Antioxidant activity and phenolic compounds of 112 traditional Chinese medicinal plants associated with anticancer

Cancer prevention and treatment using traditional Chinese medicines have attracted increasing interest. This study characterizes antioxidant activity and phenolic compounds of traditional Chinese medicinal plants associated with anticancer, comprising 112 species from 50 plant families. The improved ABTS(*+) method was used to systematically assess the total antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC) of the medicinal extracts. The TEAC values and total phenolic content for methanolic extracts of herbs ranged from 46.7 to 17,323 micromol Trolox equivalent/100 g dry weight (DW), and from 0.22 to 50.3 g of gallic acid equivalent/100 g DW, respectively. A positive, significant linear relationship between antioxidant activity and total phenolic content (all R(2) values>/=0.95) showed that phenolic compounds were the dominant antioxidant components in the tested medicinal herbs. Major types of phenolic compounds from most of the tested herbs were preliminarily identified and analyzed, and mainly included phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes, and curcuminoids. These medicinal herbs exhibited far stronger antioxidant activity and contained significantly higher levels of phenolics than common vegetables and fruits. Traditional Chinese medicinal plants associated with anticancer might be potential sources of potent natural antioxidants and beneficial chemopreventive agents.     

Comparative analysis of bioactive phenolic compounds composition from 26 medicinal plants

Bioactive phenolic compounds are powerful antioxidants in traditionally used medicinal and industrial crop plants and have attracted increased interest in the last years in their application and role in non-destructive methodology for pre-screening analysis of some stress factors. In this study the qualitative target was linked with future possible applications of received data for improving non-destructive methodology as well as for improving existing knowledge regarding antioxidant content in some plant species. Comparative analysis of total phenolics, flavonoid contents, phenolic acid composition, and antioxidant activity in known east central Europe medicinal and industrial crop plants of 26 species of families Asteraceae, Rosaceae and Lamiaceae was done. Among the investigated leaf extracts the highest total phenolic, total flavonoid contents and antioxidant activity have been seen for Stachys byzantine L. (Lamiaceae), Calendula officinalis L. (Asteraceae) and for Potentilla recta L. (Rosaceae). The highest syringic acid content has been found in the leaf extracts of plant family Asteraceae – in the range from 0.782 to 5.078 mg g^?1 DW. The representative’s family Rosaceae has a higher content of p-anisic acid in the range 0.334–3.442 mg g^?1DW compared to the leaf extracts of families Lamiaceae and Asteraceae. The comparative study showed significant differences of content of phenolic acids in the leaf extracts of different representative’s families Rosaceae, Asteraceae and Lamiaceae. We suggest that the presence of some phenolic acids can be used as a possible marker for family botanical specifications of representative families Asteraceae and Rosaceae. It was supposed that some pharmacological effects can be connected with the analyzed data.     

A potential antioxidant resource: Endophytic fungi from medicinal plants

Medicinal plants and their endophytes are important resources for discovery of natural products. Several previous studies have found a positive correlation between total antioxidant capacity (TAC) and total phenolic content (TPC) of many medicinal plant extracts. However, no information is available on whether such a relationship also exists in their endophytic fungal metabolites. We investigated the relationship between TAC and TPC for 292 morphologically distinct endophytic fungi isolated from 29 traditional Chinese medicinal plants. The antioxidant capacities of the endophytic fungal cultures were significantly correlated with their total phenolic contents, suggesting that phenolics were also the major antioxidant constituents of the endophytes. Some of the endophytes were found to produce metabolites possessing strong antioxidant activities. Several bioactive constituents from the fungal cultures and host plant extracts were identified. This investigation reveals that the metabolites produced by a wide diversity of endophytic fungi in culture can be a potential source of novel natural antioxidants.     

New phenolic constituents from Balanophora polyandra with radical-scavenging activity

The 80% acetone extract of Balanophora polyandra Griff. (Balanophoraceae) was found to exhibit high radical-scavenging activity (SC(50)=14.48 mug/ml) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Further chemical investigation led the isolation of two new hydrolysable tannins, balapolyphorins A (1) and B (2), together with 20 known phenolic compounds (3-22). Their structures were established by detailed spectroscopic analysis, and the radical-scavenging properties of all isolated compounds were determined by DPPH assay.     

Antifungal activity of extracts from five Egyptian wild medicinal plants against late blight disease of tomato

This study was carried out to evaluate the antifungal potential of water and ethanol extracts from aerial parts of five wild medicinal plants collected from Sinai Peninsula, Egypt, and the extracts were tested in vitro and in vivo against Phytophthora infestans, the causal agent of late blight disease of tomato. The five wild medicinal plants used for the study were Asclepias sinaica, Farsetia aegyptia, Hypericum sinaicum, Phagnalon sinaicum and Salvia aegyptiaca. Ethanol extracts were more effective on the pathogen than water extracts at all concentrations used. Water and ethanol extracts of all plants tested reduced mycelial growth and inhibited spore germination of the pathogen with varying degrees. Water and ethanolic extracts also reduced the disease infection with pathogen comparing with control in detached leaves technique. In all experiments, extracts of A. sinaica and F. aegyptia were most effective on the pathogen than other plant extracts. In plot experiment, the water and ethanolic extracts of A. sinaica and F. aegyptia gave the most reduction of late blight disease severity comparing with control. Also, data indicated that after the application of plant extracts, there was an increase in fruit yield of tomato corresponding with the reduction of disease severity . Scanning electron microscopy revealed a negative alteration of pathogen hyphae treated with A. sinaica extract at 20%. This concentration of the same plant extract also reflected in dramatic changes in the cyto-morphology of pathogen hyphae as observed by transmission electron microscopy. These changes resulted in an increase in vacuolisation and lipid contents with consequent reduction of cytoplasm with alteration of cell wall and plasmalemma. The overall results suggested that the use of these Egyptian wild medicinal plant extracts was promising, effective and environment-friendly management measure against Phytophthora blight of tomato and thus, may be used in the production of organically grown vegetables.     

18种中草药提取物对褐飞虱和甜菜夜蛾的杀虫活性分析

为了筛选对农产品和环境安全、对害虫高效的植物源杀虫剂,分别采用喷雾法和饲毒法,测定了18种中草药的3种溶剂（水、乙醇、石油醚）提取物对褐飞虱Nilaparvata lugens Stål的触杀活性和对甜菜夜蛾Spodoptera exigua Hübner的胃毒作用。结果表明,各种提取物（0.8 g/mL）对甜菜夜蛾的胃毒作用不明显,校正死亡率最高为33.33%;但对褐飞虱的杀虫活性较高,其中百部、黄柏、榧子、生山栀、鹤虱、木香的乙醇或石油醚提取物,对褐飞虱3龄若虫的24 h校正死亡率均在80%以上,其石油乙醚提取物的LC50值依次为：0.0826,0.0455,0.0145,0.0047,0.0038,0.0033 g/mL。采用系统溶剂法分析发现,木香和鹤虱的主要杀虫活性成分均在氯仿萃取物中,表明其杀虫成分易溶于较弱极性溶剂中。进一步通过活性追踪法,对鹤虱提取物的柱层析各流分的活性检测表明,其杀虫活性成分的Rf值为0.5556~0.5926。该研究为进一步纯化新型植物源杀虫物质并确定其分子结构,从而开发其应用前景及发现新的杀虫活性先导化合物奠定了基础。