Ethanol extract of Rehmannia glutinosa exerts antidepressant-like effects on a rat chronic unpredictable mild stress model by involving monoamines and BDNF.

The dried roots of Rehmannia glutinosa Libosch. (Scrophulariaceae) are of both medicinal and nutritional importance. Our previous study has found that the 80% ethanol extract of R. glutinosa (RGEE) produced antidepressant-like activities in mouse behavioral despair depression models. However, its mechanisms are still unclear. The present study aimed to observe the antidepressant-like mechanisms of RGEE on a rat chronic unpredictable mild stress (CUMS) model by involving monoaminergic neurotransmitters and brain-derived neurotrophic factor (BDNF). CUMS-stressed rats were orally given RGEE daily (150, 300, and 600 mg/kg) or fluoxetine hydrochloride (FH) for 3 weeks after starting the CUMS procedure. Sucrose preference test was carried out to observe depression-like behavior, and serum and brain tissues were used for neurochemical and fluorescent quantitative reverse transcription PCR analysis. Results demonstrated that CUMS induced depression-like behavior, whereas RGEE and FH administration inhibited this symptom. Furthermore, CUMS caused excessively elevated levels of serum corticosterone (CORT), an index of hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, in a manner attenuated by RGEE and FH administration. RGEE administration also further elevated monoamine neurotransmitters and BDNF levels, up-regulated the mRNA expression of BDNF and tropomyosin-related kinase B (TrkB) in hippocampus of rats suffering CUMS. Together, our findings suggest that RGEE can improve CUMS-evoked depression-like behavior, and indicate its mechanisms may partially be associated with restoring HPA axis dysfunctions, enhancing monoamineergic nervous systems, and up-regulating BDNF and TrkB expression.

Protective effects of alginate-chitosan microspheres loaded with alkaloids from Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. (Zuojin Pill) against ethanol-induced acute gastric mucosal injury in rats.

Zuojin Pill (ZJP), a traditional Chinese medicine formula, consists of Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. in a ratio of 6:1 (w/w) and was first recorded in "Danxi's experiential therapy" for treating gastrointestinal disorders in the 15th century. However, the poor solubility of alkaloids from ZJP restricted the protective effect in treating gastritis and gastric ulcer. The aim of the study was to investigate the protective mechanism of mucoadhesive microspheres loaded with alkaloids from C. chinensis Franch. and E. rutaecarpa (Juss.) Benth. on ethanol-induced acute gastric mucosal injury in rats. Surface morphology, particle size, drug loading, encapsulation efficiency, in vitro drug release, mucoadhesiveness, and fluorescent imaging of the microspheres in gastrointestinal tract were studied. The results showed that the mucoadhesive microspheres loaded with alkaloids could sustain the release of drugs beyond 12 hours and had gastric mucoadhesive property with 82.63% retention rate in vitro. The fluorescence tracer indicated high retention of mucoadhesive microspheres within 12 hours in vivo. The mucoadhesive microspheres loaded with alkaloids could reduce the gastric injury by decreasing the mucosal lesion index, increasing the percentage of inhibition and increasing the amount of mucus in the gastric mucosa in an ethanol-induced gastric mucosal injury rat model. Moreover, the mucoadhesive microspheres loaded with alkaloids reduce the inflammatory response by decreasing the levels of tumor necrosis factor-α (TNF-α), interleukin 1ß (IL-1ß), downregulating the mRNA expression of inducible nitric oxide synthase, TNF-α, and IL-1ß in gastric mucosa. All the results indicate that mucoadhesive microspheres loaded with alkaloids could not only increase the residence time of alkaloids in rat stomach, but also exert gastroprotective effects through reducing the inflammatory response on ethanol-induced gastric mucosal damage. Thus, these microspheres could be developed as a potential controlled release drug for treatment of gastric ulcer.

Kinetics and mechanism of 2,3,5,4'-tetrahydroxystilbene-2-O-ß-d-glycoside (THSG) degradation in aqueous solutions.

The hydrolytic kinetics and degradation mechanism of 2,3,5,4'-tetrahydroxystilbene-2-O-ß-d-glycoside (THSG) extracted from Radix Polygoni Multiflori (a commonly used official Chinese herbal Heshouwu), were investigated using reversed-phase high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). The influences of pH (1.5-9.9), temperature (25-60°C) and irradiation on the hydrolysis of THSG were studied in aqueous solutions. The results showed that the degradation of THSG was pH-, temperature- and irradiation-dependent and all followed first-order kinetics. The effect of temperature on the rate of THSG degradation was characterized using the Arrhenius equation. Maximum stability of THSG was found at pH 1.5 (t(0.5)=47.57 d). THSG was unstable in alkaline and irradiation conditions. The active energy (E(a)) of THSG degradation in aqueous solution at pH 6.8 (most frequently adopted extract solvent) under lucifugal and irradiation conditions was 47.7kJmol(-1) and 25.3kJmol(-1), respectively. Three hydrolytic products of THSG were identified by LC-MS. Cis-trans isomerism took place under irradiation, and hydrolysis took place in acid-base conditions. Moreover, further oxidation on aglycon occurred after hydrolytic cleavage of phenolic glycoside in acidic conditions. The possible hydrolytic pathways of THSG are proposed.

Synthesis and activity evaluation of benzoylurea derivatives as potential antiproliferative agents.

3-Haloacylamino benzoylureas (3-HBUs) consist of a new family of tubulin ligands that kill cancer cells through mitotic arrest. In exploring the structure-activity relationship (SAR), 17 analogues defined through variations of formylurea at the 1-position of the aromatic ring were synthesized. SAR analysis revealed that (i) the p-pi conjugation between the aromatic ring and formylurea was essential; (ii) suitable aryl substitutions at the N'-end increased anticancer activity with a mechanism different from that of parent compounds; and (iii) introduction of pyridyl at the N'-end provided an opportunity of making soluble salts to improve bioavailability. Among the analogues, 16c bearing 3,4,5-trimethoxyphenyl and 16g bearing 2-pyridyl at the N'-end showed an enhanced activity and were active in hepatoma cells that were resistant to tubulin ligands including the parent compounds. Furthermore, 16c and 16g killed cancer cells with a mechanism independent of mitotic arrest, indicating a change of action mode.