A Review on the Ethnomedicinal Usage, Phytochemistry, and Pharmacological Properties of Gentianeae (Gentianaceae) in Tibetan Medicine

Gentianaceae is a large plant family and is distributed worldwide. As the largest tribe in Gentianaceae, Gentianeae contains 939-968 species, and the Qinghai-Tibet Plateau and adjacent areas are the main centers of diversity for Gentianeae. Species from the Gentianeae are widely used in traditional Tibetan medicine. In this review, a systematic and constructive overview of the information on botany, ethnomedicinal usage, phytochemistry, and pharmacological properties of Gentianeae in Tibetan medicine is provided. The results of this study are based on a literature search, including electronic databases, books, websites, papers, and conference proceedings. Botanical studies showed that Gentianeae includes the subtribe Gentianeae and Swertiinae, and several new genera and taxa have been identified. Approximately 83 species from Gentianeae were used in Tibetan medicine, among which Gentiana and Swertia constituted the largest number of species with 42 and 24 species, respectively. The species from Gentianeae are mainly used as Bangjian (སྤང་རྒྱན།), Jieji (ཀྱི་ལྕེ།), Dida (ཏིག་ཏ།), and Ganggaqiong (གང་གྰཆུང་།) in Tibetan medicine with different clinical applications. More than 240 formulas were found containing Gentianeae species with different attending functions. Phytochemical studies showed that the main active components of Gentianeae species are iridoids, xanthones, flavonoids, and triterpenoids. The bioactivities of plants from Gentianeae include hepatic protection, upper respiratory tract protection, joint and bone protection, glucose regulation, antibacterial, antioxidant, anticancer, and antiviral effects. This review will provide a reference for future research on natural resource protection, plant-based drug development, and further clinical investigation.

Gentiana asclepiadea L. from Two High Mountainous Habitats: Inter- and Intrapopulation Variability Based on Species' Phytochemistry

Natural populations of Gentiana asclepiadea L., located at two mountainous sites, were HPLC-analyzed regarding the contents of six representative secondary metabolites. The contents of swertiamarin (SWM), gentiopicrin (GP), sweroside (SWZ), mangiferin (MGF), isoorientin (ISOOR), and isovitexin (ISOV) were determined in six populations (three per study site), and separately for aboveground and belowground plant parts. PCA showed a clear separation of four groups according to the contents of the analyzed secondary metabolites. Out of six analyzed compounds, five were present in all samples and only one (SWZ) was found in Golija populations (belowground parts) but not in Vlasina populations, and its presence can be indicative of the geolocation of populations. Clear separation of groups was mostly affected by the different contents of chemical compounds in plant parts (aboveground versus belowground) and by the differences related to population origin (higher content of SWM and GP in belowground parts of individuals from Vlasina populations and higher content of MGF and ISOOR of individuals from Golija populations). The results of this study contribute to the spatiochemical profiling of G. asclepiadea populations and a better understanding of inter- and intrapopulation variability of pharmacologically important compounds.

Metabolomics Combined with Multivariate Statistical Analysis for Screening of Chemical Markers between Gentiana scabra and Gentiana rigescens

Gentianae Radix et Rhizome (Longdan in Chinese, GRR) in Chinese Pharmacopoeia is derived from the dried roots and rhizomes of Gentiana scabra and G. rigescens, that have long been used for heat-clearing and damp-drying in the medicinal history of China. However, the characterization of the chemical components of two species and the screening of chemical markers still remain unsolved. In current research, the identification and characterization of chemical components of two species was performed using ultra-high-performance liquid chromatography (UHPLC) coupled with linear ion trap-Orbitrap (LTQ-Orbitrap) mass spectrometry. Subsequently, the chemical markers of two species were screened based on metabolomics and multivariate statistical analysis. In total, 87 chemical constituents were characterized in G. scabra (65 chemical constituents) and G. rigescens (51 chemical constituents), with 29 common chemical constituents being discovered. Thereafter, 11 differential characteristic components which could differentiate the two species were designated with orthogonal partial least squares discriminant analysis (OPLS-DA) and random forest (RF) iterative modeling. Finally, seven characteristic components identified as (+)-syringaresinol, lutonarin, trifloroside, 4-O-β-d-glu-trifloroside, 4″-O-β-d-glucopyranosy1-6′-O-(4-O-β-d-glucaffeoyl)-linearroside, macrophylloside a and scabraside were selected as the chemical markers for the recognition of two Gentiana species. It was implied that the results could distinguish the GRR derived from different botanical sources, and also be beneficial in the rational clinical use of GRR.

Iridoid glycosides from the Genus Gentiana (Gentianaceae) and their Chemotaxonomic Sense

The genus Gentiana is one of the largest genera in the Gentianaceae family. Many Gentiana species have been scientifically investigated for their chemical constituents and chemotaxonomic sense. To date, more than 500 chemical compounds were isolated from Gentiana plant. Several researchers have reviewed the secondary metabolites and their bioactivities of Gentiana plants. However, a survey on iridoid glycosides and their chemotaxonomic sense of the genus Gentiana are unavailable. Iridoid glycosides are the major chemicals isolated from Gentiana spp., which serve as potential chemotaxonomic markers to differentiate Gentiana species. Herein, the review systematically summarizes the scaffolds of the iridoids reported according to the biosynthetic pathway of natural iridoid glycosides. Furthermore, the taxonomy of Gentiana and chemotaxonomic sense of iridoid glycosides in the genus Gentiana were surveyed.

Simultaneous determination of six index constituents and comparative analysis of four ethnomedicines from genus Gentiana using a UPLC-UV-MS method

Many species from genus Gentiana (Gentianaceae) have a long history of applications as folk medicines in the world. A simple rapid UPLC-UV-MS/MS method has been developed and validated for the simultaneous determination of six index constituents (gentiopicroside, swertiamarin, loganic acid, sweroside, mangiferin and ferulic acid) from the four ethnomedicines (G. rigescens Franch. ex Hemsl., G. rhodantha Franch. ex Hemsl., G. scabra Bunge and G. farreri Balf. f.). The UPLC analysis was performed on Shim-Pack XR-ODS III (150 × 2.0 mm, 2.2 µm). The mobile phase was consisted of acetonitrile-0.1% formic acid water using gradient elution. The wavelength 242 nm was chose for the four iridoids as well as mangiferin and 320 nm was set for ferulic acid. Mass spectrometry was applied for identification and quantification for analytes with low concentration. All the regression equations revealed a good linear relationship (R(2)  > 0.9993). Accuracy and precision were all within the required limits. The chromatogram fingerprints analysis combined with principal component analysis showed the similarity values of the four species were <0.788 while the similarity values of G. scabra Bunge and G. rigescens Franch. ex Hemsl. were >0.993, which provided reasonable foundation for utilization and clinical application of the four ethnomedicines. This developed method appears to be a useful tool for quality control of the four ethnomedicines.

Identification of medicinal plants used as Tibetan Traditional Medicine jie-ji

AIM OF THE STUDY

Based on the authors' collection of specimens used as jie-ji in local Tibetan areas, China, and taxonomic determination, this paper aims to give a list of medicinal plants as jie-ji, formally identify the ones recognized as jie-ji ga-bao or jie-ji na-bao and to offer basic data for further studies on these Tibetan herbs.

MATERIALS AND METHODS

Local herbalists were visited in Tibetan areas, China to observe which plants were being used as jie-ji. Samples of the indigenous plants were collected at the same time. Also, the medicinal plants as jie-ji were taxonomically identified.

RESULTS

A list of medicinal plants including 10 species of jie-ji in local Tibetan areas is given, including their morphological pictures used for identification.

CONCLUSIONS

The origin of jie-ji is from 10 species of the Section Cruciata, Genus Gentiana (Gentianaceae). five species with dark blue flowers are used as jie-ji na-bao, the other five with white flowers are used as jie-ji ga-bao. Also, Gentiana macrophylla Pall. with dark blue flowers in the Section Cruciata, Genus Gentiana is not the original plant of jie-ji na-bao. The species endemic to the province are used as the original plants of jie-ji only in local Tibetan area of the province. Finally, the drug use of jie-ji in Traditional Tibetan Medicine is reasonable and it is efficacious.