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.

The Fight against Infection and Pain: Devil's Claw (Harpagophytum procumbens) a Rich Source of Anti-Inflammatory Activity: 2011-2022.

Harpagophytum procumbens subsp. procumbens (Burch.) DC. ex Meisn. (Sesame seed Family-Pedaliaceae) is a popular medicinal plant known as Devil's claw. It is predominantly distributed widely over southern Africa. Its impressive reputation is embedded in its traditional uses as an indigenous herbal plant for the treatment of menstrual problems, bitter tonic, inflammation febrifuge, syphilis or even loss of appetite. A number of bioactive compounds such as terpenoids, iridoid glycosides, glycosides, and acetylated phenolic compounds have been isolated. Harpagoside and harpagide, iridoid glycosides bioactive compounds have been reported in countless phytochemical studies as potential anti-inflammatory agents as well as pain relievers. In-depth studies have associated chronic inflammation with various diseases, such as Alzheimer's disease, obesity, rheumatoid arthritis, type 2 diabetes, cancer, and cardiovascular and pulmonary diseases. In addition, 60% of chronic disorder fatalities are due to chronic inflammatory diseases worldwide. Inflammation and pain-related disorders have attracted significant attention as leading causes of global health challenges. Articles published from 2011 to the present were obtained and reviewed in-depth to determine valuable data findings as well as knowledge gaps. Various globally recognized scientific search engines/databases including Scopus, PubMed, Google Scholar, Web of Science, and ScienceDirect were utilized to collect information and deliver evidence. Based on the literature results, there was a dramatic decrease in the number of studies conducted on the anti-inflammatory and analgesic activity of Devil's claw, thereby presenting a potential research gap. It is also evident that currently in vivo clinical studies are needed to validate the prior massive in vitro studies, therefore delivering an ideal anti-inflammatory and analgesic agent in the form of H. procumbens products.

Leucosceptoside A from Devil's Claw Modulates Psoriasis-like Inflammation via Suppression of the PI3K/AKT Signaling Pathway in Keratinocytes.

Psoriasis is a chronic inflammatory skin condition characterized by abnormal keratinocyte proliferation and differentiation that is accompanied with dysregulated immune response and abnormal vascularization. Devil's claw (Harpagophytum procumbens (Burch.) DC. ex Meisn.) tubers extract has been used both systemically and topically for treatment of chronic inflammatory diseases such as arthritis, osteoporosis, inflammatory bowel disease, among others. However, its potential mechanisms of action against psoriasis remains poorly investigated. The human keratinocyte HaCaT cell line is a well-accepted in vitro model system for inflammatory skin disorders such as psoriasis. The present study involved an exploration of the effect of biotechnologically produced H. procumbens (HP) cell suspension extract and pure phenylethanoid glycosides verbascoside (VER) and leucosceptoside A (LEU) in interferon (IFN)-γ/interleukin (IL)-17A/IL-22-stimulated HaCaT cells as a model of psoriasis-like inflammation. Changes in key inflammatory signaling pathways related to psoriasis development were detected by reverse transcription polymerase chain reaction and western blotting. Treatment with LEU, but not VER and HP extract improved psoriasis-related inflammation via suppression of the PI3K/AKT signaling in IFN-γ/IL-17A/IL-22-stimulated HaCaT cells. Our results suggest that LEU may exhibit therapeutic potential against psoriasis by regulating keratinocyte differentiation through inhibition of the PI3K/AKT pathway.

Devil's claw (Harpagophytum procumbens) and chronic inflammatory diseases: A concise overview on preclinical and clinical data.

Devil's Claw is a traditional medicine that has been long used a wide range of health conditions, including indigestion, fever, allergic reactions, and rheumatism. The main compounds are iridoid glycosides, including harpagoside, harpagide, and procumbide. However, harpagoside is the most responsible for therapeutic activity, and its content is used as reference standard. Here, we analyzed and summarized preclinical and clinical studies focusing on therapeutic efficacy of devil's claw preparations in pathological conditions in which inflammation plays a key causative role.

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. Cmax was found at 25.59 and 55.46 ng/ml, t1/2 at 2.53 and 2.32 hr, respectively, and tmax at 1 hr in both trials. AUC0-inf was 70.46 and 117.85 ng hr ml-1 , respectively. A proportional relationship between dose, Cmax and AUC was observed. Distribution (Vz /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.

Quality Assessment of Commercial Spagyric Tinctures of Harpagophytum procumbens and Their Antioxidant Properties.

Preparations from the dried tubers of Harpagophytum procumbens (Burch.) DC ex Meisn, commonly known as devil's claw, are mainly used in modern medicine to relieve joint pain and inflammation in patients suffering from rheumatic and arthritic disorders. This paper describes for the first time the chemical profile of a commercial spagyric tincture (named 019) prepared from the roots of the plant. For comparison purposes, a commercial not-spagyric devil's claw tincture (NST) was also analyzed. Chemical investigation of the content of specialized metabolites in the three samples indicated that harpagoside was the main compound, followed by the two isomers acteoside and isoacteoside. Compositional consistence over time was obtained by the chemical fingerprinting of another spagyric tincture (named 014) from the same producer that was already expired according to the recommendation on the label of the product. The two spagyric preparations did not show significant compositional differences as revealed by HPLC and MS analyses, except for a decrease in harpagide content in the expired 014 tincture. Moreover, their antioxidant capacities as assessed by 2,2'-di-phenyl-1-picrylhydrazyl (DPPH) and 2.2'-azin-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods resulted in very similar IC50 values. The expired 014 tincture showed instead a lower IC50 value compared to the 019 and NST tinctures with the ferric reducing antioxidant potential (FRAP) assay, indicating a higher ferric-reducing antioxidant ability. Overall, these results indicated that the two preparations could generally maintain good stability and biological activity at least for the four years from the production to the expiration date.

The Anti-Inflammatory Effects of Shinbaro3 Is Mediated by Downregulation of the TLR4 Signalling Pathway in LPS-Stimulated RAW 264.7 Macrophages.

Shinbaro3, a formulation derived from the hydrolysed roots of Harpagophytum procumbens var. sublobatum (Engl.) Stapf, has been clinically used in the pharamacopuncture treatment of arthritis in Korea. In the present study, Shinbaro3 inhibited NO generation in LPS-induced RAW 264.7 cells in a dose-dependent manner. Shinbaro3 also downregulated the mRNA and protein expression of inflammatory mediators in a dose-dependent manner. Three mechanisms explaining the effects of Shinbaro3 in RAW 264.7 cells were identified as follows: (1) inhibition of the extracellular signal-regulated kinase 1 and 2 (ERK1/2), stress-activated protein kinase (SAPK)/c-Jun N-terminal protein kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) pathways; (2) suppression of IκB kinase-α/ß (IKK-α/ß) phosphorylation and nuclear factor-kappa B (NF-κB) subunits in the NF-κB pathway, which are involved in MyD88-dependent signalling; and (3) downregulation of IFN-ß mRNA expression via inhibition of interferon regulatory factor 3 (IRF3) and Janus-activated kinase 1 (JAK1)/signal transducer and activator of transcription 1 (STAT1) phosphorylation, which is involved in TRIF-dependent signalling. Shinbaro3 exerted anti-inflammatory effects in LPS-stimulated RAW 264.7 macrophage cells through modulation of the TLR4/MyD88 pathways, suggesting that Shinbaro3 is a novel anti-inflammatory therapeutic candidate in the field of pharmacopuncture.

Use of Innovative (Micro)Extraction Techniques to Characterise Harpagophytum procumbens Root and its Commercial Food Supplements.

INTRODUCTION: For the determination of harpagoside and the wide phenolic pattern in Harpagophytum procumbens root and its commercial food supplements, dispersive liquid-liquid microextraction (DLLME), ultrasound-assisted DLLME (UA-DLLME), and sugaring-out liquid-liquid extraction (SULLE) were tested and compared. OBJECTIVES: In order to optimise the extraction efficiency, DLLME and UA-DLLME were performed in different solvents (water and aqueous solutions of glucose, ß-cyclodextrin, (2-hydroxypropyl)-ß-cyclodextrin, sodium chloride, natural deep eutectic solvent, and ionic liquid). MATERIAL AND METHODS: The plant material was ground and sieved to obtain a uniform granulometry before extraction. Commercial food supplements, containing H. procumbens are commercially available in Italy. RESULTS: The most effective sodium chloride-aided-DLLME was then optimised and applied for analyses followed by HPLC-PDA. For comparison, microwave-assisted extraction was performed using the same solvents and the best results were obtained using 1% of ß-cyclodextrin or 15% of sodium chloride. CONCLUSION: All commercial samples respected the European Pharmacopoeia monograph for this plant material, showing a harpagoside content ≥ 1.2%. Copyright © 2017 John Wiley & Sons, Ltd.

Anti-Osteoporotic Activity of Harpagoside by Upregulation of the BMP2 and Wnt Signaling Pathways in Osteoblasts and Suppression of Differentiation in Osteoclasts.

Harpagoside (1) is an iridoid glycoside isolated from the radix of Harpagophytum procumbens var. sublobatum, commonly called Devil's claw. The anti-osteoporotic effect of 1 was investigated in both in vitro cell cultures and in vivo using an ovariectomized (OVX) mouse model. Compound 1 induced bone formation by stimulating osteoblast proliferation, alkaline phosphatase activity, and mineralization in osteoblastic MC3T3-E1 cells. Treatment with 1 increased the mRNA and protein expression of bone formation biomarkers through regulation of the BMP2 and Wnt signaling pathway in MC3T3-E1 cells. Compound 1 also suppressed the RANKL-induced osteoclastogenesis of cultured mouse bone marrow cells. Oral administration of 1 restored the OVX-induced destruction of trabecular bone. The bone mineral density of the femur was also increased significantly by 1. The elevated serum levels of osteocalcin, C-terminal telopeptide, and tartrate-resistant acid phosphatase in the OVX mice were decreased by treatment with 1. These findings suggest that compound 1 may protect against bone loss induced by OVX in mice by regulating stimulation of osteoblast differentiation and inhibition of osteoclast resorption. Therefore, harpagoside (1) is a potential candidate for management of postmenopausal osteoporosis.

A Rosa canina - Urtica dioica - Harpagophytum procumbens/zeyheri Combination Significantly Reduces Gonarthritis Symptoms in a Randomized, Placebo-Controlled Double-Blind Study.

The special formulation MA212 (Rosaxan) is composed of rosehip (Rosa canina L.) puree/juice concentrate, nettle (Urtica dioica L.) leaf extract, and devil's claw (Harpagophytum procumbens DC. ex Meisn. or Harpagophytum zeyheri Decne.) root extract and also supplies vitamin D. It is a food for special medical purposes ([EU] No 609/2013) for the dietary management of pain in patients with gonarthritis.This 12-week randomized, placebo-controlled double-blind parallel-design study aimed to investigate the efficacy and safety of MA212 versus placebo in patients with gonarthritis.A 3D-HPLC-fingerprint (3-dimensional high pressure liquid chromatography fingerprint) of MA212 demonstrated the presence of its herbal ingredients. Ninety-two randomized patients consumed 40 mL of MA212 (n = 46) or placebo (n = 44) daily. The Western Ontario and McMaster Universities Arthritis Index (WOMAC), quality-of-life scores at 0, 6, and 12 weeks, and analgesic consumption were documented. Statistically, the initial WOMAC subscores/scores did not differ between groups. During the study, their means significantly improved in both groups. The mean pre-post change of the WOMAC pain score (primary endpoint) was 29.87 in the MA212 group and 10.23 in the placebo group. The group difference demonstrated a significant superiority in favor of MA212 (pU < 0.001; pt < 0.001). Group comparisons of all WOMAC subscores/scores at 6 and 12 weeks reached same significances. Compared to placebo, both physical and mental quality of life significantly improved with MA212. There was a trend towards reduced analgesics consumption with MA212, compared to placebo. In the final efficacy evaluation, physicians (pChi < 0.001) and patients (pChi < 0.001) rated MA212 superior to placebo. MA212 was well tolerated.This study demonstrates excellent efficacy for MA212 in gonarthritis patients.

Oral herbal medicines marketed in Brazil for the treatment of osteoarthritis: A systematic review and meta-analysis.

Herbal medications are commonly used to manage symptoms associated with osteoarthritis (OA). This systematic review evaluated the effectiveness and safety of oral medications used in Brazil for the treatment of OA. Randomized clinical trials involving adults with OA treated by a herbal medicine or a control group were eligible. The primary outcomes measured were pain, physical function, swelling, stiffness and quality of life; and the secondary outcomes were adverse events, activity limitations and treatment satisfaction. Sixteen studies were included (n = 1,741 patients) in the systematic review and nine studies in the meta-analysis, representing 6 of the 13 herbal medicines studied: Boswellia serrata (n = 2), Curcuma longa (n = 3), Harpagophytum procumbens (n = 1), Salix daphnoides (n = 3), Uncaria guianensis (n = 2) and Zingiber officinale (n = 5). B. serrata was more effective than both placebo and valdecoxib for improvement of pain and physical function. No difference was observed for H. procumbens, C. longa and U. guianensis compared with control. Z. officinale showed improvement of pain over placebo. The evidence was insufficient to support the effective and safe use of these herbal medicines, because the quality of evidence of studies was low. This study guides managers of the Brazilian public health system and prescribers in decision-making regarding the use of these herbal medicines for OA. Copyright © 2017 John Wiley & Sons, Ltd.

Optimization of Aqueous Extraction and Biological Activity of Harpagophytum procumbens Root on Ex Vivo Rat Colon Inflammatory Model.

Harpagophytum procumbens has a long story of use for the treatment of inflammatory diseases. Considering both the antiinflammatory effects of H. procumbens in multiple tissues and the stability of harpagoside in artificial intestinal fluid, the aim of the present study was to explore the possible protective role of a microwave-assisted aqueous Harpagophytum extract (1-1000 µg/mL) on mouse myoblast C2C12 and human colorectal adenocarcinoma HCT116 cell lines, and isolated rat colon specimens challenged with lipopolysaccharide (LPS), a validated ex vivo model of acute ulcerative colitis. In this context, we evaluated the effects on C2C12 and HCT116 viability, and on LPS-induced production of serotonin (5-HT), tumor necrosis factor (TNF)-α, prostaglandin (PG)E2 and 8-iso-prostaglandin (8-iso-PG)F2α . Harpagophytum extract was well tolerated by C2C12 cells, while reduced HCT116 colon cancer cell viability. On the other hand, Harpagophytum extract reduced H2 O2 -induced (1 mM) reactive oxygen species (ROS) production, in both cell lines, and inhibited LPS-induced colon production of PGE2 , 8-iso-PGF2α , 5-HT and TNFα. Concluding, we demonstrated the efficacy of a microwave-assisted Harpagophytum aqueous extract in modulating the inflammatory, oxidative stress and immune response in an experimental model of inflammatory bowel diseases (IBD), thus suggesting a rational use of Harpagophytum in the management and prevention of ulcerative colitis in humans. Copyright © 2017 John Wiley & Sons, Ltd.

Protective Effects Induced by Microwave-Assisted Aqueous Harpagophytum Extract on Rat Cortex Synaptosomes Challenged with Amyloid ß-Peptide.

Harpagophytum procumbens is a plant species that displays anti-inflammatory properties in multiple tissues. The iridoid glycosides arpagoside, harpagide, and procumbide appear to be the most therapeutically important constituents. In addition, harpagoside treatment exerted neuroprotective effects both in vitro and in vivo. Considering these findings, the aim of the present work is to explore the possible protective role of the previously described microwave-assisted aqueous extract of H. procumbens on rat hypothalamic (Hypo-E22) cells, and in rat cortex challenged with amyloid ß-peptide (1-40). In this context, we assayed the protective effects induced by H. procumbens by measuring the levels of malondialdehyde, 3-hydroxykynurenine (3-HK), brain-derived neurotrophic factor, and tumor necrosis factor-α, 3-HK. Finally, we evaluated the effects of H. procumbens treatment on cortex levels of dopamine, norepinephrine, and serotonin. H. procumbens extract was well tolerated by Hypo-E22 cells and upregulated brain-derived neurotrophic factor gene expression but down-regulated tumor necrosis factor-α gene expression. In addition, the extract reduced amyloid ß-peptide stimulation of malondialdehyde and 3-HK and blunted the decrease of dopamine, norepinephrine, and serotonin, in the cortex. In this context, our work supports further studies for the evaluation and confirmation of Harpagophytum in the management of the clinical symptoms related to Alzheimer's disease. Copyright © 2017 John Wiley & Sons, Ltd.

Risk Assessment via Metabolism and Cell Growth Inhibition in a HepG2/C3A Cell Line Upon Treatment with Arpadol and its Active Component Harpagoside.

Harpagophytum procumbens (Hp) has been used as antiinflammatory and analgesic agent for the treatment of rheumatic diseases. The principal active component of Hp is harpagoside (HA). We tested the toxicity of this new therapeutic agent in a hepatic cell line (HepG2/C3A). Hp was found to be cytotoxic, and HA was found to decrease the number of cells in S phase, increase the number of cells in G2/M phase and induce apoptosis. Neither Hp nor HA was genotoxic. The expression of CDK6 and CTP3A4 was reduced by Hp, and both HA and Hp caused a significant reduction of CYP1A2 and CYP3A4 expression. It is possible that the cytotoxicity caused by HA and Hp does not involve transcriptional regulation of the cyclins and CDKs tested but is instead related to the inhibition of metabolism. This is evidenced by the results of an MTT assay and changes in the expression of genes related to drug metabolism, leading to cell death. Indeed, the cells exhibited decreased proliferation upon exposure to Hp and HA. The data show that treatment with either Hp or HA can be cytotoxic, and this should be taken into consideration when balancing the risks and benefits of treatments for rheumatic diseases. Copyright © 2016 John Wiley & Sons, Ltd.

Two parametric cell cycle analyses of plant cell suspension cultures with fragile, isolated nuclei to investigate heterogeneity in growth of batch cultivations.

Plant cell suspensions are frequently considered to be heterogeneous with respect to growth in terms of progression of the cells through the cell cycle and biomass accumulation. Thus, segregated data of fractions in different cycle phases during cultivation is needed to develop robust production processes. Bromodeoxyuridine (BrdU) incorporation and BrdU-antibodies or 5-ethynyl-2'-deoxyuridine (EdU) click-it chemistry are frequently used to acquire such information. However, their use requires centrifugation steps that cannot be readily applied to sensitive cells, particularly if nuclei have to be extracted from the protective cellular milieu and envelopes for DNA analysis. Therefore, we have established a BrdU-Hoechst stain quenching protocol for analyzing nuclei directly isolated from delicate plant cell suspension cultures. After adding BrdU to test Harpagophytum procumbens cell suspension cultures the cell cycle distribution could be adequately resolved using its incorporation for the following 72 h (after which BrdU slowed biomass accumulation). Despite this limitation, the protocol allows resolution of the cell cycle distribution of cultures that cannot be analyzed using commonly applied methods due to the cells' fragility. The presented protocol enabled analysis of cycling heterogeneities in H. procumbens batch cultivations, and thus should facilitate process control of secondary metabolite production from fragile plant in vitro cultures. Biotechnol. Bioeng. 2016;113: 1244-1250. © 2015 Wiley Periodicals, Inc.

Harpagophytum Procumbens Ethyl Acetate Fraction Reduces Fluphenazine-Induced Vacuous Chewing Movements and Oxidative Stress in Rat Brain.

Long-term treatment with fluphenazine is associated with manifestation of extrapyramidal side effects, such as tardive dyskinesia. The molecular mechanisms related to the pathophysiology of TD remain unclear, and several hypotheses, including a role for oxidative stress, have been proposed. Harpagophytum procumbens is an herbal medicine used mainly due to anti-inflammatory effects, but it also exhibits antioxidant effects. We investigated the effect of ethyl acetate fraction of H. procumbens (EAF HP) in fluphenazine-induced orofacial dyskinesia by evaluating behavioral parameters at different times (vacuous chewing movements (VCM's) and locomotor and exploratory activity), biochemical serological analyses, and biochemical markers of oxidative stress of the liver, kidney, cortex, and striatum. Chronic administration of fluphenazine (25 mg/kg, intramuscular (i.m) significantly increased the VCMs at all analyzed times (2, 7, 14, and 21 days), and this was inhibited by EAF HP (especially at a dose of 30 mg/kg). Fluphenazine decreased locomotion and exploratory activity, and EAF HP did not improve this decrease. Fluphenazine induced oxidative damage, as identified by changes in catalase activity and ROS levels in the cortex and striatum, which was reduced by EAF HP, especially in the striatum. In the cortex, EAF HP was protective against fluphenazine-induced changes in catalase activity but not against the increase in ROS level. Furthermore, EAF HP was shown to be safe, since affected serum biochemical parameters or parameters of oxidative stress in the liver and kidney. These findings suggest that the H. procumbens is a promising therapeutic agent for the treatment of involuntary oral movements.

Involvement of the Heme-Oxygenase Pathway in the Antiallodynic and Antihyperalgesic Activity of Harpagophytum procumbens in Rats.

Harpagophytum procumbens (H. procumbens), also known as Devil's Claw, has been used to treat a wide range of pathological conditions, including pain, arthritis and inflammation. Inflammatory mediators, released at the site of injury, can sensitize nociceptive terminals and are responsible for allodynia and hyperalgesia. Carbon monoxide (CO), produced in a reaction catalyzed by the enzyme heme oxygenase (HO), may play a role in nociceptive processing and has also been recognized to act as a neurotransmitter or neuromodulator in the nervous system. This study was designed to investigate whether the HO/CO pathway is involved in the analgesic response of H. procumbens in carrageenan-induced hyperalgesia in rats. Mechanical allodynia and thermal hyperalgesia were evaluated by using von Frey filaments and the plantar test, respectively. The results of our experiments showed that pretreatment with the HO inhibitor ZnPP IX significantly decreased the antihyperalgesic effect produced by H. procumbens (800 mg/kg, i.p.) in carrageenan-injected rats. Consistently, the pretreatment with hemin, a HO-1 substrate, or CORM-3, a CO releasing molecule, before a low dose of H. procumbens (300 mg/kg, i.p.) induced a clear antiallodynic response in carrageenan injected rats. These results suggest the involvement of HO-1/CO system in the antiallodynic and antihyperalgesic effect of H. procumbens in carrageenan-induced inflammatory pain.

Herbal medicine for low-back pain.

BACKGROUND: Low-back pain (LBP) is a common condition and imposes a substantial economic burden upon people living in industrialized societies. A large proportion of people with chronic LBP use complementary and alternative medicine (CAM), visit CAM practitioners, or both. Several herbal medicines have been purported for use in treating people with LBP. This is an update of a Cochrane Review first published in 2006. OBJECTIVES: To determine the effectiveness of herbal medicine for non-specific LBP. SEARCH METHODS: We searched the following electronic databases up to September 2014: MEDLINE, EMBASE, CENTRAL, CINAHL, Clinical Trials.gov, World Health Organization International Clinical Trials Registry Portal and PubMed; checked reference lists in review articles, guidelines and retrieved trials; and personally contacted individuals with expertise in this area. SELECTION CRITERIA: We included randomized controlled trials (RCTs) examining adults (over 18 years of age) suffering from acute, sub-acute, or chronic non-specific LBP. The interventions were herbal medicines which we defined as plants used for medicinal purposes in any form. Primary outcome measures were pain and function. DATA COLLECTION AND ANALYSIS: A library scientist with the Cochrane Back Review Group conducted the database searches. One review author contacted content experts and acquired relevant citations. We downloaded full references and abstracts of the identified studies and retrieved a hard copy of each study for final inclusion decisions. Two review authors assessed risk of bias, GRADE criteria (GRADE 2004), and CONSORT compliance and a random subset were compared to assessments by a third individual. Two review authors assessed clinical relevance and resolved any disagreements by consensus. MAIN RESULTS: We included 14 RCTs (2050 participants) in this review. One trial on Solidago chilensis M. (Brazilian arnica) (20 participants) found very low quality evidence of reduction in perception of pain and improved flexibility with application of Brazilian arnica-containing gel twice daily as compared to placebo gel. Capsicum frutescens cream or plaster probably produces more favourable results than placebo in people with chronic LBP (three trials, 755 participants, moderate quality evidence). Based on current evidence, it is not clear whether topical capsicum cream is more beneficial for treating people with acute LBP compared to placebo (one trial, 40 participants, low quality evidence). Another trial found equivalence of C. frutescens cream to a homeopathic ointment (one trial, 161 participants, very low quality evidence). Daily doses of Harpagophytum procumbens (devil's claw), standardized to 50 mg or 100 mg harpagoside, may be better than placebo for short-term improvements in pain and may reduce use of rescue medication (two trials, 315 participants, low quality evidence). Another H. procumbens trial demonstrated relative equivalence to 12.5 mg per day of rofecoxib (Vioxx®) but was of very low quality (one trial, 88 participants, very low quality). Daily doses of Salix alba (white willow bark), standardized to 120 mg or 240 mg salicin, are probably better than placebo for short-term improvements in pain and rescue medication (two trials, 261 participants, moderate quality evidence). An additional trial demonstrated relative equivalence to 12.5 mg per day of rofecoxib (one trial, 228 participants) but was graded as very low quality evidence. S. alba minimally affected platelet thrombosis versus a cardioprotective dose of acetylsalicylate (one trial, 51 participants). One trial (120 participants) examining Symphytum officinale L. (comfrey root extract) found low quality evidence that a Kytta-Salbe comfrey extract ointment is better than placebo ointment for short-term improvements in pain as assessed by VAS. Aromatic lavender essential oil applied by acupressure may reduce subjective pain intensity and improve lateral spine flexion and walking time compared to untreated participants (one trial, 61 participants,very low quality evidence). No significant adverse events were noted within the included trials. AUTHORS' CONCLUSIONS: C. frutescens (Cayenne) reduces pain more than placebo. Although H. procumbens, S. alba, S. officinale L., S. chilensis, and lavender essential oil also seem to reduce pain more than placebo, evidence for these substances was of moderate quality at best. Additional well-designed large trials are needed to test these herbal medicines against standard treatments. In general, the completeness of reporting in these trials was poor. Trialists should refer to the CONSORT statement extension for reporting trials of herbal medicine interventions.

Assessment of diversity in Harpagophytum with RAPD and ISSR markers provides evidence of introgression.

The genus Harpagophytum has two species: H. procumbens which is an important medicinal plant in southern Africa, and H. zeyheri. Genetic diversity in 96 samples, obtained by germinating seeds collected from Botswana, was assessed using six inter-simple sequence repeat (ISSR) and 10 random amplified polymorphic DNA (RAPD) primers. These DNA markers yielded a total of 138 polymorphic bands. Polymorphism information content (PIC) ranged from 0.06 to 0.39 for ISSR primers, and from 0.09 to 0.43 for RAPD primers. Jaccard's similarity coefficients were highest when seedlings derived from the same fruit capsule were compared, while seedlings from different fruits on the same plant had intermediate values. The lowest values were recorded among seedlings from different plants. These results were consistent with an outcrossing breeding system in Harpagophytum. Analysis of molecular variance revealed significant differentiation (P<0.01) between taxonomic units within Harpagophytum. About 39% of the variability occurred between the two species, H. procumbens and H. zeyheri. Plants with an intermediate morphology, i.e. putative hybrids (PH), showed 21% differentiation when compared with H. procumbens ssp. procumbens (PP), and 19% when compared with H. procumbens ssp. transvaalense (PT) or with H. zeyheri (ZZ). In addition, a deviating variant of PT was identified, here termed 'procumbens new variety' (PN). PN showed only 9% differentiation when compared with PT, 22% when compared with PP or with PH, and 41% when compared with ZZ. Considerable differentiation between the two Harpagophytum species was revealed also by a cluster analysis. Introgression was, however, suggested by the intermediate position of the putative hybrid plants in a principal component analysis while inter-specific gene flow was shown by a Bayesian genetic structure analysis.

Analgesic effect of Harpagophytum procumbens on postoperative and neuropathic pain in rats.

Harpagophytum procumbens, also known as Devil's Claw, has historically been used to treat a wide range of conditions, including pain and arthritis. The study was designed to investigate whether H. procumbens extracts exhibit analgesic effects in plantar incision and spared nerve injury (SNI) rats. The whole procedure was performed on male SD rats. To evaluate pain-related behavior, we performed the mechanical withdrawal threshold (MWT) test measured by von Frey filaments. Pain-related behavior was also determined through analysis of ultrasonic vocalization (USVs). The results of experiments showed MWT values of the group that was treated with 300 mg/kg H. procumbens extract increased significantly; on the contrary, the number of 22-27 kHz USVs of the treated group was reduced at 6 h and 24 h after plantar incision operation. After 21 days of continuous treatment with H. procumbens extracts at 300 mg/kg, the treated group showed significantly alleviated SNI-induced hypersensitivity responses by MWT, compared with the control group. These results suggest that H. procumbens extracts have potential analgesic effects in the case of acute postoperative pain and chronic neuropathic pain in rats.