Thymus quinquecostatus Celak. ameliorates cerebral ischemia-reperfusion injury via dual antioxidant actions: Activating Keap1/Nrf2/HO-1 signaling pathway and directly scavenging ROS.

BACKGROUND: Thymus quinquecostatus Celak. has been widely used as a spice and a folk medicine for relieving exterior syndrome and alleviating pain in China. PURPOSE: To explore the protective effects and the underlying mechanism against cerebral ischemia-reperfusion injury (CIRI) of the T. quinquecostatus combining with its chemical composition. STUDY DESIGN AND METHODS: High-polar extract (HPE) was extracted from T. quinquecostatus and polyphenols in HPE were enriched to obtain polyphenol-rich fraction (PRF) using Macroporous resin. The free radicals and zebrafish embryos were used to compare the antioxidant activities of HPE and PRF in vitro and in vivo. Then, the transient middle cerebral artery occlusion (tMCAO) model was established in rats. Neurological deficit score, infarction rate, morphology and apoptosis of neurons were examined to investigate the protective effects of PRF on CIRI. The mRNA and protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1) and the activities of downstream antioxidant enzymes in ischemia tissues were determined to clarify the underlying mechanisms. Also, reactive oxygen species (ROS) level in zebrafish embryos were detected after incubation with PRF for a short time (2 h) to investigate whether PRF could directly eliminate free radicals. Finally, chemical composition of PRF were analyzed to investigate the material basis for antioxidant activity and anti-CIRI effect. RESULTS: Compared with HPE, PRF showed stronger antioxidant activities. PRF exhibited obvious protective effects including ameliorating neurological deficit, lowering infarction rate, and improving the cellular morphology in hippocampus CA1 and cortex after tMCAO. TUNEL staining suggested PRF dose-dependently improved the apoptosis of the neurons in ischemic cortex. RT-qPCR and Western Blot results suggested that PRF regulated oxidative stress (OS) via activating the Keap1/Nrf2/HO-1 signaling pathway. Also, PRF could directly scavenge excessive ROS in zebrafish embryos after a short-time PRF incubation. The anti-CIRI effect might be primarily attributed to the abundant polyphenols in PRF, including flavonoids, polymethoxylated flavonoids, flavonoid glycosides, and phenolic acids. CONCLUSION: T. quinquecostatus contains abundant polyphenols and exhibited a good protective effect against CIRI via dual antioxidant mechanisms, providing a reference for further research and application for this plant.

Physicochemical Aspects and Sensory Profiles as Various Potential Factors for Comprehensive Quality Assessment of Nü-Er-Cha Produced from Rhamnus heterophylla Oliv.

Nü-Er-Cha, produced from the leaves of Rhamnus heterophylla Oliv., is known as an herbal tea and used in the treatment of bleeding, irregular menstruation and dysentery. A method was developed for the quality assessment of herbal tea, Nü-Er-Cha, adopting physical parameters, chemical constituents and sensory profiles as various potential factors. Their inner relationship was mined by multivariate statistical analysis tools, and the three factors were integrated by a technique for order preference by a similarity to ideal solution (TOPSIS) approach to comprehensively analyze the characters of Nü-Er-Cha. Viscosity was also introduced to the physical parameter determination besides conductivity, pH and color. Seven common peaks of eight batches of Nü-Er-Cha were marked by a high performance liquid chromatography (HPLC) fingerprint. They were further identified by HPLC mass spectrometry/mass spectrometry (HPLC-MS/MS) as hydroxybenzoic acids and flavanol glycosides. Fifty trained members participated in the sensory evaluation. Significant correlations between total sensory scores and conductivity, viscosity as well as pH were observed, a relatively innovative result for the quality assessment of herbal teas. The common peaks, belonging to hydroxybenzoic acids and flavanol glycosides, were mainly related to the color of infusions and leaves. The result of the TOPSIS analysis showed that S3 and S4 ranked as the top two in the comprehensive quality assessment. This may be related to rhamnetin triglycoside with a galactose/glucose and two rhamnoses, which had a higher peak response in S3 and S4 than that in the other samples. The present study may contribute to a better understanding of the relationship regarding physical properties, chemical composition and sensory profiles, and it may supply ideas for the comprehensive quality assessment of the herbal tea Nü-Er-Cha.

Traditional Uses, Chemical Constituents and Biological Activities of Plants from the Genus Thymus.

The genus Thymus (Lamiaceae) comprises about 214 species throughout the world, mainly found in North Africa, Europe, and temperate Asia zone. They are traditionally used as food additives and folk medicines. This review comprehensively summarizes information about traditional uses, chemical constituents, and biological activities of this genus and provides recommendations for future investigations. All information was gathered from scientific databases including Google Scholar, Sci-Finder, Web of Science, ScienceDirect, and CNKI. Volatile oils are the most concerned constituents of this genus. Flavonoids, phenylpropanoids, tannins, organic acids, terpenoids, and phytosterols were also summarized. This genus plants possessed a variety of activities including antimicrobial, antioxidant, anti-inflammatory, cytotoxic, analgesic, and antidiabetic. In brief, this review will be helpful to provide valuable data for explorations and create more interests towards Thymus genus in the future.

Multi-Response Extraction Optimization Based on Anti-Oxidative Activity and Quality Evaluation by Main Indicator Ingredients Coupled with Chemometric Analysis on Thymus quinquecostatus Celak.

Thymus quinquecostatus Celak is a species of thyme in China and it used as condiment and herbal medicine for a long time. To set up the quality evaluation of T. quinquecostatus, the response surface methodology (RSM) based on its 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was introduced to optimize the extraction condition, and the main indicator components were found through an UPLC-LTQ-Orbitrap MSn method. The ethanol concentration, solid-liquid ratio, and extraction time on optimum conditions were 42.32%, 1:17.51, and 1.8 h, respectively. 35 components having 12 phenolic acids and 23 flavonoids were unambiguously or tentatively identified both positive and negative modes to employ for the comprehensive analysis in the optimum anti-oxidative part. A simple, reliable, and sensitive HPLC method was performed for the multi-component quantitative analysis of T. quinquecostatus using six characteristic and principal phenolic acids and flavonoids as reference compounds. Furthermore, the chemometrics methods (principal components analysis (PCA) and hierarchical clustering analysis (HCA)) appraised the growing areas and harvest time of this herb closely relative to the quality-controlled. This study provided full-scale qualitative and quantitative information for the quality evaluation of T. quinquecostatus, which would be a valuable reference for further study and development of this herb and related laid the foundation of further study on its pharmacological efficacy.