Downregulation of iNOS expression in rat mesangial cells by special extracts of Harpagophytum procumbens derives from harpagoside-dependent and independent effects

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.

Harpagophytum procumbens Inhibits Iron Overload-Induced Oxidative Stress through Activation of Nrf2 Signaling in a Rat Model of Lumbar Spinal Stenosis

Lumbar spinal stenosis (LSS) is a common degenerative spinal condition in older individuals that causes impaired walking and other disabilities due to severe lower back and leg pain. Ligamentum flavum hypertrophy is a major LSS cause that may result from oxidative stress caused by degenerative cascades, including imbalanced iron homeostasis that leads to excessive reactive oxygen species production. We investigated the effects of Harpagophytum procumbens (HP) on iron-induced oxidative stress associated with LSS pathophysiology. Primary spinal cord neuron cultures were incubated in FeSO₄-containing medium, followed by addition of 50, 100, or 200 μg/mL HP. Cell viability was assessed by CCK-8 and live/dead cell assays and by propidium iodide-live imaging. In an in vivo rat model of LSS, HP were administered at 100, 200, and 400 mg/kg, and disease progression was monitored for up to 3 weeks. We investigated the in vitro and in vivo effects of HP on iron-induced neurotoxicity by immunochemistry, real-time PCR, and flow cytometry. HP exerted neuroprotective effects and enhanced neurite outgrowths of iron-injured rat primary spinal cord neurons in vitro. HP treatment significantly reduced necrotic cell death and improved cells' antioxidative capacity via the NRF2 signaling pathway in iron-treated neurons. At 1 week after HP administration in LSS rats, the inflammatory response and oxidative stress markers were substantially reduced through regulation of excess iron accumulation. Iron that accumulated in the spinal cord underneath the implanted silicone was also regulated by HP administration via NRF2 signaling pathway activation. HP-treated LSS rats showed gradually reduced mechanical allodynia and amelioration of impaired behavior for 3 weeks. We demonstrated that HP administration can maintain iron homeostasis within neurons via activation of NRF2 signaling and can consequently facilitate functional recovery by regulating iron-induced oxidative stress. This fundamentally new strategy holds promise for LSS treatment.

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.

HR-LCMS-Based Metabolite Profiling, Antioxidant, and Anticancer Properties of Teucrium polium L. Methanolic Extract: Computational and In Vitro Study

In this study, we investigate the phytochemical profile, anticancer, and antioxidant activities of Teucrium polium methanolic extract using both in vitro and in silico approaches. The results showed the identification of 29 phytochemical compounds belonging to 13 classes of compounds and 20 tripeptides using High Resolution-Liquid Chromatography Mass Spectrometry (HR-LCMS). 13R-hydroxy-9E,11Z octadecadienoic acid, dihydrosamidin, valtratum, and cepharantine were the main compounds identified. The tested extract showed promising antioxidant activities (ABTS-IC50 = 0.042 mg/mL; 1,1-diphenyl-2-picrylhydrazyl (DPPH)-IC50 = 0.087 mg/mL, β-carotene-IC50 = 0.101 mg/mL and FRAP-IC50 = 0.292 mg/mL). Using both malignant Walker 256/B and MatLyLu cell lines, T. polium methanolic extract showed a dose/time-dependent antitumor activity. The molecular docking approach revealed that most of the identified molecules were specifically binding with human peroxiredoxin 5, human androgen, and human progesterone receptors with high binding affinity scores. The obtained results confirmed that T. polium is a rich source of bioactive molecules with antioxidant and antitumor potential.

Harpagophytum procumbens Extract Ameliorates Allodynia and Modulates Oxidative and Antioxidant Stress Pathways in a Rat Model of Spinal Cord Injury

Spinal cord injury (SCI) is a deliberating disorder with impairments in locomotor deficits and incapacitating sensory abnormalities. Harpagophytum procumbens (Hp) is a botanical widely used for treating inflammation and pain related to various inflammatory and musculoskeletal conditions. Using a modified rodent contusion model of SCI, we explored the effects of this botanical on locomotor function and responses to mechanical stimuli, and examined possible neurochemical changes associated with SCI-induced allodynia. Following spinal cord contusion at T10 level, Hp (300 mg/kg, p.o.) or vehicle (water) was administered daily starting 24 h post-surgery, and behavioral measurements made every-other day until sacrifice (Day 21). Hp treatment markedly ameliorated the contusion-induced decrease in locomotor function and increased sensitivity to mechanical stimuli. Determination of Iba1 expression in spinal cord tissues indicated microglial infiltration starting 3 days post-injury. SCI results in increased levels of 4-hydroxynonenal, an oxidative stress product and proalgesic, which was diminished at 7 days by treatment with Hp. SCI also enhanced antioxidant heme oxygenase-1 (HO-1) expression. Concurrent studies of cultured murine BV-2 microglial cells revealed that Hp suppressed oxidative/nitrosative stress and inflammatory responses, including production of nitric oxide and reactive oxygen species, phosphorylation of cytosolic phospholipases A₂, and upregulation of the antioxidative stress pathway involving the nuclear factor erythroid 2-related factor 2 and HO-1. These results support the use of Hp for management of allodynia by providing resilience against the neuroinflammation and pain associated with SCI and other neuropathological conditions.

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.

Do recent research studies validate the medicinal plants used in British Columbia, Canada for pet diseases and wild animals taken into temporary care?

ETHNOPHARMACOLOGICAL RELEVANCE

There are insufficient safe and effective treatments for chronic pain in pets. In cases such as osteoarthritis there is no commercially available cure and veterinarians use NSAIDs to manage pain. Pet owners may have to plan for a lifetime of plant-based treatment for the conditions that lead to chronic pain in pets. Phytopharmacotherapies have the advantage of being less toxic, cheap or free, readily available, are more likely to be safe for long-term use and have the potential to reset the immune system to normal functioning.

AIM OF THE STUDY

To examine the recently published medicinal plant research that matches unpublished data on ethnoveterinary medicines (EVM) used for pets in Canada (British Columbia) to see if the EVM data can provide a lead to the development of necessary drugs.

MATERIALS AND METHODS

In 2003 semi-structured interviews were conducted with 60 participants who were organic farmers or holisitic medicinal/veterinary practitioners obtained using a purposive sample. A draft manual prepared from the data was then evaluated by participants at a participatory workshop that discussed the plant-based treatments. A copy of the final version of the manual was given to all research participants. In 2018, the recently published research matching the EVM data was reviewed to see if the EVM practices could serve as a lead for further research.

RESULTS AND CONCLUSION

Medicinal plants are used to treat a range of conditions. The injuries treated in pets in British Columbia included abscesses (resulting from an initial injury), sprains and abrasions. Dogs were also treated with medicinal plants for rheumatoid arthritis, joint pain and articular cartilage injuries. More than 40 plants were used. Anal gland problems were treated with Allium sativum L., Aloe vera L., Calendula officinalis L., Plantago major L., Ulmus fulva Michx., Urtica dioica L. and Usnea longissima Ach. Arctium lappa, Hydrangea arborescens and Lactuca muralis were used for rheumatoid arthritis and joint pain in pets. Asthma was treated with: Linum usitatissimum L., Borago officinalis L., Verbascum thapsus L., Cucurbita pepo L., Lobelia inflata L., and Zingiber officinale Roscoe. Pets with heart problems were treated with Crataegus oxyacantha L., Cedronella canariensis (L.) Willd. ex Webb & Berth, Equisetum palustre L., Cypripedium calceolus L., Pinus ponderosa Douglas ex Lawson, Humulus lupulus L., Valeriana officinalis L., Lobelia inflata L., Stachys officinalis (L.) Trev., and Viscum album L. The following plants were used for epilepsy, motion sickness and anxiety- Avena sativa L., Valeriana officinalis, Lactuca muralis (L.) Fresen., Scutellaria lateriflora L., Satureja hortensis L., and Passiflora incarnata L. Plants used for cancer treatment included Phytolacca decandra, Ganoderma lucidum, Lentinula edodes, Rumex acetosella, Arctium lappa, Ulmus fulva, Rheum palmatum, Frangula purshiana, Zingiber officinale, Glycyrrhiza glabra, Ulmus fulva, Althea officinalis, Rheum palmatum, Rumex crispus and Plantago psyllium. Trifolium pratense was used for tumours in the prostate gland. Also used were Artemisia annua, Taraxacum officinale and Rumex crispus. This review of plants used in EVM was possible because phytotherapy research of the plants described in this paper has continued because few new pharmaceutical drugs have been developed for chronic pain and because treatments like glucocorticoid therapy do not heal. Phytotherapuetic products are also being investigated to address the overuse of antibiotics. There have also been recent studies conducted on plant-based functional foods and health supplements for pets, however there are still gaps in the knowledge base for the plants Stillingia sylvatica, Verbascum thapsus, Yucca schidigera and Iris versicolor and these need further investigation.

African Herbal Remedies with Antioxidant Activity: A Potential Resource Base for Wound Treatment

The use of traditional herbal remedies as alternative medicine plays an important role in Africa since it forms part of primary health care for treatment of various medical conditions, including wounds. Although physiological levels of free radicals are essential to the healing process, they are known to partly contribute to wound chronicity when in excess. Consequently, antioxidant therapy has been shown to facilitate healing of such wounds. Also, a growing body of evidence suggests that, at least, part of the therapeutic value of herbals may be explained by their antioxidant activity. This paper reviews African herbal remedies with antioxidant activity with the aim of indicating potential resources for wound treatment. Firstly, herbals with identified antioxidant compounds and, secondly, herbals with proven antioxidant activity, but where the compound(s) responsible for the activity has not yet been identified, are listed. In the latter case it has been attempted to ascribe the activity to a compound known to be present in the plant family and/or species, where related activity has previously been documented for another genus of the species. Also, the tests employed to assess antioxidant activity and the potential caveats thereof during assessment are briefly commented on.

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/β (IKK-α/β) 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-β 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.

Drug-Herb Interactions in the Elderly Patient with IBD: a Growing Concern

OPINION STATEMENT

Inflammatory bowel disease (IBD), which includes conditions such as Crohn's disease and ulcerative colitis, is becoming more prevalent with the elderly being the fastest growing group. Parallel to this, there is an increasing interest in the use of complementary and alternative medicine (CAM). Nearly half of patients with IBD have used CAM at one time. The elderly patients, however, are burdened by comorbid conditions, polypharmacy, and altered functional status. With increasing use of complementary and alternative medicine in our elderly patients with IBD, it is vital for the provider to provide counsel on drug-herb potential interactions. CAM includes herbal products, diet, dietary supplements, acupuncture, and prayer. In this paper, we will review common CAM, specifically herbs, that are used in patients with IBD including the herb background, suggested use, evidence in IBD, and most importantly, potential interactions with IBD medications used in elderly patients. Most important evidence-based adverse events and drug-herb interactions are summarized. The herbs discussed include Triticum aestivum (wheat grass), Andrographis paniculata (chiretta), Boswellia serrata, tormentil, bilberry, curcumin (turmeric), Plantago ovata (blond psyllium), Oenothera biennis (evening primrose oil), germinated barley foodstuff, an herbal preparation of myrrh, chamomile and coffee extract, chios mastic gum, wormwood (absinthe, thujone), Cannabis sativa (marijuana, THC), tripterygium wilfordii (thunder god vine), Ulmus rubra (slippery elm bark), trigonella foenugraecum (fenugreek), Dioscorea mexicana (wild yam), Harpagophytum procumbens (devil's claw), ginger, cinnamon, licorice, and peppermint.

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

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)F_2α . 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-PGF_2α , 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.

Phytomedicine in Joint Disorders

Chronic joint inflammatory disorders such as osteoarthritis and rheumatoid arthritis have in common an upsurge of inflammation, and oxidative stress, resulting in progressive histological alterations and disabling symptoms. Currently used conventional medication (ranging from pain-killers to biological agents) is potent, but frequently associated with serious, even life-threatening side effects. Used for millennia in traditional herbalism, medicinal plants are a promising alternative, with lower rate of adverse events and efficiency frequently comparable with that of conventional drugs. Nevertheless, their mechanism of action is in many cases elusive and/or uncertain. Even though many of them have been proven effective in studies done in vitro or on animal models, there is a scarcity of human clinical evidence. The purpose of this review is to summarize the available scientific information on the following joint-friendly medicinal plants, which have been tested in human studies: Arnica montana, Boswellia spp., Curcuma spp., Equisetum arvense, Harpagophytum procumbens, Salix spp., Sesamum indicum, Symphytum officinalis, Zingiber officinalis, Panax notoginseng, and Whitania somnifera.

Alteration of Neutrophil Reactive Oxygen Species Production by Extracts of Devil's Claw (Harpagophytum)

Harpagophytum, Devil's Claw, is a genus of tuberiferous xerophytic plants native to southern Africa. Some of the taxa are appreciated for their medicinal effects and have been traditionally used to relieve symptoms of inflammation. The objectives of this pilot study were to investigate the antioxidant capacity and the content of total phenols, verbascoside, isoverbascoside, and selected iridoids, as well as to investigate the capacity of various Harpagophytum taxa in suppressing respiratory burst in terms of reactive oxygen species produced by human neutrophils challenged with phorbol myristate acetate (PMA), opsonised Staphylococcus aureus, and Fusobacterium nucleatum. Harpagophytum plants were classified into different taxa according to morphology, and DNA analysis was used to confirm the classification. A putative new variety of H. procumbens showed the highest degree of antioxidative capacity. Using PMA, three Harpagophytum taxa showed anti-inflammatory effects with regard to the PBS control. A putative hybrid between H. procumbens and H. zeyheri in contrast showed proinflammatory effect on the response of neutrophils to F. nucleatum in comparison with treatment with vehicle control. Harpagophytum taxa were biochemically very variable and the response in suppressing respiratory burst differed. Further studies with larger number of subjects are needed to corroborate anti-inflammatory effects of different taxa of Harpagophytum.

Radix Scrophulariae extracts (harpagoside) suppresses hypoxia-induced microglial activation and neurotoxicity

Background

Hypoxia could lead to microglia activation and inflammatory mediators’ overproduction. These inflammatory molecules could amplify the neuroinflammatory process and exacerbate neuronal injury. The aim of this study is to find out whether harpagoside could reduce hypoxia-induced microglia activation.

Methods

In this study, primary microglia cells harvested from neonatal ICR mice were activated by exposure to hypoxia (1 % O₂ for 3 h). Harpagoside had been shown to be no cytotoxicity on microglia cells by MTT assay. The scavenger effect of harpagoside on hypoxia-enhanced microglial cells proliferation, associated inflammatory genes expression (COX-II, IL-1β and IL-6 genes) and NO synthesis were also examined.

Results

Hypoxia enhances active proliferation of microglial cells, while harpagoside can scavenge this effect. We find that harpagoside could scavenge hypoxia-enhanced inflammatory genes expression (COX-2, IL-1β and IL-6 genes) and NO synthesis of microglial cells. Under 3 h’ hypoxic stimulation, the nuclear contents of p65 and hypoxia inducible factor-1α (HIF-1α) significantly increase, while the cytosol IκB-α content decreases; these effects can be reversed by 1 h’s pre-incubation of 10⁻⁸ M harpagoside. Harpagoside could decrease IκB-α protein phosphorylation and inhibit p65 protein translocation from the cytosol to the nucleus, thus suppress NF-κB activation and reduce the HIF-1α generation.

Conclusion

These results suggested that the anti-inflammatory mechanism of harpagoside might be associated with the NF-κB signaling pathway. Harpagoside protect against hypoxia-induced toxicity on microglial cells through HIF-α pathway.

Harpagophytum procumbens extract potentiates morphine antinociception in neuropathic rats

The association of opioids and non-steroidal anti-inflammatory drugs, to enhance pain relief and reduce the development of side effects, has been demonstrated. Given many reports concerning the antinociceptive and anti-inflammatory effects of Harpagophytum procumbens extracts, the aim of our study was to investigate the advantage of a co-administration of a subanalgesic dose of morphine preceded by a low dose of H. procumbens to verify this therapeutically useful association in a neuropathic pain model. Time course, registered with the association of the natural extract, at a dose that does not induce an antinociceptive effect, followed by a subanalgesic dose of morphine showed a well-defined antiallodynic and antihyperalgesic effect, suggesting a synergism as a result of the two-drug association. H. procumbens cooperates synergistically with morphine in resolving hyperalgesia and allodynia, two typical symptoms of neuropathic pain. The results support the strategy of using an adjuvant drug to improve opioid analgesic efficacy.

Antimutagenic potential of harpagoside and Harpagophytum procumbens against 1-nitropyrene

Background:

1-nitropyrene (1-NPy) is one of the most abundant nitro-polycyclic aromatic hydrocarbons particularly in diesel exhausts. It is a mutagenic and carcinogenic pollutant very widespread in the environment. So the discovery of antimutagenic agents is essential. Harpagophytum procumbens (HP) is traditionally used as anti-inflammatory and analgesic particularly against painful osteoarthritis. Harpagoside (HS), its major iridoid glycoside, is considered as the main active component.

Objective:

The aim of the present study was to evaluate the antimutagenic activity of HS and HP extracts against mutagenic activity of 1-NPy.

Materials and Methods:

The antimutagenic activity was investigated using the in vitro cytokinesis-block micronucleus assay in cultured human lymphocytes. Cells were exposed to HS or HP extracts before (pretreatment), during (co-treatment), and after (posttreatment) treatment with 1-NPy.

Results:

Results showed that HS significantly reduced the mutagenicity of 1-NPy in pretreatment and particularly in co-treatment, whereas all HP extracts significantly reduced the genotoxicity in the three protocols.

Conclusion:

These results suggested that HS was strongly involved in antimutagenic activity of HP extracts in co-treatment, but other components in HP extracts participated in this activity in pre- and post-treatment.

Alteration of anti-inflammatory activity of Harpagophytum procumbens (devil's claw) extract after external metabolic activation with S9 mix

OBJECTIVES

Extracts of the tubers of Harpagophytum procumbens (devil's claw, DC) inhibit different proinflammatory mediators important in the pathophysiology of osteoarthritis. Many plant-derived preparations interfere with cytochrome P450 liver enzymes, which influence their different biological activities. Therefore, the present study was designed to investigate the influence of an external metabolic activation of a DC extract on the cytotoxicity and the release of proinflammatory cytokines.

METHODS

A screening experiment with a panel of 12 inflammatory cytokines identified three as suitable for the study: tumour necrosis factor-α (TNF-α), interleukin (IL) IL-6 and IL-8. They were determined using enzyme-linked immunosorbent assays in lipopolysaccharide (LPS)-stimulated monocytic THP-1 cells, which were treated with rat liver S9 mix metabolically activated DC extract (DCm). For the cytotoxity experiments, a WST-1 assay was used.

KEY FINDINGS

DC dose-dependently suppressed the release of TNF-α, IL-6 and IL-8 in LPS-stimulated monocytic THP-1 cells at non-cytotoxic concentrations (50-250 μg/ml). The metabolic activation of the DC extract by S9 mix did not alternate its cytotoxicity and did not diminish its inhibitory effect. This effect was improved in the case of TNF-α inhibition as reflected by their EC50 values of 116 ± 8.2 μg/ml and 49 ± 3.5 μg/ml for DC and DCm (P < 0.01).

CONCLUSIONS

Cytokines inhibitory activity of DC was not affected after its external metabolic activation. However, the amount of harpagoside and caffeic acid derivates was decreased. Other components of the extract might have contributed to its anti-inflammatory effect.

Roles of chemical complexity and evolutionary theory in some hepatic and intestinal enzymatic systems in chemical reproducibility and clinical efficiency of herbal derivatives

Despite the great marketing success, most physicians attribute poor efficacy to herbals. This perception is due to two situations that are an integral part of the herbal topic. The first is the poor phytochemical reproducibility obtained during the production process of herbal extracts, as herbal extracts are not always standardized in the whole manufacturing process, but only in their titer. The second problem is linked to the evolution of important enzymatic systems: cytochromes and ABC proteins. They are both enzyme classes with detoxifying properties and seem to have evolved from the molecular mould provided by active plant substances. During the evolution, as still happens today, polyphenols, saponins, terpenes, and alkaloids were ingested together with food. They do not possess any nutritional value but seem to be provided with a potential pharmacological activity. Cytochromes and ABC proteins, which evolved over time to detoxify food from vegetable chemical "actives," now seem to limit the action of herbal derivatives. The comprehension of these 2 events may explain the origin of the widespread scepticism of physicians about herbal medicine and suggests that, after correct herbal standardization, use of antagonists of cytochromes and ABC systems will make it possible to recover their pharmacological potential.

Harpagoside: from Kalahari Desert to pharmacy shelf

Harpagoside is an iridoid glycoside that was first isolated from Harpagophytum procumbens (devil's claw, Pedaliaceae), a medicinal plant in which it is the major constituent of the iridoid pool. Both the pure compound and devil's claw extracts have potent anti-rheumatic, anti-inflammatory and analgesic effects. According to the European Pharmacopoeia commercial devil's claw products should contain at least 1.2% harpagoside. However, the compound has also been isolated from several other plant species and in vitro plant culture systems. Recent advances in knowledge of harpagoside distribution, biosynthesis/accumulation and pharmacology are summarized in this review. We also discuss the possible synergism and/or antagonism between major constituents in harpagoside-containing phytopharmaceutical products. Finally, future perspectives for its potential application are highlighted.

Devil's Claw-a review of the ethnobotany, phytochemistry and biological activity of Harpagophytum procumbens

ETHNOPHARMACOLOGICAL RELEVANCE

Harpagophytum procumbens subps. procumbens (Burch.) DC. ex Meisn. (Pedaliaceae) is an important traditional medicine growing in the Kalahari region of southern Africa where it is consumed as a general health tonic and for treating diverse ailments including arthritis, pain, fever, ulcers and boils.

AIM OF THE REVIEW

To provide a comprehensive overview of the ethnobotany, phytochemistry and biological activity of H. procumbens and possibly make recommendations for further research.

MATERIALS AND METHODS

Peer-reviewed articles on H. procumbens were acquired on Scopus, ScienceDirect and SciFinder, there was no specific timeline set for the search. A focus group discussion was held with different communities in Botswana to further understand ethnobotanical uses of the plant.

RESULTS

Harpogophytum procumbens is used for a wide variety of health conditions in the form of infusions, decoctions, tinctures, powders and extracts. In addition to the common local use for arthritis and pain, other ethnomedicinal uses include dyspepsia, fever, blood diseases, urinary tract infections, postpartum pain, sprains, sores, ulcers and boils. Scientific studies revealed that H. procumbens exhibits analgesic, anti-oxidant, anti-diabetic, anti-epileptic, antimicrobial and antimalarial activities amongst others. Iridoid glycosides and phenylpropanoid glycosides have been the focus of phytochemical investigations as the biological activity has been ascribed to the iridoid glycosides (such as harpagoside and harpagide), which are common in nature and are known to possess anti-inflammatory activity. In addition, it has been shown that the hydrolysed products of harpagoside and harpagide have more pronounced anti-inflammatory activity when compared to the unhydrolysed compounds. Harpagophytum zeyheri is a close taxonomic ally of H. procumbens but H. procumbens is the favoured species of commerce, and contains higher levels of the pharmacologically active constituents. The two are used interchangeably and H. procumbens raw material is often intentionally adulterated with H. zeyheri and this may impact on the efficacy of inadequately controlled health products. The main exporter of this highly commercialised plant is Namibia. In 2009 alone, Harpagophytum exports were worth approximately €1.06 million. The high demand for health products based on this plant has led to over-harvesting, raising concerns about sustainability. Although only the secondary tubers are utilised commercially, the whole plant is often destroyed during harvesting.

CONCLUSIONS

Harpagophytum procumbens is used to treat a wide range of ailments. Some of the ethnobotanical claims have been confirmed through in vitro studies, however, when the constituents deemed to be the biologically active compounds were isolated the efficacy was lower than that of the whole extract. This necessitates the use of a different approach where all the metabolites are considered using a robust method such as spectroscopy; the phytochemical data can then be superimposed on the biological activity. Furthermore, there is a need to develop rapid and efficient quality control methods for both raw materials and products because the orthodox methods in current use are time-consuming and labour intensive.

Anti-inflammatory iridoids of botanical origin

Inflammation is a manifestation of a wide range of disorders which include; arthritis, atherosclerosis, Alzheimer's disease, inflammatory bowel syndrome, physical injury and infection amongst many others. Common treatment modalities are usually nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, paracetamol, indomethacin and ibuprofen as well as corticosteroids such as prednisone. These however, may be associated with a host of side effects due to non-selectivity for cyclooxygenase (COX) enzymes involved in inflammation and those with selectivity may be highly priced. Thus, there is a continuing search for safe and effective antiinflammatory molecules from natural sources. Research has confirmed that iridoids exhibit promising anti-inflammatory activity which may be beneficial in the treatment of inflammation. Iridoids are secondary metabolites present in various plants, especially in species belonging to the Apocynaceae, Lamiaceae, Loganiaceae, Rubiaceae, Scrophulariaceae and Verbenaceae families. Many of these ethnobotanicals have an illustrious history of traditional use alluding to their use to treat inflammation. Although iridoids exhibit a wide range of pharmacological activities such as cardiovascular, hepatoprotection, hypoglycaemic, antimutagenic, antispasmodic, anti-tumour, antiviral, immunomodulation and purgative effects this review will acutely focus on their anti-inflammatory properties. The paper aims to present a summary for the most prominent iridoid-containing plants for which anti-inflammatory activity has been demonstrated in vitro and / or in vivo.

Effect of isolated fractions of Harpagophytum procumbens D.C. (devil's claw) on COX-1, COX-2 activity and nitric oxide production on whole-blood assay

The present study evaluates the effect of isolated fractions of Harpagophytum procumbens (devil's claw) on cyclooxygenase (COX-1 and COX-2) activities and NO production using a whole blood assay. The activity of COX-1 was quantified as platelet thromboxane B(2) production in blood clotting and COX-2 as prostaglandin E(2) production in LPS-stimulated whole blood. Total NO(2) (-)/NO(3) (-) concentration was determined by Griess reaction in LPS stimulated blood. Assays were performed by incubation of isolated fractions obtained by flash chromatography monitored with HPLC, TLC and identified by (1)HNMR, containing different amounts of harpagoside with blood from healthy donors. Indomethacin and etoricoxib were the positive controls of COX-1 and COX-2 Inhibition. Data shows that fraction containing the highest concentration of harpagoside inhibited indistinctively COX-1 and COX-2 (37.2 and 29.5% respectively) activity and greatly inhibited NO production (66%). In contrast the fraction including iridoid pool increased COX-2 and did not alter NO and COX-1 activities. The fraction containing cinnamic acid was able to reduce only NO production (67%). Our results demonstrated that the harpagoside fraction is the main responsible for the effect of devils claw on these enzyme activities. However, other components from devil's claw crude extract could antagonize or increase the synthesis of inflammatory mediators.

Evidence of effectiveness of herbal medicinal products in the treatment of arthritis. Part I: Osteoarthritis

Herbal medicinal products (HMPs) are used in a variety of oral and topical forms for the treatment of osteoarthritis. The aim of this study was to update a previous systematic review published in 2000. We searched electronic databases (MEDLINE, EMBASE, CISCOM, AMED, CINAHL, Cochrane registers) to June 2007, unrestricted by date or language, and included randomized controlled trials that compared HMPs with inert (placebo) or active controls in patients with osteoarthritis. Five reviewers contributed to data extraction. Disagreements were discussed and resolved by consensus with reference to Cochrane guidelines and advice from the Cochrane Collaboration.Thirty-five studies (30 studies identified for this review update, and 5 studies included in the original review) evaluating the effectiveness of 22 HMPs were included. However, due to differing HMPs, interventions, comparators, and outcome measures, meta-analysis was restricted to data from studies of three HMPs: topical capsaicin, avocado-soybean unsaponifiables, and the Chinese herbal mixture SKI306X showed benefit in the alleviation of osteoarthritic pain.Several studies investigating products from devil's claw, and a powder from rose hip and seed, reported favorable effects on osteoarthritic pain, whereas two studies of a willow bark extract returned disparate results. Three studies of Phytodolor N(R) were of limited use because doses and measures were inconsistent among trials. The remaining single studies for each HMP provided moderate evidence of effectiveness. No serious side effects were reported with any herbal intervention.Despite some evidence, the effectiveness of none of the HMPs is proven beyond doubt. The obvious potential benefits of HMPs in the treatment of osteoarthritis are reduced reliance on synthetic medications with the associated risks of harmful adverse events, but further clinical trials are necessary before HMPs can be adopted in osteoarthritis treatment guidelines.

Effects of Devil's Claw (Harpagophytum procumbens) on the multidrug transporter ABCB1/P-glycoprotein

Devil's Claw (Harpagophytum procumbens) a plant native to Southern Africa, has historically been used in traditional medicine to treat a wide range of diseases and currently is widely employed as anti-inflammatory and pain-relieving natural remedy in Europe and other parts of the world.

AIM OF THE STUDY

Little is known about possible herb-drug interactions arising from effects of Devil's Claw on the major drug metabolizing enzymes or transporters. This study evaluated in vitro the effects of Devil's Claw on the multidrug transporter ABCB1/P-glycoprotein.

MATERIALS AND METHODS

The effects of three commercially available Devil's Claw preparations and that of pure harpagoside were studied in the human kidney (HK-2) proximal tubule cell line, constitutively expressing ABCB1/P-glycoprotein (P-gp). Pgp activity and expression were tested by the calcein-AM test and by Western blotting, respectively.

RESULTS

Commercial preparations inhibited P-gp activity, even if to a different extent, while pure harpagoside was almost ineffective. In cells cultured for three days in the presence of Devil's Claw preparations or pure harpagoside, a dose-dependent P-gp upregulation was found.

CONCLUSIONS

Our results demonstrate for the first time that Devil's Claw may interact with the multidrug transporter ABCB1/P-gp, the effect not appearing strictly related to the harpagoside relative content. Modulation of both P-gp activity and P-gp expression by Devil's Claw raise the possibility of herb-drug interactions, to be further explored in depth.

The inhibition of free radical generation by preparations of Harpagophytum procumbens in vitro

Harpagophytum procumbens (Hp), commonly known as Devil's Claw has been used as a traditional treatment for a variety of illnesses for centuries. Since the early twentieth century, it has become a popular antiinflammatory and analgesic preparation amongst European herbalists for supportive or adjuvant treatment of degenerative joint diseases. Extracts of Hp tubers have demonstrated antiinflammatory and analgesic effects in animal models of inflammation and in human trials. The mechanism(s) of action responsible for these attributes, however, remain to be elucidated. Reactive oxygen species generated in acute and chronic inflammatory diseases are known to be cytotoxic and can cause tissue damage. In this study, a root tuber extract (Hp extract) and commercially available tincture (Hp tincture) were investigated for antioxidant characteristics using in vitro test systems. Both preparations were found to effectively scavenge DPPH radical, inhibit nitrite levels in supernatants harvested from LPS-stimulated RAW 264.7 macrophages, and cause dose-dependent suppressions in the detection of fMLP- and AA-induced neutrophil MPO. The antioxidant effects demonstrated for both preparations of Hp may contribute to the antiinflammatory and analgesic properties observed for the plant.

A broad review of commercially important southern African medicinal plants

AIMS OF THE STUDY

Commercially important indigenous medicinal plants of southern Africa are reviewed in the context of fundamental knowledge about their ethnobotany, phylogeny, genetics, taxonomy, biochemistry, chemical variation, reproductive biology and horticulture. The aim is to explore the rapidly increasing number of scientific publications and to investigate the need for further research.

MATERIALS AND METHODS

The Scopus (Elsevier) reference system was used to investigate trends in the number of scientific publications and patents in 38 medicinal plant species. Fifteen species of special commercial interest were chosen for more detailed reviews: Agathosma betulina, Aloe ferox, Artemisia afra, Aspalathus linearis, Cyclopia genistoides, Harpagophytum procumbens, Hoodia gordonii, Hypoxis hemerocallidea, Lippia javanica, Mesembryanthemum tortuosum, Pelargonium sidoides, Siphonochilus aethiopicus, Sutherlandia frutescens, Warburgia salutaris and Xysmalobium undulatum.

RESULTS

In recent years there has been an upsurge in research and development of new medicinal products and new medicinal crops, as is shown by a rapid increase in the number of scientific publications and patents. Despite the fact that an estimated 10% of the plant species of the world is found in southern Africa, only a few have been fully commercialized and basic scientific information is often not available.

CONCLUSIONS

The limited available information indicates that some of the plants display remarkable regional variation in morphological, genetic and chemical characters that should be more thoroughly investigated. Basic biological information is needed to guide the rapidly accelerating commercialization process, especially the selection of superior clones, the development of new cultivars and the standardization of raw materials.

Effect of the major glycosides of Harpagophytum procumbens (Devil's Claw) on epidermal cyclooxygenase-2 (COX-2) in vitro

Harpagophytum procumbens, commonly known as Devil's Claw, is indigenous to southern Africa, and extracts of the tubers have been used for centuries in the treatment of a variety of inflammatory disorders. Its major active components, harpagoside (1), harpagide (2), 8-coumaroylharpagide (3), and verbascoside (4), are believed to interact either synergistically or antagonistically in modulating the enzymes responsible for inducing inflammation, although this has not been probed hitherto. In the current work, the ability of these compounds to inhibit the expression of COX-2 following administration to freshly excised porcine skin has been investigated. An ethanol-soluble extract of H. procumbens tubers and two of the pure compounds tested showed promising activity in Western blotting and immunocytochemical assays, with harpagoside (1) and 8-coumaroylharpagide (3) exhibiting greater reductions in COX-2 expression than verbascoside (4). Harpagide (2) caused a significant increase in the levels of COX-2 expression after 6 h of topical application. The data suggest that the efficacy of H. procumbens is dependent upon the ratios of compounds 1-4 present, which is inconsistent with some current official monograph specifications based solely on harpagoside (1) content.

Protocols on safety, efficacy, standardization, and documentation of herbal medicine (IUPAC Technical Report)

This Technical Report compiles and analyzes the current scientific knowledge on herbal medicine and highlights the practical ways for ensuring the safety of herbal preparations and evaluating their claimed efficacy. Emphasis has been given to the methods for standardization of herbal medicine and the ways and means for moving forward to achieve the difficult goal of preparing herbal medicines of consistent quality and effects. Pragmatic approaches have been recommended to overcome the difficulties in (i) protecting intellectual property rights (IPR); (ii) producing safe, potent, standardized, and affordable herbal medicine; and (iii) documenting the knowledge base on herbal medicine in an easily accessible format.

Simultaneous determination of harpagoside and cinnamic acid in rat plasma by high-performance liquid chromatography: application to a pharmacokinetic study

Radix Scrophulariae (xuanshen) is one of the famous Chinese herbal medicines widely used to treat rheumatism, tussis, pharyngalgia, arthritis, constipation, and conjunctival congestion. Harpagoside and cinnamic acid are the main bioactive components of xuanshen. The purpose of this study was to develop an HPLC-UV method for simultaneous determination of harpagoside and cinnamic acid in rat plasma and investigate pharmacokinetic parameters of harpagoside and cinnamic acid after oral administration of xuanshen extract (760 mg kg(-1)). After addition of syringin as internal standard, the analytes were isolated from plasma by liquid-liquid extraction. Separation was achieved on a Kromasil C18 column, and detection was by UV absorption at 272 nm. The described assay was validated in terms of linearity, accuracy, precision, recovery, and limit of quantification according to the FDA validation guidelines. Calibration curves for both analytes were linear with the coefficient of variation (r) for both was greater than 0.999. Accuracy for harpagoside and cinnamic acid ranged from 100.7-103.5% and 96.9-102.9%, respectively, and precision for both analytes were less than 8.5%. The main pharmacokinetic parameters found for harpagoside and cinnamic acid after oral infusion of xuanshen extract were as follows: Cmax 1488.7 +/- 205.9 and 556.8 +/- 94.2 ng mL(-1), Tmax 2.09 +/- 0.31 and (1.48 +/- 0.14 h, AUC(0-24) 10,336.4 +/- 1426.8 and 3653.1 +/- 456.4 ng h mL(-1), AUC(0-infinity) 11,276.8 +/- 1321.4 and 3704.5 +/- 398.8 ng h mL(-1), and t(1/2) 4.9 +/- 1.3 and 2.5 +/- 0.9 h, respectively. These results indicated that the proposed method is simple, selective, and feasible for pharmacokinetic study of radix Scrophulariae extract in rats.

A Review of the Efficacy and Safety of Devil's Claw for Pain Associated With Degenerative Musculoskeletal Diseases, Rheumatoid, and Osteoarthritis

Harpagophytum procumbens, known as devil's claw, has been used traditionally for the treatment of pain, fevers, and dyspepsia. Recently, it has become popular for the treatment of rheumatoid and osteoarthritis. Studies have yet to establish a clear mechanism of action; however, current research is focusing on pro-inflammatory mediators as well as on potential antioxidant characteristics.

A review of the biological and potential therapeutic actions ofHarpagophytum procumbens

Harpagophytum procumbens (Hp), commonly known as Devil's Claw is a perennial plant which thrives in arid conditions. For centuries, it has been used as a traditional treatment for a variety of illnesses, including fevers, skin complaints, arthritis and diseases of the digestive tract as well as an appetite stimulant. Since its introduction to Europe in the early twentieth century, it has become a popular antiinflammatory and analgesic preparation amongst herbalists for supportive or adjuvant treatment of degenerative joint diseases, tendonitis, headache, backache and menstrual pain. The validity of Hp as an effective antiinflammatory and analgesic preparation, particularly in the relief of arthritic symptoms, has been investigated in numerous animal, clinical and in vitro studies. Although some contradictory evidence exists, the majority of animal studies appear to indicate Hp as an effective antiinflammatory and analgesic preparation in the treatment of acute and subacute inflammation. Clinical trials support Hp as a beneficial treatment for the alleviation of pain and improvement of mobility in a variety of musculoskeletal conditions. Analysis of the in vitro and ex vivo studies that currently exist, indicate that Hp has significant effects on numerous proinflammatory markers. However, the exact mechanism(s) by which Hp may reduce inflammation remain to be elucidated.

Evidence of effectiveness of herbal antiinflammatory drugs in the treatment of painful osteoarthritis and chronic low back pain

Treatment with herbal medicines is very popular in Europe. In order to get information on the evidence of effectiveness of oral herbal medicines in the treatment of pain in the joints or lower back, OVID(MEDLINE), PUBMED and COCHRANE COLLABORATION LIBRARY were searched back to 1985 for systematic reviews. The level of evidence of effectiveness was defined as strong - at least two confirmatory studies demonstrating a clinical relevant effect, moderate - one confirmatory study with a clinical relevant effect and/or multiple exploratory studies of good quality; otherwise the evidence was insufficient or conflicting in the case of inconsistent findings. Fifteen systematic reviews were identified. The evidence of effectiveness was strong for a proprietary unsaponifiable avocado soybean fraction and Harpagophytum preparations containing > 50 mg harpagoside in the daily dosage, moderate for ginger and a proprietary rose hip and seed powder, insufficient for Boswellia serrata gum resin and other herbal preparations and inconsistent for a proprietary willow bark extract. Further rigorous studies are required to confirm the usefulness of herbal medicines in the treatment of osteoarthritic complaints and chronic low back pain in order to enable acceptance of the herbal medicines into the treatment guidelines.

Application of the "-Omic-" technologies in phytomedicine

The proof of efficacy of phytopreparations and the determination of their mode of action are permanent challenges for an evidence-based phytotherapy. The technology platform of genomics, proteomics and metabolomics ("-omic-" technologies) are high-throughput technologies. They increase substantially the number of proteins/genes that can be detected simultaneously and have the potential to relate complex mixtures to complex effects in the form of gene/protein expression profiles. Provided that phytopreparation-specific signatures in the form of gene/protein expression profiles can be developed, these technologies will be useful for the chemical and pharmacological standardization and the proof of the toxicological potential of a plant extract. Over a long-term perspective they may economize the proof of efficacy, the determination of the mode of action of phytomedicines and allow to investigate herbal extracts without prominent active principle(s). The application of this genomics revealed already that gene expression profiles induced by single drugs and the ones induced by the combination of the same drugs can be entirely different. These results make the information of the mode of action of isolated "active principles/lead substances" of phytopreparations questionable. The application of the "-omic-" technologies may lead to a change of paradigms towards the application of complex mixtures in medicine and open the new field of phytogenomics, -proteomics and -metabolomics.

Harpagoside suppresses lipopolysaccharide-induced iNOS and COX-2 expression through inhibition of NF-kappa B activation

Preparations of Harpagophytum procumbens, known as devil's claw, are used as an adjunctive therapy for the treatment of pain and osteoarthritis. Pharmacological evaluations have proven the effectiveness of this herbal drug as an anti-inflammatory and analgesic agent. The present study has investigated the mechanism of action of harpagoside, one of the major components of Harpagophytum procumbens, using human HepG2 hepatocarcinoma and RAW 264.7 macrophage cell lines. Harpagoside inhibited lipopolysaccharide-induced mRNA levels and protein expression of cyclooxygenase-2 and inducible nitric oxide in HepG2 cells. These inhibitions appeared to correlate with the suppression of NF-kappaB activation by harpagoside, as pre-treating cells with harpagoside blocked the translocation of NF-kappaB into the nuclear compartments and degradation of the inhibitory subunit IkappaB-alpha. Furthermore, harpagoside dose-dependently inhibited LPS-stimulated NF-kappaB promoter activity in a gene reporter assay in RAW 264.7 cells, indicating that harpagoside interfered with the activation of gene transcription. These results suggest that the inhibition of the expression of cyclooxygenase-2 and inducible nitric oxide by harpagoside involves suppression of NF-kappaB activation, thereby inhibiting downstream inflammation and subsequent pain events.

Contribution of conjugated linoleic acid to the suppression of inducible nitric oxide synthase expression and transcription factor activation in stimulated mouse mesangial cells

That both infiltrating macrophages and resident mesangial cells express inducible nitric oxide synthase (iNOS) and produce nitric oxide (NO) excessively is crucial to the progress of glomerulonephritis. Although several reports have mentioned the protective impacts of conjugated linoleic acid (CLA) in stimulated macrophages, the role of CLA in glomerular mesangial cells is unknown. The aim of the present study was to explore the ability of CLA to regulate iNOS expression and NO production in stimulated glomerular mesangial cells. Additionally, we evaluated the effect of CLA on activation of transcription factors which mediate iNOS expression. Exogenous CLA dose-dependently diminished iNOS mRNA and protein expression as well as NO production in lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma)-stimulated SV-40-transformed mouse mesangial cells. Electrophoretic mobility shift assay experiments demonstrated that CLA (100 microM) dramatically reduced activation of nuclear factor-kappaB (NF-kappaB), activator protein-1 (AP-1) and cAMP response element binding protein (CREB) induced by LPS/IFN-gamma. Moreover, addition of 100 microM CLA significantly diminished LPS-IFN-gamma-induced protein degradation of inhibitor kappaB-alpha (IkappaB-alpha) and the protein expression of phosphorylated IkappaB-alpha in the cytosolic fraction as well as nuclear p65 expression (P < 0.05). In summary, inhibition of NF-kappaB, AP-1 and CREB activation by CLA may be associated with the molecular basis for which CLA suppresses iNOS expression and NO production in stimulated mesangial cells.

The commercial harvest of devil's claw (Harpagophytum spp.) in southern Africa: the devil's in the details

Devil's claw is the common name for two species in the genus Harpagophytum. Their root extracts contain the iridoid glycoside, harpagoside, which has been found to be effective in the treatment of degenerative rheumatoid arthritis, osteoarthritis, tendonitis, kidney inflammation, and heart disease. Most of the world's supply comes from Namibia, with lesser amounts from South Africa and Botswana. In 2002, the peak year of export, 1018 tonnes of dried tubers were exported from southern Africa, representing the harvest of millions of plants. In 2001, sales in Germany were estimated at 30 M euros, accounting for 74% of the prescriptions for rheumatism. Harvest has improved income levels in marginalized communities but it has also raised questions of sustainability. In 2000, recommendations were made to the Convention on the International Trade in Endangered Species (CITES) to add devil's claw to Appendix II. In 2004, the proposal was formally withdrawn due to the efforts of the range states to address sustainability issues. Replacing wild collection with cultivation has generated a debate on the positive and negative effects on harvester income and rural farmers. Successful cultivation efforts have involved micropropagation techniques and growing the plant without water or fertilizers. The governments of the main range states are working with local communities to develop policies and regulations to protect the species and to determine a sustainable harvest.