Antitumor effects of polysaccharides from medicinal lower plants: A review

Ultrasound-assisted enzymatic extraction, structural characterization, and anticancer activity of polysaccharides from Rosa roxburghii Tratt fruit

In this work, Rosa roxburghii Tratt fruit polysaccharides (RPs) were extracted by ultrasound-assisted enzymatic method. The highest extraction yield of RPs was 4.78 ± 0.10 % under the optimal extraction conditions. Two purified fractions named RP1 and RP3 were obtained and systematically characterized by a combination strategy of FT-IR, monosaccharide composition, molecular weight distribution, methylation and 2D NMR spectroscopy analyses. Structural analysis showed that the main chain of RP1 was composed of rhamnogalacturonan type I (RG-I), while the side chains were rich in arabinogalactan and galactose. RP3 was composed of long homogalacturonan (HG) backbone interspersed with alternating sequences of RG-I domains, with galactose and arabinose side chains. RP1 and RP3 induced apoptosis of MCF-7 cells in a dose dependent manner in vitro especially for RP1, and had no effect on L929 cells. Furthermore, the possible anticancer mechanisms were revealed, and results suggested that RP1 induced apoptosis through ROS-dependent pathway and mitochondrial pathway. The results of this work not only provided an efficient extraction method and theoretical basis for the application of RPs, but also may contribute to develop novel functional foods or pharmaceutical products for the prevention and treatment of human breast cancer disease.

Ameliorative Effects of Korean-Red-Ginseng-Derived Polysaccharide on Antibiotic-Associated Diarrhea

This study evaluated the ameliorative effects of Korean-red-ginseng-derived polysaccharide (KRG-P) on antibiotic-associated diarrhea (AAD) induced by administering lincomycin in mice. Changes of intestinal barrier proteins, the intestinal microbiome and short-chain fatty acid (SCFA) contents were investigated. Lincomycin was orally administered for 9 days to induce diarrhea; subsequently, 100 mg/kg and 300 mg/kg of KRG-P were administered orally for 12 days. The diarrhea was observed in the AAD group; further KRG-P administration improved the diarrhea. Analysis of changes in the intestinal microbial flora of the mice revealed that the harmful bacterial flora (such as Proteobacteria) were increased in the AAD group, whereas beneficial bacterial flora (such as Firmicutes) were decreased. However, KRG-P administration resulted in decreased Proteobacteria and increased Firmicutes, supporting the improvement of the microbial flora imbalance caused by AAD. Moreover, an analysis of the SCFAs (acetic acid, propionic acid, and butylic acid) in the caecum revealed that SCFAs' contents in the AAD group were substantially reduced but tended to increase upon KRG-P administration. Based on these results, KRG-P, which is primarily composed of carbohydrates can improve lincomycin-induced diarrhea, likely owing to the recovery of SCFA content by improving the intestinal microbial imbalance and intestinal barrier proteins.

Emerging applications of anti-angiogenic nanomaterials in oncotherapy

Angiogenesis is the process of generating new blood vessels from pre-existing vasculature. Under normal conditions, this process is delicately controlled by pro-angiogenic and anti-angiogenic factors. Tumor cells can produce plentiful pro-angiogenic molecules promoting pathological angiogenesis for uncontrollable growth. Therefore, anti-angiogenic therapy, which aims to inhibit tumor angiogenesis, has become an attractive approach for oncotherapy. However, classic anti-angiogenic agents have several limitations in clinical use, such as lack of specific targeting, low bioavailability, and poor therapeutic outcomes. Hence, alternative angiogenic inhibitors are highly desired. With the emergence of nanotechnology, various nanomaterials have been designed for anti-angiogenesis purposes, offering promising features like excellent targeting capabilities, reduced side effects, and enhanced therapeutic efficacy. In this review, we describe tumor vascular features, discuss current dilemma of traditional anti-angiogenic medicines in oncotherapy, and underline the potential of nanomaterials in tumor anti-angiogenic therapy. Moreover, we discuss the current challenges of anti-angiogenic cancer treatment. We expect that this summary of anti-angiogenic nanomaterials in oncotherapy will offer valuable insights, facilitating their extensive applications in the future.