A study of pharmacokinetic interactions among co-existing ingredients in Viscum coloratum after intravenous administration of three different preparations to rats

Exploring the resources of the genus Viscum for potential therapeutic applications

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Viscum comprises approximately 100 species that are mainly distributed across Africa, Asia and Europe. The extracts and preparations of Viscum species are widely used as common complementary and alternative medicines in the treatment of rheumatism and cancer.

AIM OF THE REVIEW

This review aims to explore the medicinal properties of twelve species belonging to the genus Viscum for potential therapeutic applications.

MATERIALS AND METHODS

We collected online information (including PubMed, CNKI, Google Scholar, and Web of Science) from January 1915 to April 2021 and knowledge from classical books on Chinese herbal medicines available for 12 species of the genus Viscum, including Viscum coloratum (Kom.) Nakai, Viscum album L., Viscum articulatum Burm. f., Viscum liquidambaricola Hayata, Viscum ovalifolium DC., Viscum capitellatum Sm., Viscum cruciatum Sieber ex Boiss., Viscum nudum Danser, Viscum angulatum B.Heyne ex DC., Viscum tuberculatum A.Rich., Viscum multinerve Hayata, and Viscum diospyrosicola Hayata.

RESULTS

At least 250 different compounds have been reported across twelve Viscum species, including amino acid and peptides, alkaloids, phenolic acids, flavonoids, terpenoids, carbohydrates, fatty acids, lipids, and other types of compounds. In particular, for Viscum coloratum (Kom.) Nakai and Viscum album L., the plants, preparations, and bioactive components have been thoroughly reviewed. This has allowed to elucidate the role of active components, including lectins, viscotoxins, flavonoids, terpenoids, phenolic acids, and polysaccharides, in multiple bioactivities, such as anti-cancer, anti-rheumatism arthralgia, anti-inflammation, anti-cardiovascular diseases, enhancing immunity, and anti-chemotherapy side effects. We also evaluated quality control methods based on active compounds, in vivo exposure compounds, and discriminated chemical markers.

CONCLUSIONS

This is the first report to systematically review the pharmaceutical development history, chemical composition, clinical evidence, pharmacological activity, discriminated chemical markers, in vivo exposure, and quality control on twelve distinct species of Viscum plants with medicinal properties. The significant safety and efficacy, along with the minor side effects are constantly confirmed in clinics. The genus Viscum is thus an important medicinal resource that is worth exploring and developing in future pharmacological and chemical studies.

Study on the Plasma Protein Binding Rate and Compatibility Regularity of the Constituents Migrating to Blood of Simiao Yong'an Decoction

OBJECTIVE

To study the compatibility regularity of Simiao Yong'an decoction by determining the plasma protein binding rate with the constituents in Simiao Yong'an decoction and to preliminarily clarify the effects of the compatibility on the plasma protein binding rate of different components.

METHODS

Based on the equilibrium dialysis method, high-performance liquid chromatography was used to determine the contents of six constituents, which were divided into a single group and combination groups, in Simiao Yong'an decoction in the internal and external dialysis solutions. The obtained plasma protein binding rate through calculations was an index to evaluate the binding of the above components to plasma protein in different conditions.

RESULTS

Harpagide, harpagoside, sweroside and loganin showed low plasma protein binding rates, ferulic acid exhibited a moderate plasma protein binding rate, and glycyrrhizic acid showed a high plasma protein binding rate. The compatibility study showed that glycyrrhizic acid promoted the binding of ferulic acid to plasma protein. Glycyrrhizic acid and ferulic acid were the key compounds to promote the binding of harpagide to plasma protein. Glycyrrhizic acid, harpagide, harpagoside and loganin had a significant inhibitory effects on the binding of sweroside to plasma protein. The plasma protein binding capacities of harpagoside and loganin were reduced by the other five constituents. Glycyrrhizic acid had the strongest plasma protein binding effect, and the binding effect was not affected by other components.

CONCLUSION

This study explores the effects of compound compatibility on effective components from the perspective of plasma protein binding by high-performance liquid chromatography combined with the equilibrium dialysis method, and lays a foundation for clarifying the compatibility rule of Simiao Yong'an decoction and also provides a new idea for the study of the compatibility of traditional Chinese medicine formulas.

The complete chloroplast genome sequence of Viscum coloratum (Viscaceae), a semiparasitic medicinal plant

Viscum coloratum (Viscaceae) is a kind of semiparasitic shrub used as medicinal plant. The complete chloroplast (cp) genome of V. coloratum was sequenced and characterized in this study. Length of total cp genome is 128,744 bp, which is constructed by four typical regions including a large single-copy region (LSC, 73,684 bp), a small single-copy region (SSC, 8630 bp) and a pair of inverted-repeat regions (IRs, 23,215 bp). 100 unique genes are predicted including 68 protein-coding genes, 28 tRNA genes and four rRNA genes. Phylogenetic analysis were performed based on 30 shared genes of 12 species in Santalales using maximum likelihood method. The results showed a close relationship between V. coloratum and V. album. The complete cp genome of V. coloratum would provide valuable genetic resources for further study on phylogeny, population genetics and identification in Viscum.

Therapeutic potential of mistletoe in CNS-related neurological disorders and the chemical composition of Viscum species

ETHNOPHARMACOLOGICAL RELEVANCE

Viscum album L., commonly known as mistletoe, has been used for centuries in traditional medicine to treat various neurological diseases, including epilepsy, hysteria, nervousness, hysterical psychosis, dizziness and headaches.

AIM OF THE STUDY

The aim of this review is to summarize existing evidence confirming the influence of mistletoe on the central nervous system and to investigate the compounds that may be responsible for this activity.

MATERIALS AND METHODS

Available information from studies of various species of the Viscum L. genus was collected from scientific journals, books, and reports via a library and an electronic data search (Elsevier, Google Scholar, PubMed, Springer, Science Direct, ResearchGate, and ACS).

RESULTS

The main chemical constituents of Viscum L. species are viscotoxins, lectins, flavonoids, phenolic acids, terpenoids, sterols, phenylpropanoids, and alkaloids. Various extracts of Viscum album L. showed central nervous system activity, including antiepileptic, sedative, antipsychotic, anxiolytic, antidepressant and antinociceptive effects in mice and rats. Additionally, the extracts increased the level of brain-derived neurotrophic factor, prevented apoptotic neuronal death induced by amyloid β and weakly inhibited cholinesterase activity.

CONCLUSIONS

Numerous historical references describe the use of mistletoe for the treatment of central nervous system disorders. In recent years, studies have started to confirm the antiepileptic, antipsychotic, sedative and antinociceptive effects of mistletoe. Additionally, mistletoe can be used as a complementary treatment for Alzheimer's disease. The therapeutic effect of mistletoe might be a result of the synergistic interactions of various secondary metabolites, including mistletoe-specific lectins. Further studies of the chemical composition and CNS activity of mistletoe are required. The mechanisms of action, target sites, pharmacokinetics, metabolic mechanisms, adverse effects and interactions of mistletoe with other drugs must also be investigated, as well.

Ginseng polysaccharides enhanced ginsenoside Rb1 and microbial metabolites exposure through enhancing intestinal absorption and affecting gut microbial metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Polysaccharides and small molecules commonly co-exist in decoctions of traditional Chinese medicines (TCMs). Our previous study outlined that ginseng polysaccharides (GP) could interact with co-existing ginsenosides to produce synergistic effect in an over-fatigue and acute cold stress model via gut microbiota involved mechanisms.

AIM OF THE STUDY

This study aimed to verify the interactions by examining the impact of GP on oral pharmacokinetics of ginsenoside Rb1 (Rb1), the dominant protopanoxadiol (PPD)-type ginsenoside in Ginseng, on a dextran sulphate sodium (DSS) induced experimental colitis model which was characterized by gut dysbiosis, and to delineate the underlying mechanisms in vitro.

MATERIALS AND METHODS

Rats received drinking water (normal group), 5% DSS (UC group), or 5% DSS plus daily oral administration of GP (GP group) for 7 days and fecal samples were collected on day -3, 0 and 6. On day 7 all animals received an oral dosage of Rb1 and blood samples were withdrawn for pharmacokinetic study. The in vitro metabolism study of Rb1 in gut microbiota from normal and UC rats and the transport study of Rb1 across Caco-2 cell monolayer were carried out in presence/absence of GP. Rb1 and its bacterial metabolites ginsenoside Rd (Rd), ginsenoside F2 (F2), Compound K (CK) and PPD were determined using LC-MS/MS. Total and target bacteria in fecal samples were determined by using 16S rRNA-based RT-PCR. β-Glucosidase activity was determined by measuring 4-nitrophenol formed from 4-nitrophenyl-β-D-glucopyranoside hydrolysis.

RESULTS

DSS induction did not alter AUC_0-t and C_max of Rb1, which, however, were doubled together with elevated AUC_0-t of the metabolites, in particular Rd and CK, in GP group. GP influenced the microbial composition and showed a prebiotic-like effect. Accordingly, GP treatment could partially restore the β-glucosidase activity which was reduced by DSS induction. The presence of GP resulted in quicker microbial metabolism of Rb1 and higher Rd formation in first 8 h of incubation, while the impact on F2 and CK formation/conversion became obvious after 8 h. More interestingly, GP slightly stimulated Caco-2 cell growth and facilitated Rb1 transport across the Caco-2 monolayer in both directions, increasing the P_app of Rb1 from 10^-7 cm/s to 10^-6 cm/s.

CONCLUSIONS

GP alleviated DSS-induced colitis-like symptoms and enhanced the systemic exposure of Rb1 through enhancing microbial deglycosylation and intestinal epithelial absorption of Rb1. These findings further demonstrated the important role of gut microbiota in the multifaceted action of polysaccharides in the holistic actions of traditional decoction of TCMs.