Molecular pharmacology of inflammation: Medicinal plants as anti-inflammatory agents.

Except for an essential step for the pathology of multiple diseases including atherosclerosis and rheumatoid arthritis, inflammation is an imperative therapeutic target for developing novel approaches for pharmacological interventions. Thus, molecular understanding of inflammation not only revealed the mechanisms of drug action and their biological targets but also has spawned innovative maneuvers to influence multifaceted biological systems, providing new prospects for drug designing and suggesting important new implications for existing clinical medicine. Meanwhile, modulation of inflammation with the use of medicinal plants proposed an alternate to conventional therapeutic strategies for numerous ailments, particularly when suppression of inflammation is expected. In modern literature, several species of medicinal plants have been shown substantial antiinflammatory and immunomodulatory actions including inhibitory effects on suppression of cellular and humoral immunity, lymphocyte activation, and propagation of apoptosis. Herein, we reviewed the molecular pharmacology of inflammation, chemical components and biological activities of medicinal plants such as, curcumin from Curcuma longa, and epigallocatechin-3-gallate from Camellia sinensis as well as their mechanism of action during inflammation at molecular level. An extensive review of the literature and electronic databases was conducted, encompassing PubMed, GoogleScholar, ScienceDirect, medlineplus, www.clinicaltrial.gov, www.fda.gov, www.ema.europa.eu, www.drugbank.ca, TrialBulletin.com, www.theplantlist.org, and www.pharmacodia.com for assembling the information. Additionally, data was attained from books, ethnopharmacological literature, and relevant publications for essential elements of molecular mechanisms, signal transduction networks, transcription factors, complement system, reactive species, and clinical trials are selected for substantial understanding of biochemistry, pathophysiology as well as clinical importance of medicinal plants during inflammatory diseases.

New Cadinane Sesquiterpenes from the Stems of Kadsura heteroclita.

As part of our continual efforts to exploit 'Tujia Ethnomedicine' for their pharmacophoric functionalities, we herein investigated Kadsura heteroclita collected from a deep Wulin mountain area in northern Hunan province. The current study resulted in the isolation of three new sesquiterpenes: 6α,9α,15-trihydroxycadinan-4-en-3-one (1), (+)-3,11,12-trihydroxycalamenene (2), (-)-3,10,11,12-tetrahydroxy-calamenene (3), along with four known sesquiterpenes (4-7), and a cytochalasin H (8). Their chemical structures were elucidated by 1D-, and 2D-NMR spectroscopy, and HRESI-MS, CD spectrometry. The antioxidant, and cytotoxic activities of the compounds were evaluated. Compound 8 exhibited a strong antioxidant effect with an IC50 value of 3.67 µM on isolated human polymorphonuclear cells or neutrophils.

Lignans from Tujia Ethnomedicine Heilaohu: Chemical Characterization and Evaluation of Their Cytotoxicity and Antioxidant Activities.

Heilaohu, the roots of Kadsura coccinea, has a long history of use in Tujia ethnomedicine for the treatment of rheumatoid arthritis and gastroenteric disorders, and a lot of work has been done in order to know the material basis of its pharmacological activities. The chemical investigation led to the isolation and characterization of three new (1⁻3) and twenty known (4⁻23) lignans. Three new heilaohulignans A-C (1⁻3) and seventeen known (4⁻20) lignans possessed dibenzocyclooctadiene skeletons. Similarly, one was a diarylbutane (21) and two were spirobenzofuranoid dibenzocyclooctadiene (22⁻23) lignans. Among the known compounds, 4⁻5, 7, 13⁻15 and 17⁻22 were isolated from this species for the first time. The structures were established, using IR, UV, MS and NMR data. The absolute configurations of the new compounds were determined by circular dichroism (CD) spectra. The isolated lignans were further evaluated for their cytotoxicity and antioxidant activities. Compound 3 demonstrated strong cytotoxic activity with an IC50 value of 9.92 µM, compounds 9 and 13 revealed weak cytotoxicity with IC50 values of 21.72 µM and 18.72 µM, respectively in the HepG-2 human liver cancer cell line. Compound 3 also showed weak cytotoxicity against the BGC-823 human gastric cancer cell line and the HCT-116 human colon cancer cell line with IC50 values of 16.75 µM and 16.59 µM, respectively. A chemiluminescence assay for antioxidant status of isolated compounds implied compounds 11 and 20, which showed weak activity with IC50 values of 25.56 µM and 21.20 µM, respectively.

Advancement of Natural Compounds as Anti-rheumatoid Arthritis Agents: A Focus on Their Mechanism of Actions.

Rheumatoid Arthritis (RA) is a chronic inflammatory disease characterized by infiltration of inflammatory cells, synovial hyperplasia, pannus formation and bone destruction. RA is associated with high incidence of disability worldwide. Although several anti-RA agents are available in the market, clinical use of these drugs is limited due to their severe side effects. Several studies are currently exploring new anti-rheumatic drugs which are more effective and have fewer side effects. Notably, natural products with anti-RA effect have been identified and studies have reported the underlying molecular mechanisms of action of the novel and known compounds. This review explored naturally occurring known and novel compounds that have anti-RA activity. Further, the compounds are classified based on their molecular mechanisms of action as anti-RA agents. In addition, the safety of compounds from natural sources is compared with that of conventional drugs. In addition, clinical trials for anti-RA compounds isolated from natural plant sources were summarized in this manuscript.

Chemical characterization of constituents from Polygonatum cyrtonema Hua and their cytotoxic and antioxidant evaluation.

Twenty-four compounds were isolated from the roots of Polygonatum cyrtonema Hua, including a new octopamine dimer, named trans-bis(N-feruloyl)octopamine (1). The structure was established on the basis of spectroscopic and chemical methods. All the extracts and compounds were evaluated for cytotoxic and antioxidant activities by using MTT and chemiluminescence assay. The extracts showed activity against MCF-7 and HepG-2 cell lines from IC50 0.30 to 1.01 mg mL-1. Compound 3 exhibited activity against HepG-2 cell lines with IC50 8.99 µM. Compound 7 exhibited activity against Hela cell lines with IC50 2.53 µM and BGC-823 cell lines with IC50 7.77 µM. Moreover, compound 7 showed antioxidant with IC50 12 µM compared to the positive control with IC50 77 µM. Compound 16 exhibited activity against HepG-2 cell lines with IC50 1.05 µM and MCF-7 cell lines with IC50 1.89 µM. These results indicated that this plant might be potential in natural medicine and healthy food.

Kadsura heteroclita stem suppresses the onset and progression of adjuvant-induced arthritis in rats.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune diseased state, characterized by hyperplasia of the synovial membrane, degradation of cartilage, and bone erosion of diarthrodial joints. Kadsura heteroclita (Roxb) Craib (Schizandraceae), a traditional Tujia ethnomedicine called Xue Tong in China, has been long used for the prevention and treatment of rheumatic and arthritic diseases, especially in the southern China. This study aimed to evaluate anti-arthritic effects of the ethanol extract of Kadsura heteroclita stems (KHS) on complete Freund's adjuvant (CFA)-induced arthritis (AIA) in rats, as well as to explore the underlying mechanisms of anti-arthritis. METHODS: AIA was established in male Sprague-Dawley (SD) rats as described previously, and animals were daily treated by gavage with KHS ethanol extract (200, 400, or 800 mg/kg) or vehicle (0.3% CMCNa) throughout the 30-day experiment. The incidence and severity of arthritis were evaluated using clinical parameters. At the end of experiments, tissue swelling and bone destruction of the hind paws were assessed by computed tomography (CT) and histopathological analyses. Serum levels of tumor necrosis factor (TNF-α), interleukin-1ß (IL-1ß), IL-6, and IL-17A and IL-17F were measured by ELISA, and protein expression of matrix metalloproteinases-1 (MMP-1), MMP-3 and tissue inhibitor of MMP-1 (TIMP-1) were detected by Western blot. RESULTS: Treatment with KHS dose-dependently inhibited paw swelling and reduced arthritis scores of AIA rats. CT images displayed that KHS remarkably protected AIA rats from tissue swelling and bone erosion of joints. Histopathological analyses revealed that KHS markedly reduced inflammatory cell infiltration, synovial proliferation, and the formation of pannus in the ankle joints of AIA rats. KHS was found to significantly suppress the production of TNF-α, IL-1 ß, IL-6, IL-17A and IL-17F, inhibited the protein expression of MMP-1 and MMP-3, and elevated the protein expressions of TIMP-1. CONCLUSION: KHS demonstrates potential anti-arthritic effects via inhibiting pivotal mediators of inflammation and cartilage destruction. This study strongly supports identification and isolation of active fractions of KHS which would be a potential candidate for further investigation as a new anti-arthritic botanical drug.

Analgesic and anti-inflammatory effects and molecular mechanisms of Kadsura heteroclita stems, an anti-arthritic Chinese Tujia ethnomedicinal herb.

ETHNOPHARMACOLOGICAL RELEVANCE: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by failure of spontaneous resolution of inflammation. The stem of Kadsura heteroclite (KHS) is a well-known anti-arthritic Tujia ethnomedicinal plant, which named Xuetong in folk, has long been used for the prevention and treatment of rheumatic and arthritic diseases. AIM OF THE STUDY: The analgesic and anti-inflammatory effects and the potential mechanisms behind such effects of KHS would be investigated by using different animal models. MATERIALS AND METHODS: The abdominal writhing episodes of mice induced by intraperitoneal injection of acetic acid and the tail-flick response induced by radiant heat stimulation were used to evaluate the analgesic effect of KHS. The number of abdominal writhing episodes of mice and the latency of tail-flick in rats were measured and recorded. In acute inflammatory models, the ear edema of mice was induced by applying xylene on the ear surface, while the paw edema of male and female rats was induced by subcutaneous injection of carrageenan into the right hind paws of animals. The carrageenan-induced paw swelling in rats were selected as an anti-acute inflammatory mechanism of KHS. Serum levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α) were measured by ELISA, and protein expression of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were detected by Western blot. RESULTS: The maximal tolerated single dose of KHS was determined to be 26 g/kg in both sexes of mice. Pharmacological studies showed that KHS at the dose of 200 mg/kg significantly prolonged the reaction time of rats to radiant heat stimulation and suppressed abdominal writhing episodes of mice induced by intraperitoneal injection of acetic acid. KHS at the dose of 200, 400, and 800 mg/kg, showed dose-dependent inhibition of xylene-induced ear swelling in mice. KHS at the dose of 100, 200, 400, and 800 mg/kg demonstrated dose- and time-dependent suppression of paw edema induced by subcutaneous injection of carrageenan in both all rats. Mechanistic studies revealed that the anti-inflammatory effect of KHS was associated with inhibition of the production of pro-inflammatory cytokines IL-1ß, IL-6, and TNF-α and effectively decreased the expression of COX and iNOS proteins in the carrageenan-injected rat serum, paw tissues and inflammatory exudates. The positive reference drug, rotundine at a dosage of 100 mg/kg and indomethacin at a dosage of 10 mg/kg were used in both mice and rat models. CONCLUSION: These results suggested that KHS has significant effects on analgesia and anti-inflammation with decreasing the pro-inflammation cytokines of IL-1ß, IL-6, and TNF-α and inhibiting the proteins expression of COX-2 and iNOS.

Inhibitors of phosphatidylinositide 3-kinase: effects on reactive oxygen species and platelet aggregation.

Phosphoinositide 3-kinase (PI 3-kinase) exists in cells as a family of isoforms. The enzymes are important regulators of fundamental metabolic processes, such as energy utilization, growth, cell proliferation and survival. They are activated by cell surface receptors for hormones, and by G-protein coupled receptors. Enzyme p110 gamma, in particular, catalyzes production of second messengers from inositol phospholipids, including phosphoinositide (3,4,5) triphosphate or PtdIns (3,4,5) P3, PtdIns (3,4) P2 and Ptdins (3) P. The objective of this study was to corroborate the role of PI 3 kinase in ROS generation and in platelet aggregation through the use of four chemically unrelated inhibitors of PI 3 kinase: wortmannin, LY-294002, resveratrol and quercetin. In this study, we describe the effects of four PI 3-kinase inhibitors on the production of reactive oxygen species (ROS) and platelet aggregation induced by a diversity of agonists. Neutrophils and platelets were obtained from human blood and macrophages from mouse peritoneal cavity. ROS production was measured by a luminol-enhanced chemiluminescence assay; aggregation was measured in platelet-rich plasma (PRP) with a Chronolog Dual Channel Lumi-Aggregometer. Effects of graded concentrations of four enzyme inhibitors (wortmannin, LY-294002, resveratrol and quercetin) were evaluated. All inhibitors caused concentration-dependent depression of ROS generation and human platelet aggregation. They differed only in their potencies as revealed by concentration-response data. Moreover, inhibitors blocked activity of three chemically unrelated stimulants of aggregation: ADP, collagen and epinephrine. We conclude that inhibition of PI 3-kinase would appear to be a useful therapeutic goal in those conditions where the activities of platelets and/or phagocytes become aberrant.

Nonsteroidal anti-inflammatory drugs as potential ecto-nucleotide phosphodiesterase inhibitors

Phosphodiesterases (PDE) are group of enzymes which catalyze the hydrolysis of cAMP and cGMP. Since these cyclic phosphate moieties worked as intracellular second messengers in numerous physiological processes, their inhibition can affect normal physiology of living system. NSAIDs are among the frequently prescribed medications, because of their efficacy as analgesic, antipyretic and anti-inflammatory agents. They are known to block cyclooxygenase pathway. In limited data NSAIDs has been shown anti-tumor potential, and phosphodiesterase inhibition has assumed to be one of the mechanism. To date no further evaluation being done. Further, NSAIDs are classified as cyclooxygenase inhibitors and phosphodiesterase inhibition can imprint its side effects. This study first time investigates the effects of NSAIDs on phosphodiesterase 1 inhibition. The activity against snake venom phosphodiesterase 1 was assayed on a microtitre plate reader spectrophotometer. Selective COX-2 inhibitor, celecoxib, exhibited a potent PDE1 inhibitory activity, at therapeutic doses, with an IC50 value of 29.4 µM. The findings of our study are indicative of new pharmacological actions of cyclooxygenase inhibitors. This article presents the PDE inhibitory properties as a new effects of already existing drugs. These additional effects could be potentially helpful for researchers to assess other physiological and pathological states.