Anti-inflammatory effects of 4-methylcyclopentadecanone on edema models in mice

Spiro-fused indoline-quinazoline hybrids as smart bombs against TNF-α-mediated inflammation

Inflammation is central to numerous diseases, highlighting the need for new anti-inflammatory agents. This study explores the potential of novel spirofused indoline-quinazoline hybrids (4a-p) as anti-inflammatory compounds, inspired by a spiroisatin analogue (VI) that showed modest TNF-α inhibition. We aimed to enhance activity by modifying the isatin scaffold: first, introducing N-alkylation (propyl, butyl, or isobutyl) to improve hydrophobic interactions within the TNF-α dimer active site; second, adding halogens (F, Cl, Br) at the 5-position to increase lipophilicity. Anti-inflammatory activity against TNF-α was confirmed in-vivo for all synthesized analogues, with 4b, 4e, 4k, and 4n emerging as the top candidates. Further studies on these four compounds assessed their analgesic effects, as well as their impact on PGE2, NF-κB, paw thickness, and paw weight. In-vitro analyses revealed nanomolar TNFR2-TNF-α binding inhibition for the four leads. Safety evaluations included histopathology, ulcerogenic potential, kidney and liver functions, and acute hemotoxicity. In-silico studies examined drug-likeness, pharmacokinetics, and TNF-α dimer interactions. These results suggest that the four lead compounds possess promising profiles compared to standard therapies.

Anti-Inflammatory, Wound Healing, and Anti-Diabetic Effects of Pure Active Compounds Present in the Ryudai Gold Variety of Curcuma longa

Turmeric (Curcuma longa) contains curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC). Nevertheless, curcumin is the most researched active ingredient for its numerous pharmacological effects. We investigated the impact of these curcuminoids found in Ryudai gold, an approved cultivar of Curcuma longa, on wound healing, inflammation, and diabetes. Sub-planter injections of carrageenan induced acute paw inflammation in rats. The wound-healing ability of 1% curcuminoids was examined by making a 6 mm round wound on the shaved dorsum of the mice with a biopsy punch. A single intraperitoneal injection of streptozotocin (50 mg/kg) was used to induce diabetes in mice. Curcuminoids at a dose rate of 100 mg/kg body weight were used with feed and as a gastric gavage to treat diabetes and inflammation in experimental animals. Paw thickness was measured at 1, 3, and 6 h following carrageenan injection. After three hours, mean paw volume was 58% in carrageenan-injected mice, which was 35%, 37%, and 31% in the curcumin, DMC, and BDMC groups, respectively. Histopathology of the paw tissue demonstrated severe infiltration of inflammatory cells and thickening of the dermis, which were remarkably improved by the curcuminoids. The wound-healing abilities were significantly higher in the curcumin- (95.0%), DMC- (93.17%), and BDMC-treated (89.0%) groups, in comparison to that of the control (65.09%) group at day nine. There were no significant differences in wound-healing activity among the groups treated with 1% curcuminoids throughout the study. Streptozotocin-induced diabetes was characterized by an increased blood glucose (552.2 mg/dL) and decreased body weight (31.2 g), compared to that of the control rats (145.6 mg/dL and 46.8 g blood glucose and body weight, respectively). It also caused an increase in serum alanine aminotransferase (ALT; 44.2 U/L) and aspartate aminotransferase (AST; 55.8 U/L) compared to that of the control group (18.6 U/L and 20.1 U/L, respectively). Histopathological examination of the liver showed that diabetes caused hepatic cellular necrosis, congestion of the central vein, and parenchymatous degeneration. However, all three curcuminoids significantly decreased blood glucose levels, ALT, and AST and improved the histopathological score of the liver. These results evidenced that not only curcumin but also DMC and BDMC have potent anti-inflammatory, wound healing, and anti-diabetic efficacy, and the Ryudai gold variety of turmeric could be used as a functional food supplement.

Fenamates and ibuprofen as foundational components in the synthesis of innovative, targeted COX-2 anti-inflammatory drugs, undergoing thorough biopharmacological assessments and in-silico computational studies

Cyclooxygenase-2 plays a vital role in inflammation by catalyzing arachidonic acid conversion toward prostaglandins, making it a prime therapeutic objective. Selective COX-2 inhibitors represent significant progress in anti-inflammatory therapy, offering improved efficacy and fewer side effects. This study describes the synthesis of novel anti-inflammatory compounds from established pharmaceutically marketed agents like fenamates III-V and ibuprofen VI. Through rigorous in vitro testing, compounds 7b-c, and 12a-b demonstrated substantial in vitro selective inhibition, with IC50 values of 0.07 to 0.09 μM, indicating potent pharmacological activity. In vivo assessment, particularly focusing on compound 7c, revealed significant anti-inflammatory effects. Markedly, it demonstrated the highest inhibition of paw thickness (58.62 %) at the 5-hr mark compared to the carrageenan group, indicating its potency in mitigating inflammation. Furthermore, it exhibited a rapid onset of action, with a 54.88 % inhibition observed at the 1-hr mark. Subsequent comprehensive evaluations encompassing analgesic efficacy, histological characteristics, and toxicological properties indicated that compound 7c did not induce gastric ulcers, in contrast to the ulcerogenic tendency associated with mefenamic acid. Moreover, compound 7c underwent additional investigations through in silico methodologies such as molecular modelling, field alignment, and density functional theory. These analyses underscored the therapeutic potential and safety profile of this novel compound, warranting further exploration and development in the realm of pharmaceutical research.

Alcoholic extracts of Teucrium polium exhibit remarkable anti-inflammatory activity: In vivo study

Teucrium polium (germander, Lamiaceae) is a local plant in Qatar that has been used in folk medicine to treat numerous illnesses. It is known for its antioxidant, analgesic, anticancer, and antibacterial activities. This study aimed to evaluate the anti-inflammatory activity of Teucrium polium (TP) extract by α-carrageen-induced paw edema in adult Sprague Dawley rats. The animals were randomly grouped into control, acute inflammation, and plant extract groups. Acute inflammation was induced by a sub-plantar injection of 100 µL of 1% α-carrageenan into the rat's right hind paw. Three different doses of the ethanolic extract of TP were tested at different time periods (1, 3, and 5 hours). All doses of the TP ethanolic extract showed significant inhibition of α-carrageenan-induced rat paw edema in a dose-dependent manner in both early and late phases of edema formation. The size of the α-carrageen induced paw edema was significantly reduced one, three, and five hours after TP extract injection compared to the acute inflammation group. This inhibition was accompanied by high expression of interleukin 10 (IL-10) and low expression of monocyte chemoattractant protein 1 (MCP-1), IL-1β and tumor necrosis factor alpha (TNF-α). The results indicated that the ethanolic extracts of TP possess significant anti-inflammatory and potential pharmaceutical properties.

Targeted Nanocarriers for Systemic Delivery of IRAK4 Inhibitors to Inflamed Tissues

Persistent and uncontrolled inflammation is the root cause of various debilitating diseases. Given that interleukin-1 receptor-associated kinase 4 (IRAK4) is a critical modulator of inflammation, inhibition of its activity with selective drug molecules (IRAK4 inhibitors) represents a promising therapeutic strategy for inflammatory disorders. To exploit the full potential of this treatment approach, drug carriers for efficient delivery of IRAK4 inhibitors to inflamed tissues are essential. Herein, the first nanoparticle-based platform for the targeted systemic delivery of a clinically tested IRAK4 inhibitor, PF-06650833, with limited aqueous solubility (57 µg mL-1 ) is presented. The developed nanocarriers increase the intrinsic aqueous dispersibility of this IRAK4 inhibitor by 40 times. A targeting peptide on the surface of nanocarriers significantly enhances their accumulation after intravenous injection in inflamed tissues of mice with induced paw edema and ulcerative colitis when compared to non-targeted counterparts. The delivered IRAK4 inhibitor markedly abates inflammation and dramatically suppresses paw edema, mitigates colitis symptoms, and reduces proinflammatory cytokine levels in the affected tissues. Importantly, repeated injections of IRAK4 inhibitor-loaded nanocarriers have no acute toxic effect on major organs of mice. Therefore, the developed nanocarriers have the potential to significantly improve the therapeutic efficacy of IRAK4 inhibitors for different inflammatory diseases.

ASPP 092, a phenolic diarylheptanoid from Curcuma comosa suppresses experimentally-induced inflammatory ear edema in mice

Curcuma comosa Roxb., family Zingiberaceae, exhibits diverse biological activities. This study was aimed to investigate the anti-inflammatory potential of a major phenolic diarylheptanoid isolated from C. comosa, ASPP 092 [(3S)-1-(3,4-dihydroxy-phenyl)-7-phenyl-(6E)-6-hepten-3-ol] in an experimentally-induced inflammatory ear edema model in mice. Ear edema in the mice was induced by the topical application of irritant, ethyl phenylpropiolate (EPP). The topical application of ASPP 092 at the edema site was directed immediately after the EPP application. The edematous responses were assessed at different time points by measuring the thickness of each ear before and after the EPP application followed by histopathology analysis. The expressions of major inflammatory cytokines were analyzed by real-time RT-PCR followed by the immunohistochemistry analysis of cyclooxygenase (COX-2). The topical application of ASPP 092 effectively suppressed the EPP-induced edematous formation in the ear of mice. Histopathological analysis showed substantial improvements in epidermal hyperplasia and inflammatory cell infiltration. ASPP 092 treatment also modulated the expressions of inflammatory cytokines including Tumor Necrosis Factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-1β (IL-1β), and Matrix metalloproteinase-13 (MMP-13). The expressions of cyclooxygenases (COX) including COX-1 and COX-2 were significantly reduced by ASPP 092 treatment. For the first time, our results suggest the efficacy of ASPP 092 to suppress experimentally-induced inflammation in a preclinical model in mice; however, a more detailed evaluation of its mechanism of action is necessary before evaluating its efficacy and safety in randomized trials.

Rotundic acid reduces LPS-induced acute lung injury in vitro and in vivo through regulating TLR4 dimer

Acute lung injury (ALI) is a serious clinical disease. Rotundic acid (RA), a natural ingredient isolated from Ilex rotunda Thunb, exhibits multiple pharmacological activities. However, RA's therapeutic effect and mechanism on ALI remain to be elucidated. The present study aimed to further clarify its regulating effects on inflammation in vitro and in vivo. Our results indicated that RA significantly inhibited the overproduction of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). RA decreased ROS production and calcium influx. In addition, RA inhibited the activation of PI3K, MAPK, and NF-κB pathways and enhanced the activity of nuclear factor E2-related factor 2 (Nrf2) signaling. The cellular thermal shift assay and docking results indicated that RA bind to TLR4 to block TLR4 dimerization. Furthermore, RA pretreatment effectively inhibited ear edema induced by xylene and LPS-induced endotoxin death and had a protective effect on LPS-induced ALI. Our findings collectively indicated that RA has anti-inflammatory effects, which may serve as a potential therapeutic option for pulmonary inflammation.

Molecular Insight into the Anti-Inflammatory Effects of the Curcumin Ester Prodrug Curcumin Diglutaric Acid In Vitro and In Vivo

Curcumin diglutaric acid (CurDG), an ester prodrug of curcumin, has the potential to be developed as an anti-inflammatory agent due to its improved solubility and stability. In this study, the anti-inflammatory effects of CurDG were evaluated. The effects of CurDG on inflammatory mediators were evaluated in LPS-stimulated RAW 264.7 macrophage cells. CurDG reduced the increased levels of NO, IL-6, and TNF- α, as well as iNOS and COX-2 expression in cells to a greater extent than those of curcumin, along with the potent inhibition of MAPK (ERK1/2, JNK, and p38) activity. The anti-inflammatory effects were assessed in vivo by employing a carrageenan-induced mouse paw edema model. Oral administration of CurDG demonstrated significant anti-inflammatory effects in a dose-dependent manner in mice. The effects were significantly higher compared to those of curcumin at the corresponding doses (p < 0.05). Moreover, 25 mg/kg curcumin did not exert a significant anti-inflammatory effect for the overall time course as indicated by the area under the curve data, while the equimolar dose of CurDG produced significant anti-inflammatory effects comparable with 50, 100, and 200 mg/kg curcumin (p < 0.05). Similarly, CurDG significantly reduced the proinflammatory cytokine expression in paw edema tissues compared to curcumin (p < 0.05). These results provide the first experimental evidence for CurDG as a promising anti-inflammatory agent.

Antioxidant and anti-inflammatory properties of Erythroxylum cuneatum alkaloid leaf extract

Erythroxylum cuneatum (E. cuneatum) which belongs to Erythroxylaceae family is a tropical flowering plant from the genus of Erythroxylum. It is used in Malaysia and Thailand's traditional medicines, yet there is limited scientific reports on its medicinal value. This study aimed at exploring the antioxidative and anti-inflammatory properties of E. cuneatum alkaloid leaf extract. The alkaloid extract was obtained through Soxhlet heat extraction method, while the antioxidantive properties were assessed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, ferric reducing antioxidant power (FRAP) and xanthine oxidase inhibition (XOI) assays. Further, anti-inflammatory property of the extract was evaluated on rat's model of carrageenan induced paw model of edema via physical measurements and histology. The extract exhibited antioxidant activity with an EC₅₀ value of 1482 μg/ml in the DPPH radical scavenging assay, an EC₁ value of 2191 μg/ml in the FRAP assay and 10.15 ± 6.20% in the XOI assay. Rats pretreated with the extract have shown dose dependent decrease in paw edema when compared to non-treated group of rats. The highest dose (50 mg/kg) of extract exhibited similar effects to aspirin in terms of reducing paw thickness, leucocytes infiltration and disruption of collagen. In conclusion, the E. cuneatum alkaloid leaf extract possesses both antioxidative and anti-inflammatory properties suggesting its potentials for future development of antioxidant and anti-inflammatory drugs.

Ginsenoside Rb1 exerts anti-inflammatory effects in vitro and in vivo by modulating toll-like receptor 4 dimerization and NF-kB/MAPKs signaling pathways

BACKGOUND

Ginsenoside Rb1, the main active constituent of Panax ginseng, displays significant anti-inflammatory activity, although the mechanism has not been clearly unraveled. In this study, Rb1's mechanism of anti-inflammatory effects were investigated.

METHODS

The flow cytometry and enzyme-linked immunosorbent assay (ELISA) were empolyed to detect pro-inflammatory cytokines release. The related protein and gene expression was investigated by western blotting and qRT-PCR. The dimerization of TLR4 was measured by co-immunoprecipitation and molecular docking assays. Cellular thermal shift assay was used for the determination of the binding of Rb1 and TLR4. For animal moldels, LPS- or cantharidin-induced acute kidney injury, LPS-induced septic death, and dimethyl benzene-induced ear edema were employed to investigate Rb1's anti-inflammatory activity in vivo.

RESULTS

Rb1 significantly decreased inflammatory cytokines release in LPS-stimulated RAW264.7 cells and BMDMs, as well as COX-2 and iNOS amounts. Rb1 reduced LPS-associated calcium influx, ROS production, and NO generation. The NF-κB and MAPK axes participated in Rb1's anti-inflammatory effects. Molecular docking simulation indicated Rb1 bound to TLR4 to prevent TLR4 dimerization, as confirmed by co-immunoprecipitation and cellular thermal shift assay. Furthermore, MyD88 recruitment and TAK1 expression were altered by reduced TLR4 dimerization, indicating the TLR4-MyD88-NF-κB/MAPK pathways contributed to Rb1's anti-inflammatory process. In animal models, Rb1 markedly alleviated LPS- or cantharidin-induced acute kidney injury, rescued LPS-induced septic mice from death, and inhibited dimethyl benzene-induced mouse ear edema.

CONCLUSION

Overall, these findings demonstrate Rb1 exhibits marked anti-inflammatory effects, suggesting Rb1 represents an optimal molecule for treating inflammatory diseases.

Evidence of anti-inflammatory activity of Schizandrin A in animal models of acute inflammation

Schisandrin A (Sch A) is a lignin extracted from the fruit of Schisandra chinensis, which has potential anti-inflammatory properties and is used for treating various inflammatory diseases. In this study, we aimed to evaluate the anti-inflammatory effects of Sch A and the underlying mechanisms in animal models of acute inflammation. First, the anti-inflammatory effects of Sch A were evaluated preliminarily in an animal model of xylene-induced ear edema. Sch A pretreatment significantly decreased the degree of edema and inhibited telangiectasia in the ear. Second, a mouse model of paw edema was used to investigate the anti-inflammatory effects and mechanisms of Sch A. Pretreatment with Sch A significantly inhibited carrageenan-induced paw edema in mice. Hematoxylin-eosin (HE) staining of paw tissues demonstrated that Sch A inhibited the infiltration of inflammatory cells in the mouse model of paw edema. Enzyme-linked immunosorbent assay (ELISA) results indicated that the levels of inflammatory factors decreased. The western blot and immunohistochemical assay results revealed that the toll-like receptor 4/nuclear factor kappa-B (TLR4/NF-κB) pathway could play a role in the anti-inflammatory functions of Sch A. The findings demonstrated that Sch A exerts anti-inflammatory effects and may provide possible strategies for the treatment of inflammatory diseases.

Muscone reduced the hypnotic and analgesic effect of ketamine in mice

BACKGROUND

The aim of this study was to determine the effects of different concentrations of muscone on the ketamine requirement for hypnosis and analgesia and possible mechanism in mice.

METHODS

In the hypnotic response experiment, muscone (0.5, 1.0, 2.0, 4.0, and 8.0 mg/kg) was administered 15 minutes before ketamine by intraperitoneal injection. The hypnotic response was evaluated by loss of righting reflex (LORR). In the analgesia experiment, muscone (0.5, 1.0, 2.0, and 4.0 mg/kg) was administered 15 minutes before 50 mg/kg ketamine injection. Pain threshold was assessed by measuring the tail-flick latency induced by heat radiation. Twenty minutes after ketamine injection, the mRNA expression of N-methyl-D-aspartate receptors (NR) subunits, γ-aminobutyric acid (GABA) receptors subunits, opioid receptors subunits, and some Na and Ca channels were detected by qPCR in the hippocampus of mice.

RESULTS

The 50% effective dose (ED50) with 95% confidence interval of ketamine-induced LORR was 49.2 (43.4-56.4) mg/kg. About 4.0 or 8.0 mg/kg muscone increased ED50 of ketamine-induced hypnosis, which was 82.7 (70.0-98.4) mg/kg or 72.0 (65.4-85.7) mg/kg, respectively. In the analgesic experiment, ketamine alone caused an obvious analgesic effect, whereas different dose of muscone decreased pain threshold in the presence of ketamine; 4.0 mg/kg muscone up-regulated the mRNA expression of NR1 and inhibited ketamine-induced increase of δ-opioid receptor mRNA level. Muscone also inhibited Cav2.1 mRNA expression in the presence of ketamine.

CONCLUSION

Muscone reduced the hypnotic and analgesic effect of ketamine in dose-independent manner in mice, which may be related to the changes of NR1 and δ-opioid receptor.

Antibacterial, anti-inflammatory and peroxidase-mediated cyclooxygenase-1 inhibitory properties of Fusarium solani extract

Context: Nigerian soil fungi population is unexplored. It is hypothesized that they harbour new bioactive chemicals. This hypothesis is based on the large percentage of currently approved medicines that originated from soil-inhabiting micro-organisms Objectives: To investigate the antimicrobial and anti-inflammatory properties of Fusarium solani ethyl acetate (EtOAc) extract selected based on its broad spectrum of antimicrobial potential in an overlay experiment with seven other soil fungi strains. Materials and methods: Fungus number 6 (F6), identified by molecular characterization as Fusarium solani (Mart.) Sacc (Nectriaceae) was selected for studies from eight purified soil fungi due to its superior broad-spectrum antibiotics producing potential following agar overlay experiment. F6 was fermented for 21 d and the minimum inhibitory concentration (MIC) of its EtOAc fermentation extract (dose range: 12.5-100 µg/mL) was determined using agar dilution method for Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and anti-inflammatory properties determined using rat-paw (250-500 mg/kg) and xylene induced oedema (250-500 µg/kg) (in Swiss albino rats and mice) models, respectively. The ability of the extract to inhibit cyclooxygenase (COX) enzyme was also determined in vitro using Cayman test kit-760111. Result: The MIC of the EtOAc extract was <12.5 µg/mL for S. aureus, P. aeruginosa and Escherichia coli. It inhibited xylene induced oedema by 65% compared with 61% observed for diclofenac and was significantly (p < 0.05) better than diclofenac in rat-paw-oedema model within the first phase of inflammation. The extract inhibited COX-1 peroxidase-mediated activities with an IC₅₀ below 5 µg/mL. Conclusions: The extract exhibited strong antibacterial and anti-inflammatory properties, warranting further investigations into therapeutic potential of this fungus. This study design can be adapted in soil fungi metabolomic investigations. We report for the first time the potent anti-inflammatory property of the ethyl acetate extract of soil strain of F. solani with a possible mechanism of action that involves the inhibition of COX enzyme.

Ursolic acid exhibits anti-inflammatory effects through blocking TLR4-MyD88 pathway mediated by autophagy

There is an urgent need for effective treatments to reduce the large and growing burden of acute kidney injury (AKI) and its consequences. Inflammation is believed to play a vital role in the pathophysiology of AKI. Macrophage autophagy is considered protective against inflammation. Previous study discovered that ursolic acid (UA), a natural pentacyclic triterpene carboxylic acid found in many plants as apples, bilberries, cranberries and so on, promoted cancer cell autophagy. In the present study, we aimed to explore the effect of UA on ameliorating AKI and the role of macrophage autophagy in the context of inflammation. The data from in vivo experiments showed that pretreatment of mice with UA significantly suppressed xylene-induced ear oedema as well as protected against LPS-induced AKI. Related mechanisms were further studied through in vitro experiment. As expected, UA decreased inflammatory factors TNF-α, IL-6 and IL-1β secretion in macrophages in response to lipopolysaccharide (LPS) stimulation. Furthermore, UA blocked LPS-induced TLR4/MyD88 pathway. More importantly, enhanced autophagy of macrophages by UA through increasing the expression of both LC3B and Beclin-1 led to alter macrophage function. What is more, similar to UA, autophagy inhibitor 3-MA obviously decreased inflammation factors releases hinting the vital role of autophagy in regulating inflammation. In all, above study suggested that UA is a potential anti-inflammatory natural compound for treating AKI by inducing autophagy.

The acyl-glucuronide metabolite of ibuprofen has analgesic and anti-inflammatory effects via the TRPA1 channel

Ibuprofen is a widely used non-steroidal anti-inflammatory drug (NSAID) that exerts analgesic and anti-inflammatory actions. The transient receptor potential ankyrin 1 (TRPA1) channel, expressed primarily in nociceptors, mediates the action of proalgesic and inflammatory agents. Ibuprofen metabolism yields the reactive compound, ibuprofen-acyl glucuronide, which, like other TRPA1 ligands, covalently interacts with macromolecules. To explore whether ibuprofen-acyl glucuronide contributes to the ibuprofen analgesic and anti-inflammatory actions by targeting TRPA1, we used in vitro tools (TRPA1-expressing human and rodent cells) and in vivo mouse models of inflammatory pain. Ibuprofen-acyl glucuronide, but not ibuprofen, inhibited calcium responses evoked by reactive TRPA1 agonists, including allyl isothiocyanate (AITC), in cells expressing the recombinant and native human channel and in cultured rat primary sensory neurons. Responses by the non-reactive agonist, menthol, in a mutant human TRPA1 lacking key cysteine-lysine residues, were not affected. In addition, molecular modeling studies evaluating the covalent interaction of ibuprofen-acyl glucuronide with TRPA1 suggested the key cysteine residue C621 as a probable alkylation site for the ligand. Local administration of ibuprofen-acyl glucuronide, but not ibuprofen, in the mouse hind paw attenuated nociception by AITC and other TRPA1 agonists and the early nociceptive response (phase I) to formalin. Systemic ibuprofen-acyl glucuronide and ibuprofen, but not indomethacin, reduced phase I of the formalin response. Carrageenan-evoked allodynia in mice was reduced by local ibuprofen-acyl glucuronide, but not by ibuprofen, whereas both drugs attenuated PGE₂ levels. Ibuprofen-acyl glucuronide, but not ibuprofen, inhibited the release of IL-8 evoked by AITC from cultured bronchial epithelial cells. The reactive ibuprofen metabolite selectively antagonizes TRPA1, suggesting that this novel action of ibuprofen-acyl glucuronide might contribute to the analgesic and anti-inflammatory activities of the parent drug.

Formulation development of self-nanoemulsifying drug delivery system of celecoxib for the management of oral cavity inflammation

The oral administration of celecoxib (CLX) is a real problem because of its low aqueous solubility that results in high variability in absorption and its severe adverse effect such as cardiotoxic effects and gastrointestinal toxicity. Self-nanoemulsifying drug delivery systems (SNEDDS) can enhance the poor dissolution and erratic absorption of poorly water-soluble drugs such as CLX. This study was conducted to investigate the potential of SNEDDS to enhance the efficacy of CLX on inflamed mucous tissue and reduce systemic adverse effects by increasing its poor dissolution properties. A pseudo-ternary phase diagram was derived from the results of CLX solubility experiments in various excipients. These studies revealed the use of Labrafil M 2515 CS as oil, tween 80 as a surfactant, and polyethylene glycol 400 as a co-surfactant for the optimization of SNEDDS formulations. Eight formulations were formulated and characterized by their particle size, polydispersity index, viscosity, globular shape, drug solubility, self-emulsification efficiency, in vitro drug release, and permeation. The anti-inflammatory effect of CLX-SNEDDS was evaluated by carrageenan-induced cheek oedema in rats. The cheeks were treated with CLX-SNEDDS before oedema induction and then noticed for narrow periods (2 h) followed by histopathological studies to determine the efficacy of treatment. The selected formulations (F3 and F5) showed spherical morphologies under transmission electron microscopy, mean droplet sizes of 116.9 ± 1.78 and 124 ± 1.87 nm, respectively, complete in vitro drug release, and high cumulative amounts of drug permeation in 8 h. They also showed significant remarkable cheek oedema inhibition in comparison with the control groups (p < 0.05). CLX-SNEDDS was found to achieve effective local therapeutic concentration and intended to reduce cheek oedema, congestive capillary, inflammatory cells, and side effects due to lower dose size.

Simultaneous purification of dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA from Salvia miltiorrhiza and their anti-inflammatory activities investigation

Dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA are major lipid-soluble constituents isolated from Salvia miltiorrhiza Bunge (Danshen). In the present study, a systematic method was developed to simultaneously isolate and purify those compounds using macroporous adsorption resins and semi-preparative HPLC with a dynamic axial compress (DAC) system. The Danshen extract (95% alcohol) was divided into three fractions using different concentrations of alcohol (0%, 45%, and 90%) on D101 column. The content of total tanshinones of 90% alcohol eluent (TTS) was over 97%. Furthermore, the anti-inflammatory effects of those samples were investigated on LPS-stimulated RAW264.7 cells and three animal models. The results showed that the anti-inflammatory effect of TTS in vitro was superior to the one of any other sample including 0% and 45% eluent, and total tanshinones capsules. In addition, TTS exhibited a stronger anti-inflammatory effect than that of dihydrotanshinone, tanshinone IIA, cryptotanshinone, and tanshinone I, respectively. For animal models, TTS could significantly suppress xylene-induced ear oedema and rescue LPS-induced septic death and acute kidney injury in mice. In summary, the separation process developed in the study was high-efficiency, economic, and low-contamination, which was fit to industrial producing. TTS is a potential agent for the treatment of inflammatory diseases.

Simultaneous purification of dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA from Salvia miltiorrhiza and their anti-inflammatory activities investigation

Dihydrotanshinone, tanshinone I, cryptotanshinone, and tanshinone IIA are major lipid-soluble constituents isolated from Salvia miltiorrhiza Bunge (Danshen). In the present study, a systematic method was developed to simultaneously isolate and purify those compounds using macroporous adsorption resins and semi-preparative HPLC with a dynamic axial compress (DAC) system. The Danshen extract (95% alcohol) was divided into three fractions using different concentrations of alcohol (0%, 45%, and 90%) on D101 column. The content of total tanshinones of 90% alcohol eluent (TTS) was over 97%. Furthermore, the anti-inflammatory effects of those samples were investigated on LPS-stimulated RAW264.7 cells and three animal models. The results showed that the anti-inflammatory effect of TTS in vitro was superior to the one of any other sample including 0% and 45% eluent, and total tanshinones capsules. In addition, TTS exhibited a stronger anti-inflammatory effect than that of dihydrotanshinone, tanshinone IIA, cryptotanshinone, and tanshinone I, respectively. For animal models, TTS could significantly suppress xylene-induced ear oedema and rescue LPS-induced septic death and acute kidney injury in mice. In summary, the separation process developed in the study was high-efficiency, economic, and low-contamination, which was fit to industrial producing. TTS is a potential agent for the treatment of inflammatory diseases.

Anti-inflammatory effect of 4-methylcyclopentadecanone in rats submitted to ischemic stroke

This study aimed to investigate the anti-inflammatory effect of 4-methylcyclopentadecanone (4-MCPC) in rats suffering from a cerebral ischemia/reperfusion (I/R) injury. In this study, the focal cerebral ischemia in rats was induced by middle cerebral artery occlusion (MCAO) for 2 h, and the rats were treated with 4-MCPC (8 mg/kg) just 0.5 h before reperfusion. The ischemic infarct volume was recorded 24 h after the MCAO. In addition, myeloperoxidase (MPO) activity and TNF-α and IL-1β levels in the ischemic cerebral cortex were determined by ELISA, while nuclear translocation of NF-κB p65 subunit and expression of p-IκBα were investigated by Western blotting. Our results showed that 4-MCPC treatment decreased infarct volume significantly, compared with I/R group (16.8%±7.5% vs. 39.7%±10.9%); it reduced MPO activity (0.43 ± 0.10 vs. 1.00 ± 0.51 U/g) and expression levels of TNF-α (18.90 ± 3.65 vs. 35.87 ± 4.87 ng/g) and IL-1β (1.68 ± 0.23 vs. 2.67 ± 0.38 ng/g) in ischemic brain tissues of rats. Further study revealed that 4-MCPC treatment markedly reduced nuclear translocation of NF-κB p65 subunit and expression of p-IκBα in ischemic cerebral cortex. Taken together, our results suggest that 4-MCPC protects against cerebral I/R injury and displays anti-inflammatory actions through inhibition of the NF-κB signal pathway.

Isoacteoside, a dihydroxyphenylethyl glycoside, exhibits anti-inflammatory effects through blocking toll-like receptor 4 dimerization

BACKGROUND AND PURPOSE

Isoacteoside (is a phenylethanoid isolated from Monochasma savatieri Franch. ex Maxim., which is an anti-inflammatory herb widely used in traditional Chinese medicine. However, the exact mechanism of the anti-inflammatory activity of isoacteoside is not completely understood. In this study, its anti-inflammatory mechanism was elucidated in mouse macrophages.

EXPERIMENTAL APPROACH

The expression of the NF-κB pathway, MAPK pathway, iNOS, TNF-α, IL-6 and IL-1β was evaluated using Western blotting, quantitative real-time PCR or ELISA. TLR4 dimerization was determined by transfecting HEK293T cells with TLR4 plasmids. The in vivo anti-inflammatory effect of isoacteoside was determined using mouse models of xylene-induced ear oedema, LPS-induced endotoxic shock and LPS-induced endotoxaemia-associated acute kidney injury (AKI).

KEY RESULTS

Isoacteoside suppressed COX-2, iNOS, TNF-α, IL-6 and IL-1β expression. Furthermore, isoacteoside attenuated the LPS-induced transcriptional activity of NF-κB by decreasing the levels of phosphorylated IκB-α and IKK and NF-κB/p65 nuclear translocation. In addition, isoacteoside inhibited LPS-induced transcriptional activity of AP-1 by reducing the levels of phosphorylated JNK1/2 and p38MAPK. Isoacteoside blocked LPS-induced TLR4 dimerization, resulting in a reduction in the recruitment of MyD88 and TIR-domain-containing adapter-inducing interferon-β (TRIF) and the phosphorylation of TGF-β-activated kinase-1 (TAK1). Pretreatment of mice with isoacteoside effectively inhibited xylene-induced ear oedema and LPS-induced endotoxic death and protected against LPS-induced AKI.

CONCLUSIONS AND IMPLICATIONS

Isoacteoside blocked TLR4 dimerization, which activates the MyD88-TAK1-NF-κB/MAPK signalling cascades and TRIF pathway. Our data indicate that isoacteoside is a potential lead compound for the treatment of inflammatory diseases.

Total tanshinones exhibits anti-inflammatory effects through blocking TLR4 dimerization via the MyD88 pathway

Tanshinones belong to a group of lipophilic constituents of Salvia miltiorrhiza Bunge (Danshen), which is widely used in traditional Chinese medicine. A deluge of studies demonstrated that tanshinones exert anti-inflammatory effects, but the underlying mechanisms remain unclear to date. This study investigated the anti-inflammatory effects and mechanisms of total tanshinones (TTN). TTN suppressed the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) and the secretion of TNF-α, IL-6, and IL-1β in RAW264.7 cells, bone marrow-derived macrophages, and THP-1 cells. TTN attenuated the LPS-induced transcriptional activity of NF-κB and decreased IκB-α and IKK phosphorylation and NF-κB/p65 nuclear translocation. Furthermore, TTN inhibited the LPS-induced transcriptional activity of AP-1, which was induced by the reduction of JNK1/2, ERK1/2, and p38MAPK phosphorylation. TTN blocked LPS-induced Toll-like receptor 4 (TLR4) dimerization, which consequently decreased MyD88 recruitment and TAK1 phosphorylation. In addition, TTN pretreatment effectively inhibited xylene-induced ear edema and LPS-induced septic death and improved LPS-induced acute kidney injury in mice. TTN exerts anti-inflammatory effects in vitro and in vivo by blocking TLR4 dimerization to activate MyD88–TAK1–NF-κB/MAPK signaling cascades, which provide the molecular basis of the anti-inflammatory effect of Danshen and suggest that TTN is a potential agent for the treatment of inflammatory diseases.

Aceclofenac cocrystal nanoliposomes for rheumatoid arthritis with better dermatokinetic attributes: a preclinical study

AIM

The aim of present research was to complex aceclofenac with lysine (LYS) and the developed aceclofenac-LYS cocrystal was encapsulated in lipid bilayers of liposomes by employing dual carrier approach for the treatment of pain-related disorders in rheumatoid arthritis (RA).

MATERIALS & METHODS

The developed carriers were characterized for particle size, drug release, ex vivo and in vivo studies, dermatokinetic modeling, complete freund's adjuvant (CFA)-induced RA rat model, radiant heat tail-flick method, formalin-induced paw-licking model, paw edema model and xylene-induced ear edema model in mice.

RESULTS

The developed nanoliposomes offered nanometric size, controlled drug release and enhanced drug permeation. Further, hydrogel incorporated nanoproduct was found to be rheologically acceptable and substantially compatible with rodent skin.

CONCLUSION

The studies indicated the superiority of LYS-conjugated liposome-entrapped nanocarriers for improved management of conditions like RA over the marketed product.

Muscone Induces CYP1A2 and CYP3A4 Enzyme Expression in L02 Human Liver Cells and CYP1A2 and CYP3A11 Enzyme Expression in Kunming Mice

AIM

To examine the effect of synthetic muscone on the expression of CYP1A2 and CYP3A4 enzymes in human liver L02 cells and in the liver tissue of Kunming mice.

METHODS

The L02 hepatic cell line was used to study the effect of low (10-4 μmol/L), middle (10-3 μmol/L), and high concentrations (10-2 μmol/L) of muscone on the expression of CYP1A2 and CYP3A4 enzymes. In addition, the cytochrome P450 (CYP) expression was investigated in Kunming mice after the administration of 10 mg/kg (low), 50 mg/kg (middle), and 100 mg/kg (high) dose of muscone for 6 days. A mixture of phenobarbital (30 mg/kg) and β-napthoflavone (80 mg/kg) was used as positive control and the effects of the compounds on CYP expression were investigated at the end of 6- and 12-day periods.

RESULTS

Muscone induced the expression of CYP1A2 (middle and low concentrations) and of CYP3A4 (high concentration) enzymes in L02 cells. In vivo, administration of muscone in Kunming mice revealed significant weight reduction at the end of 6- and 12-day periods (middle and high doses, respectively), compared to the control group (p < 0.05). Liver toxicity scores indicated that the liver injuries in the positive control and high doses of muscone group were significantly higher in the 6- and 12-day periods, compared to those in the blank control group (p < 0.05). Furthermore, muscone induced CYP1A2 and CYP3A11 expressions in Kunming mice at the middle dose and all doses during the 12-day period as demonstrated by immunoblotting experiments. A low dose of mucone induced the CYP enzyme expression more rapidly, whereas a high dose of muscone caused the longest inductive effect. The results were confirmed by immunohistochemistry experiments and real-time PCR studies, where similar patterns of muscone-mediated inductive effects were noted.

CONCLUSIONS

Muscone induces CYP1A2 and CYP3A4 expression in liver cells in vitro and in vivo. In addition, it exhibits liver toxicity in Kunming mice at concentrations higher than 50 mg/kg. The CYP-inductive effect that is caused by muscone encompasses a 6- to 12-day period of activity after drug administration as demonstrated by follow-up in vivo studies.

Anti-hyperalgesic and Anti-inflammatory Activity of Alternanthera Maritima Extract and 2″-O-α-L-rhamnopyranosylvitexin in Mice

Alternanthera maritima are used in Brazilian popular medicine for the treatment of inflammatory and infectious diseases. Species of Alternanthera have demonstrated biological activities in previous scientific studies. The aim of this study was to determine whether the ethanol extract of the aerial parts of A. maritima (EEAM) and the isolated compound 2″-O-α-L-rhamnopyranosyl-vitexin inhibit mechanical hyperalgesia and parameters of inflammation in mice. The oral administration of EEAM significantly inhibited carrageenan (Cg)-induced paw edema and reduced leukocyte migration into the pleural cavity. 2″-O-α-L-rhamnopyranosylvitexin significantly inhibited paw edema and reduced both leukocyte migration and the leakage of protein into the pleural cavity. Both EEAM and 2″-O-α-L-rhamnopyranosylvitexin significantly prevented the Cg-induced hyperalgesia. Local administration of 2″-O-α-L-rhamnopyranosylvitexin significantly prevented the Cg- and tumor necrosis factor (TNF)-induced hyperalgesia. In conclusion, this study demonstrated that EEAM is an anti-inflammatory and anti-hyperalgesic agent, and the results suggested that 2″-O-α-L-rhamnopyranosylvitexin is responsible for the effects of EEAM and the mechanism involves the TNF pathway.

The TRPA1 channel mediates the analgesic action of dipyrone and pyrazolone derivatives

BACKGROUND AND PURPOSE

Although still used by hundreds of millions of people worldwide, the mechanism of the analgesic action of the pyrazolone derivatives (PDs), dipyrone, propyphenazone and antipyrine remains unknown. The transient receptor potential ankyrin 1 (TRPA1) channel, expressed by nociceptors, is emerging as a major pain transduction pathway. We hypothesized that PDs target the TRPA1 channel and by this mechanism produce their analgesic effect.

EXPERIMENTAL APPROACH

Calcium responses and currents were studied in cultured TRPA1-expressing rodent dorsal root ganglion neurons and human cells. Acute nociception and mechanical hypersensitivity were investigated in naïve and genetically manipulated mice.

KEY RESULTS

Pyrazolone and PDs selectively inhibited calcium responses and currents in TRPA1-expressing cells and acute nocifensor responses in mice evoked by reactive channel agonists (allyl isothiocyanate, acrolein and H2 O2 ). In line with recent results obtained with TRPA1 antagonists and TRPA1 gene deletion, the two most largely used PDs, dipyrone and propyphenazone, attenuated TRPA1-mediated nociception and mechanical allodynia in models of inflammatory and neuropathic pain (formalin, carrageenan, partial sciatic nerve ligation and the chemotherapeutic drug, bortezomib). Notably, dipyrone and propyphenazone attenuated carrageenan-evoked mechanical allodynia, without affecting PGE2 levels. The main metabolites of PDs did not target TRPA1 and did not affect TRPA1-dependent nociception and allodynia.

CONCLUSIONS AND IMPLICATIONS

Evidence that in rodents the nociceptive/hyperalgesic effect produced by TRPA1 activation is blocked by PDs suggests that a similar pathway is attenuated by PDs in humans and that TRPA1 antagonists could be novel analgesics, devoid of the adverse haematological effects of PDs.

Development and evaluation of curcumin-loaded elastic vesicles as an effective topical anti-inflammatory formulation

Curcumin has diverse biological activities including antioxidant and anti-inflammatory activity. However, its clinical use for topical application is limited due to its poor aqueous solubility and thus, minimal cutaneous bioavailability. Elastic vesicles (EVs) of curcumin were prepared to improve its cutaneous bioavailability and to use it for topical anti-inflammatory effect. Ex vivo skin permeation and retention studies were performed to check if incorporation of curcumin into EVs could improve its permeation into and retention in the skin. Evaluation of acute and chronic anti-inflammatory effect was done using xylene-induced acute ear edema in mice and cotton pellet-induced chronic inflammation in rats, respectively. A significant improvement in flux (nine times) across murine skin was observed when aqueous dispersion of curcumin (flux - 0.46 ± 0.02 μg/h/cm(2)) was compared with curcumin-loaded EVs (flux - 4.14 ± 0.04 μg/h/cm(2)). Incorporation of these curcumin-loaded EVs into a hydrophilic ointment base resulted in higher skin retention (51.66%) in contrast to free curcumin ointment (1.64%) and a marketed formulation (VICCO® turmeric skin cream). The developed ointment showed an effect similar (p < 0.05) to the marketed diclofenac sodium ointment (Omni-gel®) in suppression of acute inflammation in mouse; a significant inhibition (28.8% versus 3.91% for free curcumin) of cotton pellet-induced chronic inflammation was also observed. Thus, curcumin-loaded EVs incorporated in hydrophilic ointment is a promising topical anti-inflammatory formulation.

Pattern of inflammatory response to Loxosceles intermedia venom in distinct mouse strains: a key element to understand skin lesions and dermonecrosis by poisoning

Envenomation caused by spiders Loxosceles induce intense dermonecrosis at the bite site and systemic disease. In this work we described the hyaluronidase and collagenase activities in vitro of the Loxosceles intermedia venom, but no phospholipase A2 activity. In vivo, we evaluated the effect of L. intermedia venom used different strain of mice, C57BL/6, BALB/c and Swiss. All mice developed paw edema after venom injection, persistent for 24 h in BALB/c and C57BL/6 mice. Histopathological analysis of the skin after venom injection revealed vascular congestion in Swiss mice and an inflammatory reaction in BALB/c and C57BL/6 mice. The mobilization of inflammatory cells from bone marrow, spleen and blood was investigated. Typical innate immune response with mobilization of myeloid cells and cytotoxic CD8 T lymphocytes was observed in C57BL/6 mice. In contrast, typical acquired/humoral immune response was observed in BALB/c mice, with preferential involvement of conventional B lymphocytes and CD4 T helper cells. The skin inflammation associated to mobilization of inflammatory cells indicated that mice models are strongly recommended to investigate specific cell types involved with immune response to the envenomation and mechanisms to inhibit skin lesions.

Anti-Inflammatory and Antihyperalgesic Activities of Ethanolic Extract and Fruticulin A from Salvia lachnostachys Leaves in Mice

The anti-inflammatory and analgesic effects of the ethanolic extract (SLEE) and fruticulin A from the leaves of Salvia lachnostachys were evaluated in mice, using experimental models of inflammation (paw oedema and pleurisy induced by carrageenan injection) and hyperalgesia (electronic Von Frey). Oral administration of SLEE (30, 100, and 300 mg/kg) and fruticulin A (0.3 and 3.0 mg/kg) decreased the total leucocytes number in pleural lavage, protein extravasation, and paw oedema. SLEE (100 mg/kg) and fruticulin A (3 mg/kg) also exhibited antihyperalgesic activity in carrageenan induced mechanical hyperalgesia. In addition, fruticulin A (3 mg/kg) prevented mechanical hyperalgesia, inhibiting TNF but not L-DOPA-induced mechanical hyperalgesia. In conclusion, SLEE and fruticulin A display anti-inflammatory and analgesic properties. Therefore, fruticulin A is at least partially responsible for the activity observed in the ethanolic extract of Salvia lachnostachys.