Progesterone plants

An important transformation in steroid biochemistry is the conversion of pregnenolone into progesterone. Progesterone is a female sex hormone, a progestogen, but this reaction is also involved in the production of corticosteroids such as hydrocortisone and aldosterone. The reaction also occurs in plants, and features in the formation of cardioactive glycosides, such as digitoxin in foxglove. 

As indicated earlier, plant products can be useful as starting materials for the semisynthetic preparation of other drugs. An important example in this regard is the Mexican yam, which produces a steroid precursor (diosgenin) vital to the synthesis of steroidal hormones used in oral contraceptives (i.e., progesterone). The availability of diosgenin eliminates numerous expensive steps in the organic synthesis of the basic steroid molecule. It was this discovery that contributed to the development of the pharmaceutical company Syntex (now a subsidiary of Hoffman LaRoche) and the development of the first birth control pill. 

Gavidia, L, Tarrio, R., Rodriguez-Trelles, R, Perez-Bermudez, P. and Seitz, H.U. (2007) Plant progesterone 5p-reductase is not homologous to the animal enzyme. Molecular evolutionary characterization of P5fJR from Digitalis purpurea. Phytochemistry, 68, 853-64. 

Herl, V., Albach, D., Mueller-Uri, R, Braeuchler, C., Heubl, G. and Kreis, W. (2008) Using progesterone 5p-reductase, a gene encoding a key enzyme in the cardenolide biosynthesis, to infer the phylogeny of the genus Digitalis. Plant Syst. Evol., 271, 65-78. 

An uncontrolled study in 2002 by Lucks examined the effects of 3-month dermal application of V. agnus-castus essential oil (oil distilled at some point in the shrubs development of the fruit but while some leaves were still on the plant) on menopausal and perimenopausal symptoms. A 1.5% solution of the essential oil was incorporated in a bland cream or lotion and applied once a day, 5 to 7 days/week, for 3 months. Descriptive outcome measures were self-report via a survey of symptomatic relief (major, moderate, mild, none, worse) and side effects. A total of 33% of women reported major improvement in symptoms, with the most often area of improvement being hot flashes/ night sweats. Both improvement and worsening occurred in the areas of emotions and menstruation flow. Subjects who were also on progesterone supplementation reported breakthrough bleeding (7). 

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