Potency of a novel saw palmetto ethanol extract, SPET-085, for inhibition of 5α-reductase II
- Pilar Pais
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The nicotinamide adenine dinucleotide phosphate (NADPH)-dependent membrane protein 5α-reductase irreversibly catalyses the conversion of testosterone to the most potent androgen, 5α-dihydrotestosterone (DHT). In humans, two 5α-reductase isoenyzmes are expressed: type I and type II. Type II is found primarily in prostate tissue. Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). The mechanisms of the pharmacological effects of SPE include the inhibition of 5α-reductase, among other actions. Clinical studies of SPE have been equivocal, with some showing significant results and others not. These inconsistent results may be due, in part, to varying bioactivities of the SPE used in the studies.
The aim of the present study was to determine the in vitro potency of a novel saw palmetto ethanol extract (SPET-085), an inhibitor of the 5α-reductase isoenzyme type II, in a cell-free test system. On the basis of the enzymatic conversion of the substrate androstenedione to the 5α-reduced product 5α-androstanedione, the inhibitory potency was measured and compared to those of finasteride, an approved 5α-reductase inhibitor.
SPET-085 concentration-dependently inhibited 5α-reductase type II in vitro (IC50=2.88±0.45 μg/mL). The approved 5α-reductase inhibitor, finasteride, tested as positive control, led to 61% inhibition of 5α-reductase type II.
SPET-085 effectively inhibits the enzyme that has been linked to BPH, and the amount of extract required for activity is very low compared to data reported for other extracts. It can be concluded from data in the literature that SPET-085 is as effective as a hexane extract of saw palmetto that exhibited the highest levels of bioactivity, and is more effective than other SPEs tested. This study confirmed that SPET-085 has prostate health-promoting bioactivity that also corresponds favorably to that reported for the established prescription drug standard of therapy, finasteride.
- Shirakawa, T., Okada, H., Acharya, B. (2004) Messenger RNA levels and enzyme activities of 5 alphareductase types 1 and 2 in human benign prostatic hyperplasia (BPH) tissue. Prostate 58: pp. 33-40 CrossRef
- Boudon, C., Lobaccaro, J.M. (1995) 5 alpha-reductase activity in cultured epithelial and stromal cells from normal and hyperplastic human prostates - effect of finasteride (Proscar), a 5 alpha-reductase inhibitor. Cell Mol Biol 41: pp. 1007-1015
- Comhaire, F., Mahmoud, A. (2004) Preventing diseases of the prostate in the elderly using hormones and nutriceuticals. Aging Male 7: pp. 155-169 CrossRef
- Lee, J., Andriole, G., Avins, A. (2009) Redesigning a large-scale clinical trial in response to negative external trial results: the CAMUS study of phytotherapy for benign prostatic hyperplasia. Clin Trials 6: pp. 628-636 CrossRef
- Edwards, J.L. (2008) Diagnosis and management of benign prostatic hyperplasia. Am Fam Physician 77: pp. 1403-1410
- Abe, M., Ito, Y., Suzuki, A. (2009) Isolation and pharmacologic characterization of fatty acids from saw palmetto extract. Anal Sci 25: pp. 553-557 CrossRef
- Scaglione, F., Lucini, V., Pannacci, M. (2008) Comparison of the potency of different brands of Serenoa repens extract on 5alpha-reductase types I and II in prostatic co-cultured epithelial and fibroblast cells. Pharmacology 82: pp. 270-275 CrossRef
- Bent, S., Kane, C., Shinohara, K. (2006) Saw palmetto for benign prostatic hyperplasia. N Engl J Med 354: pp. 557-566 CrossRef
- Log, T. (2008) Serenoa repens in benign prostatic hyperplasia. Tidsskr Nor Laegeforen 128: pp. 1293-1294
- Reichert, W., Harmann, R.W., Jose, J. (2001) Stable expression of the human 5alpha-reductase isoenzymes type I and type II in HEK293 cells to identify dual and selective inhibitors. Proc Natl Acad Sci U S A 16: pp. 47-53
- Anderson, S., Russell, D.W. (1990) Structural and biochemical properties of cloned and expressed human and rat steroid 5α-reductases. Proc Natl Acad Sci U S A 87: pp. 3640-3644 CrossRef
- Delos, S., Lehle, C., Martin, P.M. (1994) Inhibition of the activity of ‘basic’ 5 alpha-reductase (type 1) detected in DU 145 cells and expressed in insect cells. Steroid Biochem Mol Biol 48: pp. 347-352 CrossRef
- Habib, F.K., Ross, M., Ho, C.K. (2005) Serenoa repens (Permixon) inhibits the 5 alpha-reductase activity of human prostate cancer cell lines without interfering with PSA expression. Int J Cancer 114: pp. 190-194 CrossRef
- Wilt, T.J., Ishani, A., Rutks, I., MacDonald, R. (2000) Phytotherapy for benign prostatic hyperplasia. Public Health Nutr 3: pp. 459-472 CrossRef
- Gerber, G.S., Kuznetsov, D. (2001) Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract infections. Urology 58: pp. 960-964 CrossRef
- Hizli, F., Uygur, M.C. (2007) A prospective study of the efficacy of Serenoa repens, tamsulosin, and Serenoa repens plus tamsulosin treatment for patients with benign prostate hyperplasia. Int Urol Nephrol 39: pp. 879-886 CrossRef
- Lowe, F.C., Ku, J.C. (1996) Phytotherapy in treatment of benign prostatic hyperplasia: a critical review. Urology 48: pp. 12-20 CrossRef
- Wilt T, Ishani A, MacDonald R. Serenoa repens for benign prostatic hyperplasia. Cochrane database Syst Rev. 2002;(3):CD001423.
- Potency of a novel saw palmetto ethanol extract, SPET-085, for inhibition of 5α-reductase II
Advances in Therapy
Volume 27, Issue 8 , pp 555-563
- Cover Date
- Print ISSN
- Online ISSN
- Springer Healthcare Communications
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- benign prostatic hyperplasia
- saw palmetto ethanol extract
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- Pilar Pais (1)
- Author Affiliations
- 1. Euromed, C/Rec de Dalt, 21-23, 08100 Mollet del Vallès, Barcelona, Spain