Anisodus acutangulus

Anisodus (Solanaceae) comprises four species and three varieties, e.g. A. luridus, A. luridus var. fischerianus, A. acutangulus, A. acutangulus var. breviflorus, A. mairei, A. tanguticus, A. tanguticus var. viridulus. All of these are distributed in China, and only one (A. luridus) in Nepal, Bhutan, and India. They are perennial herbs or subshrubs. Stems are dichotomous or trichotomous; roots thick and fleshy; leaves simple, alternate or subopposite, entire or large-toothed, petiolate. Flowers solitary, axillary, lateral or between branches, usually pendulous. Calyx campanulate-funnel or funnel-shaped with ten veins, lobes four or five, with varying forms and length; Corolla campanulate with 15 veins, four to five lobed, imbricate. Stamens five, nearly equal length, anther ovate, introrse, longitudinally split, pistil a little longer than stamen, pyramid-shaped ovary. Capsila globose or nearly globose.

All four species are raw material for the commercial production of various tropanes, of which scopolamine (also known as hyoscine) and hyoscyamine (atropine) are particularly important drugs. Two drugs are used as a remedy for stomach pains, fractures, rheumatic pains, arthritis, spamolysis etc.. Hyoscyamine has a stimulatory action on the central nervous system, scopolamine is the parasympatholytic agent. In China, rhizome, stem and leaves of A. acutangulus are used as natural Chinese herbs and their medicinal compounds, scopolamine and hyoscyamine, are used medicinally as a remedy for the above-mentioned ailments. However, the contents of scopolamine and hyoscyamine in plants from natural sources are generally much lower, especially those of scopolamine. The value and curative effect of scopolamine are higher than that of hyoscyamine and the amount of scopolamine medicinally used is lower than that of hyoscyamine.

As well known, the plant cells are totipotent, the revelation of which depends on the presence of proper internal and external factors. Similarly, the dedifferen-tiated cells should possess the “totipotency” to produce all the medicinal compounds found in the whole plant. In order to apply the biotechnology of cell culture for industrial production of medicinal substances, it is necessary to satisfy the following points: (1) Pharmacological activities should be definitive and chemical identification methods should be reliable for medicinal compounds by cell cultures. (2) The growth rate of cells and medicinal contents should be high enough to give a good yield of the final product in a short period of time. (3) The cultured cells should be genetically stable to ensure constant production. (4) Production costs should be low enough to be profitable to the producer. (5) Valuable stock cultures could be stored to regulate industrial production. Thus the main objective of the present chapter is to provide evidence for biotechnological applications of cell cultures for the production of medicinal compounds in Anisodus acutangulus.

Anisodus acutangulus: Conclusions

1. The in vitro cultured cells of Anisodus acutangulus possessed the ability to synthesize scopolamine and hyoscyamine originally found in the plant, and the chemical identification methods were reliable.

2. Cells could be subcultured from solid static cultures to cell suspensions and then into fermenter cultures. By these methods, the growth rate was 15 times that in the original callus, and increased by at least once a day. The contents of the two alkaloids were six times those of original callus, especially for scopolamine, whose content was ten times that of the original callus.

3. Production costs could be reduced by the use of non-ionic water instead of distilled water, and confectioner’s sugar instead of sucrose.

4. Stock cultures could be stored by cryopreservation (at -196° C) of callus and the suspension cultures.

The results of these investigations on various aspects of the in vitro cultures provide evidences for biotechnological application to Anisodus acutangulus, which could well be employed to produce scopolamine and hyoscyamine cells on an industrial scale.

 

Selections from the book: “Medicinal and Aromatic Plants II”, 1989.