this level of activity is confirmed in more than one strain of P. falciparum, from a different continent or with different drug sensitivity, and +2 if confirmed in 2 or more strains.

ISSN: 1475-2875