Formulation development and evaluation of gastroretentive floating beads with Brucea javanica oil using ionotropic gelation technology

In the present study, a gastric retention floating system for Brucea javanica oil, composed of alginate and carrageenan, was prepared using ionotropic gelation. Parameters for floatability, drug load, encapsulation efficiency, bead morphology, in vitro release, and in vivo gastric retention were evaluated. The optimized formulation via Box–Behnken design consisted of 1.7% alginate(W/V), 1.02% carrageenan(W/V), 1.4% CaCO_3(W/V), and a gelling bath of pH 0.8. The alginate–carrageenan–Brucea javanica oil beads had a porous structure and exhibited up to 24 h of in vitro floatability with a load capacity of 45%–55% and an encapsulation efficiency of 70%–80%. A 6-h sustained release was observed in vitro. The beads had a prolonged gastric retention(> 60% at 6 h) in fasted rats, compared to non-floating beads(15% at 6 h), as measured by gamma scintigraphy with single-photon emission tomography/computed tomography(SPET/CT). In conclusion, the alginate–carrageenan–Brucea javanica oil system showed enhanced oil encapsulation efficiency, excellent floating and gastric retention abilities, and a favorable release behavior.

L‑Tyrosine Metabolic Pathway in Microorganisms and Its Application in the Biosynthesis of Plant‑Derived Natural Products

L-tyrosine,an aromatic amino acid,is an important upstream precursor for the synthesis of a series of valuable natural products such as flavonoids and phenolic acids.In recent years,regulation of the L‑tyrosine metabolic pathway has been devoted to enhancing the production of L-tyrosine and the derived bioactive compounds in microorganisms,usually by increasing the supply of precursors,blocking competitive routes,and modulating the transport system.Here,we reviewed the strategies to promote L-tyrosine production in microbial hosts and the common strategies to produce bioactive compounds in engineered Escherichia coli and Saccharomyces cerevisiae to better understand and utilize the L-tyrosine metabolic pathway for microbial overproduction of diverse valuable aromatic compounds in the future.

Effect of Yanggan Jiedu Sanjie formula on human hepatocellular carcinoma Bel-7402 cells

OBJECTIVE: To observe the effect of Yanggan Jiedu Sanjie(YGJDSJ) formula on human hepatocellular carcinoma Bel-7402 cells.METHODS: Bel-7402 cells were treated with YGJDSJ. Cell proliferation was detected by cell counting kit-8 assay. Cell apoptosis was identified by Hoechst 33258 staining and flow cytometric analysis. Cell cycle distribution was quantified by flow cytometric analysis. Caspase activities were measured by commercial kit. Cell senescence was detected by senescence-associated β-galactosidase(SA-β-gal)staining. Protein expression and phosphorylation were identified by Western blot. Protein expression was knocked-down by siRNA.RESULTS: YGJDSJ inhibited proliferation of Bel-7402 cells in a dose-and time-dependent manner.YGJDSJ induced apoptosis and activated caspase-3, 8, and 9 in Bel-7402 cells. YGJDSJ-induced apoptosis was completely abrogated by a pan caspase inhibitor, Z-VAD-FMK. YGJDSJ also induced cell senescence, up-regulated cyclin-dependent kinase inhibitor 1 a(CDKN1 a) and CDKN2 a expression and down-regulated retinoblastoma protein(RB) phosphorylation in Bel-7402 cells. Specific knockdown of CDKN1 a and CDKN2 a significantly reduced YGJDSJ-induce cell senescence in Bel-7402 cells.CONCLUSION: YGJDSJ inhibited cell proliferation,induced caspase-dependent apoptosis and CDKN1 a/CDKN2 a-RB signalling mediated cell senescence in Bel-7402 cells. Our findings suggest that YGJDSJ might be potential for hepatocellular carcinoma treatment.

Progress in active compounds effective on ulcerative colitis from Chinese medicines

Ulcerative colitis(UC), a chronic inflammatory disease affecting the colon, has a rising incidence worldwide. The known pathogenesis is multifactorial and involves genetic predisposition, epithelial barrier defects, dysregulated immune responses, and environmental factors. Nowadays, the drugs for UC include 5-aminosalicylic acid, steroids, and immunosuppressants. Long-term use of these drugs, however, may cause several side effects, such as hepatic and renal toxicity, drug resistance and allergic reactions. Moreover, the use of traditional Chinese medicine(TCM) in the treatment of UC shows significantly positive effects, low recurrence rate, few side effects and other obvious advantages. This paper summarizes several kinds of active compounds used in the experimental research of anti-UC effects extracted from TCM, mainly including flavonoids, acids, terpenoids, phenols, alkaloids, quinones, and bile acids from some animal medicines. It is found that the anti-UC activities are mainly focused on targeting inflammation or oxidative stress, which is associated with increasing the levels of anti-inflammatory cytokine(IL-4, IL-10, SOD), suppressing the levels of pro-inflammatory cytokines(TNF-α, IL-1β, IL-6, IL-8, IL-23, NF-κB, NO), reducing the activity of MPO, MDA, IFN-γ, and iNOS. This review may offer valuable reference for UC-related studies on the compounds from natural medicines.

一种基于血糖仪的简便且微量的β-葡萄糖苷酶活性检测方法（英文）

目的:β-葡萄糖苷酶活性是新生儿坏死性小肠结肠炎早期诊断和药用植物有效成分改变的重要指标。现有活性检测方法操作时间长,试剂消耗大,且需要昂贵的仪器设备和专业的技术人员,不利于β-葡萄糖苷酶的快速、实时检测。本文尝试构建一种基于血糖仪的酶活性检测方法,为实际样品中β-葡萄糖苷酶活性的快速检测提供科学依据。创新点:首次将便携式血糖仪引入β-葡萄糖苷酶活性检测中,通过酶反应条件优化、方法学考察、实际样品中的应用以及现有方法的比较,建立β-葡萄糖苷酶活性检测新方法。方法:采用单因素试验,以酶反应溶液、pH值、反应温度、反应时间和底物浓度为指标,优化酶活性测定条件;通过考察精密度、稳定性、重复性、加样回收率、专一性等指标验证方法的可行性;通过实际样品中新方法的应用以及与现有二硝基水杨酸(DNS)法和4-硝基苯基-β-D-吡喃葡萄糖苷(pN PG)法的比较,研究新方法在实际样品检测中的适用性。结论:酶活性测定最优条件为以柠檬酸-柠檬酸钠缓冲液(0.05 mol/L,pH 5.0)为反应溶液,0.03 g/mL水杨苷为底物,在50°C条件下,反应30 min。新方法具有良好的精密度、准确性、重复性、稳定性和耐用性,且不受β-葡聚糖酶、蜗牛酶、β-半乳糖苷酶、半纤维素酶和葡萄糖醛酸的影响,专一性较强。β-葡萄糖苷酶在缓冲液和大鼠血清中线性关系良好,线性范围分别为0.0873～1.5498U/m L和0.4076～2.9019U/m L。该方法已成功应用于苦杏仁、燀苦杏仁、酶制剂以及黑曲霉培养的一系列β-葡萄糖苷酶活性检测中,结果与现有方法所测的基本相符。