A new aromatic glycoside from Glehnia littoralis

Glehnia littoralis Fr. Schmidtex Miq.: A systematic review on ethnopharmacology, chemical composition, pharmacology and quality control

ETHNOPHARMACOLOGICAL RELEVANCE

Glehnia littoralis Fr. Schmidtex Miq. is a well-known perennial herb that is used in traditional medicine in China, Japan and Korea. G. littoralis has the effects of treating the lungs with heat, nourishing yin and blood, and acting as an expectorant. Traditional Chinese medicine (TCM) prescriptions containing G. littoralis have various clinical applications, such as clearing heat, relieving coughs, treating hepatic fibrosis, resolving phlegm, and treating esophagitis.

AIM OF THE REVIEW

This paper aims to provide a comprehensive and productive review of G. littoralis, mainly including traditional application, ethnopharmacology, chemical composition, pharmacological activities, and quality control.

MATERIALS AND METHODS

Literature search was conducted through the Web of Science, ScienceDirect, Springer Link, PubMed, Baidu Scholar, CNKI, and WanFang DATA by using the keywords "Glehnia littoralis", "Radix Glehniae", "Bei Shashen", "Clinical application", "Chemical composition", "Quality control" and "pharmacological action". In addition, information was collected from relevant ancient books, reviews, and documents (1980-2022).

RESULTS

G. littoralis is a traditional Chinese herbal medicine with great clinical value and rich resources. More than 186 components, including coumarins, lignans, polyacetylenes, organic acids, flavonoids, and terpenoids, have been isolated and identified from G. littoralis. The pharmacological activities of more than half of these chemicals are yet unknown. Polyacetylenes and coumarins are the most important bioactive compounds responsible for pharmacological activities, such as antiproliferative, anti-oxidation, anti-inflammatory, antibacterial, antitussive, immune regulation and analgesic. In this study, the progress in chemical analysis of G. littoralis, including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (MS), and HPLC-MS, were summarized.

CONCLUSION

In this paper reviewed the previous literature regarding ethnopharmacological, phytochemical, pharmacological, and quality evaluation of the processing of G. littoralis was reviewed, providing potential reference information for future investigation and clinical applications. However, research on the relationship between chemical constituents and traditional uses of G. littoralis is lacking, and the comprehensive pharmacological effects and mechanisms of G. littoralis require further detailed exploration. In addition, an efficient method for chemical profiling is still unavailable to obtain potent bioactive markers for quality control. Perfect quality standards, which are also the basis for further drug development of G. littoralis, are urgently needed to ensure its quality and clinical application.

Sporogenesis, gametophyte development and embryogenesis in Glehnia littoralis

BACKGROUND

Glehnia littoralis is an economic herb with both medicinal and edible uses. It also has important ecological value and special phylogenetic status as it is a monotypic genus species distributing around beach. Little information on its reproductive biology has been reported so far, which has hindered conservation and application of this species. In this study, we observed morphological changes from buds emergence to seeds formation and internal changes during sporogenesis, gametophyte development and embryo and endosperm development of G. littoralis using paraffin-embedded-sectioning and stereo microscope.

RESULTS

The results showed that the stages of internal development events of G. littoralis corresponded to obvious external morphological changes, most of developmental features were consistent with other Apiaceae species. The development of male and female gametophytes was not synchronized in the same flower, however, exhibited temporal overlap. From mid-late April to mid-May, the anther primordial and ovule primordial developed into the trinucleate pollen grain and eight-nuclear embryo sac, respectively. From late-May to mid-July, the zygote developed into mature embryo. In addition, some defects in gynoecium or ovule development and abnormal embryo and endosperm development were found. We induced that the possible causes of abortion in G. littoralis were as follows: nutrient limitation, poor pollination and fertilization, and bad weather.

CONCLUSIONS

This study revealed the whole process and morphological characteristics of the development of reproductive organ in G. littoralis, which not only provided important data for the study of systematic and conservation biology, but also provided a theoretical basis for cross breeding.

Multiple Fingerprint Profiles and Chemometrics Analysis of Polysaccharides From the Roots of Glehnia littoralis

The quality of polysaccharides from different regions was studied by using multiple fingerprint analysis and chemometric analysis. Polysaccharides from 10 batches of Glehnia littoralis were compared based on Fourier-transform infrared spectroscopy (FT-IR), high-performance liquid chromatography (HPLC), gel permeation chromatography (GPC), and proton nuclear magnetic resonance (1H-NMR). According to the results, the 10 batches of polysaccharides from G littoralis had high similarity by analyzing HPLC, FT-IR, 1H-NMR, and GPC fingerprints. Through cluster analysis, samples and adulterants in different regions could be classified. Three monosaccharides (galactose, glucose, and galacturonic acid), molecular weights (4.33 × 105-4.91 × 105, 4.04 × 104-4.71 × 104, and 5.02 × 103-5.83 × 103), and H-1 (4.99, 5.39, and 5.42 ppm) of α-glucose could be used as markers for quality control of medicinal materials of the roots of G littoralis.

Structural elucidation, anti-radical and immunomodulatory activities of polysaccharides from the roots of Glehnia littoralis

This study investigated the structural elucidation, anti-radical and immunomodulatory activities of polysaccharides from the roots of Glehnia littoralis. A crude polysaccharide was extracted from the roots of G. littoralis through the ultrasonic-assisted extraction and further purified by DEAE-52 cellulose and Sephadex G-100 gel column, a major polysaccharide fraction named GLP80-1 was obtained. The chemical properties and structure of GLP and GLP80-1 were characterized by acid hydrolysis, methylation analysis, along with high performance gel permeation chromatography, Fourier transform infrared, nuclear magnetic resonance, scanning electron microscope, thermogravimetric analysis and X-ray diffraction. The molecular weight distributions of GLP were determined as 1.89 × 10⁶ and 1.26 × 10⁴ Da. The monosaccharide composition of GLP was glucose, glucuronic acid, galactose and arabinose with molar ratios of 0.91:0.04:0.03:0.02, respectively. The average molecular weight of GLP80-1 was determined as 1.63 × 10⁴ Da. The structure of GLP80-1 was deduced to be a homogenous glucan, comprised a main chain of (1→4)-linked-α-D-Glcp with a single α-D-Glcp branch substituted at C-6. The results of biological activities in vitro showed that GLP and GLP80-1 exhibited free radical scavenging effects, and displayed promotion for the proliferation of mouse spleen lymphocytes and RAW264.7 cells. The data indicated that GLP and GLP80-1 had the potential to be explored as novel natural antioxidant and immunomodulator for application in functional food.

Ethnopharmacology, Phytochemistry, and Pharmacology of the Genus Glehnia: A Systematic Review

Glehnia littoralis Fr. Schmidt ex Miq, the sole species in the genus Glehnia (Apiaceae), has long been used in traditional Chinese medicine to treat fatigue, weakness, stomach-yin deficiency, lung heat, cough, dry throat, and thirst. Recently, G. littoralis has also been incorporated into a wide range of Chinese vegetarian cuisines. Based on the comprehensive information, advances in botany, known uses, phytochemistry, pharmacology, and toxicity of G. littoralis, we aim to highlight research gaps and challenges in studying G. littoralis as well as to explore its potential use in plant biotechnology. This may provide more efficient therapeutic agents and health products from G. littoralis. A literature search of SciFinder, ScienceDirect, Scopus, TPL, Google Scholar, Baidu Scholar, and Web of Science, books, PhD and MSc dissertations, and peer-reviewed papers on G. littoralis research was conducted and comprehensively analyzed. We confirmed that the ethnomedical uses of G. littoralis have been recorded in China, Japan, and Korea for thousands of years. A phytochemical investigation revealed that the primary active compounds were phenylpropanoids, coumarins, lignanoids, and flavonoids, organic acids and derivatives, terpenoids, polyacetylenes, steroids, nitrogen compounds, and others. Our analysis also confirmed that the extracts of G. littoralis possess immunoregulatory, antitumor, anti-inflammatory, hepatoprotective, antioxidant, neuroprotective, antibacterial, antifungal, and analgesic properties. Although further studies are required, there is strong evidence of the antitumor and immunoregulatory potential of G. littoralis. Also, more studies are needed to elucidate the mechanisms of action of its active compounds (e.g., falcarinol and panaxydiol) before any clinical studies can be carried out.

Phytochemical Study of Stem and Leaf of Clausena lansium

Clausena lansium Lour. Skeels (Rutaceae) is widely distributed in South China and has historically been used as a traditional medicine in local healthcare systems. Although the characteristic components (carbazole alkaloids and coumarins) of C. lansium have been found to possess a wide variety of biological activities, little attention has been paid toward the other components of this plant. In the current study, phytochemical analysis of isolates from a water-soluble stem and leaf extract of C. lansium led to the identification of 12 compounds, including five aromatic glycosides, four sesquiterpene glycosides, two dihydrofuranocoumarin glycosides, and one adenosine. All compounds were isolated for the first time from the genus Clausena, including a new aromatic glycoside (1), a new dihydrofuranocoumarin glycoside (6), and two new sesquiterpene glycosides (8 and 9). The phytochemical structures of the isolates were elucidated using spectroscopic analyses including NMR and MS. The existence of these compounds demonstrates the taxonomic significance of C. lansium in the genus Clausena and suggests that some glycosides from this plant probably play a role in the anticancer activity of C. lansium to some extent.

Chemical constituents from Glehnia littoralis and their chemotaxonomic significance

Phytochemical investigation of the roots of Glehnia littoralis Fr. Schmidt. ex Miq. led to the isolation of 16 known compounds, including three β-carboline alkaloids (1-3), four phenylpropanoids (4-7), five phenolic acids (8-12), three polyacetylenes (13-15) and one fatty acid (16). The structures of these compounds were elucidated on the basis of spectral analysis and comparison with those reported in literatures. To the best of knowledge, the report of the first β-carboline alkaloid in the Umbelliferae family. Additionally, compounds 1-5, 9, 10 and 16 have not been reported from any species in Umbelliferae family, compounds 7, 8 and 12 were isolated from the genus Glehnia for the first time and could be of the chemotaxinomic significance and serve as valuable chemotaxonomic makers for G. littoralis. The chemotaxonomic significance of the isolated compounds was summarised.

Conservation choice on the rare endangered plants Glehnia littoralis

The coastal herbs Glehnia littoralis have been domesticated as traditional medicines for many centuries. The domestication may have caused changes or declines of cultivated G. littoralis (CGL) relative to wild G. littoralis (WGL). By comparing fruit properties of CGL and WGL, we tested the hypothesis that domesticated G. littoralis have suffered major declines, and human cultivation cannot be sufficient to conserve this species. We collected fruits of CGL and WGL in the Shandong peninsula, China, and compared their buoyancy in seawater, germination potential after seawater immersion, and thousand-grain weights. Float rates of the WGL and CGL fruits were 95.6 (mean) ± 2.6% (standard deviation) and 30.0 ± 7.1%, respectively. The germination potential of CGL was significantly reduced, although the thousand-grain weights of CGL (21.85 ± 0.17 g) were higher than those of the WGL fruits (14.73 ± 0.21 g). These results suggest that the CGL have experienced significant declines relative to the WGL, presumably due to the loss of seawater inundation, selection and dispersal. These declines disfavour the persistence of CGL, and human domestication and cultivation are believed to be insufficient for conserving G. littoralis. Sand coasts where WGL still persists should be designated timely as nature reserves to conserve this species.