Therapeutic and medicinal effects of snowdrop (Galanthus spp.) in Alzheimer's disease: A review

Genus Galanthus (Amaryllidaceae) is an early spring flowering bulbous plant. Galanthus species contain alkaloids that have shown pharmacological activity. Galanthamine is an alkaloid that was extracted from Galanthus and other Amaryllidaceae. Owing to its acetylcholinesterase (AChE) inhibitory activity, galanthamine is used and marketed to treat Alzheimer's disease (AD). The aim of the present study, while introducing the botanical and pharmacological characteristics and various aspects of the medicinal plant Galanthus, is to emphasize the effect of this plant in the treatment of AD. In this web-based study in 2021, articles indexed in scientific databases in English language, including ISI Web of Knowledge, PubMed, Scopus, MedLib, Medknow, SID, ISC, and also articles and e-books published in Springer, Elsevier, John Wiley and Sons, and Taylor and Francis were evaluated from 1990 to 2021, using the following keywords: "Galanthus" "galanthamine," "Alzheimer's disease." Amaryllidaceae-type alkaloids possess an anticholinesterase activity. The most studied Galanthus alkaloid, galanthamine, is a long-acting, selective, reversible, competitive inhibitor of AChE and an allosteric modulator of the neuronal nicotinic receptor for acetylcholine (ACh). Owing to its AChE inhibitory activity, galanthamine is used to treat certain stages of AD. Galantamine can act as a parasympathomimetic agent, especially as a reversible cholinesterase inhibitor. Galantamine is not structurally associated with other AChE inhibitors. Hence, its proposed mechanism of action involves the reversible inhibition of AChE, preventing hydrolysis of ACh that results in an increased concentration of ACh at cholinergic synapses.

In vitro micropropagation and alkaloids analysis by GC-MS of Chilean Amaryllidaceae plants: Rhodophiala pratensis

INTRODUCTION

Plants from Amaryllidaceae family are of interest since they produce a particular type of alkaloid useful for the treatment of neurodegenerative diseases of the central nervous system, such as Galanthamine. Given the low content of these secondary metabolites in the plant, it is necessary to study mechanisms to increase the productivity of them.

OBJECTIVE

To obtain fast qualitative and quantitative analysis of the alkaloids and extend the understanding of biosynthesis and metabolism in these kinds of plants. Furthermore, establish a reliable, simple and fast analytical method for the in vitro callus culture of vegetative organs for Rhodophiala pratensis species.

METHODS

The alkaloids composition of the callus culture of R. pratensis were analysed by gas chromatography coupled with mass spectrometry (GC-MS).

RESULTS

A methodology for the qualitative and quantitative analysis of the alkaloids present in fresh callus culture of this wild plant species was established. The analysis showed alternation in the alkaloids type ratio and number of compounds between wild bulbs, in vitro bulbs and callus. It was possible to identify 24 alkaloids from a pool of 60 signals whose fragmentation pattern corresponds to the alkaloids of Amaryllidaceae plants. Together with the aforementioned, the amount and type of alkaloid present in the plant material obtained by in vitro culture of R. pratensis was determined in the same way. The results show the high biosynthetic potential of in vitro grown bulbs and callus tissue that are able to produce significant amounts of pharmacologically relevant alkaloids from R. pratensis in various proportions that depend on the culture conditions such as supplementation with growth substances. The in vitro grown bulbs produce an alkaloidal extract that contain a 52.6% w/w of alkaloids.

CONCLUSION

This study allowed the alkaloid content in callus culture of R. pratensis to be found by means of GC-MS. These results allowed a relationship between the type of growth regulator and the type of alkaloids found to be established. Finally, we can say that the results achieved to state that the production of alkaloids using different combinations of growth regulators could be directed during in vitro micropropagation from provided plant material.

Amaryllidaceae andSceletiumalkaloids

Recent progress on the isolation, identification, biological activity and synthetic studies of Amaryllidaceae alkaloids, as well as the structurally close alkaloids from theSceletiumgenus, published from July 2015 to June 2017 are reviewed.