Structures and anti-melanoma activities of two polysaccharides from Angelica sinensis (Oliv.) Diels.

Polysaccharide is one of the necessary macromolecules in life activities, and it is also a very promising natural product for tumor prevention and treatment. In this study, two homogeneous polysaccharides (APS-4I and APS-4II) were isolated from Angelica sinensis (Oliv.) Diels. APS-4I was a linear glucan with molecular weight of 16.1 kDa, which was composed of 88.4% α-1,6-Glcp, 4.1% α-1,2-Glcp, 3.9% α-1,3-Glcp, and 2.8% α-T-Glcp. APS-4II was a novel polysaccharide with molecular weight of 11.1 kDa, which consisted of 55.4% α-1,6-Glcp, 10.4% α-1,3,5-Araf, 8.7% α-T-Araf, 9.2% α-1,5-Araf, 4.0% α-1,3-Araf, 3.6% α-1,4-Galp, and 9.1% ß-1,3-Galp. NMR results demonstrated that APS-4II has a backbone composed of →6)-α-Glcp-(1 → 6)-α-Glcp-(1 → 5)-α-Araf-. (1 → 5)-α-Araf-(1 → 3,5)-α-Araf-(1 → 3)-ß-Galp-(1 → 3)-ß-Galp-(1 → 4)-α-Galp-(1 → 3)-α-Araf-(1 → 3,5)-α-Araf-(1→. Both APS-4I and APS-4II inhibited the tumor growth of B16-bearing mice, and the suppressive effect of APS-4II reached 64.7 ± 7.3%. Meanwhile, there were higher lymphocyte numbers and the levels of IL-2, IFN-γ, and TNF-α in peripheral blood of APS-4II-treated mice than those in APS-4I-treated mice. Furthermore, APS-4II showed a higher inhibitory effect on the proliferation of B16 cells and stronger promoting effects on the proliferation of splenocytes, the phagocytosis of peritoneal macrophages, and the cytotoxicity of NK cells. These results demonstrated that APS-4II could be a promising therapeutic agent for melanoma.

Structures and anti-atherosclerotic effects of 1,6-α-glucans from Fructus Corni.

In this study, two homogeneous polysaccharides (PFC-1 and PFC-2) having anti-atherosclerotic activity were isolated from Fructus Corni. PFC-1 and PFC-2 were 1,6-α-glucans with the molecular weight of 4.4 kDa and 82.0 kDa, respectively. In the in vitro experiments, PFC-1 and PFC-2 showed significant inhibitory effects on the cholesterol accumulation in RAW264.7 macrophages induced by oxidized low-density lipoproteins (ox-LDL), and the inhibitory rate of PFC-2 was 81.62%. Apolipoprotein E-deficient (ApoE-/-) mice fed high-fat diet (HFD) were used to evaluate the anti-atherosclerotic effects of PFC-2 in vivo. The aortic root lipid area decreased by 55.01% in the PFC-2-administered group as compared to the model group. PFC-2 decreased the levels of serum low-density lipoprotein cholesterol, total cholesterol, triglycerides, and malondialdehyde, increased the superoxide dismutase activity, and reduced the contents of lipid and macrophages in the aortic sinus plaque in ApoE-/- mice fed with HFD. Furthermore, PFC-2 markedly inhibited the expression of type A1 scavenger receptor (SR-A1) and cluster of differentiation 36 (CD36) in ox-LDL-treated macrophages. Taken together, 1,6-α-glucans from Fructus Corni showed significant anti-atherogenic effect, and the mechanism is related to enhanced antioxidant activity of the ApoE-/- mice and down-regulated the expression of SR-A1 and CD36 proteins in macrophages.