Novel pectin from crude polysaccharide of Syzygium aromaticum against SARS-CoV-2 activities by targeting 3CLpro

To date, COVID-19 is still a severe threat to public health, hence specific effective therapeutic drugs development against SARS-CoV-2 is urgent needed. 3CLpro and PLpro and RdRp are the enzymes required for the SARS-CoV-2 RNA synthesis. Therefore, binding to the enzyme may interfere the enzyme function. Before, we found that sulfated polysaccharide binding to 3CLpro might block the virus replication. Hence, we hypothesize that negative charged pectin glycan may also impede the virus replication. Here we show that 922 crude polysaccharide from Syzygium aromaticum may near completely block SARS-CoV-2 replication. The inhibition rate was 99.9% (EC50 : 0.90 M). Interestingly, 922 can associates with 3CLpro, PLpro and RdRp. We further show that the homogeneous glycan 922211 from 922 may specifically attenuate 3CL protease activity. The IC50s of 922 and 922211 against 3CLpro are 4.73 {+/-} 1.05 {micro}M and 0.18 {+/-} 0.01 {micro}M, respectively. Monosaccharide composition analysis reveals that 922211 with molecular weight of 78.7 kDa is composed of rhamnose, galacturonic acid, galactose and arabinose in the molar ratio of 8.21 : 37.81 : 3.58 : 4.49. The structure characterization demonstrated that 922211 is a homogalacturonan linked to RG-I pectin polysaccharide. The linear homogalacturonan part in the backbone may be partly methyl esterified while RG-I type part bearing 1, 4-linked -GalpA, 1, 4-linked -GalpAOMe and 1, 2, 4-linked -Rhap. There are four branches attached to C-1 or C4 position of Rhamnose glycosyl residues on the backbone. The branches are composed of 1, 3-linked {beta}-Galp, terminal (T)-linked {beta}-Galp, 1, 5-linked -Araf, T-linked -Araf, 4-linked -GalpA and/or 4-linked {beta}-GalpA. The above results suggest that 922 and 922211 might be a potential novel leading compound for anti-SARS-CoV-2 new drug development.

Structural characterization of cocktail-like targeting polysaccharides from Ecklonia kurome Okam and their anti-SARS-CoV-2 activities in vitro

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent responsible for the worldwide coronavirus disease 2019 (COVID-19) outbreak. Investigation has confirmed that polysaccharide heparan sulfate can bind to the spike protein and block SARS-CoV-2 infection. Theoretically, similar structure of nature polysaccharides may also have the impact on the virus. Indeed, some marine polysaccharide has been reported to inhibit SARS-Cov-2 infection in vitro, however the convinced targets and mechanism are still vague. By high throughput screening to target 3CLpro enzyme, a key enzyme that plays a pivotal role in the viral replication and transcription using nature polysaccharides library, we discover the mixture polysaccharide 375 from seaweed Ecklonia kurome Okam completely block 3Clpro enzymatic activity (IC50, 0.48 {micro}M). Further, the homogeneous polysaccharide 37502 from the 375 may bind to 3CLpro molecule well (kD value : 4.23 x 10-6). Very interestingly, 37502 also can potently disturb spike protein binding to ACE2 receptor (EC50, 2.01 {micro}M). Importantly, polysaccharide 375 shows good anti-SARS-CoV-2 infection activity in cell culture with EC50 values of 27 nM (99.9% inhibiting rate at the concentration of 20 {micro}g/mL), low toxicity (LD50: 136 mg/Kg on mice). By DEAE ion-exchange chromatography, 37501, 37502 and 37503 polysaccharides are purified from native 375. Bioactivity test show that 37501 and 37503 may impede SARS-Cov-2 infection and virus replication, however their individual impact on the virus is significantly less that of 375. Surprisingly, polysaccharide 37502 has no inhibition effect on SARS-Cov-2. The structure study based on monosaccharide composition, methylation, NMR spectrum analysis suggest that 375 contains guluronic acid, mannuronic acid, mannose, rhamnose, glucouronic acid, galacturonic acid, glucose, galactose, xylose and fucose with ratio of 1.86 : 9.56 : 6.81 : 1.69 : 1.00 : 1.75 : 1.19 : 11.06 : 4.31 : 23.06. However, polysaccharide 37502 is an aginate which composed of mannuronic acid (89.3 %) and guluronic acid (10.7 %), with the molecular weight (Mw) of 27.9 kDa. These results imply that mixture polysaccharides 375 works better than the individual polysaccharide on SARS-Cov-2 may be the cocktail-like polysaccharide synergistic function through targeting multiple key molecules implicated in the virus infection and replication. The results also suggest that 375 may be a potential drug candidate against SARS-CoV-2.

Methods and key points of literature collation and mining of classic prescriptions in ethnic medicine / 中国中药杂志

The systematic collation and mining of ethnic medicine literature is the key to the screening and textual research of classic prescriptions. This study focused on the textual research of such key issues as the source of prescriptions, the translation of minority languages into Chinese characters and their corresponding medical terms, the original plants of drugs, and the standard dosage. It is believed that the methods and experience of textual research of classic prescriptions in traditional Chinese medicine(TCM) can be utilized by the ethnic medicine. At the same time, the prominent problems unique to ethnic medicine cannot be neglected.(1)Attention should be paid to extraterritorial traditional medical literature in the textual research of the source of prescriptions. For instance, Indian medical literature is the source of many classic prescriptions in Tibetan medicine, Ibn Sina's Canon of Medicine the source of those in Uygur and Hui medicine, and ancient Indian Buddhist classics the source of those in Dai medicine.(2)The translation and comparison of medical terms in different language systems requires the cooperation of linguists, historians, and medical experts, the combination of historical research, historical linguistics and clinical research methods, and the use of cross-language comparison. In recent years, the related research achievements like multiple translated and annotated versions of classical literature in ethnic medicine and their respective terminology standards have been constantly emerging.(3)In textual research of the original plants of drugs, the following two points deserve attention: one is that the same drug is used in different ethnic medical systems, but there are differences in the understanding of drug properties and active parts; the other is that the original plants of the same drug vary in different ethnic medical systems.(4)The derivation of some classic prescriptions in ethnic medicine from foreign classics results in the difference among measurement systems. In addition, the detailed dosage fails to be covered in some ethnic literature, so the dosage standard should be determined depending on clinical practice and expert consensus.

Cordycepin inhibits pancreatic cancer cell growth in vitro and in vivo via targeting FGFR2 and blocking ERK signaling / 中国天然药物

Cordycepin (3'-deoxyadenosine) from Cordyceps militaris has been reported to have anti-tumor effects. However, the molecular target and mechanism underlying cordycepin impeding pancreatic cancer cell growth in vitro and in vivo remain vague. In this study, we reported functional target molecule of cordycepin which inhibited pancreatic cancer cells growth in vitro and in vivo. Cordycepin was confirmed to induce apoptosis by activating caspase-3, caspase-9 and cytochrome c. Further studies suggested that MAPK pathway was blocked by cordycepin via inhibiting the expression of Ras and the phosphorylation of Erk. Moreover, cordycepin caused S-phase arrest and DNA damage associated with activating Chk2 (checkpoint kinase 2) pathway and downregulating cyclin A2 and CDK2 phosphorylation. Very interestingly, we showed that cordycepin could bind to FGFR2 (K = 7.77 × 10) very potently to inhibit pancreatic cancer cells growth by blocking Ras/ErK pathway. These results suggest that cordycepin could potentially be a leading compound which targeted FGFR2 to inhibit pancreatic cells growth by inducing cell apoptosis and causing cell cycle arrest via blocking FGFR/Ras/ERK signaling for anti-pancreatic cancer new drug development.

A review of isolation methods, structure features and bioactivities of polysaccharides from Dendrobium species / 中国天然药物

Dendrobium, orchid, is a traditional Chinese herb medicine applied extensively as tonic and precious food for thou-sands of years recorded in ancient Chinese medical book "Shen Nong's Materia Medica". It's well known that bioactivities are usually related to the ingredients' basis. Based on the previous research, Dendrobium species contain amino acid, sesquiterpenoids, alkaloids and polysaccharides. As the bioactive substances, carbohydrate shows extensive activities in antitumor, antiglycation, immune-enhancing, antivirus, antioxidant, antitumor and etc. Therefore, as the main biologically active substance, the exact structures and latent activities of polysaccharides from Dendrobium species are widely focused on. In this review, we focus on the advancements of extraction methods and diversity of structures and bioactivities of polysaccharides obtained from Dendrobium species.

Transumbilical single-port laparoscopic cholecystectomy for chronic cholecystitis with cholecystolithiasis / 中华肝胆外科杂志

Objective@#To study the feasibility, safety and aesthetics of laparoscopic cholecystectomy using a single-port through the umbilicus in patients with chronic cholecystitis with cholecystolithiasis.@*Methods@#From Jan 2007 to Jun 2017, the clinical data of 4790 patients who underwent single-port, 4 426 patients conventional three-ports, and 3 304 patients two-ports laparoscopic cholecystectomy were retrospectively studied.@*Results@#There were no death in all the three groups. There were no significant differences in the incidences of postoperative bleeding, bile leakage, biliary tract injury and other significant short-term complications (all P>0.05). The operation time of transumbilical single-port laparoscopic cholecystectomy was significantly longer than that of two-ports and three-ports laparoscopic cholecystectomy [(35.3±9.0)min vs. (28.4±7.2)min vs. (23.3±6.4)min, P<0.05]. Looking only in a single year, there was no significant difference in the operation time of the three groups in the year 2017 (P>0.05). There were no significant differences among the three groups in intraoperative blood loss, first postoperative passing of flatus, postoperative pain, and length of hospital stay (all P>0.05). The satisfaction score of surgical scar in the single-port group was higher than that in the two-ports and three-ports groups [(9.6±1.6) vs. (7.6±1.9) vs. (6.7±2.0), P<0.05].@*Conclusions@#Transumbilical single-port laparoscopic cholecystectomy was safe and feasible, with good aesthetics and other advantages. It was more difficult than the traditional laparoscopic technique. After the learning curve, the operation time could be comparable to the three-ports technique.

Transumbilical single-port laparoscopic cholecystectomy for chronic cholecystitis with cholecystolithi-asis / 中华肝胆外科杂志

Objective To study the feasibility, safety and aesthetics of laparoscopic cholecystectomy using a single-port through the umbilicus in patients with chronic cholecystitis with cholecystolithiasis. Methods From Jan 2007 to Jun 2017, the clinical data of 4790 patients who underwent single-port, 4426 patients conventional three-ports, and 3304 patients two-ports laparoscopic cholecystectomy were retrospec-tively studied. Results There were no death in all the three groups. There were no significant differences in the incidences of postoperative bleeding, bile leakage, biliary tract injury and other significant short-term complications (all P>0. 05). The operation time of transumbilical single-port laparoscopic cholecystectomy was significantly longer than that of two-ports and three-ports laparoscopic cholecystectomy [(35. 3 ± 9. 0) min vs. (28. 4 ± 7. 2)min vs. (23. 3 ± 6. 4)min, P<0. 05]. Looking only in a single year, there was no significant difference in the operation time of the three groups in the year 2017 (P>0. 05). There were no significant differences among the three groups in intraoperative blood loss, first postoperative passing of flatus, postoperative pain, and length of hospital stay (all P>0. 05). The satisfaction score of surgical scar in the single-port group was higher than that in the two-ports and three-ports groups [ ( 9. 6 ± 1. 6 ) vs. (7. 6 ± 1. 9) vs. (6. 7 ± 2. 0), P < 0. 05]. Conclusions Transumbilical single-port laparoscopic cholecystectomy was safe and feasible, with good aesthetics and other advantages. It was more difficult than the traditional laparoscopic technique. After the learning curve, the operation time could be comparable to the three-ports technique.

Research advances in the treatment of Alzheimer's disease with polysaccharides from traditional Chinese medicine / 中国天然药物

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the loss of patients' memory and their cognitive abilities and the mechanism is not completely clear. Although a variety of drugs have been approved for the AD treatment, substances which can prevent and cure AD are still in great need. The effect of polysaccharides from traditional Chinese medicine (TCM) on anti-AD has gained great progress and attained more and more attention in recent years. In this review, research advances in TCM-polysaccharides on AD made in this decade are summarized.

WT inhibit human hepatocellular carcinoma BEL-7402 cells growth by modulating Akt and ERK1/2 phosphorylation / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate effects of Akt and ERK1/2 signaling pathways on waltonitone (WT) induced cell growth inhibition in human hepatocellular carcinoma BEL-7402 cells.</p><p><b>METHOD</b>Cell viability of BEL-7402 cells was examined using MTT assay. Phosphorylation of E Akt and RK1/2 were detected by Western blot analysis, while cell cycle distribution of BEL7402 cells was analyzed by flow cytometry.</p><p><b>RESULT</b>WT could inhibit the BEL-7402 cells growth, induce the S-phase cell cycle arrest, activate Akt and ERK1/2 phosporylation. Moreover, the cell growth inhibition and S-phase cell cycle arrest induction of WT on BEL-7402 cells could be blocked by Akt and ERK1/2 inhibitors.</p><p><b>CONCLUSION</b>WT induce the cell cycle arrest and inhibit the cell growth on BEL-7402 cells by modulating Akt and ERK1/2 phosphorylation.</p>

Isolation, purification and structural analysis of GL-PP-3A, an active polysaccharide peptide from Ganoderma lucidum / 药学学报

GL-PP-3A, an active polysaccharide peptide, was isolated and purified from Ganoderma lucidum, and then its structure was analyzed. Crude polysaccharide peptides were extracted from Ganoderma lucidum with hot water, precipitated with ethanol and then dialyzed from Ganoderma lucidum. Subsequently GL-PP-3A was isolated and purified from the crude polysaccharide peptides by fractional precipitation and chromatography of Bio-Gel P-10 column. The repetitive unit of GL-PP-3A was analyzed by high performance gel permeation chromatography (HPGPC), monosaccharide composition and methylation analysis, 1H NMR and 13C NMR. GL-PP-3A is a heteropolysaccharide which is composed mainly of glucose (Glc), and also contains saccharide residues such as rhamnose (Rha), xylose (Xyl), mannose (Man) and galactose (Gal) and 17 kinds of amino acids. Its weight-average molecular weight (Mw) and number-average molecular weight (Mn) were 1.7 x 10(4) and 1.1 x 10(4), respectively, with the ratio of Mw/Mn ( molecular weight distribution) being of 1.49. Its backbone chain is composed of 1,6-linked beta-D-Glcp and 1,3-liked beta-D-Glcp at a ratio of 2:1. Some of 1,6-linked glucose residuals of the backbone chain are substituted at 2-0 or 3-0, and there are 1 to 3 1,6-linked beta-D-Galp or 1,3-linked alpha-D-Manp in the branched chains, the nonreducing ends of which consist mainly of beta-D-Glcp and a few Rha.