Isolation and characterization of quinine from Polygonatum verticillatum: A new marker approach to identify substitution and adulteration

Pharmacological properties of Polygonatum and its active ingredients for the prevention and treatment of cardiovascular diseases

Despite continued advances in prevention and treatment strategies, cardiovascular diseases (CVDs) remain the leading cause of death worldwide, and more effective therapeutic methods are urgently needed. Polygonatum is a traditional Chinese herbal medicine with a variety of pharmacological applications and biological activities, such as antioxidant activity, anti-inflammation, antibacterial effect, immune-enhancing effect, glucose regulation, lipid-lowering and anti-atherosclerotic effects, treatment of diabetes and anticancer effect. There has also been more and more evidence to support the cardioprotective effect of Polygonatum in recent years. However, up to now, there has been a lack of comprehensive studies on the active ingredients and their pharmacotoxicological effects related to cardiovascular diseases. Therefore, the main active components of Polygonatum (including Polysaccharides, Flavonoids, Saponins) and their biological activities were firstly reviewed in this paper. Furthermore, we summarized the pharmacological effects of Polygonatum's active components in preventing and treating CVDs, and its relevant toxicological investigations. Finally, we emphasize the potential of Polygonatum in the prevention and treatment of CVDs.

A Review of Polygonatum Mill. Genus: Its Taxonomy, Chemical Constituents, and Pharmacological Effect Due to Processing Changes

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Polygonatum Tourn, ex Mill. contains numerous chemical components, such as steroidal saponins, polysaccharides, flavonoids, alkaloids, and others, it possesses diverse pharmacological activities, such as anti-aging, anti-tumor, immunological regulation, as well as blood glucose management and fat reducing properties.

AIM OF THE REVIEW

This study reviews the current state of research on the systematic categorization, chemical composition, pharmacological effects, and processing changes of the plants belonging to the genus Polygonatum, to provide a theoretical foundation for their scientific development and rational application.

MATERIALS AND METHODS

The information was obtained by searching the scientific literature published between 1977 and 2022 on online databases (including PubMed, CNKI, SciFinder, and Web of Science) and other sources (such as the Chinese Pharmacopoeia 2020 edition, and Chinese herbal books).

RESULTS

The genus Polygonatum contains 79 species, and 233 bioactive chemical compounds were identified in them. The abundance of pharmacological activities, such as antioxidant activities, anti-fatigue activities, anti-inflammatory activities, etc., were revealed for the representatives of this genus. In addition, there are numerous processing methods, and many chemical constituents and pharmacological activities change after the unappropriated processing.

CONCLUSIONS

This review summarizes the taxonomy classification, chemical composition, pharmacological effects, and processing of the plants belonging to the genus Polygonatum, providing references and research tendencies for plant-based drug development and further clinical applications.

Isolation of Sinapic Acid from Habenaria intermedia D. Don: A New Chemical Marker for the Identification of Adulteration and Substitution

Background:

Vriddhi is one of the Rasayana herbs in Ayurveda broadly used in vitality, strengthening Ayurvedic formulations. To fulfill steeply increased demand and declined supply, tubers have been collected in destructive manner resulting in reduced plant population and pushing the plant in Red list of IUCN endangered species. However, manufacturers are using substitutes and other substandard drugs leading to adulteration which puts the importance of therapeutically rich herbal plants at stake. Lack of chemical markers is the main inability of regulatory authorities for not taking any action against this adulteration.

Objective:

Isolation of chemical marker of plant that can be used as a reference compound for identification of unauthorized substitution.

Methods:

Preliminary phytochemical screening of methanolic and toluene extract of H. intermedia D. Don was done using standard methods followed by column chromatography for the isolation of phytoconstituents. A total of 3004 fractions were collected with Thin Layer Chromatography (TLC) profiling and different fractions were pooled. A single compound was isolated and confirmed by chemical test, melting point, spectral analysis and compared with the literature.

Results:

Phytochemical screening of extracts shows the presence of alkaloids, carbohydrates, steroids, terpenoids, flavonoids, tannins and phenolics. A pure white crystalline powder was isolated by column chromatography which was characterized as 3,5-dimethoxy-4- hydroxycinnamic acid (Sinapic acid) with the help of IR and Mass spectroscopy.

Conclusion:

This is the first report of Sinapic acid as a novel compound from Vriddhi, Habenaria genus and Orchidaceae family. It can be used as a marker for the identification of unauthorized substitution and adulteration claiming the use of Vriddhi.

Characterization of the complete chloroplast genome of Polygonatum sibiricum (Liliaceae), a well-known herb to China

Polygonatum sibiricum is a famous and well-known TCH (Traditional Chinese Herb) in China. In this paper, the complete chloroplast genome of P. sibiricum was studied and illustrated to add more genetic information and data. The chloroplast genome is 152,960 bp in length and a typical quadripartite structure, which exhibits a large single-copy region (LSC) of 81,471 bp, a small single-copy region (SSC) of 18,485 bp and a pair of inverted-repeat regions (IRs) of 26,502 bp in each. The overall nucleotide composition of chloroplast genome is: 30.7% A, 31.4% T, 19.3% C, 18.6% G and the total GC content 37.9%. A total of 136 genes were annotated that included 90 protein-coding genes (PCGs), 38 transfer RNA (tRNAs) and 8 ribosome RNA (rRNAs). The phylogenetic ML tree shown that P. sibiricum is closely related to P. cyrtonema on genetic position relationship by the Maximum-Likelihood (ML) method.

Toward Improving Medication Adherence: The Suppression of Bitter Taste in Edible Taste Films

Bitter taste is aversive to humans, and many oral medications exhibit a bitter taste. Bitter taste can be suppressed by the use of inhibitors or by masking agents such as sucralose. Another approach is to encapsulate bitter tasting compounds in order to delay their release. This delayed release can permit the prior release of bitter masking agents. Suppression of bitter taste was accomplished by encapsulating a bitter taste stimulus in erodible stearic acid microspheres, and embedding these 5 µmeter diameter microspheres in pullulan films that contain sucralose and peppermint oil as masking agents, along with an encapsulated masking agent (sucralose). Psychophysical tests demonstrated that films which encapsulated both quinine and sucralose produced a significant and continuous sweet percept when compared to films without sucralose microspheres. Films with both quinine and sucralose microspheres also produced positive hedonic scores that did not differ from control films that contained only sucralose microspheres or only empty (blank) microspheres. The encapsulation of bitter taste stimuli in lipid microspheres, and embedding these microspheres in rapidly dissolving edible taste films that contain masking agents in both the film base and in microspheres, is a promising approach for diminishing the bitter taste of drugs and related compounds.

Co-nanoencapsulation of antimalarial drugs increases their in vitro efficacy against Plasmodium falciparum and decreases their toxicity to Caenorhabditis elegans

Drugs used for the treatment and prevention of malaria have resistance-related problems, making them ineffective for monotherapy. If properly associated, many of these antimalarial drugs may find their way back to the treatment regimen. Among the therapeutic arsenal, quinine (QN) is a second-line treatment for uncomplicated malaria but has side effects that limit its use. Curcumin (CR) is a natural compound with anti-plasmodial activities and low bioavailability. In this context, the aim of this work was to develop and characterize co-encapsulated QN + CR-loaded polysorbate-coated polymeric nanocapsules (NC-QC) to evaluate their activity on Plasmodium falciparum and the safety of the nanoformulations for Caenorhabditis elegans. NC-QC displayed a diameter of approximately 200 nm, a negative zeta potential and a slightly basic pH. The drugs are homogeneously distributed in the NCs in the amorphous form. Co-encapsulated NCs exhibited a significant reduction in P. falciparum parasitemia, better than QN/CR. The worms exposed to NC-QC showed higher survival and longevity and no decrease in their reproductive capacity compared to free and associated drugs. It was possible to prove that the NCs were absorbed orally by the worms using fluorescence microscopy. Co-encapsulation of QN and CR was effective against P. falciparum, minimizing the toxic effects caused by chronic exposure of the free drugs in C. elegans.

De Novo Assembly and Analysis of Polygonatum sibiricum Transcriptome and Identification of Genes Involved in Polysaccharide Biosynthesis

Polygonatum sibiricum polysaccharides (PSPs) are used to improve immunity, alleviate dryness, promote the secretion of fluids, and quench thirst. However, the PSP biosynthetic pathway is largely unknown. Understanding the genetic background will help delineate that pathway at the molecular level so that researchers can develop better conservation strategies. After comparing the PSP contents among several different P. sibiricum germplasms, we selected two groups with the largest contrasts in contents and subjected them to HiSeq2500 transcriptome sequencing to identify the candidate genes involved in PSP biosynthesis. In all, 20 kinds of enzyme-encoding genes were related to PSP biosynthesis. The polysaccharide content was positively correlated with the expression patterns of β-fructofuranosidase (sacA), fructokinase (scrK), UDP-glucose 4-epimerase (GALE), Mannose-1-phosphate guanylyltransferase (GMPP), and UDP-glucose 6-dehydrogenase (UGDH), but negatively correlated with the expression of Hexokinase (HK). Through qRT-PCR validation and comprehensive analysis, we determined that sacA, HK, and GMPP are key genes for enzymes within the PSP metabolic pathway in P. sibiricum. Our results provide a public transcriptome dataset for this species and an outline of pathways for the production of polysaccharides in medicinal plants. They also present more information about the PSP biosynthesis pathway at the molecular level in P. sibiricum and lay the foundation for subsequent research of gene functions.