Determination of the potency of a novel saw palmetto supercritical CO₂ extract (SPSE) for 5α-reductase isoform II inhibition using a cell-free in vitro test system

Figures & data

Table 1 HPLC gradients (test and reference items)

Androstenedione, 5α-androstanedione (minutes)	Mobile phase
	A (%)	B (%)
0	5	95
0.2	5	95
1.0	97	3
2.5	97	3
2.6	5	95
4.0	5	95

Notes: A, acetonitrile/0.1% (v/v) formic acid; B, 10 mM ammonium formate/0.5% formic acid.

Abbreviation: HPLC, high-performance liquid chromatography.

Table 2 Mass spectrometry and chromatographic parameters (test and reference items)

	Analyte
	Androstenedione	5α-androstanedione	ISTD (griseofulvin)
Molecular weight (g/mol)	286.4	288.4	352.8
[M+H]^+ (m/z)	287.1	289.1	353.2
Monitoring ion (m/z)	109	213	215
Scan time (seconds)	0.15	0.15	0.05
Collision energy (V)	25	25	20
Retention time (minutes)	2.6	2.7	2.5

Abbreviations: ISTD, internal standard; m/z, mass-to-charge ratio.

Table 3 Inhibition of 5α-reductase isotype II by saw palmetto supercritical CO₂ extract in vitro (5α-reductase isotype II-containing cell fractions, concentration finding 1)

Concentration (μg/mL)	200	100	50	6 nM finasteride
Mean inhibition (%), n=2	99	99	99	61

Table 4 Inhibition of 5α-reductase isotype II by saw palmetto supercritical CO₂ extract in vitro (5α-reductase isotype II-containing cell fractions, concentration finding 2)

Concentration (μg/mL)	100	10	1	6 nM finasteride
Mean inhibition (%), n=2	99	93	22	63

Figure 1 Inhibition of 5α-reductase isotype II by saw palmetto supercritical CO₂ extract in vitro (5α-reductase isotype II-containing cell fractions, determination of IC₅₀ value, mean ± SEM).

Abbreviations: IC₅₀, half-maximal inhibitory concentration; SEM, standard error of mean.

Figure 2 Inhibition of 5α-reductase isotype II by finasteride extract in vitro (5α-reductase isotype II-containing cell fractions, determination of the IC₅₀ value, mean ± SEM).

Abbreviations: IC₅₀, half-maximal inhibitory concentration; SEM, standard error of mean.