Preparative Separation and Purification of Four Glycosides from Gentianae radix by High-Speed Counter-Current Chromatography and Comparison of Their Anti-NO Production Effects

An Insight of Plant Source, Toxicological Profile, and Pharmacological Activities of Iridoid Loganic Acid: A ComprehensiveReview

This study evaluates the pharmacological effects of iridoid glucoside loganic acid, a plant constituent with diverse properties, based on literature, and explores the underlying cellular mechanisms for treating several ailments. Data were collected from reliable electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar, etc. The results demonstrated the anti-inflammatory, anti-oxidant, and other protective effects of loganic acid on metabolic diseases and disorders such as atherosclerosis, diabetes, and obesity, in addition to its osteoprotective and anticancer properties. The antioxidant activity of loganic acid demonstrates its capacity to protect cells from oxidative damage and mitigates inflammation by reducing the activity of inflammatory cytokines involving TNF-α and IL-6, substantially upregulating the expression of PPAR-γ/α, and decreasing the clinical signs of inflammation-related conditions related to hypertriglyceridemia and atherosclerosis. Meanwhile, loganic acid inhibits bone loss, exhibits osteoprotective properties by increasing mRNA expression levels of bone synthesizing genes such as Alpl, Bglap, and Sp7, and significantly increases osteoblastic proliferation in preosteoblast cells. Loganic acid is an anti-metastatic drug that reduces MnSOD expression, inhibits EMT and metastasis, and prevents cellular migration, proliferation, and invasion in hepatocellular carcinoma cells. However, additional clinical trials are required to assess its safety, efficacy, and human dose.

Metagenomic and phytochemical analyses of kefir water and its subchronic toxicity study in BALB/c mice

BACKGROUND

In recent years, researchers are interested in the discovery of active compounds from traditional remedies and natural sources, as they reveal higher therapeutic efficacies and improved toxicological profiles. Among the various traditional treatments that have been widely studied and explored for their potential therapeutic benefits, kefir, a fermented beverage, demonstrates a broad spectrum of pharmacological properties, including antioxidant, anti-inflammation, and healing activities. These health-promoting properties of kefir vary among the kefir cultures found at the different part of the world as different media and culture conditions are used for kefir maintenance and fermentation.

METHODS

This study investigated the microbial composition and readily found bioactive compounds in water kefir fermented in Malaysia using 16S rRNA microbiome and UHPLC sequencing approaches. The toxicity effects of the kefir water administration in BALB/c mice were analysed based on the mice survival, body weight index, biochemistry profile, and histopathological changes. The antioxidant activities were evaluated using SOD, FRAP, and NO assays.

RESULTS

The 16S rRNA amplicon sequencing revealed the most abundant species found in the water kefir was Lactobacillus hilgardii followed by Lactobacillus harbinensis, Acetobacter lovaniensis, Lactobacillus satsumensis, Acetobacter tropicalis, Lactobacillus zeae, and Oenococcus oeni. The UHPLC screening showed flavonoid and phenolic acid derivatives as the most important bioactive compounds present in kefir water which has been responsible for its antioxidant activities. Subchronic toxicity study showed no toxicological signs, behavioural changes, or adverse effects by administrating 10 mL/kg/day and 2.5 mL/kg/day kefir water to the mice. Antioxidants assays demonstrated enhanced SOD and FRAP activities and reduced NO level, especially in the brain and kidney samples.

CONCLUSIONS

This study will help to intensify the knowledge on the water kefir microbial composition, available phytochemicals and its toxicological and antioxidant effects on BALB/c mice since there are very limited studies on the water kefir grain fermented in Malaysia.

An improved method for the isolation of amarogentin, the bitter principle of yellow gentian roots

Amarogentin is well known to be among the most bitter naturally occurring compound. Either as an individual one or extracts, amarogentin is used as a food additive and as a dietary supplement. The aim of the present investigation is to set-up a convenient process to selectively isolate amarogentin from the ethanolic roots extract of Gentiana lutea. The process consisted in the treatment of an aqueous suspension of such an extract with a panel of 21 solid inorganic / organic sorbents followed by filtration, desorption, and high performance liquid chromatography (HPLC) analyses. Among the solid materials tested, those containing Mg⁺² in the frame of a lamellar structure provided very good adsorption yields in the range 86.4% - 99.9% (p < 0.05 at Student's t-test). The method we set up could be in principle useful to obtain a pure nature-derived food additive to provide bitter taste to foods and beverages.

Genus Gentiana: A review on phytochemistry, pharmacology and molecular mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

As the largest genus of Gentianaceae family, the Gentiana genus harbors over 400 species, widely distributed in the alpine areas of temperate regions worldwide. Plants from Gentiana genus are traditionally used to treat a wide variety of diseases including easing pain dispelling rheumatism, and treating liver jaundice, chronic pharyngitis and arthritis in China since ancient times. In this review, a systematic and constructive overview of the traditional uses, phytochemistry, molecular mechanisms, toxicology and pharmacological activities of the researched species of genus Gentiana is provided.

MATERIALS AND METHODS

The used information in this review is based on various databases (PubMed, Science Direct, Wiley online library, Wanfang Data, Web of Science) through a search using the keyword "Gentiana" in the period of 1981-2019. Besides, other ethnopharmacological information was acquired from Chinese herbal classic books and Chinese pharmacopoeia 2015 edition.

RESULTS

The plants from Gentiana genus have a long tradition of various medicinal uses in Europe and Asia. Phytochemical studies showed that the main bioactive components isolated from this genus includes iridoids xanthones and flavonoids. These compounds and extracts isolated from this genus show a wide range of protective activities including hepatic protection, gastrointestinal protection, cardiovascular protection, immunomodulation, joint protection, pulmonary protection, bone protection and reproductive protection. Molecular mechanism studies also indicated several potential therapeutic targets in the treatment of certain diseases by plants from this genus. Besides, natural products from this plant show no significant animal toxicity, cytotoxicity or genotoxicity.

CONCLUSION

This review summarized the traditional medicinal uses, phytochemistry, pharmacology, toxicology and molecular mechanism of genus Gentiana, providing references and research tendency for plant-based drug development and further clinical studies.

Preparative separation of mangiferin glycosides by high speed counter current chromatography and comparison of their antioxidant and antitumor activities

Mangiferin, a xanthonoid with various bioactivities. The low solubility of mangiferin limits the use in pharmacological fields. In this study, high-speed counter-current chromatography (HSCCC) was used to separate and purify mangiferin glycosides from the crude sample after enzymatic glycosylation of mangiferin. Two fructosyl mangiferin were successfully purified by HSCCC with a two-phase-solvent system composed of n-butanol–methanol–water (6 : 1 : 6, v/v). A total of 18 mg of mangiferin (I), 73 mg of β-d-fructofuranosyl-(2 → 6)-mangiferin (II), and 58 mg of β-d-difructofuranosyl-(2 → 6)-mangiferin (III) were obtained in one-step separation from 150 mg of the crude sample with purities of 99.2%, 98.7% and 98.9%, respectively. The chemical structures were identified by HRMS, ¹H-NMR, ¹³C-NMR and 2D NMR. Mangiferin glycosides showed higher antioxidant and antitumor activities compared to that of mangiferin by employing DPPH scavenging effect, reducing power and cytotoxicity assay. Therefore, these novel fructosyl mangiferin exhibit a great potential to be developed into new medicines.

High-speed counter-current chromatography is an efficient method for separation of mangiferin glycosides from enzymatic glycosylation.

Pharmacokinetics and metabolic profiles of swertiamarin in rats by liquid chromatography combined with electrospray ionization tandem mass spectrometry

Swertiamarin, a typical compound of secoiridiod glycosides with various pharmacological effects which is the major iridoid glicoside of Swertia. In this study, we have established a fast and sensitive LC-MS/MS method. The aim was to conduct pharmacokinetic studies of swertiamarin in vivo of rats. Gentiopicroside was used as internal standard and a C18 column was employed for the separation of analytes. The selected reaction monitoring transitions were m/z 375→177, 357.1→195 for swertiamarin and the internal standard, respectively, in a positive ion mode. The results showed that swertiamarin had a good linearity in the range of 2-8000 ng/mL (r ＞ 0.997) and its limit of detection (LLOD) was 0.5 ng/mL. The developed method subsequently successfully used in the pharmacokinetic study of swertiamarin in rats after oral administration (50, 100, and 150 mg/kg). We obtained a series of pharmacokinetic parameters, and the half-time of swertiamarin was 1 h, while the oral bioavailability was between 5.6-7.6%. Six metabolites of swertiamarin were identified based on accurate mass measurements of protonated molecules and their MS/MS spectrum by ultra-high-performance chromatography/tandem quadrupole time-of-flight mass spectrometry. Furthermore, metabolites were classified into three groups and the metabolic pathway of swertiamarin was proposed. The finding may help for the understanding of effectiveness and safety of swertiamarin.

Application of Centrifugal Partition Chromatography for Bioactivity-Guided Purification of Antioxidant-Response-Element-Inducing Constituents from Atractylodis Rhizoma Alba

Activity-guided separation of antioxidant response element (ARE)-inducing constituents from the rhizomes of Atractylodis Rhizoma Alba was performed by the combination of centrifugal partition chromatography (CPC) and an ARE luciferase reporter assay. From 3 g of the active n-hexane fraction, one polyacetylene, (6E,12E)-tetradeca-6,12-dien-8,10-diyne-1,3-diyl diacetate (47.3 mg), and two sesquiterpenes, atractylenolide I (40.9 mg), and selina-4(14),7(11)-dien-8-one (6.0 mg) were successfully isolated by CPC with n-hexane–ethyl acetate–methanol–water (8:2:8:2, v/v). The chemical structures of the isolated compounds were determined by ¹H- and ¹³C-NMR and ESI-MS. Among the isolated compounds, (6E,12E)-tetradeca-6,12-diene-8,10-diyne-1,3-diol diacetate and selina-4(14),7(11)-dien-8-one increased ARE activity 32.9-fold and 16.6-fold, respectively, without significant cytotoxicity, when 5 µM sulforaphane enhanced ARE activity 27.1-fold. However, atractylenolide I did not increase ARE activity at 100 µM, and showed cytotoxicity at concentrations over 10 µM.

Isolation and Purification of Two Isoflavones from Hericium erinaceum Mycelium by High-Speed Counter-Current Chromatography

High-speed counter-current chromatography (HSCCC) was used to separate and purify two isoflavones for the first time from Hericium erinaceum (H. erinaceum) mycelium using a two-phase solvent system composed of chloroform-dichloromethane-methanol-water (4:2:3:2, v/v/v/v). These two isoflavones were identified as genistein (4′,5,7-trihydroxyisoflavone, C₁₅H₁₀O₅) and daidzein (4′,7-dihydroxyisoflavone, C₁₅H₁₀O₄), using infrared spectroscopy (IR), electro-spary ionisation mass (ESI-MS), ¹H-nuclear magnetic resonance (NMR) and ¹³C-NMR spectra. About 23 mg genistein with 95.7% purity and 18 mg daidzein with 97.3% purity were isolated from 150 mg ethanolic extract of H. erinaceum mycelium. The results demonstrated that HSCCC was a feasible method to separate and purify genistein and daidzein from H. erinaceum mycelium.