Profiling of the Major Phenolic Compounds and Their Biosynthesis Genes in Sophora flavescens Aiton

Chemical diversity, biological activities and Traditional uses of and important Chinese herb Sophora

BACKGROUND

Sophora flavescens Aiton (SF), also known as Kushen (Chinese:), has been an important species in Chinese medicine since the Qin and Han dynasties. It is also recognized as a plant resource suitable for the globalization of Chinese medicine. Traditionally, it has been used in various ethnic medical systems in East Asia, especially in China, to kill insects and dispel dampness. Sophora flavescens is commonly used for clearing heat-clearing, killing worms, and diuretic. Nowdays, accumulating studies demonstrated its anticancer and cardioprotection.

OBJECTIVE OF THE REVIEW

This paper aims to systematically review information on the genus, pharmacological and toxicological significance, chemical composition and biological activity of Sophora flavescens. To promoting its development and application. To summarize recent findings regarding to the metabolism, pharmacological/toxicological effects of Sophora flavescens.

MATERIAL AND METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Sophora flavescens Aiton", "Ku shen", "Pharmacology", "Active ingredient", "Toxicology" and combinations to include published studies of Sophora flavescens Aiton primarily from 1970-2021. Several critical previous studies beyond this period were also included and other related terms.

CONCLUSION

Sophora flavescens has a broad spectrum of biological activities associated with Sophora flavescens has been considered a valuable resource in both traditional and modern medicine. However, there is a lack of in-depth studies on the medicinal uses of Sophora flavescens. Moreover, further studies on single chemical components should be conducted based on the diversity of chemical structures, significant biological activities and clinical applications. The discovery of its bioactive molecules and multi-component interactions would be of great importance for the clinical application of Sophora flavescens spp. Detailed pharmacological and toxicological studies on the classic prescriptions of Sophora flavescens are also needed. It is more beneficial to the wide application of SF plant and facilitates the worldwide promotion of modern Chinese medicine. However, an increasing number of reports indicate that the administration of Sophora flavescens has serious adverse effects. Its main toxic effects are neurotoxicity and acute toxicity, which have caused widespread concern worldwide. In addition, the alkaloids of Sophora flavescens are distributed in the heart, liver, stomach and large intestine. They are excreted from the body through gluconeogenesis, which is the mode of action of certain therapeutic mechanisms of action such as anticancer. The detailed metabolic study of alkaloids and other components of Sophora flavescens in vivo needs to be further investigated. It is important to improve the pharmacological effects and reduce the toxicity of Sophora flavescens. For this purpose, structural modification of active components of Sophora flavescens or combination with other drugs is very essential.

Flavivirus infections induce a Golgi stress response in vertebrate and mosquito cells

The stress of the Golgi apparatus is an autoregulatory mechanism that is induced to compensate for greater demand in the Golgi functions. No examples of Golgi stress responses due to physiological stimuli are known. Furthermore, the impact on this organelle of viral infections that occupy the vesicular transport during replication is unknown. In this work, we evaluated if a Golgi stress response is triggered during dengue and Zika viruses replication, two flaviviruses whose replicative cycle is heavily involved with the Golgi complex, in vertebrate and mosquito cells. Using GM-130 as a Golgi marker, and treatment with monensin as a positive control for the induction of the Golgi stress response, a significant expansion of the Golgi cisternae was observed in BHK-21, Vero E6 and mosquito cells infected with either virus. Activation of the TFE3 pathway was observed in the infected cells as indicated by the translocation from the cytoplasm to the nucleus of TFE3 and increased expression of pathway targeted genes. Of note, no sign of activation of the stress response was observed in CRFK cells infected with Feline Calicivirus (FCV), a virus released by cell lysis, not requiring vesicular transport. Finally, dilatation of the Golgi complex and translocation of TFE3 was observed in vertebrate cells expressing dengue and Zika viruses NS1, but not NS3. These results indicated that infections by dengue and Zika viruses induce a Golgi stress response in vertebrate and mosquito cells due to the increased demand on the Golgi complex imposed by virion and NS1 processing and secretion.

Biosyntheses characterization of alkaloids and flavonoids in Sophora flavescens by combining metabolome and transcriptome

Sophora flavescens are widely used for their pharmacological effects. As its main pharmacological components, alkaloids and flavonoids are distributed in the root tissues wherein molecular mechanisms remain elusive. In this study, metabolite profiles are analyzed using metabolomes to obtain biomarkers detected in different root tissues. These biomarkers include alkaloids, phenylpropanoids, and flavonoids. The high-performance liquid chromatography analysis results indicate the differences in principal component contents. Oxymatrine, sophoridine, and matrine contents are the highest in the phloem, whereas trifolirhizin, maackiain, and kushenol I contents are the highest in the xylem. The transcript expression profiles also show tissue specificity in the roots. A total of 52 and 39 transcripts involved in alkaloid and flavonoid syntheses are found, respectively. Among them, the expression levels of LYSA1, LYSA2, AO2, AO6, PMT1, PMT17, PMT34, and PMT35 transcripts are highly and positively correlated with alkaloids contents. The expression levels of 4CL1, 4CL3, 4CL12, CHI5, CHI7, and CHI9 transcripts are markedly and positively correlated with flavonoids contents. Moreover, the quantitative profiles of alkaloids and flavonoids are provided, and the pivotal genes regulating their distribution in S. flavescens are determined. These results contribute to the existing data for the genetic improvement and target breeding of S. flavescens.

Metabolomics Reveals Distinct Metabolites between Lonicera japonica and Lonicera macranthoides Based on GC-MS

Lonicera japonica Thunb. (LJ) and Lonicera macranthoides Hand. -Mazz. (LM) have been widely used in Chinese medicine for thousands of years. Although the morphological characteristics of LJ and LM are quite similar, there are significant distinctions of medicinal ingredients (mainly the secondary metabolites) and clinical indications between them. However, the in-depth differences of primary metabolites have not thoroughly been studied yet. Therefore, gas chromatography-mass spectrometry- (GC-MS-) based metabolomics method combined with chemometric methods were performed to analyze the distinction in this study. The results showed that LJ and LM were obviously classified into two groups. 10 metabolites were obtained as biomarkers on account of their p values, pcorr values, and differing variable importance in projection (VIP) values. Metabolic pathway analysis showed that the galactose metabolism and starch and sucrose metabolism gathered as potential pathways caused these extraordinary differences of primary metabolites between LJ and LM. Further, we found that the differences of main medicinal ingredients between LJ and LM could be interpreted from these metabolites according to the analysis of mainly related pathways. The metabolites involved in the starch and sucrose metabolism presented upregulated in LJ, while almost all metabolites in the galactose metabolism, the TCA cycle, and the phenolic acid part of phenylpropanoid metabolism were downregulated in LJ. Therefore, the energy stored in the starch and sucrose metabolism may be saved to produce flavonoid, which could be the reason that the level of flavonoid of phenylpropanoid metabolism is higher in LJ compared to LM. Consequently, this study presented an effective tool for quality evaluation of LJ and LM and laid a foundation for further studies of the metabolic mechanisms and high-quality manufacturing of them.

Variation in phenolic compounds, α-linolenic acid and linoleic acid contents and antioxidant activity of purslane (Portulaca oleracea L.) during phenological growth stages

Purslane (Portulaca oleracea L.) contains a variety of natural products with different biological properties. The objective of this research was to estimate changes in total phenolics, flavonoids, and fatty acids (α-linolenic acid and linoleic acid) contents as well as antioxidant activity of P. oleracea at different growth stages. Seeds were germinated in soil-filled plastic pots at greenhouse. Leaves and stems were collected at the vegetative and flowering stages. Total phenol and flavonoid contents of the samples were determined by Folin-Ciocalteau and aluminum chloride methods, respectively. The contents of α-linolenic and linoleic acids were determined using gas chromatography analysis after transesterification of fatty acids. Furthermore, Ferric reducing antioxidant power and 1,1-diphenyl-2-picrylhydrazyl assays were used to determine the antioxidant activities. The highest contents of total phenols (698.6 mg GAE 100 g^-1 DW), flavonoids (46.9 mg QE 100 g^-1 DW), α-linolenic acid (2.7 mg g^-1 DW) and linoleic acid (0.8 mg g^-1 DW) were determined in the leaves at flowering stage. Free radical scavenging capacity was significantly affected (P ≤ 0.05) by age; and the leaves of purslane had more antioxidant potential compared to stems. A positive correlation was observed between the antioxidant activities and total phenols content. Overall, purslane leaves at flowering stage can be regarded as a valuable source of fatty acids (especially α-linolenic acid) and antioxidants in human diet.

The Synergistic Effect of Co-Treatment of Methyl Jasmonate and Cyclodextrins on Pterocarpan Production in Sophora flavescens Cell Cultures

Pterocarpans are derivatives of isoflavonoids, found in many species of the family Fabaceae. Sophora flavescens Aiton is a promising traditional Asian medicinal plant. Plant cell suspension cultures represent an excellent source for the production of valuable secondary metabolites. Herein, we found that methyl jasmonate (MJ) elicited the activation of pterocarpan biosynthetic genes in cell suspension cultures of S. flavescens and enhanced the accumulation of pterocarpans, producing mainly trifolirhizin, trifolirhizin malonate, and maackiain. MJ application stimulated the expression of structural genes (PAL, C4H, 4CL, CHS, CHR, CHI, IFS, I3’H, and IFR) of the pterocarpan biosynthetic pathway. In addition, the co-treatment of MJ and methyl-β-cyclodextrin (MeβCD) as a solubilizer exhibited a synergistic effect on the activation of the pterocarpan biosynthetic genes. The maximum level of total pterocarpan production (37.2 mg/g dry weight (DW)) was obtained on day 17 after the application of 50 μM MJ on cells. We also found that the combined treatment of cells for seven days with MJ and MeβCD synergistically induced the pterocarpan production (trifolirhizin, trifolirhizin malonate, and maackiain) in the cells (58 mg/g DW) and culture medium (222.7 mg/L). Noteworthy, the co-treatment only stimulated the elevated extracellular production of maackiain in the culture medium, indicating its extracellular secretion; however, its glycosides (trifolirhizin and trifolirhizin malonate) were not detected in any significant amounts in the culture medium. This work provides new strategies for the pterocarpan production in plant cell suspension cultures, and shows MeβCD to be an effective solubilizer for the extracellular production of maackiain in the cell cultures of S. flavescens.

A target-group-change couple with mass defect filtering strategy to identify the metabolites of "Dogel ebs" in rats plasma, urine and bile

"Dogel ebs" was known as Sophora flavescens Ait., a classical traditional Chinese Mongolian herbal medicine, which had the effects on damp-heat dysentery, scrofula, and syndrome of accumulated dampness toxicity. Although the chemical constituents have been clarified by our previous studies, the metabolic transformation of "Dogel ebs" in vivo was still unclear. To explore the mechanism of "Dogel ebs," the metabolites in plasma, bile, and urine samples were investigated. A fast positive and negative ion switching technology was used for the simultaneous determination of flavonoids and alkaloids in "Dogel ebs" in a single run. And a target-group-change coupled with mass defect filtering strategy was utilized to analyze the collected data. 89 parent compounds and 82 metabolites were characterized by high-performance liquid chromatography with quadrupole exactive Orbitrap mass spectrometry. Both phase I and phase II metabolites were observed and the metabolic pathways involved in oxidation, demethylation, acetylation, and glucuronidation. 69 metabolites of "Dogel ebs," including three hydroxyls bonding xanthohumol, formononetin-7-O-glucuronide, 2'-hydroxyl-isoxanthohumol decarboxylation metabolite, oxysophocarpine dehydrogen, 9α-hydroxysophoramine-O-glucuronide, etc. were reported for the first time.

Advanced Analytical Methods for Phenolics in Fruits

Phenolic compounds are a group of secondary plant metabolites, many with health-promoting properties that are present in all parts of plants. They have an aromatic structure, including either one or more hydroxyl groups giving them the ability to stabilize free radicals and protect biological tissues against damage related to reactive oxygen species. Phenolic compounds are concentrated in the fruit of plants, and therefore, the fruit can be an important dietary source of these phytochemicals, which exist as monomers, or bound to one another. Polyphenolic compounds are classified into different subclasses based upon the number of phenol ring systems that they contain, saturation, and length of the carbon chain that bind the rings to one another. The phenolic acids present in fruit tissues protect the plant against disease, infections, UV radiation, and insect damage. For this reason, the beneficiary effects of phenolic compounds are continually being investigated for their health-promoting properties and for meeting increased consumer demand for healthy nutritious food. Due to the functional properties of polyphenolic compounds, there is increased interest on improving extraction, separation, and quantification techniques of these valuable bioactive compounds, so they can be used as value-added ingredients in foods, pharmaceuticals, and cosmetics. This review provides information on the most advanced methods available for the analysis of phenolics in fruits.