Remodeling the blood-brain barrier microenvironment by natural products for brain tumor therapy

Brain tumor incidence shows an upward trend in recent years; brain tumors account for 5% of adult tumors, while in children, this figure has increased to 70%. Moreover, 20%-30% of malignant tumors will eventually metastasize into the brain. Both benign and malignant tumors can cause an increase in intracranial pressure and brain tissue compression, leading to central nervous system (CNS) damage which endangers the patients' lives. Despite the many approaches to treating brain tumors and the progress that has been made, only modest gains in survival time of brain tumor patients have been achieved. At present, chemotherapy is the treatment of choice for many cancers, but the special structure of the blood-brain barrier (BBB) limits most chemotherapeutic agents from passing through the BBB and penetrating into tumors in the brain. The BBB microenvironment contains numerous cell types, including endothelial cells, astrocytes, peripheral cells and microglia, and extracellular matrix (ECM). Many chemical components of natural products are reported to regulate the BBB microenvironment near brain tumors and assist in their treatment. This review focuses on the composition and function of the BBB microenvironment under both physiological and pathological conditions, and the current research progress in regulating the BBB microenvironment by natural products to promote the treatment of brain tumors.

Tissue distribution of ginsenoside Rg1 before and after modification by PEG / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate targeted distribution of ginsenoside Rg1 in mice tissues before and after modification by the PEG.</p><p><b>METHOD</b>SD mice were randomly divided into two groups and given Rg1 and PEG-Rg1 by intravenous injection respectively. Their samples of blood and organ tissues were taken at different time points. The content of Rg1 in samples were determined by UPLC and used as indicator to observe the targeted distribution of Rg1 in mice tissues.</p><p><b>RESULT</b>The AUC of ginsenoside Rg1 in tissues of the Rg1 group were in the order of liver, kidney, lung, heart and spleen, with the liver targeting coefficient was of 2.01. While the AUC of ginsenoside Rg1 in tissues of the PEG-modified group were in the order of the kidney, liver, lung, heart, spleen, with the liver targeting coefficient was of 9.21.</p><p><b>CONCLUSION</b>PEG modified Rg1 can increase Rg1's targeting selectivity to the liver, kidney and lung in mice.</p>

Modification and stability of ginsenoside Rg1PEG / 中国中药杂志

<p><b>OBJECTIVE</b>To study the stability of ginsenoside Rg1 before and after being modified by PEG (PEG-Rg1) in isolated rat stomachs.</p><p><b>METHOD</b>SD rats, after 18 h of fasting, were randomly divided into the Rg1 group and the PEG-Rg1 group. Rg1 stomach perfusion fluid and PEG-Rg1 infusion fluid were accurately extracted and injected into their stomachs in vitro, with oscillation at 37 degrees C. Samples were taken in different time points and contents of ginsenoside Rg1 were determined by UPLC to observe and compare the stability of ginsenoside Rg1 and PEG-Rg1 in rat stomachs in vitro.</p><p><b>RESULT</b>Rg1 in rat stomachs showed poor stability, Rg1 was measured to be 26.8% in 2 h, with degradation of 73.2%. Its stability in PEG-Rg1 was improved in rat stomachs, Rg1 was measured to be 81.8% in 2 h, with degradation of only 18.2%.</p><p><b>CONCLUSION</b>PEG-modified ginsenoside Rg1 can enhance the stability of ginsenoside Rg1 in stomach and improve degradation and poor stability of ginsenoside Rg1 in stomach.</p>

Absorption kinetics of dehydrocavidine in rats' stomachs and intestines / 中国中药杂志

<p><b>OBJECTIVE</b>To study the absorption kinetics of dehydrocavidine in rats' stomachs and intestines.</p><p><b>METHOD</b>The absorption kinetics was investigated by the in situ perfusion in rats and the concentrations of drug perfusion solutions were determined by HPLC.</p><p><b>RESULT</b>The hourly absorption percentages of dehydrocavidine in stomach, small intestine were 8.88%, 2.08%, respectively. Although the absorption rate constants of dehydrocavidine in duodenum and jejunum are more than that in ileum and colon, there is no significance difference between them. The absorption rate constants kept at the same level when the concentrations of drug perfusion solution are at middle and high level. The increase of the pH of perfusion solution didnt significantly affect the absorption rate constants of the drug.</p><p><b>CONCLUSION</b>Dehydrocavidine was absorbed poorly at stomach and all segments of intestine in rats, but the absorptions in stomach are better than intestine. Dehydrocavidine was absorbed mainly via passive transport mechanism between middle and high concentration levels.</p>

Extraction of Banxiaxiexin Decoction / 中成药

AIM: To optimize the extraction process for Banxiaxiexin Decoction (Rhizoma pinelliae, Radix Scutellariae, Rhizoma coptidis, Radix Ginsenp, Rhizoma zinpiberis, Fruents Jujubae, and Radix Glycyrrhizae). METHODS: The content of berberine、baicalin and total solid in extract liquor were determined by orthogonal design and single factor experiment in combination with glycyrrhizic acid content and identification of Rhizoma zingiberis, Radix Ginseng and Rhizoma Pinelliae. RESULTS: The extracting was arrived at in the condition of adding eighteen times of 70% alcohol as much as crude drug and refluxing 2 times, 2h and 1h, respectively. CONCLUSION: The extraction is stable and feasible.

Isolation and antitumor activity in vitro of three kinds of bufadienolides / 中成药

AIM: To isolate three kinds of bufadienolides composition from Venenum bufonis in order to investigate their antitumor activity in vitro.METHODS: Alcohol extraction and isolation by Silica gel colume were employed in this study.Their antitumor activities in vitro were evaluated by MTT colorimetric method.RESULTS: With such methods,three kinds of bufadienolides,including Bufalin,cinobufagin,and resibufogenin with purity above 90% were prepared.The in-vitro results showed that three kinds of bufadienolides had prominent inhibition effect on human lung cancer A549 cells,human breast cancer MDA-MB-435 cells in the range of 0.001 ?g/mL ～ 100 ?g/mL.CONCLUSION: Isolation by Silica gel colume can be used to separate three kinds of bufadienolides from Venenum bufonis and its constituents has prominent anti-cancer effects.