Bufadienolides and ecdysteroids from the whole plants of Helleborus niger and their cytotoxicity

Yokosuka, Akihito; Inomata, Mina; Yoshizawa, Yuka; Iguchi, Tomoki; Mimaki, Yoshihiro

doi:10.1007/s11418-021-01481-6

Cited by 14 publications

(15 citation statements)

References 17 publications

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“…Regarding the steroidrich composition of H. caucasicus, studies have shown that these natural compounds are involved in reducing the viability of tumor cells by inducing apoptosis due to decreased expression of the GRP78 gene [56]. Similarly, by performing a spectroscopic analysis of the whole plant of H. niger, it was determined that due to the composition of bufadienolide and ecdysteroid, the extract has antitumor capacity by inducing apoptosis [57].…”

Section: Discussionmentioning

confidence: 99%

Comparative Evaluation of the Potential Antitumor of Helleborus purpurascens in Skin and Breast Cancer

Pilut

Manea

Macaşoi

et al. 2022

Plants

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In the field of oncology, the plant kingdom has an inexhaustible supply of bioactive compounds. Phytochemical compounds isolated from Helleborus species have been found to be useful in various chronic diseases. This has brought Helleborus to the attention of medical researchers. H. purpurascens is a plant characteristic of the Carpathian area, known since ancient times for its beneficial effects. The aim of the study was to evaluate the flavonoids composition of a hydroalcoholic extract of H. purpurascens, as well as to assess its antioxidant activity and antitumor potential at the level of two healthy cell lines and four tumor cell lines. In addition, the expression of the genes involved in the apoptotic process (Bcl-2, Bad, and Bax) were evaluated. The results indicated that the extract has a high concentration of flavonoids, such as epicatechin, quercetin, and kaempferol. The extract has an increased antioxidant activity, very similar to that of the standard, ascorbic acid and cytotoxic effects predominantly in the breast cancer cell line, being free of cytotoxic effects in healthy cell lines. Underlying the cytotoxic effect is the induction of the process of apoptosis, which in the present study was highlighted by decreasing the expression of anti-apoptotic genes (Bcl-2) and increasing the expression of pro-apoptotic genes (Bad and Bax). In conclusion, the hydroalcoholic extract of H. purpurascens can be considered an important source for future medical applications in cancer therapy.

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Section: Discussionmentioning

confidence: 99%

Comparative Evaluation of the Potential Antitumor of Helleborus purpurascens in Skin and Breast Cancer

Pilut

Manea

Macaşoi

et al. 2022

Plants

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“…27 This finding was supported by two independent studies, which both found that the proliferation of tumor cells can be inhibited by Helleborus niger root and whole plant extracts. 28,29…”

Section: Introductionmentioning

confidence: 99%

“…27 This finding was supported by two independent studies, which both found that the proliferation of tumor cells can be inhibited by Helleborus niger root and whole plant extracts. 28,29 The chemistry of the active ingredients in the above-ground parts of Helleborus niger has been investigated in a few studies. In 1973, Martinek 30 isolated a crystalline compound from the ethanol extract of dried stems, leaves, and flowers of Helleborus niger L. which had been collected in the Austrian Alps (South Carinthia).…”

Section: Introductionmentioning

confidence: 99%

Efficient Isolation and Structure Analysis of (+)-Ranuncoside, a Unique Tricyclic Spiroacetal Glycoside, from Christmas Rose (Helleborus niger L.)

Cuny

Klingler²

2022

Natural Product Communications

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The use of medicinal herbs as remedies reaches back to the Stone Age, and their importance as a source of drugs has continuously increased since then. Herbal ingredients can serve as active pharmaceuticals themselves or as lead substances for the development of synthetic pharmaceuticals with less toxicity, higher effectiveness or with new properties. To date, only 6% of the ∼600,000 plants on earth have been tested pharmacologically. Among these, the medicinal plant Helleborus niger L. (Christmas rose) is especially promising because its leaves contain ( + )-ranuncoside 1, characterized by a spiroacetal ring system, a motif which is responsible for the biological activity of a multitude of natural products. Structure-activity relationship studies of ( + )-ranuncoside 1 are lacking and no synthesis of 1 has been described yet. Therefore, we developed a protocol for the rapid and efficient isolation of 1 from the leaves of cultivated Christmas rose. Crystals of high purity were obtained that enabled us to study the stereochemistry of 1 by NMR spectroscopy in solution for the first time. The spiro configuration, the absolute stereochemistry, and the geometry of all three rings was then confirmed by x-ray structure analysis. Our data will enable future structure-activity relationship studies to assess the potential of 1 as a lead substance for the development of novel antibiotics and anticancer agents.

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“…15 Furthermore, extracts of roots and the whole plant have been shown to inhibit the proliferation of tumor cells. 16,17…”

Section: Introductionmentioning

confidence: 99%

Biomimetic Total Synthesis of ( + )-Ranuncoside, a Unique Tricyclic Spiroacetal Glycoside of Christmas Rose (Helleborus niger L.)

Cuny

Fohrer

Klingler³

2022

Natural Product Communications

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Christmas Rose ( Helleborus niger L.) is an alpine plant belonging to the Ranunculaceae family. Typical for this popular ornamental plant are white flowers that appear during winter. Root extracts contain numerous medicinally active ingredients and potent cardiac glycosides. Recent findings indicate that Helleborus root extracts possess the potential for cancer treatment and inhibit the proliferation of tumor cells. In 2022, we published a practical extraction method of ( + )-ranucoside 1 from the dried leaves of H niger L. Here, we describe for the first time the total synthesis of 1. Starting from 5-hydroxylevulinic acid methyl ester 8 and acetobromo-α-D-glucose 13, the β-glycoside 14 is formed stereoselectively on the application of Koenigs-Knorr conditions. Subsequent cleavage of the acetyl-protecting groups and saponification of the ester function yields the pyrano dioxane derivative 17. Its lactonization gives ( + )-ranuncoside 1. The presented synthesis is practical and very efficient, consisting of 6 steps from D-glucose and giving 22% overall yield. Furthermore, it is biomimetic due to its concordance with the biosynthesis of ( + )-ranuncoside 1 in H foetidus.

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Bufadienolides and ecdysteroids from the whole plants of Helleborus niger and their cytotoxicity

Cited by 14 publications

References 17 publications

Comparative Evaluation of the Potential Antitumor of Helleborus purpurascens in Skin and Breast Cancer

Comparative Evaluation of the Potential Antitumor of Helleborus purpurascens in Skin and Breast Cancer

Efficient Isolation and Structure Analysis of (+)-Ranuncoside, a Unique Tricyclic Spiroacetal Glycoside, from Christmas Rose (Helleborus niger L.)

Biomimetic Total Synthesis of ( + )-Ranuncoside, a Unique Tricyclic Spiroacetal Glycoside of Christmas Rose (Helleborus niger L.)

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