Two different modes of inhibition of the rat brain Na+, K(+)-ATPase by triterpene glycosides, psolusosides A and B from the holothurian Psolus fabricii

Marine natural products targeting the eukaryotic cell membrane

The cell membrane, with high fluidity and alternative curvatures, maintains the robust integrity to distinguish inner and outer space of cells or organelles. Lipids are the main components of the cell membrane, but their functions are largely unknown. Even the visualization of lipids is not straightforward since modification of lipids often hampers its correct physical properties. Many natural products target cell membranes, some of which are used as pharmaceuticals and/or research tools. They show specific recognition on lipids, and thus exhibit desired pharmacological effects and unique biological phenotypes. This review is a catalog of marine natural products that target eukaryotic cell membranes. Chemical structures, biological activities, and molecular mechanisms are summarized. I hope that this review will be helpful for readers to notice the potential of marine natural products in the exploration of the function of lipids and the druggability of eukaryotic cell membranes.

Acetylated Triterpene Glycosides and Their Biological Activity from Holothuroidea Reported in the Past Six Decades

Sea cucumbers have been valued for many centuries as a tonic and functional food, dietary delicacies and important ingredients of traditional medicine in many Asian countries. An assortment of bioactive compounds has been described in sea cucumbers. The most important and abundant secondary metabolites from sea cucumbers are triterpene glycosides (saponins). Due to the wide range of their potential biological activities, these natural compounds have gained attention and this has led to their emergence as high value compounds with extended application in nutraceutical, cosmeceutical, medicinal and pharmaceutical products. They are characterized by bearing a wide spectrum of structures, such as sulfated, non-sulfated and acetylated glycosides. Over 700 triterpene glycosides have been reported from the Holothuroidea in which more than 145 are decorated with an acetoxy group having 38 different aglycones. The majority of sea cucumber triterpene glycosides are of the holostane type containing a C18 (20) lactone group and either Δ(7(8)) or Δ(9(11)) double bond in their genins. The acetoxy group is mainly connected to the C-16, C-22, C-23 and/or C-25 of their aglycone. Apparently, the presence of an acetoxy group, particularly at C-16 of the aglycone, plays a significant role in the bioactivity; including induction of caspase, apoptosis, cytotoxicity, anticancer, antifungal and antibacterial activities of these compounds. This manuscript highlights the structure of acetylated saponins, their biological activity, and their structure-activity relationships.

Relationships between chemical structures and functions of triterpene glycosides isolated from sea cucumbers

Many marine triterpene glycosides have in vitro and in vivo activities with very low toxicity, suggesting that they are suitable agents for the prevention and treatment of different diseases, particularly cancer. However, the molecular mechanisms of action of natural marine compounds in cancer, immune, and other various cells are not fully known. This review focuses on the structural characteristics of marine triterpene glycosides and how these affect their biological activities and molecular mechanisms. In particular, the membranotropic and membranolytic activities of frondoside A and cucumariosides from sea cucumbers and their ability to induce cytotoxicity and apoptosis have been discussed, with a focus on structure-activity relationships. In addition, the structural characteristics and antitumor effects of stichoposide C and stichoposide D have been reviewed along with underlying their molecular mechanisms.

Safety and efficacy assessment of chungpyesagan-tang for acute ischemic stroke

Chungpyesagan-tang is one of the most well-known traditional herbal formulations frequently used for treatment of acute stroke in Korea. Therefore, this study aims to assess the clinical safety and efficacy of chungpyesagan-tang on acute ischemic stroke. We recruited acute cerebral infarction subjects within 1 week after onset time. Then, we prescribed chungpyesagan-tang to an Oriental medical treatment group (OM-group) for 2 weeks and enrolled a Western medical treatment group (WM-group) which received only Western biomedical care as a control. In this study, the OM-group was composed of 75 subjects. However, 14 of them dropped out, as two had progressive stroke while 12 complained of diarrhea. Thus, 61 cases were included in the analysis and compared to the 76 cases of the WM-group. The improvement of OM-group was better than that of the WM-group according to the National Institute of Health Stroke Scale (NIHSS), but not by the Modified Barthel Index (MBI). There were no definite abnormalities on labortory safety asessment. Therefore, we suggest that chungpyesagan-tang may have therapeutic effects, acting to reduce the severity of stroke and improving functional recovery without definite hepatic or renal toxicity when given for the first 2 weeks after a stroke.