ABSTRACT
The nervous system controls eccentric exercise in a special way. During eccentric exercise, excitability increases in cortex, and inhibition decreases, causing excitability decrease in spinal cords. In another hand, increased cortical excitability results in extra excitatory compensation for spinal inhibition. The excitability of the corticospinal pathway depends on the balance between excitability and inhibition of the spinal cord level finally, which usually decreases. Many factors, such as the intensity of contraction, can affect the balance of corticospinal excitability. There is a cross-over effect in eccentric exercise, which promotes corticospinal excitability in untrained limbs. However, the effects and mechanisms of muscle length, fatigue and training duration are still unclear, and current researches have focused in the healthy populations. More researches are needed to explore the effects of eccentric exercise on ill populations.
ABSTRACT
Pterocarpans, ubiquitous in Fabaceae, are protective active substances produced by the chemical defense system of plants. A total of 144 pterocarpans had been discovered before 2006. For the first time, we reported the 89 pterocarpans identified in 2006-2020. These pterocarpans not only demonstrate novel complex diversified genus-specific stereostructures but also display strong anti-microbial, anti-tumor, antioxidant, insecticidal, and anti-inflammatory activities. Through the projection of their biogenetic pathways and study of the pharmacological activities, the structure-activity correlation was further confirmed. The distribution of Leguminosae plants rich in pterocarpans has obvious regional characteristics. Therefore, the research and utilization of Leguminosae plant resources in China should be strengthened, and the popularity and application value of the geographical indicator plant resources should be improved. This paper serves as a reference for further research, development, and utilization of pterocarpans and their plant sources.
Subject(s)
Anti-Inflammatory Agents , Antioxidants , Fabaceae , Plant Extracts/pharmacology , Pterocarpans/pharmacologyABSTRACT
Objective To optimize the extraction and purification process of oleanolic acid in Ligustrum lucidum fruits with macroporous resin. Methods Grinding degree, temperature, liquid ratio, extraction time, extraction times, ethanol volume fraction and pH were selected as factors, which may influence the extraction of oleanolic acid from L. lucidum. Single factor experiments were carried out on these factors. The optimal extraction conditions were determined, and the best type of resin was chosen for separation and purification of oleanolic acid in the optimal conditions. Results The optimal technological conditions were as follows: the temperature was controlled at 80°C, ethanol solution was 60%, liquid material ratio was 1:11, extraction time was 120 min, and extraction times were twice. The crude extraction was processed at pH 12, and then the pH was adjusted to 2 to further purify the processed crude extraction. The content of oleanolic acid in the extract was 9.5% by UV visible spectrophotometric method. This extraction was further separated and purified by AB- 8 resin, and the content of oleanolic acid detected by ultraviolet visible spectrophotometr was 15.2%o Conclusion The optimal process of the oleanolic acid extraction is reproducible, simple and feasible. It may provide reference for using macroporous resin to extract oleanolic acid from L. lucidum in the industry production.
ABSTRACT
A novel method combining ultra-high performance liquid chromatography (UHPLC) fingerprint and simultaneous quantitative analysis of eight phenolic components was developed and validated for quality evaluation of Tetrastigma hemsleyanum leaves. For fingerprint analysis, 15 peaks were selected as the common peaks to evaluate the similarities among 41 batches of T. hemsleyanum leaves collected from different regions. Additionally, simultaneous quantification of eight markers, including neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, isoorientin, orientin, vitexin-2-O-rhamnoside,vitexin and isovitexin, was performed and the obtained data demonstrated that our method has achieved desired linearity, precision and accuracy. Clustering statistical analysis was further application in T. hemsleyanum leaves from different regions. The results indicated that new approach conbine ultra-high performance liquid chromatography (UHPLC) fingerprint and simultaneous quantitative analysis of eight phenolic components was applicable in quality control of T. hemsleyanum leaves.
ABSTRACT
Ligustrum lucidum can be used as immunomodulatory and to treat acute hepatitides and chronic hepatitis, and has many other bioactivities such as anti-aging activity, decreasing the level of the blood sugar, anti-inflammatory activity and anti-tumor activity. The chemical constituents of its fruits include pentacyclic triterpenoid, dammarane tetracyclic triterpenoids, flavones, secoiridoids, phenolic glucosides, and other components such as polysaccharide, amino acid, fatty acid, volatile components, pigment, microelement, and so on. This paper summarizes the research advances on the chemical constitutents of Ligustrum lucidum and the structure-activity relationship.