Herbal Science Research - pharmacology

Some phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): A review [...]

Site Editor — Fri, 02 Nov 2007 15:49:24 -0700

Some phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): A review of recent research.: Food Chem Toxicol. 2007 Sep 18; Ali BH, Blunden G, Tanira MO, Nemmar A

Ginger (Zingiber officinale Roscoe, Zingiberacae) is a medicinal plant that has been widely used in Chinese, Ayurvedic and Tibb-Unani herbal medicines all over the world, since antiquity, for a wide array of unrelated ailments that include arthritis, rheumatism, sprains, muscular aches, pains, sore throats, cramps, constipation, indigestion, vomiting, hypertension, dementia, fever, infectious diseases and helminthiasis. Currently, there is a renewed interest in ginger, and several scientific investigations aimed at isolation and identification of active constituents of ginger, scientific verification of its pharmacological actions and of its constituents, and verification of the basis of the use of ginger in some of several diseases and conditions. This article aims at reviewing the most salient recent reports on these investigations. The main pharmacological actions of ginger and compounds isolated therefrom include immuno-modulatory, anti-tumorigenic, anti-inflammatory, anti-apoptotic, anti-hyperglycemic, anti-lipidemic and anti-emetic actions. Ginger is a strong anti-oxidant substance and may either mitigate or prevent generation of free radicals. It is considered a safe herbal medicine with only few and insignificant adverse/side effects. More studies are required in animals and humans on the kinetics of ginger and its constituents and on the effects of their consumption over a long period of time.

Alkamides from Echinacea inhibit cyclooxygenase-2 activity in human neuroglioma cells.

Site Editor — Fri, 13 Jul 2007 18:39:55 -0700

Alkamides from Echinacea inhibit cyclooxygenase-2 activity in human neuroglioma cells.: >Biochem Biophys Res Commun. 2007 Jun 19; Hinz B, Woelkart K, Bauer R

During past years inhibition of the cyclooxygenase-2 (COX-2) enzyme has been proven as an effective strategy to suppress pain and inflammation. Based on this and other mechanistic findings, interest has also renewed in the molecular pathways underlying the anti-inflammatory effects of herbal drugs. The present study addressed this issue and investigated the impact of several polyunsaturated alkamides isolated from a CO(2) extract of the roots of Echinacea angustifolia DC on both activity and expression of COX-2. A 48-h treatment of H4 human neuroglioma cells with the CO(2) extract led to a significant suppression of prostaglandin (PG) E(2) formation. Analysis of eight different alkamides revealed a contribution of undeca-2Z-ene-8,10-diynoic acid isobutylamide (A5), dodeca-2E-ene-8,10-diynoic acid isobutylamide (A7), and dodeca-2E,4Z-diene-8,10-diynoic acid 2-methylbutylamide (A8) to this response. Using an established short-term COX-2 activity assay, all three alkamides were shown to interfere with COX-2 activity. In contrast, none of the COX-2-suppressing nor any other tested alkamide was found to inhibit COX-2 mRNA and protein expression. Instead, increased COX-2 mRNA and protein levels were registered in the presence of the CO(2) extract and most of the analyzed alkamides which caused, however, no stimulation of PG formation. Overall, our results suggest that certain alkamides derived from E. angustifolia roots may contribute to the pharmacological action of the herbal extract by inhibiting COX-2-dependent PGE(2) formation at sites of inflammation.

An updated systematic review of the pharmacology of silymarin.

Site Editor — Fri, 13 Jul 2007 18:19:17 -0700

An updated systematic review of the pharmacology of silymarin.: Forsch Komplementarmed. 2007 Apr;14(2):70-80 Authors: Saller R, Melzer J, Reichling J, Brignoli R, Meier R

BACKGROUND: Recent years have seen an explosion of scientific papers that deal with drugs from the fruits of milk thistle and its active substances silymarin (standardized mixture of flavonolignanes), thus justifying an updated systematic review. METHODS: Electronic databases identified silymarin, silibinin, silicristin or milk thistle as descriptors in >700 papers (34% published in last 5 years; 92% dealt with animal pharmacological). Only papers adequately reporting on experimental conditions, dosing, variables tested and statistics were analysed. RESULTS: Silymarin was found to modify specifically the functions related to various transporters and receptors located in the cell membranes; that is, organic anion uptake transporter peptides (OATP), ABC transporters (P-gp), bile salt export pump, as well as TNF-alpha-dependent and possibly selectin-dependent phenomena. In the cytoplasm, some antioxidant properties and the inhibition of the lipoxygenase pathway seem quite selective and could concur to the antitoxic effects. Some effects like the inhibition of inducible nitric-oxide synthase, of nuclear factor kappa B, and reduction of collagen synthesis are indicative of DNA/RNA-mediated effects. Several studies using 'in vitro' and 'in vivo' cancer models suggest a potential of silymarin in such diseases. Topical and systemic silymarin has skin protective properties against UV-induced damage in epidermis and causes an up-regulation of tumour-suppressor genes p53- and p21CIP1. There were no data on hepatic viral replication, viremia or spontaneous tumours in the data examined. CONCLUSIONS: Data presented here do not solve the question about the complex mechanism(s) of action of the medicinal herbal drug silymarin. Silymarin may be a natural multi-functional and multi-target drug.

PMID: 17464157 [PubMed - indexed for MEDLINE]

Use of Artemisinin (Qinghaosu) derivatives in the treatment of malaria.

Site Editor — Fri, 13 Jul 2007 18:05:01 -0700

Use of Artemisinin (Qinghaosu) derivatives in the treatment of malaria.: Afr J Health Sci. 1998 Feb;5(1):8-11 Authors: Kokwaro GO

Derivatives of the Chinese herbal remedy ginghaosu (artemisinin) are useful in the treatment of multiple-drug resistant malaria. This review covers the discovery, development, clinical pharmacology and toxicology of these compounds, with emphasis on those derivatives currently in use in parts of Africa.

PMID: 17580987 [PubMed - in process]

Use of Artemisinin (Qinghaosu) derivatives in the treatment of malaria.

Site Editor — Sat, 23 Jun 2007 05:26:28 -0700

Use of Artemisinin (Qinghaosu) derivatives in the treatment of malaria.:

Use of Artemisinin (Qinghaosu) derivatives in the treatment of malaria.

Afr J Health Sci. 1998 Feb;5(1):8-11

Authors: Kokwaro GO

PMID: 17580987 [PubMed - in process]

Taraxacum--a review on its phytochemical and pharmacological profile.

Site Editor — Thu, 01 Feb 2007 16:31:57 -0800

Taraxacum--a review on its phytochemical and pharmacological profile.: J Ethnopharmacol. 2006 Oct 11;107(3):313-23 Authors: Schütz K, Carle R, Schieber A

The genus Taraxacum is a member of the family Asteraceae, subfamily Cichorioideae, tribe Lactuceae and widely distributed in the warmer temperate zones of the Northern Hemisphere. The perennial weed has been known since ancient times for its curative properties and has been utilized for the treatment of various ailments such as dyspepsia, heartburn, spleen and liver complaints, hepatitis and anorexia. However, its use has mainly been based on empirical findings. This contribution provides a comprehensive review of the pharmacologically relevant compounds of Taraxacum characterized so far and of the studies supporting its use as a medicinal plant. Particular attention has been given to diuretic, choleretic, anti-inflammatory, anti-oxidative, anti-carcinogenic, analgesic, anti-hyperglycemic, anti-coagulatory and prebiotic effects. Finally, research needs such as quantification of individual Taraxacum constituents and assessment of their pharmacological activities in humans have briefly been outlined.

The Design and Evaluation of Placebo Material for Crude Herbals: Artemisia afra Herb as a Model.

Site Editor — Wed, 31 Jan 2007 19:11:05 -0800

The Design and Evaluation of Placebo Material for Crude Herbals: Artemisia afra Herb as a Model.: Phytother Res. 2007 Jan 30; Authors: Dube A, Manthata LN, Syce JA

Herbal materials are known to present significant challenges with regard to designing credible placebos. This study intended to demonstrate the possibility of designing placebo material for crude herbals and used Artemisia afra, a popular traditional herbal medicine in South Africa, as a model. To produce the placebo, step-wise solvent extractions were conducted on the plant leaves and the process was monitored spectrophotometrically and using high performance liquid chromatography (HPLC) with diode array detection. The odour and taste between the placebo and A. afra was matched by inclusion of linalool and sodium saccharin, respectively. The muscle relaxant activity of the placebo was evaluated using an isolated guinea-pig tracheal muscle preparation. The UV absorbance of the extracts and the HPLC chromatograms, showed that most of the phytochemical constituents had been removed and the placebo closely resembled the A. afra leaves. The EC(50) of the placebo and the leaves were 4846.00 and 68.49 mg/mL, respectively, which showed that not only did the A. afra leaves possess muscle relaxant activity, but that the placebo did not possess any significant activity compared with the A. afra leaves (p value 0.0001). These results demonstrated that it is possible to design credible, pharmacologically inert placebo material for crude herbals. Copyright (c) 2007 John Wiley & Sons, Ltd.

Dendritic cells as a pharmacological target of traditional chinese medicine.

Site Editor — Wed, 31 Jan 2007 19:05:39 -0800

Dendritic cells as a pharmacological target of traditional chinese medicine.: Cell Mol Immunol. 2006 Dec;3(6):401-10 Authors: Chen X, Yang L, Howard OM, Oppenheim JJ

Dendritic cells (DCs) represent a heterogeneous population of professional antigen-presenting cells (APCs) that play a central role in the initiation and regulation of immune responses. There is considerable evidence that DCs can be used as therapeutic targets for pharmacological modulation of immune responses. Traditional Chinese medicine (TCM) has a long-standing history of using herbal medicine in the treatment of variety of human diseases. Many of the clinical effects of TCM have reportedly been attributed to the up- or down-regulation of immune responses. Accumulating evidence indicates that TCM and its components can interfere with immune responses at the earliest stage by targeting key functions of DCs. Here, we review those published studies of TCM with respect to their effects on immunobiological functions of DCs. Investigations based on both chemical entities derived from TCM as well as TCM herbal mixtures are presented. These studies suggest that various TCM herbal medicines have the capacity to inhibit or promote major functions of DCs, such as differentiation, maturation, cytokine production, survival, antigen uptake and presentation as well as trafficking. These studies have revealed novel biological effects of TCM and documented the utility of this approach to discover novel biological modifier of DC functions derived from natural sources.

[Pharmacological effects of flavonoids from Scutellaria baicalensis]

Site Editor — Tue, 09 Jan 2007 06:08:15 -0800

[Pharmacological effects of flavonoids from Scutellaria baicalensis]: Przegl Lek. 2006;63(2):95-6 Authors: Kowalczyk E, Krzesiński P, Kura M, Niedworok J, Kowalski J, Błaszczyk J

Scutellaria baicalensis is a plant widely used in Chinese and Japanese herbal medicine. Dry roots of Scutellaria baicalensis are used, especially as alcohol extracts. Flavonoids isolated from Radix Scutellariae have beneficial effects in hepatitis. Flavonoids derived from Scutellaria baicalensis produce antioxidative, antineoplastic, cardiomiocyte-protective activity. They inhibit agregation of platelets, permeability of capillary vessels, have antibacterial and anty-angiogenic effects.

Risk and safety assessment on the consumption of Licorice root (Glycyrrhiza sp.), its extract and powder as a food ingredient...

Site Editor — Wed, 04 Oct 2006 18:26:50 -0700

Risk and safety assessment on the consumption of Licorice root (Glycyrrhiza sp.), its extract and powder as a food ingredient, with emphasis on the pharmacology and toxicology of glycyrrhizin.: Regul Toxicol Pharmacol. 2006 Jul 31; Isbrucker RA, Burdock GA

Licorice (or 'liquorice') is a plant of ancient origin and steeped in history. Licorice extracts and its principle component, glycyrrhizin, have extensive use in foods, tobacco and in both traditional and herbal medicine. As a result, there is a high level of use of licorice and glycyrrhizin in the US with an estimated consumption of 0.027-3.6mg glycyrrhizin/kg/day. Both products have been approved for use in foods by most national and supranational regulatory agencies. Biochemical studies indicate that glycyrrhizinates inhibit 11beta-hydroxysteroid dehydrogenase, the enzyme responsible for inactivating cortisol. As a result, the continuous, high level exposure to glycyrrhizin compounds can produce hypermineralocorticoid-like effects in both animals and humans. These effects are reversible upon withdrawal of licorice or glycyrrhizin. Other in vivo and clinical studies have reported beneficial effects of both licorice and glycyrrhizin consumption including anti-ulcer, anti-viral, and hepatoprotective responses. Various genotoxic studies have indicated that glycyrrhizin is neither teratogenic nor mutagenic, and may possess anti-genotoxic properties under certain conditions. The pharmacokinetics of glycyrrhizin have been described and show that its bioavailability is reduced when consumed as licorice; this has hampered attempts to establish clear dose-effect levels in animals and humans. Based on the in vivo and clinical evidence, we propose an acceptable daily intake of 0.015-0.229mg glycyrrhizin/kg body weight/day.

Cytotoxic and antitumor activity of liposome-incorporated sclareol against cancer cell lines and human colon cancer xenografts.

Site Editor — Fri, 09 Jun 2006 07:20:26 -0700

Cytotoxic and antitumor activity of liposome-incorporated sclareol against cancer cell lines and human colon cancer xenografts.: Pharmacol Res. 2006 Jan;53(1):80-7 Authors: Hatziantoniou S, Dimas K, Georgopoulos A, Sotiriadou N, Demetzos C

The aim of this study was to design and prepare liposome-incorporated sclareol--a highly lipophilic natural product-to overcome its water insolubility and develop suitable formulations for in vivo administration. The bioactive labdane-type diterpene sclareol was incorporated into liposomes composed of egg phosphatidylcholine and dipalmitoylphosphatidylglycerol prepared by the thin-film hydration method followed by sonication. A formulation of egg phosphatidylcholine/dipalmitoylphosphatidylglycerol/sclareol (9:0.1:5 molar ratio) was developed and characterized. The lipid recovery and the sclareol to lipid molar ratio were measured using high-performance thin-layer chromatography/flame ionization detection. In vitro drug release was measured in supplemented RPMI-1640 at 37 degrees C. The liposomal and the free sclareol were initially tested in vitro for their activity against human cancer cell lines using the sulphorhodamine B assay. Liposomes incorporating sclareol at a drug to lipid molar ratio of 0:43, suggesting an incorporation efficiency of almost 80%, showed reduced growth rate of human colon cancer tumors (HCT116) developed in SCID mice, without any significant side effects.

A Preadipocyte Differentiation Assay as a Method for Screening Potential Anti-Type II Diabetes Drugs from Herbal Extracts.

Site Editor — Fri, 09 Jun 2006 07:14:26 -0700

A Preadipocyte Differentiation Assay as a Method for Screening Potential Anti-Type II Diabetes Drugs from Herbal Extracts.: Planta Med. 2006 Jan;72(1):14-9 Authors: Xu ME, Xiao SZ, Sun YH, Ou-Yang Y, Guan C, Zheng XX

A cell-based method for screening drug candidates from herbal extracts that have possible anti-type II diabetic effects was established. The differentiation of preadipocytes into adipocytes was used as a sensitive primary indicator of a drug's potential effect on type II diabetes. We established a quantitative method by using a computer image analysis system for assessing the morphological alterations. The assay was validated by screening compounds extracted from Chinese herbs and the known drug rosiglitazone for their capability of modulating PPARgamma gene expression and glucose uptake by adipocytes. Two drug candidates having possible anti-type II diabetic effects were identified. Abbreviations. DMEM:Dulbecco's modified Eagle's medium FCS:fetal calf serum RT-PCR:reverse transcriptase-polymerase chain reaction WST:water-soluble tetrazolium PPARgamma:peroxisome proliferator-activated receptor FITC:fluorescein isothiocyanate PI:propidium iodide PS:phosphatidyl serine.