Mechanism of antiviral activity of triterpenoid saponins
三萜皂苷是天然存在的三萜糖结合物，具有各种生物活性，包括抗病毒作用。从天然来源分离的两种物质针对单纯疱疹病毒1型复制进行了测试。他们没有在抗病毒测试条件下显示出细胞毒性的证据。从巴西植物（s21）分离的三萜皂苷代表齐墩果烷基团并抑制单纯疱疹病毒1型DNA合成。从中国植物中分离出的三萜皂苷（s17）代表了ursane基团，似乎抑制了1型单纯疱疹病毒的病毒衣壳蛋白合成。版权所有©1999 John Wiley＆Sons，Ltd。
C. M.O.SimõesM。Amoros L. Girre博士
Triterpenoid saponins are naturally occurring sugar conjugates of triterpenes possessing various biological activities, including antiviral action. Two substances isolated from natural sources were tested against herpes simplex virus type 1 replication. They did not show evidence of cytotoxicity under antiviral test conditions. The triterpenoid saponin, isolated from a Brazilian plant (s21), represents the oleanane group and inhibited herpes simplex virus type 1 DNA synthesis. The triterpenoid saponin, isolated from a Chinese plant (s17), represents the ursane group and seemed to inhibit viral capsid protein synthesis of herpes simplex virus type 1. Copyright © 1999 John Wiley & Sons, Ltd.
Dr. C. M. O. Simões M. Amoros L. Girre
First published: 18 June 1999 https://doi.org/10.1002/(SICI)1099-1573(199906)13:4<323::AID-PTR448>3.0.CO;2-C
Saponin From Wikipedia, the free encyclopedia
Saponins are a class of chemical compounds found in particular abundance in various plant species. More specifically, they are amphipathic glycosides grouped phenomenologically by the soap-like foam they produce when shaken in aqueous solutions, and structurally by having one or more hydrophilic glycoside moieties combined with a lipophilic triterpene derivative.
Role in plant ecology and impact on animal foraging
In plants, saponins may serve as anti-feedants, and to protect the plant against microbes and fungi. Some plant saponins (e.g. from oat and spinach) may enhance nutrient absorption and aid in animal digestion. However, saponins are often bitter to taste, and so can reduce plant palatability (e.g., in livestock feeds), or even imbue them with life-threatening animal toxicity. Some saponins are toxic to cold-blooded organisms and insects at particular concentrations. Further research is needed to define the roles of these natural products in their host organisms, which have been described as "poorly understood" to date.[4
Established research bioactivities and therapeutic claims
One research use of the saponin class of natural products involves their complexation with cholesterol to form pores in cell membrane bilayers, e.g., in red cell (erythrocyte) membranes, where complexation leads to red cell lysis (hemolysis) on intravenous injection. In addition, the amphipathic nature of the class gives them activity as surfactants that can be used to enhance penetration of macromolecules such as proteins through cell membranes.
Saponins from the Gypsophila paniculata (baby’s breath) plant have been shown to significantly augment the cytotoxicity of immunotoxins and other targeted toxins directed against human cancer cells. The research groups of Professor Hendrik Fuchs (Charité University, Berlin, Germany) and Dr David Flavell (Southampton General Hospital, United Kingdom) are working together toward the development of Gypsophila saponins for use in combination with immunotoxins or other targeted toxins for patients with leukaemia, lymphoma and other cancers.
Saponins have also been used as adjuvants in vaccines, e.g. Quil A component QS-21, isolated from the bark of Quillaja saponaria Molina, to stimulate both the Th1 immune response and the production of cytotoxic T-lymphocytes (CTLs) against exogenous antigens. This makes them ideal for use in subunit vaccines and vaccines directed against intracellular pathogens as well as for therapeutic cancer vaccines but with the aforementioned side-effects of hemolysis.
In their use as adjuvants in the production of vaccines, toxicity associated with sterol complexation remains a major issue for attention.
Saponins are being promoted commercially as dietary supplements and food ingredients. There is evidence of the presence of saponins in traditional medicine preparations from licorice, where oral administrations might be expected to lead to hydrolysis of glycoside from terpenoid (and obviation of any toxicity associated with the intact molecule). But as is often the case with wide-ranging commercial therapeutic claims for natural products:
the claims for organismal/human benefit are often based on very preliminary biochemical or cell biological studies; and
mention is generally omitted of the possibilities of individual chemical sensitivity, or to the general toxicity of specific agents, and high toxicity of selected cases.
While such statements require constant review (and despite the myriad web claims to the contrary), it appears that there are very limited US, EU, etc. agency-approved roles for saponins in human therapy. Therapeutic benefit is a result of careful administration of an appropriate dose. Very great care needs to be exercised in evaluating or acting on specific claims of therapeutic benefit from ingesting saponin-type and other natural products.
Use in animal feeding
Saponins are used widely for their effects on ammonia emissions in animal feeding. The mode of action seems to be an inhibition of the urease enzyme, which splits up excreted urea in feces into ammonia and carbon dioxide. Animal trials have shown that a reduced ammonia level in farming operations causes less damages to the respiratory tract of animals, and may help to make them less vulnerable to diseases.