Flavonoids with iNOS inhibitory activity from Pogonatherum crinitum

Luteolin: A promising natural agent in management of pain in chronic conditions

Pain due to chronic conditions is a frequent and insufficiently addressed problem. Current drug options for pain management (either in cases of chronic inflammatory conditions or neuropathy) do not adequately treat pain. Moreover, they are associated with important adverse events in long term use. Luteolin is a flavonoid widely present in the plant kingdom and its sources have been assembled in a comprehensive list of this paper. Luteolin has shown in several research studies a range of pharmacological properties; anti-inflammatory, antioxidant, neuroprotective, and analgesic. In this article, we summarize the effects and potential benefits from introducing luteolin as an adjuvant agent in established protocols for pain management. We review the most indicative in vivo and in vitro evidence of how luteolin can target the molecular pathways involved in pathogenesis of chronic inflammatory and neuropathic pain. The data reviewed strongly support luteolin's promising benefits in pain management and raise the need for further clinical trials that can establish its role in clinical practice.

Anti-inflammatory effects of flavonoids and phenylethanoid glycosides from Hosta plantaginea flowers in LPS-stimulated RAW 264.7 macrophages through inhibition of the NF-κB signaling pathway

BACKGROUND

The flower of Hosta plantaginea (Lam.) Aschers has traditionally been used in China as an important Mongolian medicine for the treatment of inflammatory diseases with limited scientific evidence. In previous studies, 16 flavonoids and 3 phenylethanoid glycosides (1-19) were isolated from the ethanolic extract of H. plantaginea flowers. Nevertheless, the anti-inflammatory effects of these constituents remain unclear. In the present study, the anti-inflammatory effects of these 19 constituents and their underlying mechanisms were assessed in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

METHODS

The viability of RAW 264.7 macrophages was detected by Cell Counting Kit-8 (CCK-8) assay. Meanwhile, nitric oxide (NO) production was measured by Griess assay, while the secretion of tumor necrosis factor α (TNF-α), prostaglandin E2 (PGE2), interleukin 1β (IL-1β) and IL-6 in LPS-induced macrophages was determined by enzyme-linked immunosorbent assay (ELISA). Furthermore, the protein expression of nuclear factor kappa B (NF-κB) p65 and phosphorylated NF-κB p65 was evaluated by Western blot analysis.

RESULTS

All constituents effectively suppressed excessive NO production at a concentration of 40 μM with no toxicity to LPS-induced RAW 264.7 macrophages. Among them, five flavonoids (1, 4-6 and 15) and one phenylethanoid glycoside (17) remarkably prevented the overproduction of NO with median inhibitory concentration (IC50) values in the range of 12.20-19.91 μM. Moreover, compounds 1, 4-6, 15 and 17 potently inhibited the secretion of TNF-α, PGE2, IL-1β and IL-6, and had a prominent inhibitory effect on the down-regulation of the phosphorylated protein level of NF-κB p65.

CONCLUSION

Taken together, compounds 1, 4-6, 15 and 17 may be useful in managing inflammatory diseases by blocking the NF-κB signaling pathway and suppressing the overproduction of inflammatory mediators.

A Major Diplotaxis harra-Derived Bioflavonoid Glycoside as a Protective Agent against Chemically Induced Neurotoxicity and Parkinson's Models; In Silico Target Prediction; and Biphasic HPTLC-Based Quantification

Oxidative stress and chronic inflammation have a role in developing neurodegenerative diseases such as Parkinson’s disease (PD) and inflammatory movement disorders such as rheumatoid arthritis that affect millions of populations. In searching for antioxidant and anti-inflammatory molecules from natural sources that can counteract neurodegenerative diseases and arthritis, the flavonoid-rich extract of Diplotaxis harra (DHE) was selected based on its in vitro antioxidant and anti-inflammatory activities. DHE could inhibit the inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions in the lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages from 100% to the level of 28.51 ± 18.67 and 30.19 ± 5.00% at 20 μg/mL, respectively. A TLC bioautography of DHE fractions using 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) led to the isolation of a major antioxidant compound which was identified by X-ray diffraction analysis as isorhamnetin-3-O-β-D-glucoside (IR3G). IR3G also exhibited a potent anti-inflammatory activity, particularly by suppressing the upregulation of iNOS expression, similar to that of dexamethasone (DEX) at 10 μM to the level of 35.96 ± 7.80 and 29.34 ± 6.34%, respectively. Moreover, IR3G displayed a strong neuroprotectivity (>60% at 1.0−4−1.0−3 μM) against 6-hydroxydopamine (6-OHDA)-challenged SHSY5Y neuroblastoma, an in vitro model of dopaminergic neurons for Parkinson’s disease (PD) research. Accordingly, the in vivo anti-Parkinson potentiality was evaluated, where it was found that IR3G successfully reversed the 6-OHDA-induced locomotor deficit in a zebrafish model. A study of molecular docking and molecular dynamic (MD) simulation of IR3G and its aglycone isorhamnetin (IR) against human acetylcholine esterase (AChE), monoamine oxidase B (MAO-B), and Polo-like kinase-2 (PLK2) was performed and further outlined a putative mechanism in modulating neurodegenerative diseases such as PD. The free radical scavenging, anti-inflammatory through anti-iNOS and anti-COX-2 expression, and neuroprotective activities assessed in this study would present partial evidence for the potentiality of D. harra-derived IR3G as a promising natural therapeutic agent against neurodegenerative diseases and inflammatory arthritis. Finally, a biphasic HPTLC method was developed to estimate the biomarker IR3G in D. harra quantitatively.

Elucidation of the Metabolite Profile of Yucca gigantea and Assessment of Its Cytotoxic, Antimicrobial, and Anti-Inflammatory Activities

The acute inflammation process is explained by numerous hypotheses, including oxidative stress, enzyme stimulation, and the generation of pro-inflammatory cytokines. The anti-inflammatory activity of Yucca gigantea methanol extract (YGME) against carrageenan-induced acute inflammation and possible underlying mechanisms was investigated. The phytochemical profile, cytotoxic, and antimicrobial activities were also explored. LC-MS/MS was utilized to investigate the chemical composition of YGME, and 29 compounds were tentatively identified. In addition, the isolation of luteolin-7-O-β-d-glucoside, apigenin-7-O-β-d-glucoside, and kaempferol-3-O-α-l-rhamnoside was performed for the first time from the studied plant. Inflammation was induced by subcutaneous injection of 100 μL of 1% carrageenan sodium. Rats were treated orally with YGME 100, 200 mg/kg, celecoxib (50 mg/kg), and saline, respectively, one hour before carrageenan injection. The average volume of paws edema and weight were measured at several time intervals. Levels of NO, GSH, TNF-α, PGE-2, serum IL-1β, IL-6 were measured. In additionally, COX-2 immunostaining and histopathological examination of paw tissue were performed. YGME displayed a potent anti-inflammatory influence by reducing paws edema, PGE-2, TNF-α, NO production, serum IL-6, IL-1β, and COX-2 immunostaining. Furthermore, it replenished the diminished paw GSH contents and improved the histopathological findings. The best cytotoxic effect of YGME was against human melanoma cell line (A365) and osteosarcoma cell line (MG-63). Moreover, the antimicrobial potential of the extract was evaluated against bacterial and fungal isolates. It showed potent activity against Gram-negative, Gram-positive, and fungal Candida albicans isolates. The promoting multiple effects of YGME could be beneficial in the treatment of different ailments based on its anti-inflammatory, antimicrobial, and cytotoxic effects.

Synthesis of Resveratrol Loaded Hybrid Silica-PAMAM Dendrimer Nanoparticles With Emphases on Inducible Nitric Oxide Synthase and Cytotoxicity

Resveratrol is a naturally occurring polyphenolic compound exhibiting therapeutic activities. However, the stability can be altered by UV light, pH and changes in temperature. Encapsulation would be an ideal strategy to improve the stability and bioavailability. Thus, trans-resveratrol (Res) was encapsulated within hybrid nanoparticles consisted with silica and G4 polyamidoamine dendrimer (PAMAM) by sol-gel method. The diameters of synthesized nanoparticles (NPs) were at a range of 212-574 nm and the encapsulation efficiency was 86 %. RAW 264.7 murine macrophage cell line induced with endotoxin/lipopolysaccharide was treated with free resveratrol and Res-loaded NPs for assessing inhibition of inducible nitric oxide synthase (iNOS), where IC₅₀ values of free resveratrol and Res-loaded NPs were 122.68 µM and 249.74 µM. As for cytotoxicity, IC₅₀ values of free resveratrol were found as 176.57 µM and 201.54 µM for MCF-7 and MDA-MB-231 cells, whereas 197.16 µM and 219.07 µM for Res-loaded NPs for the respective cell lines. Overall, sol-gel technique proved to be an ideal technology as can be carried out under mild conditions and Res-loaded NPs have potential to be utilized in the industry.

Cosmosporasides F-H, three new sugar alcohol conjugated acyclic sesquiterpenes from a Fusarium oxysporum fungus

Three new sugar alcohol conjugated acyclic sesquiterpenes, cosmosporasides F-H (1-3), were isolated from the fermented cultures of Fusarium oxysporum SC0002. Their structures were elucidated by extensive analysis of spectroscopic data, including ¹H-¹³C long-range coupling constants (J_C,H). Their antibacterial, cytotoxic and anti-inflammatory activities were evaluated.

An Ethnobotanical Study on Qīng-Căo-Chá Tea in Taiwan

Herbal tea, a beverage prepared from a variety of plant materials excluding the leaves of the tea plant Camellia sinensis (L.) Kuntze of the family Theaceae, for a long time, has been consumed by most Chinese people for preventive and/or therapeutic health care. Usually, it is brewed or prepared as a decoction of local plants in water. The qīng-căo-chá tea, a commercial herbal tea, is the most common among many differently formulated herbal teas in Taiwan. For hundreds of years, qīng-căo-chá tea has played an important role in the prevention and treatment of diseases associated with the environmental conditions in Taiwan. However, research studies in this field have been insufficient. The raw material formulas of qīng-căo-chá tea have always been passed down from “masters” to “apprentices.” Hence, there is no systematic collation or record, and, therefore, there is a need to assess and confirm the composition, safety, and effectiveness of the raw materials. This study aimed to document the uses of Taiwan's qīng-căo-chá tea through a semi-structured interview survey and investigate the background of traditional practitioners, tea compositions, and plant origins and uses. This will improve our understanding of the knowledge inherited by the practitioners and the theoretical basis of the medicinal uses of these teas. In our field investigation, we visited 86 shops and assessed 71 raw ingredients of qīng-căo-chá tea. A semi-structured questionnaire was used to conduct the interviews. During the interviews, in addition to written records, audio and video recordings were made, and photographs were taken with the permission of the interviewees. The qīng-căo-chá raw materials have long been used as herbal teas, although more research should clarify their efficacy and safety. Traditional sellers of qīng-căo-chá tea were mainly males, and most shops have been in operation for more than 71 years. Some of the raw materials were derived from multiple sources, including different plants, and were often mixed without any safety concerns. To our knowledge, this is the first systematic ethnobotanical study on qīng-căo-chá tea that assesses and confirms its herbal ingredients. Our study represents a reference for herbal teas in Taiwan that can be used by the public and regulatory agencies.

Animal Models of Inflammation for Screening of Anti-inflammatory Drugs: Implications for the Discovery and Development of Phytopharmaceuticals

Inflammation is one of the common events in the majority of acute as well as chronic debilitating diseases and represent a chief cause of morbidity in today's era of modern lifestyle. If unchecked, inflammation leads to development of rheumatoid arthritis, diabetes, cancer, Alzheimer's disease, and atherosclerosis along with pulmonary, autoimmune and cardiovascular diseases. Inflammation involves a complex network of many mediators, a variety of cells, and execution of multiple pathways. Current therapy for inflammatory diseases is limited to the steroidal and non-steroidal anti-inflammatory agents. The chronic use of these drugs is reported to cause severe adverse effects like gastrointestinal, cardiovascular, and renal abnormalities. There is a massive need to explore new anti-inflammatory agents with selective action and lesser toxicity. Plants and isolated phytoconstituents are promising and interesting sources of new anti-inflammatories. However, drug development from natural sources has been linked with hurdles like the complex nature of extracts, difficulties in isolation of pure phytoconstituents, and the yield of isolated compounds in minute quantities that is insufficient for subsequent lead development. Although various in-vivo and in-vitro models for anti-inflammatory drug development are available, judicious selection of appropriate animal models is a vital step in the early phase of drug development. Systematic evaluation of phytoconstituents can facilitate the identification and development of potential anti-inflammatory leads from natural sources. The present review describes various techniques of anti-inflammatory drug screening with its advantages and limitations, elaboration on biological targets of phytoconstituents in inflammation and biomarkers for the prediction of adverse effects of anti-inflammatory drugs. The systematic approach proposed through present article for anti-inflammatory drug screening can rationalize the identification of novel phytoconstituents at the initial stage of drug screening programs.

Bioassay-Guided Isolation of Fungistatic Compounds from Mimosa caesalpiniifolia Leaves

A bioassay-guided phytochemical study of a Mimosa caesalpiniifolia leaf extract with antifungal activity permitted the identification of 28 compounds, including the new 6-(β-boivinopyranosyl)apigenin (1), 8-(β-oliopyranosyl)apigenin (2), (E)-6-(2-carboxyethenyl)apigenin (3), (E)-8-(2-carboxyethenyl)apigenin (4), and 7,5″-anhydro-6-(α-2,6-dideoxy-5-hydroxyarabinohexopyranosyl)apigenin (5). The structures of the new compounds were determined by comprehensive spectroscopic analysis, including 1D and 2D NMR techniques, and by mass spectrometry. Compound 3 showed promising activity and selectivity against Candida krusei (IC₅₀ 44 nM), which exhibits resistance to azoles. The association of the major components 3-β-d-glucopyranosyloxysitosterol (8) and ethyl gallate (10) was synergistic against C. krusei, especially the IC values of compound 10, which were reduced by more than 100-fold.

The medicinal uses, toxicities and anti-inflammatory activity of Polyalthia species (Annonaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Polyalthia is one of the largest and notable genera in Annonaceae family. Polyalthia species have been widely used in folklore medicine for the treatment of rheumatic fever, gastrointestinal ulcer and generalized body pain. Numerous in vitro and in vivo studies on Polyalthia Species have also corroborated the significant anti-inflammatory potential of its extracts and secondary metabolites.

AIM OF THE STUDY

This review is an attempt to assess the anti-inflammatory activity of Polyalthia species by giving critical appraisal and establishing evidences of their traditional uses. Moreover this review will highlight the lead compounds for future drug development that can serve as a potential anti-inflammatory drug with comparative efficacy and minimum side effects.

MATERIALS AND METHODS

An extensive literature review, focusing the anti-inflammatory potential of Polyalthia species was conducted using the following databases:PubMed, ScienceDirect, SpringerLink, Ovid, Scopus and ProQuest, as well as the locally available books, journals and relevant documents. The reference lists of retrieved papers were also searched for additional studies.

RESULTS

The Polyalthia species have shown significant anti-inflammatory activity through various mechanism of action. The most significant anti-inflammatory mechanism includes the inhibition of nuclear factor kappa B (NF-κB), prostaglandins (PGs), pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS). The data suggests that hydroxycleroda-3,13-dien-15,16-olide and 16-oxocleroda-3,13-dien-15-oic acid, quercetin, rutin, spinasterol, α-spinasterol, goniothalamin and (-)-5-hydroxygoniothalamin are the most potent anti-inflammatory compounds from Polyalthia species with comparable IC₅₀ with positive controls.

CONCLUSIONS

Numerous pharmacological studies have supported the use of Polyalthia species against pain, rheumatic fever, haemorrhages and inflammation in traditional medicine. Flavonoids, diterpenoids, sterols and styrylpyrones from genus Polyalthia are the most significant class of compounds with potent anti-inflammatory activity. Secondary metabolites from these classes should be brought into further research to fill the gaps of knowledge in pharmacokinetics, pharmacodynamics, bioavailability, and toxicity in order to convert the pre-clinical results into clinical data for further investigation.

Pogonatherumol, a Novel Highly Oxygenated Norsesquiterpene with Flavone C-Glycosides from Pogonatherum crinitum

A novel highly oxygenated norsesquiterpene, pogonatherumol (1), with two known flavone C-glycosides (2-3), was isolated from Pogonatherum crinitum. The structure of the new compound was illuminated based on its spectroscopic data and X-ray analysis. Compounds 1 and 3 inhibited NO production in the mouse peritoneal macrophage (64.5 ± 7.2% and 61.6 ± 5.8%, respectively, at a concentration of 50 μM). The three compounds were inactive when tested against two human cancer cell lines (IC50 values > 50 μM).

Physicochemical Characterization, Microbiological Quality and Safety, and Pharmacological Potential of Hancornia speciosa Gomes

Hancornia speciosa Gomes is a fruit tree, commonly known as the mangaba tree, which is widespread throughout Brazil. The leaves of this plant are used in traditional medicine for medicinal purposes. Thus, the objective of this study was to perform a physicochemical characterization, identify the lipophilic antioxidants and fatty acids, and determine the microbiological quality and safety of H. speciosa leaves. In addition, the antioxidant, antimutagenic, and inhibitory activities of the ethanolic extract of H. speciosa leaves (EEHS) against enzymes related to neurodegenerative diseases, inflammation, obesity, and diabetes were investigated. Furthermore, this study aimed at assessing the in vivo effects of the EEHS on the glycemia of normoglycemic and diabetic Wistar rats. Physicochemical characterization was performed by colorimetry and gas-liquid chromatography with flame ionization detection (GC-FID). The total number of colonies of aerobic mesophiles, molds, and yeasts was determined. The total coliforms and Escherichia coli were counted using the SimPlates kit, and sulphite-reducing Clostridium spores were quantified using the sulphite-polymyxin-sulfadiazine agar method. Salmonella spp. were detected using the 1-2 Test. The antioxidant activity of the EEHS was measured by its inhibition of 2,2'-azobis(2-amidinopropane) dihydrochloride- (AAPH-) induced oxidative hemolysis of human erythrocytes. The antimutagenic activity was determined using the Ames test. The acetylcholinesterase, butyrylcholinesterase, tyrosinase, hyaluronidase, lipase, α-amylase, and α-glycosidase enzyme-inhibiting activities were assessed and compared with commercial controls. The in vivo effects of the EEHS were assessed using the oral glucose tolerance test in normoglycemic Wistar rats and measuring the blood glucose levels in diabetic rats. The results demonstrated physical-chemical parameters of microbiological quality and safety in the leaves of H. speciosa, as well as antioxidant and antimutagenic activities and inhibition of enzymes related to neurodegenerative diseases, inflammation, obesity, and diabetes. In in vivo assays, it was shown that the normoglycemic rats challenged with glucose overload show significantly decreased blood glucose levels when treated with the EEHS. Taken together, the results ensure the microbiological quality and safety as well as showing the contents of carotenoids and polyunsaturated fatty acids of H. speciosa leaves. Additionally, the antioxidant, antimutagenic, anti-inflammatory, anti-Alzheimer's disease, anti-Parkinson's disease, antiobesity, and antihyperglycemic activities of the EEHS were demonstrated.

Naringin and Rutin Alleviates Episodic Memory Deficits in Two Differentially Challenged Object Recognition Tasks

Background:

Cognitive decline or dementia is a debilitating problem of neurological disorders such as Alzheimer's and Parkinson's disease, including special conditions like chemobrain. Dietary flavonoids proved to be efficacious in delaying the incidence of neurodegenerative diseases. Two such flavonoids, naringin (NAR) and rutin (RUT) were reported to have neuroprotective potential with beneficial effects on spatial and emotional memories in particular. However, the efficacy of these flavonoids is poorly understood on episodic memory, which comprises an important form of autobiographical memory.

Objective:

This study objective is to evaluate NAR and RUT to reverse time-delay-induced long-term and scopolamine-induced short-term episodic memory deficits in Wistar rats.

Materials and Methods:

We have evaluated both short-term and long-term episodic memory forms using novel object recognition task. Open field paradigm was used to assess locomotor activity for any confounding influence on memory assessment. Donepezil was used as positive control and was effective in both models at 1 mg/kg, i.p.

Results:

Animals treated with NAR and RUT at 50 and 100 mg/kg, p.o. spent significantly more time exploring novel object compared to familiar one, whereas control animals spent almost equal time with both objects in choice trial. NAR and RUT dose-dependently increased recognition and discriminative indices in time-induced long-term as well as scopolamine-induced short-term episodic memory deficit models without interfering with the locomotor activity.

Conclusion:

We conclude that, NAR and RUT averted both short- and long-term episodic memory deficits in Wistar rats, which may be potential interventions for neurodegenerative diseases as well as chemobrain condition.

SUMMARY

Incidence of Alzheimer's disease is increasing globally and the current therapy is only symptomatic. Curative treatment is a major lacuna. NAR and RUT are natural flavonoids proven for their pleiotropic pharmacological effects with potential neuroprotective benefits. The study evaluated these flavonoids for their potential to improve the most common form of episodic memory (memory of autobiographical events in relation to time, places etc.) in two differential animal models assessing short-term and long-term memory, respectively. We also found that NAR and RUT were able to reverse both short-term and long-term memory deficits dose dependently in female Wistar rats.

Abbreviations used: AD: Alzheimer's disease, AChE: Acetylcholinesterase, COX: Cyclooxygenase, DI: Discriminative index, ITI: Inter trial interval, NAR: Naringin, RUT: Rutin, NORT: Novel object recognition task, NOS: Nitric oxide synthase, QOL: Quality of life, RI: Recognition index, WFI: Water for injection

New Anti-HBV C-Boivinopyranosyl Flavones from Alternanthera philoxeroides

C-boivinopyranosyl flavones have rarely been isolated from nature. In the search for anti-HBV (hepatitis b virus) constituents of Alternanthera philoxeroides, two new compounds, luteolin-6-C-β-d-boivinopyranosyl-3′-O-β-d-glucopyranoside (1) and chrysoeriol-6-C-β-d-boivinopyranosyl-4′-O-β-d-glucopyranoside (2), along with three known C-boivinopyranosyl flavones (compounds 3–5) were isolated. Their structures were determined by spectroscopic analyses including 1D and 2D NMR, HR-ESI-MS, IR spectra. Compounds 1, 2 and 3 showed significant anti-HBV activities through specifically inhibiting the secretion of HBsAg in HepG2.2.15.

Modulation of nitric oxide by flavonoids

One of the main mechanisms by which dietary flavonoids are thought to influence cardiovascular disease is via protection of the bioactivity of the endothelium-derived nitric oxide (NO). Additionally, flavonoids may also interfere with the signalling cascades of inflammation and prevent overproduction of NO and its deleterious consequences in shock and ischemia-reperfusion injury. In the present paper we review the evidence of the effects of flavonoids on NO. Flavonoids exert complex actions on the synthesis and bioavailability of NO which may result both in enhanced or decreased NO levels: (1) in cell free systems, several flavonoids may scavenge NO via its pro-oxidant properties by increasing superoxide. However, under conditions of oxidative stress, flavonoids may also protect NO from superoxide-driven inactivation. (2) In intact healthy tissues, some flavonoids increase eNOS activity in endothelial cells. Paradoxically this effect involves a pro-oxidant effect which results in Ca(2+)-dependent activation of eNOS. As inhibitors of PI3K, flavonoids may potentially inhibit the PI3K/Akt-dependent activation of eNOS. (3) Under conditions of inflammation and oxidative stress, flavonoids may prevent the inflammatory signalling cascades via inhibition of NFκB and thereby downregulate iNOS. On the other hand, they also prevent the overexpression of ROS generating enzymes, reducing superoxide and peroxynitrite levels, and hence preventing superoxide-induced NO inactivation and eNOS uncoupling. Therefore, the final effect of flavonoids on NO levels will depend on the flavonoid structure and the concentrations used, on the cell type under study and particularly on the presence of inflammatory/oxidative conditions.

Biological evaluation of secondary metabolites from the roots of Myrica adenophora

Bioassay-guided fractionation of the roots of Myrica adenophora led to isolation of 24 known compounds and hitherto unknown compounds, including three A-type proanthocyanidins [adenodimerins A-C], two esters of sucrose [myricadenins A and B ], and the phenolic glycoside 6'-O-galloyl orbicularin. Spectroscopic analyses were used to determine their structures. Adenodimerin A, myricananin C, and myricetin showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities, with SC50 values of 7.9, 16.3, and 15.9 μM, respectively. Adenodimerin A, myricanone, myricananin C, (-)-myricanol, myricanol 11-O-β-D-glucopyranoside, and myricetin showed stronger 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities than the positive control, with SC50 values of 7.5, 19.6, 12.0, 22.3, 19.6, and 15.6 μM, respectively. 5-Deoxymyricanone, porson, 12-hydroxymyricanone (-)-myricanol, and (+)-galeon exhibited anti-tubercular activity against Mycobacterium tuberculosis H37Rv in vitro and MICs values of 25.8, 40.0, 35.8, 30.0, and 15.0 μg/mL, respectively. Myricadenin A, myricanone, myricananin C, and (-)-myricanol exhibited anti-inflammatory activities in the iNOS assay with EC50 values of 18.1, 1.00, 13.0, and 7.5 μM, respectively.

Oral administration of the flavonoid myricitrin prevents dextran sulfate sodium-induced experimental colitis in mice through modulation of PI3K/Akt signaling pathway

SCOPE

We investigated the protective effect of the flavonoid myricitrin in dextran sulfate sodium (DSS) induced colitis as promising candidate for the treatment of ulcerative colitis which is considered an important worldwide public health problem.

METHODS AND RESULTS

Male CD1 mice were provided with a solution of filtered water containing 3% w/v DSS ad libitum over a 5-day period followed by 2 days with normal drinking water. Myricitrin was administered orally, once a day, at the doses 1, 3, and 10 mg/kg of body weight. At the end of day 7th, the animals were euthanized and the colonic tissue was collected to be analyzed by RT-PCR, immunohistochemistry and Western blot. Our results showed that oral treatment with myricitrin exerts consistent anti-inflammatory action in DSS-induced acute colitis in mice by the inhibition of the Akt/phosphatidylinositol-3 kinase-dependent phosphorylation. Consequently, the phosphorylation of mitogen-activated protein kinases (MAPK) p38, extracellular signal-regulated protein kinase (ERK1/2), and c-Jun N-terminal kinase and of the nuclear factor B (NF-κB) was reduced and prevented an increase in the cytokines/chemokines levels.

CONCLUSION

Together, these data reveal that the anti-inflammatory effect of myricitrin in DSS-induced colitis in mice is likely associated with its ability to prevent the activation of upstream kinases, such as phosphatidylinositol-3 kinase-dependent Akt, NF-κB, and mitogen-activated protein kinase.

Anti-inflammatory components from the root of Solanum erianthum

Two new norsesquiterpenoids, solanerianones A and B (1-2), together with nine known compounds, including four sesquiterpenoids, (-)-solavetivone (3), (+)-anhydro-β-rotunol (4), solafuranone (5), lycifuranone A (6); one alkaloid, N-trans-feruloyltyramine (7); one fatty acid, palmitic acid (8); one phenylalkanoid, acetovanillone (9), and two steroids, β-sitosterol (10) and stigmasterol (11) were isolated from the n-hexane-soluble part of the roots of Solanum erianthum. Their structures were elucidated on the basis of physical and spectroscopic data analyses. The anti-inflammatory activity of these isolates was monitored by nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW264.7 cells. The cytotoxicity towards human lung squamous carcinoma (CH27), human hepatocellular carcinoma (Hep 3B), human oral squamous carcinoma (HSC-3) and human melanoma (M21) cell lines was also screened by using an MTT assay. Of the compounds tested, 3 exhibited the strongest NO inhibition with the average maximum inhibition (Emax) at 100 μM and median inhibitory concentration (IC50) values of 98.23% ± 0.08% and 65.54 ± 0.18 μM, respectively. None of compounds (1-9) was found to possess cytotoxic activity against human cancer cell lines at concentrations up to 30 μM.

Naturally derived anti-inflammatory compounds from Chinese medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE

Though inflammatory response is beneficial to body damage repair, if it is out of control, it can produce adverse effects on the body. Although purely western anti-inflammatory drugs, orthodox medicines, can control inflammation occurrence and development, it is not enough. The clinical efficacy of anti-inflammation therapies is unsatisfactory, thus the search for new anti-inflammation continues. Chinese Material Medica (CMM) remains a promising source of new therapeutic agents. CMM and herbal formulae from Traditional Chinese Medicine (TCM), unorthodox medicines, play an improtant anti-inflammatory role in multi-targets, multi-levels, and multi-ways in treating inflammation diseases in a long history in China, based on their multi-active ingredient characteristics. Due to these reasons, recently, CMM has been commercialized as an anti-inflammation agent which has become increasingly popular in the world health drug markets. Major research contributions in ethnopharmacology have generated vast amount of data associated with CMM in anti-inflammtion aspect. Therefore, a systematic introduction of CMM anti-inflammatory research progress is of great importance and necessity.

AIM OF THE STUDY

This paper strives to describe the progress of CMM in the treatment of inflammatory diseases from different aspects, and provide the essential theoretical support and scientific evidence for the further development and utilization of CMM resources as a potential anti-inflammation drug through a variety of databases.

MATERIAL AND METHODS

Literature survey was performed via electronic search (SciFinder®, Pubmed®, Google Scholar and Web of Science) on papers and patents and by systematic research in ethnopharmacological literature at various university libraries.

RESULTS

This review mainly introduced the current research on the anti-inflammatory active ingredient, anti-inflammatory effects of CMM, their mechanism, anti-inflammatory drug development of CMM, and toxicological information.

CONCLUSION

CMM is used clinically to treat inflammation symptoms in TCM, and its effect is mediated by multiple targets through multiple active ingredients. Although scholars around the world have made studies on the anti-inflammatory studies of CMM from different pathways and aspects and have made substantial progress, further studies are warranted to delineate the inflammation actions in more cogency models, establish the toxicological profiles and quality standards, assess the potentials of CMM in clinical applications, and make more convenient preparations easy to administrate for patients. Development of the clinically anti-inflammatory drugs are also warranted.

Isolation and characterization of sesquiterpenes from Arecophila saccharicola YMJ96022401 with NO production inhibitory activity

Sesquiterpenes, arecoic acids A-F and arecolactone, were isolated from the ethyl acetate extracts of the fermented broth of Arecophila saccharicola YMJ96022401 along with two known analogues 1,7α,10α-trihydroxyeremophil-11(13)-en-12,8-olide and 1,10α,13-trihydroxyeremophil-7(11)-en-12,8-olide. Their structures were elucidated on the basis of spectroscopic data analyses. The inhibitory effects of all of these compounds on nitric oxide (NO) production in lipopolysaccharide (LPS, 200 μg/mL)-activated murine macrophage RAW264.7 cells were also evaluated. Among these compounds, 1,7α,10α-trihydroxyeremophil-11(13)-en-12,8-olide significantly inhibited NO production without any cytotoxicity, and its average maximum inhibition (E(max)) at 100 μM and median inhibitory concentration (IC₅₀) were 85.7%±0.8% and 16.5±1.0 μM, respectively. Arecolactone was the most potent, with the E(max) at 12.5 μM and IC₅₀ being 94.7%±0.8% and 1.32±0.1 μM, respectively, but displayed cytotoxicity at considerable higher concentrations than 25 μM. Analyses of Western blotting indicated that arecolactone (0.8-12.5 μM) inhibited induction of inducible NO synthase (iNOS) by LPS, which involved suppression of NF-κB activation and the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun NH₂-terminal kinase (JNK) and p38 mitogen-activated protein kinases (MAPKs) in activated RAW 264.7 cells. In addition, arecolactone concentration-dependently prevented the vascular hyporeactivity to phenylephrine induced by LPS (300 ng/mL) through iNOS pathway in isolated rat thoracic aortic rings. These results indicated that both of these naturally occurring iNOS inhibitors may provide a rationale for the potential anti-inflammatory effect of A. saccharicola YMJ96022401.

Intestinal anti-inflammatory activity of red wine extract: unveiling the mechanisms in colonic epithelial cells

The development of new therapeutic approaches, combining efficacy and safety against intestinal inflammation, notably inflammatory bowel disease (IBD), has emerged as an important goal due to the significant side effects and the lack of effectiveness of standard current therapies. Recently, several studies described the health-promoting effects of red wine, including anti-inflammatory properties, but the molecular mechanisms underlying its beneficial role remain largely unknown. Red wine is rich in phenolic compounds and it has been suggested that the positive effect of red wine intake might be attributed not only to the antioxidant properties of these compounds but also to the modulation of signalling cascades in connection with physiological and pathophysiological conditions such as inflammatory processes. This study assesses the potential anti-inflammatory action of a red wine extract (RWE) enriched in polyphenols in a cellular model of intestinal inflammation using cytokines-stimulated HT-29 colon epithelial cells. RWE suppressed cytokines-induced IκB degradation and interleukin-8 production in a dose-dependent manner. Coherently, key inflammatory mediators downstream NF-κB activation; notably cyclooxygenase-2 and inducible nitric oxide synthase were maintained at low levels by RWE in the presence of the cytokines. Additionally, RWE inhibited both the increase of nitric oxide derived from iNOS and of protein tyrosine nitration, a biomarker of nitrosative stress that typically requires the reaction of nitric oxide with the superoxide radical. Taken together, the anti-inflammatory action of RWE, mechanistically supported by the modulation of cascades orchestrated by NF-κB and involving nitric oxide, suggests that RWE (a readily straightforward preparation when compared with the purification of specific compounds) may represent a simple and inexpensive therapeutic strategy in the context of intestinal inflammation.

Facilitated cellular uptake and suppression of inducible nitric oxide synthase by a metabolite of maritime pine bark extract (Pycnogenol)

Many natural products exhibit anti-inflammatory activity by suppressing excessive nitric oxide (NO) production by inducible NO synthase (iNOS). The maritime pine bark extract Pycnogenol has been formerly shown to decrease nitrite generation, taken as an index for NO, but so far it was not clear which constituent of the complex flavonoid mixture mediated this effect. The purpose of this study was to elucidate whether the in vivo generated Pycnogenol metabolite M1 (δ-(3,4-dihydroxyphenyl)-γ-valerolactone) displayed any activity in the context of induction of iNOS expression and excessive NO production. For the first time we show that M1 inhibited nitrite production (IC(50) 1.3 μg/ml, 95% CI 0.96-1.70) and iNOS expression (IC(50) 3.8 μg/ml, 95% CI 0.99-14.35) in a concentration-dependent fashion. This exemplifies bioactivation by metabolism because the M1 precursor molecule catechin is only weakly active. However, these effects required application of M1 in the low-micromolar range, which was not consistent with concentrations previously detected in human plasma samples after ingestion of maritime pine bark extract. Thus, we investigated a possible accumulation of M1 in cells and indeed observed high-capacity binding of this flavonoid metabolite to macrophages, monocytes, and endothelial cells. This binding was distinctly decreased in the presence of the influx inhibitor phloretin, suggesting the contribution of a facilitated M1 transport into cells. In fact, intracellular accumulation of M1 could explain why in vivo bioactivity can be observed with nanomolar plasma concentrations that typically fail to exhibit measurable activity in vitro.

Secondary metabolites from the roots of Neolitsea daibuensis and their anti-inflammatory activity

Bioassay-guided fractionation of the roots of Neolitsea daibuensis afforded three new β-carboline alkaloids, daibucarbolines A-C (1-3), three new sesquiterpenoids, daibulactones A and B (4 and 5) and daibuoxide (6), and 20 known compounds. The structures of 1-6 were determined by spectroscopic analysis and single-crystal X-ray diffraction. Daibucarboline A (1), isolinderalactone (7), 7-O-methylnaringenin (8), and prunetin (9) exhibited moderate iNOS inhibitory activity, with IC₅₀ values of 18.41, 0.30, 19.55, and 10.50 μM, respectively.

Anti-inflammatory endiandric acid analogues from the roots of Beilschmiedia tsangii

Bioassay-guided fractionation of roots of Beilschmiedia tsangii led to the isolation of six new endiandric acid analogues: tsangibeilin A (1), tsangibeilin B (2), endiandramide A (3), endiandric acid K (4), endiandric acid L (5), and endiandramide B (6). Also isolated were two new lignans, beilschminol A (7) and tsangin C (8), and six known compounds. The structures of 1-8 were determined by spectroscopic techniques. Compounds 3 and 6 exhibited potent iNOS inhibitory activity, with IC(50) values of 9.59 and 16.40 μM, respectively.

Sesquiterpene glycosides from Cosmospora joca

Five novel sesquiterpene glycosides, namely, cosmosporasides A-E (1-5), were isolated from the ethyl acetate extract of the fermented broth of Cosmospora joca. The structures of 1-5 were elucidated on the basis of spectroscopic data analyses, monosaccharide composition analyses, and monosaccharide chirality analyses. The relative configuration of the sesquiterpene moiety of 3-5 was determined by J-based configuration analyses and supported by NOESY assignments. The inhibitory effects of 1-5 on the nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW264.7 cells were evaluated; all except 3 inhibited NO production at 100 μM. 4 was the most potent, with an average maximum inhibition and a median inhibitory concentration value of 71.70 ± 1.23% and 65.98 ± 0.53 μM, respectively.

Characterization, anti-oxidative and anti-inflammatory effects of Costa Rican noni juice (Morinda citrifolia L.)

AIM OF THE STUDY

Noni fruit (Morinda citrifolia L.) juice has been used for more than 2000 years in Polynesia as a traditional folk medicine. The aim of the present study was to finely characterize noni juice from Costa Rica and to evaluate its anti-oxidative and anti-inflammatory activities.

MATERIALS AND METHODS

A microfiltrated noni juice was prepared with Costarican nonis. HPLC-DAD and Electro Spray Ionization Mass Spectrometric detection (HPLC-ESI-MS) were used to identify phenolic compounds and iridoids. The anti-oxidative activity of noni juice was measured in vitro by both Oxygen Radical Absorbance Capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging methods. The anti-inflammatory effects of noni juice were investigated in vitro by: measuring its effect on nitric oxide and prostaglandin E2 production by activated macrophages, evaluating its inhibitory activities on cyclooxygenase (COX)-1 and -2 and in vivo on a carrageenan-induced paw oedema model in rats.

RESULTS

Several polyphenols belonging to the coumarin, flavonoid and phenolic acid groups, and two iridoids were identified. Noni juice demonstrated a mean range free radical scavenging capacity. Furthermore, it also reduced carrageenan-induced paw oedema, directly inhibited cyclooxygenase COX-1 and COX-2 activities and inhibited the production of nitric oxide (NO) and prostaglandins E(2) (PGE(2)) in activated J774 cells, in a dose dependent manner.

CONCLUSIONS

This study showed that noni's biological effects include: (1) anti-oxidant properties probably associated with phenolic compounds, iridoids and ascorbic acid and (2) anti-inflammatory action through NO and PGE(2) pathways that might also be strengthened by anti-oxidant effects.

Synthesis and structure-activity relationships of fenbufen amide analogs

The previous discoveries of butyl fenbufen amide analogs with antitumor effects were further examined. The amide analogs with 1, 3, 4 and 8 carbons chains were prepared in 70–80% yield. Fenbufen had no cytotoxic effects at concentrations ranging from 10 to 100 μM. Methyl fenbufen amide had significant cytotoxic effects at a concentration of 100 μM. As the length of the alkyl amide side chain increased, the cytotoxic effects increased, and the octyl fenbufen amide had the greatest cytotoxic effect. After treatment with 30 μM octyl fenbufen amide, nearly seventy percent of the cells lost their viability. At the concentration of 10 μM, fenbufen amide analogs did not show cytotoxicity according to the MTT assay results. The NO scavenging activities of the fenbufen amide analogs were not significantly different from those of fenbufen.

Pancreatic lipase inhibition by C-glycosidic flavones Isolated from Eremochloa ophiuroides

Activity-guided fractionation of a methanolic extract of the leaves of Eremochloa ophiuroides (centipede grass) using a pancreatic lipase inhibitory assay led to the isolation and identification of a new C-glycosidic flavone, luteolin 6-C-β-D-boivinopyranoside (1), as well as eight known compounds. The structures of these compounds were established on the basis of interpretation of their spectroscopic data. Among these isolates, the C-glycosidic flavones 1–5 showed potent inhibitory effects on pancreatic lipase, with IC₅₀ values ranging from 18.5 ± 2.6 to 50.5 ± 3.9 μM.

Antioxidant flavone glycosides from the leaves of Fargesia robusta

The aqueous methanolic leaf extract of Fargesia robusta var. Pingwu was evaluated in vitro for its antioxidant capacity using the TEAC and ORAC assays. C-Glycosyl flavones, farobin A (1) and farobin B (2), together with three known compounds, tricin-5-O-glucopyranoside (3), 2''-O-α-rhamnosyl-6-C-(6-deoxy-ribo-hexos-3-ulosyl)luteolin (4), and luteolin-6-C-glucopyranoside (homoorientin) (5), were isolated from the hydroalcoholic extract of the leaves of F. robusta. The structures of the compounds were determined by spectroscopic analyses including UV, 1D and 2D NMR, and MS. Compounds 1, 4, and 5 exhibited potent antioxidant activity in the TEAC assay, while compounds 1, 3, and 5 showed the highest antioxidant capacity in the ORAC assay.

The effects of rutin on the development of pentylenetetrazole kindling and memory retrieval in rats

Individuals with epilepsy often complain about memory deficits. Various synthetic derivatives of natural flavonoids are known to have neuroactive properties. Rutin is a flavonoid that is an important dietary constituent of foods and plant-based beverages. The aim of the present study was to investigate the effects of rutin on memory retrieval in pentylenetetrazole (PTZ)-kindled rats using a step-through passive avoidance task. We administered rutin and PTZ intraperitoneally every other day prior to the start of training. Two retention tests were subsequently performed to assess memory in these rats. The results suggest that pretreatment with rutin at 50 and 100mg/kg can attenuate seizure severity during the kindling procedure. Furthermore, rutin administration significantly increased the step-through latency in the passive avoidance paradigm. Taken together, these results indicate that rutin has a potential role in enhancing memory retrieval in kindled rats.

Gastroprotective effect of rutin against indomethacin-induced ulcers in rats

Several reports have indicated that indomethacin-induced gastropathy is mediated through generation of free radicals, neutrophil infiltration and disturbance in nitric oxide production. Rutin is a potent antioxidant flavonoid. Recently, rutin was reported to inhibit neutrophil infiltration and to modulate nitric oxide production in gastric mucosa. Therefore, the aim of this study was to investigate the protective effect of rutin against indomethacin-induced gastric injury. Accordingly, four groups of rats were used. The first three groups were injected orally with vehicle, rutin (200 mg/kg) and indomethacin (48 mg/kg) respectively. The fourth group was injected with rutin 1 hr before indomethacin. Animals were killed after 6 hr of indomethacin administration. Gastric juice acidity and gastric injury were evaluated directly. Moreover, the activities of myeloperoxidase, superoxide dismutase and the contents of reduced glutathione, thiobarbituric acid reactive substance and total nitrite/nitrate (as a marker of nitric oxide production) were determined in mucosal tissues. Indomethacin increased gastric ulcer index, gastric myeloperoxidase activity, gastric acidity and thiobarbituric acid reactive substance contents compared with control. On the other hand, indomethacin decreased glutathione, nitrite/nitrate contents and superoxide dismutase activity. Histopathological examination of the stomachs of indomethacin-treated rats revealed degenerative changes in gastric tissues. Pre-treatment with rutin protected gastric tissues against indomethacin-induced gastropathy as demonstrated from reduction in the ulcer index, attenuation of histopathological changes and amelioration of the altered oxidative stress and biochemical parameters. These results indicate that rutin has a protective effect against indomethacin-induced gastropathy probably through inhibiting neutrophil infiltration, suppression of oxidative stress generation and replenishing nitrite/nitrate levels regardless of gastric acidity.

Synthesis of a novel series of diphenolic chromone derivatives as inhibitors of NO production in LPS-activated RAW264.7 macrophages

A novel series of diphenolic chromone derivatives were synthesized and their inhibitory activity on nitric oxide (NO) production and cytotoxicity were evaluated using LPS-activated murine macrophages RAW264.7 assay and MTT method, respectively. Among these compounds, (5,7-dihydroxy-4-oxo-4H-chromen-3-yl) methyl esters (6b, 6c, 6f, 6g, and 6h) showed quite potent inhibitory activities with IC(50) values of 2.20, 3.48, 0.35, 0.80, and 0.61microM, respectively. The MTT results showed that all of the active compounds exhibited no cytotoxicity at the effective concentrations. The preliminary mechanism of the most potent compounds (6b, 6c, 6f, 6g, and 6h) was further examined based on the RT-PCR results and the compounds 6f, 6g, and 6h inhibited NO production by suppressing the expression of iNOS mRNA in a dose dependent manner. Furthermore, a computational analysis of physicochemical parameters revealed that the most of the compounds possessed drug-like properties.

The effects of rutin on a passive avoidance test in rats

Various synthetic derivatives of natural flavonoids are known to have neuroactive properties. The aim of the present study was to investigate the effects of rutin (3, 3', 4', 5, 7-pentahydroxyflavone-3-rhamnoglucoside), a flavonoid that is an important dietary constituent of foods and plant-based beverages, on memory retrieval in rats. To this end, we assessed the effect of rutin on memory retrieval using a step-through passive avoidance task. Rutin (5, 10, and 100mg/kg) was administered intraperitoneally (i.p.) one week before the start of training. Three retention tests were performed to assess memory in rats. Rutin (10mg/kg) significantly increased the step-through latency of the passive avoidance response compared to the control in the three retention tests of the passive avoidance paradigm. These results indicate that rutin has a potential role in enhancing memory retrieval. Several mechanisms may contribute to the potential role of rutin in memory enhancement. This result supports the potential beneficial effects of rutin as a dietary supplement on memory retrieval in a passive avoidance task.