Membrane-active agents, effects

Wagner E (1998) Effects of membrane-active agents in gene delivery. J Control Release 53 155-158... 

When oat roots were used for bioassay, zoospores were first attracted and then caused lysis which raises the possibility that oat crops and their residues might be used to reduce soil populations of zoosporic plant pathogens. The cystospores were insensitive to concentrations of saponins or oat root extract that lysed zoospores. The zoospores lytic principle in oat root extract/exudate was believed to be a saponin, avenacin (61). The effects of avenacin (61) or root extracts on zoospores were identical to those of /0-aescin and consistent with a role of membrane active agents. Toxic effects of saponins on zoospores were also observed in Pseudoperonospora humuli Miyabe Takah. and Phytophthora spp. [139,140]. 

Much useful information on the mechanism of action of membrane-active agents has come from studies of their effects upon artificial lipid membranes... 

Chlorhexidine (7) is another membrane-active agent which has an effect upon the outer membrane of Gram-negative bacteria. Hugo and Longworth [47]... 

Especially remarkable is the high activity of PCMC against lipophilic, enveloped viruses, such as Herpes, simplex, Hepatitis B or HIV viruses. As other phenolic membrane active agents also PCMC exhibits a weak effect only on naked viruses and resistant bacterial spores (e.g. bacillus spores). However, a fully virucidal effect is achievable by combining PCMC formulations with small concentrations of glutaraldehyde (2.5.). 

Conventional and novel PKC isozymes are potently activated by phorbol esters, heterocyclic compounds found in the milky sap exuded by plants of the Euphorbiaccae family. This sap was used medicinally as a counterirritant and cathartic agent over the millennia we now know that the active ingredients, phorbol esters, specifically bind to the Cl domain, the diacylglycerol sensor described above. In fact, their ability to recruit PKC to membranes is so effective that phorbol esters cause maximal activation of conventional PKCs, bypassing the requirement for Ca2+. This module is found in a number of other proteins in addition to PKC, so the profound effects of phorbol esters on cells are mediated by other proteins in addition to PKC. 

Mechanism of Action A topical agent that binds DNA, inhibiting synthesis of nucleic protein, and reduces mitotic activity. Therapeutic Effect Results in damage to DNA sugar and enhances membrane lipid peroxidation, which may play a critical role in the antipsoriatic action. 

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