Table 2.

Estrogen receptor binding data for Piper hispidum extracts and compounds.

Compound/extract (Plant part)	IC50 a (M)	RBAb (%)
estradiol	4.27 × 10−9	100
Piper hispidum elhanol extract (Ph-E)	5.54 × 10−6	0.14
Piper hispidum infusion (Ph-I)	25.2 × 10−5	0.008
Compound 1	11.7 × 10−5	0.017
Compound 2	29.4 × 10−5	0.003
Compound 3	5.14 × 10−5	0.003

^aIC₅₀ , concentration giving 50% inhibitory competition.

^bRelative binding affinity = IC₅₀ [estradiol]/lC₅₀ [competitor (extracts)] × 100.

LF = leaves; E = ethanol