Recently, the studies on the antiviral activities of marine natural products, especially marine polysaccharides, are attracting more and more attention all over the world. Marine-derived polysaccharides and their lower molecular weight oligosaccharide derivatives have been shown to possess a variety of antiviral activities. This paper will review the recent progress in research on the antiviral activities and the mechanisms of these polysaccharides obtained from marine organisms. In particular, it will provide an update on the antiviral actions of the sulfated polysaccharides derived from marine algae including carrageenans, alginates, and fucans, relating to their structure features and the structure–activity relationships. In addition, the recent findings on the different mechanisms of antiviral actions of marine polysaccharides and their potential for therapeutic application will also be summarized in detail.

Herb pair Danggui-Honghua has been frequently used for treatment of blood stasis syndrome (BSS) in China, one of the most common clinical pathological syndromes in traditional Chinese medicine (TCM). However, its therapeutic mechanism has not been clearly elucidated. In the present study, a feasible system pharmacology model based on chemical, pharmacokinetic and pharmacological data was developed via network construction approach to clarify the mechanisms of this herb pair. Thirty-one active ingredients of Danggui-Honghua possessing favorable pharmacokinetic profiles and biological activities were selected, interacting with 42 BSS-related targets to provide potential synergistic therapeutic actions. Systematic analysis of the constructed networks revealed that these targets such as HMOX1, NOS2, NOS3, HIF1A and PTGS2 were mainly involved in TNF signaling pathway, HIF-1 signaling pathway, estrogen signaling pathway and neurotrophin signaling pathway. The contribution index of every active ingredient also indicated six compounds, including hydroxysafflor yellow A, safflor yellow A, safflor yellow B, Z-ligustilide, ferulic acid, and Z-butylidenephthalide, as the principal components of this herb pair. These results successfully explained the polypharmcological mechanisms underlying the efficiency of Danggui-Honghua for BSS treatment, and also probed into the potential novel therapeutic strategies for BSS in TCM.

Cudrania tricuspidata is a perennial plant of the family Moraceae with numerous medicinal and nutritional applications. It has been widely used in East Asia as an important traditional folk medicine for the treatment of many ailments such as eczema, mumps, tuberculosis, contusions, insomnia and acute arthritis. The whole plant of C. tricuspidata, including the roots, leaves, bark, stems and fruits, has been found to contain diverse phytochemicals, including xanthones, flavonoids, organic acids, and polysaccharides, with various bioactivities. In particular, xanthones and flavonoids, as the main active constituents, isolated from C. tricuspidata have been proven to possess notable anti-inflammatory, antioxidative, antitumor, hepatoprotective, neuroprotective and anti-obesity effects. This review summarizes the botany, traditional uses, phytochemistry and pharmacology of C. tricuspidata, and the limitations of studies on this species have also been discussed such that to serve as the basis for further research and development on this medicinal plant.