Biological and Toxicological Activities

Echinacea is promoted as an immune-enhancing herbal product and could be easily incorporated into cereal-based products (Wilson, 1998) to create a functional food. There are over 300 research articles dealing with the biological activity of Echinacea. In addition, over two million prescriptions 

Administration, via mouse chow, of E. purpurea root extracts at 0.45 mg/day per mouse was found to enhance the number of NK cells in healthy young and old mice (Sun et al., 1999 Currier and Miller, 2000) and leukemic mice (Currier and Miller, 2001, 2002). The number of NK cells increased in both the spleen and bone marrow, and paralleled cell cytolytic 

Combination of low doses of cyclophosphamide, E. purpurea extract (Echinacin ) and thymostimulin enhanced the immune functions of terminally ill cancer patients (Lersch et al., 1990, 1992). NK cells increased between 17 and 29% whereas lymphokine activated killer cell activity increased from 180 to 195%. In contrast, polysaccharides isolated from cell cultures of E. purpurea did not enhance the phagocytic activity of granulocytes in chemotherapy patients (Melchart et al., 2002). 

The CAP have been reported to inhibit HIV type 1 (HIV-1) integrase and HIV-1 replications at concentrations as low as 10 p,M (McDougall et al., 1998 King et al., 1999 Reinke et al., 2002). Cichoric acid inhibited 50% of the integrase activity and blocked HIV-1 infections by 50% at concentrations of 0.3 and 4 p,M, respectively (Robinson et al., 1996a,b). Hexane extracts of Echinacea roots were found to have antiviral activity against the Herpes simplex virus type 1 at a 0.12 mg/ml concentration (Binns et al., 2002d). 

The in vitro antifungal activity of the lipophilic extracts and commercial tinctures of Echinacea was enhanced after exposure to UV irradiation (Binns et al, 2000). These authors noted that E. purpurea flowers and a commercial tea product were the only products that lacked antifungal activity after UV exposure. The photooxidation of the alkamide, ketoalkenes and ketoalkynes contributed to the enhanced antifungal activity (Binns et al., 2000). 

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Table 4. Biological and Toxicological Activities of Environmentally Persistent Methyl Sulfone Polychlorinated Biphenyls3... 

This dynamic distribution results in accumulation of persistent congeners in all tissues and depletion from all tissues of those congeners that can be cleared (Matthews and Dedrick 1984). Metabolites, however, may accumulate in specific tissues due to solubility differences as well as tissue binding (Section 3.4.3). Relatively little is known regarding the biological and toxicological activity of these persistent PCB metabolites. 

There is an increasing awareness of the potential environmental and health hazards of trace levels of pesticides, their trace impurities as well as metabolites and/or degradation products. Hence, there is a need to develop and refine requisite analytical and toxicological methodologies for the detection and estimation of these agents as well as their biological and toxicological activity. 

Prior to the initiation of chronic toxicity studies, there should be characterization of test chemical. Information on chemical identity and structure can sometimes be used in an analysis based on structure activity relationships to indicate biological or toxicologic activity. The physical and chemical characteristics of the test chemical provide important information for the selection of administration routes, study design, and handling and storage of the test chemical. 

The nutritional, chemical, biological, and toxicological properties of a chemical element are known to be critically dependent on the form in which it occurs in food. The recognition of this fact has spurred the development of species-selective (speciation) analytical methods for food additives and contaminants. According to the IUPAC s dehnition, speciation analysis deals with the analytical activities of identification and/or measurement of the quantities of one or more individual chemical species in a given sample [1], The analytical approach is usually based on the combination of a chromatographic separation technique with an element-specif>c detection technique. The former ensures that the analyte compound leaves the column unaccompanied by other species of the analyte element, whereas the latter enables a sensitive and specil>c detection of the target element. Coupled (also called hyphenated) techniques have become a fundamental tool for speciation analysis and have been discussed in many published reviews [2D6]. 

Quantitative structure-activity relationship (QSAR) dates back to the nineteenth century and is a computer-based tool that attempts to correlate variations in structural or molecular properties of compounds with their biological activities. These physicochemical descriptors, which include parameters to account for hydrophobicity, topology, electronic properties, and steric effects, are determined empirically or, more recently, by computational methods. The premise is that the structure of a chemical determines the physiochemical properties and reactivities that underlie its biological and toxicological properties. Being able to predict potential adverse effects not only aids in the designed development of new chemicals but also reduces the need for animal testing. It may ultimately or potentially lead to better... 

E. The 2R, aR isomer has greatly reduced biological and toxicological properties when compared with other fenvalerate isomers. Isomers with an R configuration in the acid moiety degraded slightly faster than the insecticidally-active 25, aS, and 25, aR isomers. 

Fujii-Kuriyama Y, Kawajiri K (2012) Regulation of AhR activity by the AhR repressor (AhRR). In Pohjanvirta R (ed) The AH receptor in biology and toxicology. Willey, New York, pp 101-108... 

Menthol is a natural compound isolated from a variety of plants and it has been mostly used as analgesic. Recently, it was demonstrated by a number of studies that menthol produces cool sensation which is mediated by the activation of TRPM8 channels. Experimental work from different laboratories has demonstrated that menthol has several additional pharmacological activities that compose its pharmacological features. In this chapter, we have pointed out a scenario where menthol is posed as the main actor toward the understanding of its biological and toxicological effects. 

These substances include many simple salts, herbal remedies and components of veterinary homeopathic formulations. Others include medical gases, drugs that are rapidly metabolised to materials which are not pharmacologically and toxicologically active and biologically inert materials such as some... 

Lee, L.E.J. Clemons, J.H. Bechtel, D.G. Caldwell, S.J. Han, K.B. Pastischmiak-Arts, M. Mosser, D.D. Bols, N.C. 1993. Development and characterization of rainbow trout liver cell line expressing cytochrome P 450-dependent monooxygenases activity. Cell Biology and Toxicology, v.9, p.279-294. 

S., Vatter, S., Chahbane, N., Lenoir, D., Schramm, K.W. and Scherer, G. (2005) Biological activity and physicochemical parameters of marine halogenated natural products 2,3,3, 4,4, 5,5 -heptachloro-l -methyl-1,2 -bipyrrole and 2,4,6-tribromoanisole. Archives of Environmental Contamination and Toxicology, 48, 1-9. 

The optical activity of biologically-active chemicals is important to their activity and toxicology. Pure enantiomers, or optical isomers, of pharmaceuticals and agrochemicals can in many cases be made by enantiospecific synthesis. An alternative method is to use a less complicated synthesis followed by chromatographic resolution of the racemic mixture into its enantiomers. 

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