Phenolic Compounds from Cell Cultures

Cell cultures of G. uralensis and G. glabra also produce eehinatin (304, Table 13). Licodione (305) has also been isolated from cultured alfalfa cells stimulated by a naphthoquinone or yeast extract (377, 378). 

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Fauconneau, B., Waffo-Teguo, P., Huguet, F., Barrier, L., Decendit, A., and Merillon, J.M., Comparative study of radical scavenger and antioxidant properties of phenolic compounds from Vitis vinifera cell cultures using in vitro tests. Life Sci., 61 (21), 2103-2110, 1997. 

In this chapter an attempt has been made to discuss the methods available for the isolation and analysis of higher plant cell walls. Because the structures and properties of the cell wall polymers from various tissue tyjDes show considerable differences, it is emphasized that, where possible, separation of the tissues in a plant organ prior to preparation of the cell walls is desirable. Attention is drawn to the problems associated with coprecipitation of intracellular compounds with cell wall polymers, particularly in view of the occurrence of small amounts of proteoglycan and proteoglycan-polyphenol complexes in the walls and the covalent attachment of phenolics and phenolic esters with some of the cell wall polymers of parenchymatous and suspension-cultured tissues. The preparation of gram quantities of relatively pure cell walls from starch- and protein-rich tissues is discussed at some length because of the importance of dietary fiber in human nutrition and an understanding of the composition, structure, and properties of dietary fiber would be hampered without such methods (Selvendran, 1984). 

Observations of lower rates of certain chronic diseases in several Asian countries compared to the United States served as the impetus for studies that were conducted to identify the factors that were accountable (Tham et al., 1998). Consumption of soy is one factor that correlated with these lower rates. From this information, much research focused on soy protein and accompanying bioactive compounds with regard to elucidating mechanisms associated with risk markers for chronic disease, particularly CVD. The combination of macro- (protein, fiber, fat) and micro-components (isoflavones, saponins, tocopherols) as part of many traditional soy foods may underlie the epidemiological observations associated with soy intake. A body of cell culture and animal data shows potential health effects of a multitude of bioactive components in soy (i.e., saponins, phenolic acids, peptides). However, studies determining the independent effects of saponins, phenolic acids, and protease inhibitors in humans are yet to be conducted. 

Aside from general caveats that apply to many in vitro models, there is one concern specific to research on AGs and cisplatin. Their mechanisms of toxicity involve the formation of ROS and are therefore sensitive to the antioxidant capacity of the incubation medium. This parameter is rarely controlled and different standard media contain varying amounts of redox-active amino acids, glutathione, or other compounds. Even the common pH indicator phenol red is an important contributor to the total antioxidant capacity of cell and tissue culture media [97]. Thus, the antioxidative capacity of the incubation media may differ from the endolymph and comparable media need to be used to compare therapeutic efficiencies. The concern applies not only to studies of ototoxic mechanisms of these drugs but perhaps even more also to attempts to identify protective treatments which most frequently include therapeutics with antioxidant properties. 

Studies of the methanolic extract of Alpinia oxyphylla have shown that this extract suppresses the promotion of skin tumors in mice and that it induces apoptosis in cultured human promyelocytic leukemia cells. In addition, two phenolic diarylheptano ids isolated from the active extract, yakuchinone A and yakuchinone B, were found to ameliorate tumor promotion as well as inhibit both TPA-induced epidermal ornithine decarboxylase (ODC) activity and ODC RNA expression. Moreover, yakuchinones A and B reduced production of the TNF-a in the TPA-stimulated skin of mice. Furthermore, both compounds inhibited the TPA-induced expression of COX-2 at both transcriptional and... 

Chlorinated derivatives of phenols, cresol, and xylenol elicit the release of [ C]-glutamate from E. colt [92]. These compounds are effective bactericides and are used in crude disinfectant and antiseptic preparations such as LysoT and Det-tol . Their abUity to denature protein is probably responsible for their disruptive action upon microbial cell membranes. In addition to damaging the membrane [92], phenol exerts a lytic action upon the cell wall lysis occurs in growing cultures of E. coll [93] and is particularly noted in synchronous cultures at the point of cell division [94]. 

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