Ruxue Zhang

The genus Scutellaria an ethnopharmacological and phytochemical review

Scutellaria (HUANG QIN) (Lamiaceae), which includes about 350 species commonly known as skullcaps, is widespread in Europe, the United States and East Asia. Some species are taken to clear away the heat-evil and expel superficial evils in traditional Chinese medicine (TCM). The present paper reviews the ethnopharmacology, the biological activities and the correlated chemical compounds of Scutellaria species. More than 295 compounds have been isolated, among them flavonoids and diterpenes. Studies show that Scutellaria and its active principles possess wide pharmacological actions, such as antitumor, anti-angiogenesis, hepatoprotective, antioxidant, anticonvulsant, antibacterial and antiviral activities. Currently, effective monomeric compounds or active parts have been screened for pharmacological activity from Scutellaria in vivo and in vitro. Increasing data supports application and exploitation for new drug development.

Rehmannia glutinosa: Review of botany, chemistry and pharmacology

Rehmannia glutinosa, a widely used traditional Chinese herb, belongs to the family of Scrophulariaceae, and is taken to nourish Yin and invigorate the kidney in traditional Chinese medicine (TCM) and has a very high medicinal value. In recent decades, a great number of chemical and pharmacological studies have been done on Rehmannia glutinosa. More than 70 compounds including iridoids, saccharides, amino acid, inorganic ions, as well as other trace elements have been found in the herb. Studies show that Rehmannia glutinosa and its active principles possess wide pharmacological actions on the blood system, immune system, endocrine system, cardiovascular system and the nervous system. Currently, the effective monomeric compounds or active parts have been screened for the pharmacological activity of Rehmannia glutinosa and the highest quality scientific data is delivered to support the further application and exploitation for new drug development.

Experimental Study on the Hemostatic Activity of the Tibetan Medicinal Herb Lamiophlomis rotata

The blood hemostatic activity of the Tibetan medicinal herb Lamiophlomis rotata was evaluated in BALB/c mice and Wistar rats. L. rotata aqueous extract (LRAE) was given to mice at concentrations of 0.5, 1.0, 2.0 g/kg body weight and 0.75, 1.5, 3.0 g/kg to rats. The hemostatic activity of LRAE was estimated by changes in bleeding time (BT), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (FIB). At the same time hepatic function and blood fat indexes including AST, ALT, Alb, Chol and LDL‐C were measured also. The results showed that an appropriate level of LRAE could shorten the BT and TT values and increase the Alb level paralleling that of FIB. However, the shortening of the PT was only possible by a high and long administration of LRAE, and no change in APTT was observed. On the other hand, LRAE showed some effects in improving the liver function and reducing blood lipids by decreasing the levels of AST, ALT, Chol and LDL‐C. All these changes had a significant dose‐effect and time‐effect relationship. These results confirm the hemostatic and thromboplastic effects of L. rotata and these effects might be implemented by improving the synthetic function of the liver. Copyright

Ameliorating effect and potential mechanism of Rehmannia glutinosa oligosaccharides on the impaired glucose metabolism in chronic stress rats fed with high-fat diet

The aim of this study was to determine whether the Rehmannia glutinosa oligosaccharides (ROS) ameliorate the impaired glucose metabolism and the potential mechanism in chronic stress rats fed with high-fat diet. The rats were fed by a high-fat diet and simultaneously stimulated by chronic stress over 5 weeks. Body weight, fasting plasma glucose, intraperitoneal glucose tolerance test (IPGTT), plasma lipids, gluconeogenesis test (GGT), glycogen content, and corticosterone, insulin and leptin levels were measured. The results showed that ROS administration (100, 200 mg/kg, i.g.) for 5 weeks exerted the effects of increasing the organ weights of thymus and spleen, lowering the fasting plasma glucose level, improving impaired glucose tolerance, increasing the contents of liver and muscle glycogen, decreasing the gluconeogenesis ability, plasma-free fatty acids level, as well as plasma triglyceride and total cholesterol levels in chronic stress and high-fat fed rats, especially in the group of 200mg/kg; while the plasma corticosterone level was decreased, and plasma leptin level was increased. These results suggest that ROS exert an ameliorating effect of impaired glucose metabolism in chronic stress rats fed with high-fat diet, and the potential mechanism may be mediated through rebuilding the glucose homeostasis in the neuroendocrine immuno-modulation (NIM) network through multilinks and multitargets.

Isolation and identification of hemostatic ingredients from Lamiophlomis rotata (Benth.) Kudo.

Lamiophlomis rotata (Benth.) Kudo (LR) is a traditional drug used by Chinese minorities such as Tibetans, Mongolians and Na Xi with the beneficial effects of hemostasis and alleviating pain. Flavonoids ingredients (P1), iridoid glycosides ingredients (P2) and maximus polarity components ingredients (P3) were isolated from the aqueous extract of LR (AELR) with polyamide and macroporous adsorptive resins chromatographic columns. The hemostatic activity of these ingredients was estimated by the changes in bleeding time (BT), clotting time (CT) and blood coagulation parameters in mice or rats. RP‐HPLC was used to analyze the chemical composition of P2. As a result, AELR and P2 significantly shortened BT, CT and thrombin time (TT), and increased fibrinogen (FIB), but P1 and P3 showed no hemostatic effect during the experiment. Moreover, P2 showed satisfactory hemostatic effect with dose‐effect relationship and low toxicity in mice. 8‐Dehydroxy shanzhiside, phloyoside II, shanzhiside methylester, loganin, and 8‐O‐acetylshanzhiside methylester were detected as the main iridoid glycosides in P2 by RP‐HPLC. Our results suggest that iridoid glycosides may be the hemostatic activity ingredients of L. rotata and are a potential hemostatic medicine. Copyright

Development of a validated HPLC-PAD-APCI/MS method for the identification and determination of iridoid glycosides in Lamiophlomis rotata

An HPLC-photodiode array detector (PAD)-APCI/MS method was developed for the identification of iridoid glycosides in Lamiophlomis rotata (Benth.) Kudo. The regularities of characteristic ions of iridoid glycosides obtained in APCI-MS were analyzed and used to deduce the structure of iridoid glycosides. Compared with the literature on ESI-MS, the deprotonated molecular ions were more outstanding in APCI-MS. Five major active constituents, namely, 8-O-acetylshanzhiside methyl ester, loganin, 8-deoxyshanzhiside, phloyoside II, and shanzhiside methyl ester, were simultaneously determined in ten samples by HPLC. A comprehensive validation of the method included tests of sensitivity, linearity, precision, and accuracy. The linear regressions were acquired with r > 0.999. The precision was evaluated by intra- and inter-day assays, after which relative standard deviation (R.S.D.) values were reported within 2.5%. The recovery studies for the quantified compounds were observed in the range of 95.6-101.2% with R.S.D. values less than 2.1%. The overall procedure may be suitable for the qualitative and quantitative analyses of iridoid glycosides in L. rotata and its preparations.

Neu-P11, a novel MT1/MT2 agonist, reverses diabetes by suppressing the hypothalamic-pituitary-adrenal axis in rats

&NA; Excessive glucocorticoid (GC) in type 2 diabetes mellitus (T2DM) reduces insulin sensitivity, impairs &bgr;‐cell function, increases gluconeogenesis and glycogenolysis, impairs glucose uptake and metabolism, and reduces the insulinotropic effects of glucagon‐like peptide 1. Melatonin, which serves as a physiological regulator of the hypothalamic‐pituitary‐adrenal (HPA) axis, has been suggested to have anti‐diabetic effects. The objective of the present study was to investigate the effect of the MT1/MT2 melatonin agonist Neu‐P11 on glucose and lipid metabolism in T2DM rats induced by a high fat diet combined with low doses of streptozotocin. T2DM rats were intragastrically administered melatonin (20 mg/kg), Neu‐P11 (20, 10, 5 mg/kg), or a vehicle for 4 weeks. The results showed that the increased food intake, water consumption, hyperglycemia, glucose intolerance, and insulin resistance in T2DM rats were all improved by Neu‐P11 treatment. Neu‐P11 increased GC receptor expression and suppressed 11&bgr;‐hydroxysteroid dehydrogenase 1 activity in the hippocampus by enhancing GC sensitivity and HPA feedback, thus decreasing the high GC levels. Transcript levels of the glucose metabolism‐related genes peroxisome proliferator‐activated receptor‐&ggr;, glucose transporter type‐4, and adiponectin in adipose tissue were significantly increased after Neu‐P11 treatment, while leptin mRNA was significantly decreased. Furthermore, MT1 and MT2 protein levels were enhanced by Neu‐P11. These data suggest that normalization of the hyperactivated HPA axis by melatonin and Neu‐P11 in T2DM regulates metabolic profiles and insulin sensitivity, which may attenuate insulin resistance and glucose homeostasis. Because Neu‐P11 has superior pharmacokinetics and a longer half‐life than melatonin, it might be beneficial in treating obesity and T2DM.

Retracted: Phytochemical and Biological Studies of Plants from the Genus Meconopsis

Retracted: The following article from the journal Chemistry & Biodiversity, ‘Phytochemical and Biological Studies of Plants from the Genus Meconopsis’ by Mao‐Xing Li, Jin‐Hui Wang, Xi‐Rui He, Peng‐Cheng Fan, Ru‐Xue Zhang, and Zheng‐Ping Jia*, published in 2010, Vol. 7, No. 8, p. 1930 – 1948, has been retracted by agreement between the authors, the Editor‐in‐Chief M. V. Kisakürek, and the publisher Verlag Helvetica Chimica Acta AG.

Melatonin Receptor Agonist Piromelatine Ameliorates Impaired Glucose Metabolism in Chronically Stressed Rats Fed a High-Fat Diet

Modern lifestyle factors (high-caloric food rich in fat) and daily chronic stress are important risk factors for metabolic disturbances. Increased hypothalamic-pituitary-adrenal (HPA) axis activity and the subsequent excess production of glucocorticoids (GCs) in response to chronic stress (CS) leads to increases in metabolic complications, such as type 2 diabetes and insulin resistance (IR). Melatonin (MLT), which protects several regulatory components of the HPA axis from GC-induced deterioration, might improve glucose homeostasis. Piromelatine is a melatonin receptor-1/melatonin receptor-2 (MT1/MT2) agonist with high affinity for MLT receptors and a longer duration of action than MLT. The objective of the present study was to explore the potential effects of piromelatine on glucose and lipid metabolism and insulin sensitivity in rats with IR induced by a high-fat diet combined with CS (CF). The results showed that piromelatine prevented the suppression of body weight gain and energy intake induced by CF and normalized CF-induced hyperglycemia and homeostasis model assessment–IR index, which suggests that piromelatine prevented whole-body IR. Piromelatine also prevented CF-induced dysregulation of genes involved in glucose and lipid metabolism, including proinflammatory cytokines, in adipose tissue. In addition, piromelatine also attenuated CF-induced excess free corticosterone release, increased glucocorticoid receptor expression, and decreased 11β-hydroxysteroid dehydrogenase-1 expression, suggesting that piromelatine might ameliorate impaired glucose metabolism and prevent IR by normalizing HPA-axis functions. In conclusion, piromelatine might be a novel therapeutic agent for glucose intolerance and IR.

Iridoid glycosides and phenylethanoid glycosides from Phlomis younghusbandii roots

0009-3130/11/4705-0848 2011 Springer Science+Business Media, Inc. 1) Department of Pharmacy, Lanzhou General Hospital of PLA, Lanzhou, 730050, P. R. China, fax: 86931 266-1767, e-mail: limaox2005@yahoo.com.cn; 2) Department of Pharmacy, Changhai Hospital, Second Military Medical University, Shanghai, 200433, P. R. China; 3) Department of Life Sciences, Lanzhou University, Lanzhou, 730000, P. R. China. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 740–741, September–October, 2011. Original article submitted June 15, 2010. Chemistry of Natural Compounds, Vol. 47, No. 5, November, 2011 [Russian original No. 5, September–October, 2011]