Ethyl Acetate Fraction of Harpagophytum procumbens Prevents Oxidative Stress In Vitro and Amphetamine-Induced Alterations in Mice Behavior

Microglial activation has been associated to the physiopathology of neurodegenerative diseases, such as schizophrenia, and can occur during inflammation and oxidative stress. Pharmacological treatment is associated with severe side effects, and studies for use of plant extracts may offer alternatives with lower toxicity. Harpagophytum procumbens (HP) is a plant known for its anti-inflammatory properties. In the present study, we characterized the ethyl acetate fraction of HP (EAF HP) by ESI-ToF-MS and investigated the effects EAF HP in a lipopolysaccharide (LPS) induced inflammation model on microglial cells (BV-2 lineage). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), DCFH-DA (2',7'-dichlorofluorescein diacetate) and cell cycle flow cytometer analysis were performed. In vivo was investigated the amphetamine-induced psychosis model through behavioral (locomotor and exploratory activities, stereotypies and working memory) and biochemical (DCFH-DA oxidation and protein thiols) parameters in cortex and striatum of mice. EAF HP reduced activation and proliferation of microglial cells in 48 h (300 µg/mL) and in 72 h after treatments (50-500 µg/mL). Reactive oxygen species levels were lower at the concentration of 100 µg/mL EAF HP. We detected a modulatory effect on the cell cycle, with reduction of cells in S and G2/M phases. In mice, the pre-treatment with EAF HP, for 7 days, protected against positive and cognitive symptoms, as well as stereotypies induced by amphetamine. No oxidative stress was observed in this amphetamine-induced model of psychosis. Such findings suggest that EAF HP can modulate the dopaminergic neurotransmission and be a promising adjuvant in the treatment of locomotor alterations, cognitive deficits, and neuropsychiatric disorders.

A liquid chromatography-tandem mass spectrometry method for the analysis of primary aromatic amines in human urine

Aromatic amines are widely used in personal care products and human exposure to this class of chemicals is widespread. Bioanalytical methods to determine trace levels of aromatic amines in human urine are scarce. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to determine 39 primary aromatic amines (AAs) along with nicotine and cotinine in human urine. Chromatographic separation of the 41 analytes was achieved on an Ultra Biphenyl (100 mm × 2.1 mm, 5 µm) column. Mass spectrometry was operated in electrospray ionization positive ion multiple reaction monitoring (MRM) mode. The method exhibited excellent linear dynamic range (0.1-50 ng/mL) with correlation coefficients (r) > 0.999 for all analytes. Urine samples (2 mL) were hydrolyzed using 10 M NaOH at 95 °C for 15 h and target analytes were extracted using methyl-tert-butyl ether (MTBE). Addition of 15 µL of 0.25 M HCl to the sample extracts improved the recoveries of several target analytes. The method was validated through the analysis of fortified quality control (QC) samples and a certified standard reference material (SRM). Relative recoveries (%) of target analytes fortified in QC samples were in the range of 75-114% for 37 of the 41 analytes while the other analytes exhibited lower recoveries (16-74%). The limits of detection (LOD) and limits of quantification (LOQ) of target analytes were in the range of 0.025-0.20 ng/mL and 0.1-1.0 ng/mL, respectively. Intra-day and inter-day precision of the method assessed through the analysis of fortified urine QC samples at three different concentrations were < 11.7% and < 15.9% (measured as RSD), respectively. The method was applied in the analysis of urine samples from the general population and known smokers; aniline, para-anisidine, para-toluidine, ortho/meta-toluidine, 3-chloroaniline, 4-chloroaniline, 3,4-dichloroaniline, and 4,4'-methylenedianiline were found in all smoker's urine at sum concentrations ranging from 0.04 to 9.16 ng/mL.

From Bush Medicine to Modern Phytopharmaceutical: A Bibliographic Review of Devil's Claw (Harpagophytum spp.)

Devil's claw (Harpagophytum spp., Pedaliaceae) is one of the best-documented phytomedicines. Its mode of action is largely elucidated, and its efficacy and excellent safety profile have been demonstrated in a long list of clinical investigations. The author conducted a bibliographic review which not only included peer-reviewed papers published in scientific journals but also a vast amount of grey literature, such as theses and reports initiated by governmental as well as non-governmental organizations, thus allowing for a more holistic presentation of the available evidence. Close to 700 sources published over the course of two centuries were identified, confirmed, and cataloged. The purpose of the review is three-fold: to trace the historical milestones in devil's claw becoming a modern herbal medicine, to point out gaps in the seemingly all-encompassing body of research, and to provide the reader with a reliable and comprehensive bibliography. The review covers aspects of ethnobotany, taxonomy, history of product development and commercialization, chemistry, pharmacology, toxicology, as well as clinical efficacy and safety. It is concluded that three areas stand out in need of further investigation. The taxonomical assessment of the genus is outdated and lacking. A revision is needed to account for intra- and inter-specific, geographical, and chemo-taxonomical variation, including variation in composition. Further research is needed to conclusively elucidate the active compound(s). Confounded by early substitution, intermixture, and blending, it has yet to be demonstrated beyond a reasonable doubt that both (or all) Harpagophytum spp. are equally (and interchangeably) safe and efficacious in clinical practice.

Doping detection in animals: A review of analytical methodologies published from 1990 to 2019

Despite the impressive innate physical abilities of horses, camels, greyhounds, or pigeons, doping agents might be administered to these animals to improve their performance. To control these illegal practices, anti-doping analytical methodologies have been developed. This review compiles the analytical methods that have been published for the detection of prohibited substances administered to animals involved in sports over 30 years. Relevant papers meeting the search criteria that discussed analytical methods aiming to detect and/or quantify doping substances in animal biological matrices published from 1990 to 2019 were considered. A total of 317 studies were included, of which 298 were related to horses, demonstrating significant advances toward the development of doping detection methods for equine sports. However, analytical methods for the detection of doping agents in sports involving other species are lacking. Due to enhanced accuracy and specificity, chromatographic analysis coupled to mass spectrometry detection is preferred over immunoassays. Regarding biological matrices, blood and urine remain the first choice, although alternative biological matrices, such as hair and feces, have been considered. With the increasing number and type of drugs used as doping agents, the analytes addressed in the published papers are diverse. It is very important to continue to detect and quantify these drugs, recognizing those that are most frequently used, in order to punish the abusers, protect animals' health, and ensure a healthier and genuine competition.

Pharmacokinetics of harpagoside in horses after intragastric administration of a Devil's claw (Harpagophytum procumbens) extract

Devil's claw is used for the treatment of inflammatory symptoms and degenerative disorders in horses since many years, but without the substantive pharmacokinetic data. The pharmacokinetic parameters of harpagoside, the main active constituent of Harpagophytum procumbens DC ex Meisn., were evaluated in equine plasma after administration of Harpagophytum extract FB 8858 in an open, single‐dose, two‐treatment, two‐period, randomized cross‐over design. Six horses received a single dose of Harpagophytum extract, corresponding to 5 mg/kg BM harpagoside, and after 7 days washout period, 10 mg/kg BM harpagoside via nasogastric tube. Plasma samples at certain time points (before and 0–24 hr after administration) were collected, cleaned up by solid‐phase extraction, and harpagoside concentrations were determined by LC‐MS/MS using apigenin‐7‐glucoside as internal standard. Plasma concentration‐time data and relevant parameters were described by noncompartmental model through PKSolver software. Harpagoside could be detected up to 9 hr after administration. C_max was found at 25.59 and 55.46 ng/ml, t_1/2 at 2.53 and 2.32 hr, respectively, and t_max at 1 hr in both trials. AUC_0–inf was 70.46 and 117.85 ng hr ml⁻¹, respectively. A proportional relationship between dose, C_max and AUC was observed. Distribution (V_z/F) was 259.04 and 283.83 L/kg and clearance (CL/F) 70.96 and 84.86 L hr⁻¹ kg⁻¹, respectively. Treatment of horses with Harpagophytum extract did not cause any clinically detectable side effects.

Pharmacokinetics of 8-O-acetylharpagide and harpagide after oral administration of Ajuga decumbens Thunb extract in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ajuga decumbens Thunb is a medicinal plant native to China popularly used to treat chronic pelvic inflammation and hysteromyoma. Its main bioactive components are iridoid glycosides, such as 8-O-acetylharpagide and harpagide that had presented antibacterial, anti-inflammatory, and antiviral activities.

AIM OF THE STUDY

To establish a sensitive LC-MS/MS method and compare the pharmacokinetics of 8-O-acetylharpagide and harpagide in rats after oral administration of their pure forms and from compounds obtained from Ajuga decumbens extract.

MATERIALS AND METHODS

Rats received orally 15 mg/kg (equivalent of 6 mg/kg 8-O-acetylharpagide and 1.5mg/kg harpagide), 30 mg/kg and 60 mg/kg of Ajuga decumbens Thunb extract and were compared to animals that received 12 mg/kg of 8-O-acetylharpagide or 3mg/kg of harpagide p.o. Concentrations of 8-O-acetylharpagide and harpagide in plasma were determined by LC-MS/MS method at different time points and all pharmacokinetic parameters were estimated by non-compartmental analysis.

RESULTS

Results showed that the iridoid glycosides were quickly absorbed by oral route and showed a dose-dependence profile. Pharmacokinetic parameters of both glycosides were essentially the same except Tmax when dosed as the extract or pure forms.

CONCLUSION

8-O-acetylharpagide was metabolized to harpagide, which affected the pharmacokinetic profiles of harpagide when dosed as the extract. This pharmacokinetic study seems to be useful for a further clinical study of Ajuga decumbens Thunb extract.

An in vivo microdialysis measurement of harpagoside in rat blood and bile for predicting hepatobiliary excretion and its interaction with cyclosporin A and verapamil

Harpagoside, a major bioactive iridoid glucoside in genus Scrophularia, has been widely used in clinical practice for the treatment of pain in the joints and lower back for its neuroprotective and anti-inflammation activities. To investigate the pharmacokinetics and hepatobiliary excretion, an in vivo microdialysis method coupled with high performance liquid chromatography was developed to monitor the concentration of harpagoside in blood and bile. The harpagoside bile-to-blood distribution ratio (AUC(bile)/AUC(blood)) up to 986.28+/-78.46 significantly decreased to 6.41+/-0.56 or 221.20+/-18.92 after co-administration of cyclosporin A or verapamil. The results indicated that harpagoside went through concentrative elimination from the bile which was probably regulated by P-glucoprotein, providing possible clinical trials of co-administration of transporter inhibitors to decrease drug efflux, thus to enhance the curative effects.