This article is available online at http://dmd.aspetjournals.org ABSTRACT:Even though the degradation of ginsenosides has been thoroughly studied in animals and in vitro using acids, enzymes, and intestinal bacteria, knowledge concerning the systemic availability of ginsenosides and their degradation products in humans is generally lacking. Therefore, the attention in this article is focused on the identification of ginsenosides and their hydrolysis products reaching the systemic circulation in man. This is of great importance in understanding clinical effects, preventing herb-drug interactions, and optimizing the biopharmaceutical properties of ginseng preparations. Using a sensitive mass spectrometric method, which is specific for the identification of ginsenosides in complex biological matrices, the degradation pathway of ginsenosides in the gastrointestinal tract of humans could be elucidated following the oral administration of ginseng. Within the frame of a pilot study, human plasma and urine samples of two subjects were screened for ginsenosides and their possible degradation products. In general, the urine data coincided well with the plasma data. In both volunteers the same hydrolysis products, which are not originally present in the Ginsana extract (Pharmaton S.A., Lugano, Switzerland) ingested, were identified in plasma and urine. It was shown that two hydrolysis products of the protopanaxatriol ginsenosides, namely G-Rh 1 and G-F 1 may reach the systemic circulation. In addition, compound-K, the main intestinal bacterial metabolite of the protopanaxadiol ginsenosides, was detected in plasma and urine. These products are probably responsible for the action of ginseng in humans. In opposition to previous reports, G-Rb 1 was identified in plasma and urine of one subject.

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand activated transcription factor, belonging to the metazoan family of nuclear hormone receptors. Activation of PPARgamma increases the transcription of enzymes involved in primary metabolism, leading to lower blood levels of fatty acids and glucose. Hence, PPARgamma represents the major target for the glitazone type of drugs currently being used clinically for the treatment of type 2 diabetes. Furthermore, activators of PPARgamma show beneficial anti-inflammatory and anti-tumour effects. Utilizing a fusion receptor of the yeast Gal4-DNA binding domain joined to the hinge region and ligand binding domain of the human PPARgamma in combination with a Gal4-driven luciferase reporter gene, cotransfected into Cos7 cells, we tested sage and rosemary extracts prepared with 80 % aqueous ethanol for possible PPARgamma activation. This revealed that both extracts are capable of selectively activating Gal4-PPARgamma fusion receptor, in a concentration-dependent manner, with EC (50) values of 22.8 +/- 8.4 mg/L and 33.7 +/- 7.3 mg/L for rosemary and sage, respectively. Subsequent analysis of the characteristic constituents revealed the phenolic diterpene compounds carnosol, present in both herbs, and carnosic acid to be active principles of these extracts, showing EC (50) values of 41.2 +/- 5.9 microM and 19.6 +/- 2.0 microM, respectively. Thus it can be concluded that the glucose lowering effect reported recently for rosemary may be attributed to PPARgamma activation. Moreover, our observations may also explain the anti-inflammatory and antiproliferative effects of both compounds published previously.

Non-steroidal anti-inflammatory drug (NSAID) intake is associated with high prevalence of gastrointestinal or cardiovascular adverse effects. All efforts to develop NSAIDs that spare the gastrointestinal tract and the cardiovasculature are still far from achieving a breakthrough. In the last two decades, preparations of the gum resin of Boswellia serrata (a traditional ayurvedic medicine) and of other Boswellia species have experienced increasing popularity in Western countries. Animal studies and pilot clinical trials support the potential of B. serrata gum resin extract (BSE) for the treatment of a variety of inflammatory diseases like inflammatory bowel disease, rheumatoid arthritis, osteoarthritis and asthma. Moreover, in 2002 the European Medicines Agency classified BSE as an 'orphan drug' for the treatment of peritumoral brain oedema. Compared to NSAIDs, it is expected that the administration of BSE is associated with better tolerability, which needs to be confirmed in further clinical trials. Until recently, the pharmacological effects of BSE were mainly attributed to suppression of leukotriene formation via inhibition of 5-lipoxygenase (5-LO) by two boswellic acids, 11-keto-β-boswellic acid (KBA) and acetyl-11-keto-β-boswellic acid (AKBA). These two boswellic acids have also been chosen in the monograph of Indian frankincense in European Pharmacopoiea 6.0 as markers to ensure the quality of the air-dried gum resin exudate of B. serrata. Furthermore, several dietary supplements advertise the enriched content of KBA and AKBA. However, boswellic acids failed to inhibit leukotriene formation in human whole blood, and pharmacokinetic data revealed very low concentrations of AKBA and KBA in plasma, being far below the effective concentrations for bioactivity in vitro. Moreover, permeability studies suggest poor absorption of AKBA following oral administration. In view of these results, the previously assumed mode of action - that is, 5-LO inhibition - is questionable. On the other hand, 100-fold higher plasma concentrations have been determined for β-boswellic acid, which inhibits microsomal prostaglandin E synthase-1 and the serine protease cathepsin G. Thus, these two enzymes might be reasonable molecular targets related to the anti-inflammatory properties of BSE. In view of the results of clinical trials and the experimental data from in vitro studies of BSE, and the available pharmacokinetic and metabolic data on boswellic acids, this review presents different perspectives and gives a differentiated insight into the possible mechanisms of action of BSE in humans. It underlines BSE as a promising alternative to NSAIDs, which warrants investigation in further pharmacological studies and clinical trials.

Background: Research on medicinal plants and extracts derived from them differs from studies performed with single compounds. Extracts obtained from plants, algae, fungi, lichens or animals pose some unique challenges: they are multicomponent mixtures of active, partially active and inactive substances, and the activity is often not exerted on a single target. Their composition varies depending on the method of preparation and the plant materials used. This complexity and variability impact the reproducibility and interpretation of pharmacological, toxicological and clinical research.Objectives: This project develops best practice guidelines to ensure reproducibility and accurate interpretations of studies using medicinal plant extracts. The focus is on herbal extracts used in pharmacological, toxicological, and clinical/intervention research. Specifically, the consensus-based statement focuses on defining requirements for: 1) Describing the plant material/herbal substances, herbal extracts and herbal medicinal products used in these studies, and 2) Conducting and reporting the phytochemical analysis of the plant extracts used in these studies in a reproducible and transparent way.The process and methods: We developed the guidelines through the following process: 1) The distinction between the three main types of extracts (extract types A, B, and C), initially conceptualised by the lead author (MH), led the development of the project as such; 2) A survey among researchers of medicinal plants to gather global perspectives, opportunities, and overarching challenges faced in characterising medicinal plant extracts under different laboratory infrastructures. The survey responses were central to developing the guidelines and were reviewed by the core group; 3) A core group of 9 experts met monthly to develop the guidelines through a Delphi process; and. 4) The final draft guidelines, endorsed by the core group, were also distributed for feedback and approval to an extended advisory group of 20 experts, including many journal editors.Outcome: The primary outcome is the “Consensus statement on the Phytochemical Characterisation of Medicinal Plant extracts“ (ConPhyMP) which defines the best practice for reporting the starting plant materials and the chemical methods recommended for defining the chemical compositions of the plant extracts used in such studies. The checklist is intended to be an orientation for authors in medicinal plant research as well as peer reviewers and editors assessing such research for publication.