A reverse translational approach reveals the protective roles of Mangifera indica in inflammatory bowel disease.

Inflammatory bowel diseases (IBDs) are chronic intestinal disorders often characterized by a dysregulation of T cells, specifically T helper (Th) 1, 17 and T regulatory (Treg) repertoire. Increasing evidence demonstrates that dietary polyphenols from Mangifera indica L. extract (MIE, commonly known as mango) mitigate intestinal inflammation and splenic Th17/Treg ratio. In this study, we aimed to dissect the immunomodulatory and anti-inflammatory properties of MIE using a reverse translational approach, by initially using blood from an adult IBD inception cohort and then investigating the mechanism of action in a preclinical model of T cell-driven colitis. Of clinical relevance, MIE modulates TNF-α and IL-17 levels in LPS spiked sera from IBD patients as an ex vivo model of intestinal barrier breakdown. Preclinically, therapeutic administration of MIE significantly reduced colitis severity, pathogenic T-cell intestinal infiltrate and intestinal pro-inflammatory mediators (IL-6, IL-17A, TNF-α, IL-2, IL-22). Moreover, MIE reversed colitis-induced gut permeability and restored tight junction functionality and intestinal metabolites. Mechanistic insights revealed MIE had direct effects on blood vascular endothelial cells, blocking TNF-α/IFN-γ-induced up-regulation of COX-2 and the DP2 receptors. Collectively, we demonstrate the therapeutic potential of MIE to reverse the immunological perturbance during the onset of colitis and dampen the systemic inflammatory response, paving the way for its clinical use as nutraceutical and/or functional food.

New biologic (Ab-IPL-IL-17) for IL-17-mediated diseases: identification of the bioactive sequence (nIL-17) for IL-17A/F function.

OBJECTIVES: Interleukin (IL) 17s cytokines are key drivers of inflammation that are functionally dysregulated in several human immune-mediated inflammatory diseases (IMIDs), such as rheumatoid arthritis (RA), psoriasis and inflammatory bowel disease (IBD). Targeting these cytokines has some therapeutic benefits, but issues associated with low therapeutic efficacy and immunogenicity for subgroups of patients or IMIDs reduce their clinical use. Therefore, there is an urgent need to improve the coverage and efficacy of antibodies targeting IL-17A and/or IL-17F and IL-17A/F heterodimer. METHODS AND RESULTS: Here, we initially identified a bioactive 20 amino acid IL-17A/F-derived peptide (nIL-17) that mimics the pro-inflammatory actions of the full-length proteins. Subsequently, we generated a novel anti-IL-17 neutralising monoclonal antibody (Ab-IPL-IL-17) capable of effectively reversing the pro-inflammatory, pro-migratory actions of both nIL-17 and IL-17A/F. Importantly, we demonstrated that Ab-IPL-IL-17 has less off-target effects than the current gold-standard biologic, secukinumab. Finally, we compared the therapeutic efficacy of Ab-IPL-IL-17 with reference anti-IL-17 antibodies in preclinical murine models and samples from patients with RA and IBD. We found that Ab-IPL-IL-17 could effectively reduce clinical signs of arthritis and neutralise elevated IL-17 levels in IBD patient serum. CONCLUSIONS: Collectively, our preclinical and in vitro clinical evidence indicates high efficacy and therapeutic potency of Ab-IPL-IL-17, supporting the rationale for large-scale clinical evaluation of Ab-IPL-IL-17 in patients with IMIDs.

Synthesis, Biological Activity and Molecular Docking of Chimeric Peptides Targeting Opioid and NOP Receptors.

Recently, mixed opioid/NOP agonists came to the spotlight for their favorable functional profiles and promising outcomes in clinical trials as novel analgesics. This study reports on two novel chimeric peptides incorporating the fragment Tyr-c[D-Lys-Phe-Phe]Asp-NH2 (RP-170), a cyclic peptide with high affinity for µ and κ opioid receptors (or MOP and KOP, respectively), conjugated with the peptide Ac-RYYRIK-NH2, a known ligand of the nociceptin/orphanin FQ receptor (NOP), yielding RP-170-RYYRIK-NH2 (KW-495) and RP-170-Gly3-RYYRIK-NH2 (KW-496). In vitro, the chimeric KW-496 gained affinity for KOP, hence becoming a dual KOP/MOP agonist, while KW-495 behaved as a mixed MOP/NOP agonist with low nM affinity. Hence, KW-495 was selected for further in vivo experiments. Intrathecal administration of this peptide in mice elicited antinociceptive effects in the hot-plate test; this action was sensitive to both the universal opioid receptor antagonist naloxone and the selective NOP antagonist SB-612111. The rotarod test revealed that KW-495 administration did not alter the mice motor coordination performance. Computational studies have been conducted on the two chimeras to investigate the structural determinants at the basis of the experimental activities, including any role of the Gly3 spacer.

Calceolarioside A, a Phenylpropanoid Glycoside from Calceolaria spp., Displays Antinociceptive and Anti-Inflammatory Properties.

Phenylpropanoid glycosides are a class of natural substances of plant origin with interesting biological activities and pharmacological properties. This study reports the antinociceptive and anti-inflammatory effects of calceolarioside A, a phenylpropanoid glycoside previously isolated from various Calceolaria species. In models of acute nociception induced by thermal stimuli, such as the hot plate and tail flick test, calceolarioside administered at doses of 1, 5, and 10 µg in the left cerebral ventricles did not modify the behavioral response of mice. In an inflammatory based persistent pain model as the formalin test, calceolarioside A at the high dose tested (100 µg/paw) reduced the licking activity induced by formalin by 35% in the first phase and by 75% in the second phase of the test. In carrageenan-induced thermal hyperalgesia, calceolarioside A (50 and 100 µg/paw) was able to significantly reverse thermal hyperalgesia induced by carrageenan. The anti-inflammatory activity of calceolarioside A was then assessed using the zymosan-induced paw edema model. Calceolarioside A (50 and 100 µg/paw) induced a significant reduction in the edema from 1 to 4 h after zymosan administration. Measuring IL-6, TNFα, and IL-1ß pro-inflammatory cytokines released from LPS-stimulated THP-1 cells, calceolarioside A in a concentration-dependent manner reduced the release of these cytokines from THP-1 cells. Taken together, our results highlight, for the first time, the potential and selective anti-inflammatory properties of this natural-derived compound, prompting its rationale use for further investigations.

Selective MOR activity of DAPEA and Endomorphin-2 analogues containing a (R)-γ-Freidinger lactam in position two.

The use of α-amino-γ lactam of Freidinger (Agl) may serve as an impressive method to increase the biological stability of peptides and an appropriate tool to elucidate their structure-activity relationships. The endomorphin-2 (EM-2) and [D-Ala2, des-Leu5] enkephalin amide (DAPEA) are two linear opioid tetrapeptides agonists of MOR and MOR/DOR respectively. Herein, we investigated the influence of the incorporation of (R/S)-Agl in position 2 and 3 on the biological profile of the aforementioned products in vitro and in vivo. Receptor radiolabeled displacement and functional assays were used to measure in vitro the binding affinity and receptors activation of the novel analogues. The mouse tail flick and formalin tests allowed to observe their antinociceptive effect in vivo. Data revealed that peptide A2D was able to selectively bind and activate MOR with a potent antinociceptive effect after intracerebroventricular (i.c.v.) administration, performing better than the parent compounds EM-2 and DAPEA. Molecular docking calculations helped us to understand the key role exerted by the Freidinger Agl moiety in A2D for the interaction with the MOR binding pocket.

In Silico Identification of Tripeptides as Lead Compounds for the Design of KOR Ligands.

The kappa opioid receptor (KOR) represents an attractive target for the development of drugs as potential antidepressants, anxiolytics and analgesics. A robust computational approach may guarantee a reduction in costs in the initial stages of drug discovery, novelty and accurate results. In this work, a virtual screening workflow of a library consisting of ~6 million molecules was set up, with the aim to find potential lead compounds that could manifest activity on the KOR. This in silico study provides a significant contribution in the identification of compounds capable of interacting with a specific molecular target. The main computational techniques adopted in this experimental work include: (i) virtual screening; (ii) drug design and leads optimization; (iii) molecular dynamics. The best hits are tripeptides prepared via solution phase peptide synthesis. These were tested in vivo, revealing a good antinociceptive effect after subcutaneous administration. However, further work is due to delineate their full pharmacological profile, in order to verify the features predicted by the in silico outcomes.

IL-17A neutralizing antibody regulates monosodium urate crystal-induced gouty inflammation.

Gout is a paradigm of acute, self-limiting inflammation caused by the deposition of monosodium urate (MSU) crystals within intra-and/or peri-articular areas, leading to excruciating pain, joint swelling and stiffness. The infiltration of leukocytes drives the inflammatory response and remains an attractive target for therapeutic intervention. In this context, emerging evidence supports the view that systemic differentiation of Th17 cells and their in situ infiltration as one of the potential mechanisms by which these cells, and their main product IL-17, causes damage to target tissues. To test if IL-17 was having a detrimental role in gouty onset and progression we targeted this cytokine, using a neutralizing antibody strategy, in an experimental model of gout. Joint inflammation was induced in CD-1 mice by the intra-articular (i.a.) administration of MSU crystals (200 µg/20 µl). Animals from IL-17Ab-treated groups received 1, 3 and 10 µg (i.a.) in 20 µl of neutralizing antibody after MSU crystals administration. Thereafter, joints were scored macroscopically, and knee joint oedema determined with a caliper. Histological analysis, myeloperoxidase assay and western blots analysis for COX-2/mPGEs-1/IL-17R pathway were conducted at 18 h (peak of inflammation) to evaluate leukocytes infiltration and activation, followed by the analysis, in situ, of pro/anti-inflammatory cytokines and chemokines. Flow cytometry was also used to evaluate the modulation of infiltrated inflammatory monocytes and systemic Th17 and Treg profile. Treatment with IL-17Ab revealed a dose-dependent reduction of joint inflammation scores with maximal inhibition at 10 µg. The neutralizing antibody was also able to significantly reduce leukocytes infiltration and MPO activity as well the expression of JE, IL-1α, IL-1ß, IL-16, IL-17, C5a, BLC and, with a less extent IP-10, Rantes, KC, TIMP-1, SDF-1 and metalloproteinases in inflamed tissues. Biochemical analysis also revealed that IL-17Ab treatment modulated COX-2/mPGEs-1 pathway (and related PGE2 production) without interfering with IL-17R expression. Furthermore, flow cytometry analysis highlighted a selective modulation of infiltrating inflammatory monocytes (B220-/GR1hi-F480hi/CD115+) and circulating Th17, but not Treg, cells after IL-17Ab treatment. Collectively the results of this study report for the first time, that i.a. injection of MSU crystals stimulates in vivo production of Th17 cells and Th17-related inflammatory cyto-chemokines. In addition, we have demonstrated that the administration of a neutralizing antibody against IL-17 attenuates joint symptoms, swelling and leukocytes infiltration to the inflamed tissue, possibly providing a new strategy for the treatment of gouty inflammation and/or arthritis.

Long-Lasting Anti-Inflammatory and Antinociceptive Effects of Acute Ammonium Glycyrrhizinate Administration: Pharmacological, Biochemical, and Docking Studies.

The object of the study was to estimate the long-lasting effects induced by ammonium glycyrrhizinate (AG) after a single administration in mice using animal models of pain and inflammation together with biochemical and docking studies. A single intraperitoneal injection of AG was able to produce anti-inflammatory effects in zymosan-induced paw edema and peritonitis. Moreover, in several animal models of pain, such as the writhing test, the formalin test, and hyperalgesia induced by zymosan, AG administered 24 h before the tests was able to induce a strong antinociceptive effect. Molecular docking studies revealed that AG possesses higher affinity for microsomal prostaglandin E synthase type-2 compared to type-1, whereas it seems to locate better in the binding pocket of cyclooxygenase (COX)-2 compared to COX-1. These results demonstrated that AG induced anti-inflammatory and antinociceptive effects until 24-48 h after a single administration thanks to its ability to bind the COX/mPGEs pathway. Taken together, all these findings highlight the potential use of AG for clinical treatment of pain and/or inflammatory-related diseases.

Antinociceptive potency of a fluorinated cyclopeptide Dmt-c[D-Lys-Phe-p-CF3-Phe-Asp]NH2.

Opioid peptides and opiate drugs such as morphine, mediate their analgesic effects, but also undesired side effects, mostly through activation of the mu opioid receptor. However, delta- and kappa-opioid receptors can also contribute to the analgesic effects of opioids. Recent findings showed that simultaneous activation of multiple opioid receptors may result in additional analgesia with fewer side effects. Here, we evaluated the pharmacological profile of our formerly developed mixed mu/kappa-opioid receptor ligands, Dmt-c[D-Lys-Phe-Phe-Asp]NH2 (C-36) and Dmt-c[D-Lys-Phe-p-CF3-Phe-Asp]NH2 (F-81). The ability of these peptides to cross the blood-brain barrier was tested in the parallel artificial membrane permeability (PAMPA) assay. On the basis of the hot-plate test in mice after central and peripheral administration, analog F-81 was selected for the anti-nociceptive and anti-inflammatory activity assessment after peripheral administration.

pH-sensitive niosomes: Effects on cytotoxicity and on inflammation and pain in murine models.

pH-sensitive nonionic surfactant vesicles (niosomes) by polysorbate-20 (Tween-20) or polysorbate-20 derivatized by glycine (added as pH sensitive agent), were developed to deliver Ibuprofen (IBU) and Lidocaine (LID). For the physical-chemical characterization of vesicles (mean size, size distribution, zeta potential, vesicle morphology, bilayer properties and stability) dynamic light scattering (DLS), small angle X-ray scattering and fluorescence studies were performed. Potential cytotoxicity was evaluated on immortalized human keratinocyte cells (HaCaT) and on immortalized mouse fibroblasts Balb/3T3. In vivo antinociceptive activity (formalin test) and anti-inflammatory activity tests (paw edema induced by zymosan) in murine models were performed on drug-loaded niosomes. pH-sensitive niosomes were stable in the presence of 0 and 10% fetal bovine serum, non-cytotoxic and able to modify IBU or LID pharmacological activity in vivo. The synthesis of stimuli responsive surfactant, as an alternative to add pH-sensitive molecules to niosomes, could represent a promising delivery strategy for anesthetic and anti-inflammatory drugs.

Exploring the first Rimonabant analog-opioid peptide hybrid compound, as bivalent ligand for CB1 and opioid receptors.

Cannabinoid (CB) and opioid systems are both involved in analgesia, food intake, mood and behavior. Due to the co-localization of µ-opioid (MOR) and CB1 receptors in various regions of the central nervous system (CNS) and their ability to form heterodimers, bivalent ligands targeting to both these systems may be good candidates to investigate the existence of possible cross-talking or synergistic effects, also at sub-effective doses. In this work, we selected from a small series of new Rimonabant analogs one CB1R reverse agonist to be conjugated to the opioid fragment Tyr-D-Ala-Gly-Phe-NH2. The bivalent compound (9) has been used for in vitro binding assays, for in vivo antinociception models and in vitro hypothalamic perfusion test, to evaluate the neurotransmitters release.

Evaluation of the analgesic effect of 4-anilidopiperidine scaffold containing ureas and carbamates.

Fentanyl is a powerful opiate analgesic typically used for the treatment of severe and chronic pain, but its prescription is strongly limited by the well-documented side-effects. Different approaches have been applied to develop strong analgesic drugs with reduced pharmacologic side-effects. One of the most promising is the design of multitarget drugs. In this paper we report the synthesis, characterization and biological evaluation of twelve new 4-anilidopiperidine (fentanyl analogues). In vivo hot-Plate test, shows a moderate antinociceptive activity for compounds OMDM585 and OMDM586, despite the weak binding affinity on both µ and δ-opioid receptors. A strong inverse agonist activity in the GTP-binding assay was revealed suggesting the involvement of alternative systems in the brain. Fatty acid amide hydrolase inhibition was evaluated, together with binding assays of cannabinoid receptors. We can conclude that compounds OMDM585 and 586 are capable to elicit antinociception due to their multitarget activity on different systems involved in pain modulation.

Antinociceptive profile of potent opioid peptide AM94, a fluorinated analogue of biphalin with non-hydrazine linker.

AM94 is a fluorinated analog of biphalin with non-hydrazine linker that has an in vitro affinity for µ-opioid and δ-opioid receptors tenfold higher than biphalin. Furthermore, in vivo evaluation in rats showed that AM94 has in hot plate test - after both intracerebroventricular and intravenous administrations - a greater and more durable efficacy than biphalin. Here, the antinociceptive profile of AM94 is further evaluated by following two different administration routes, intrathecal and subcutaneous, and two different animal species, rats and mice. The analgesic potency of AM94 is compared with that of both the parent peptide biphalin and morphine. Results show that in rats (tail flick test) and in mice (formalin test), AM94 has a higher and more durable analgesic effect than biphalin after intrathecal and subcutaneous administrations. Conformational properties of biphalin and AM94 were also investigated by variable-temperature (1)H NMR and energy minimization.

Design of Analgesic Trivalent Peptides with Low Withdrawal Symptoms: Probing the Antinociceptive Profile of Novel Linear and Cyclic Peptides as Opioid Pan Ligands.

The discovery of efficacious and safe analgesics with reduced side effects is the foremost challenge in the pain field. In this work, we report the in vitro and in vivo evaluation of linear and cyclic analogues of biphalin with the aim to complete the series of structural modifications previously applied in the development of opioid peptides incorporating a xylene bridge. Replacement of Tyr1,1' by Dmt (2,5-dimethyltyrosine) in the linear biphalin analogue AM94 and cyclic analogue MACE4 resulted in two new compounds (namely, MJ2 and MJ5) endowed with improved KOR/MOR/DOR binding affinity. Both compounds showed a strong antinociceptive profile in in vivo models of nociception, allodynia, and hyperalgesia via the tail flick, hot plate, and formalin tests after intracerebroventricular and subcutaneous administration. One of these ligands, MJ2, was also tested in tolerance and dependence studies, exhibiting very little withdrawal symptoms.

Food-inspired peptides from spinach Rubisco endowed with antioxidant, antinociceptive and anti-inflammatory properties.

Rubiscolin-6 (amino acid sequence: YPLDLF) is a selective δ-opioid receptor peptide isolated from spinach Rubisco. Its synthetic analogue, peptide YPMDIV is the most potent described so far for its increased opioid activity, thus in this work it was considered as lead compound for the design of twelve new analogues e.g. LMAS1-12. Firstly all the novel compounds have been tested for their antinociceptive and anti-inflammatory capacity in vitro and in vivo in order to evaluate their ability to maintain or loss the original activity. Among them peptides LMAS5-8 gave the best results, thus their antioxidant properties have been investigated along with their enzymatic inhibitory ability. Peptide LMAS6 shows a strong antioxidant (154.25 mg TE/g CUPRAC) and inhibitor activity on tyrosinase (84.49 mg KAE/g), indicating a potential role in food industry as anti-browning agent, while peptides LMAS5 and LMAS7 possess a modest cholinesterase inhibitory activity suggesting a conceivable use for nutraceuticals production.

Rimonabant-Based Compounds Bearing Hydrophobic Amino Acid Derivatives as Cannabinoid Receptor Subtype 1 Ligands.

In this study, 1H-pyrazole-3-carboxylic acids related to the cannabinoid type 1 (CB1) receptor antagonist rimonabant were amidated with valine or tert-leucine, and the resulting acids were further diversified as methyl esters, amides, and N-methyl amides. In vitro receptor binding and functional assays demonstrated a wide series of activities related to the CB1 receptors (CB1Rs). Compound 34 showed a high CB1R binding affinity (K i = 6.9 nM) and agonist activity (EC50 = 46 nM; E max = 135%). Radioligand binding and [35S]GTPγS binding assays also demonstrated its selectivity and specificity to CB1Rs. Moreover, in vivo experiments revealed that 34 was slightly more effective than the CB1 agonist WIN55,212-2 in the early phase of the formalin test, indicating a short duration of the analgesic effect. Interestingly, in a mouse model of zymosan-induced hindlimb edema, 34 was able to maintain the percentage of paw volume below 75% for 24 h following subcutaneous injection. After intraperitoneal administration, 34 increased the food intake of mice, suggesting potential activity on CB1Rs.

Food-Specific IgG4 Antibody-Guided Exclusion Diet Improves Conditions of Patients with Chronic Pain.

INTRODUCTION: Chronic pain is related to gastrointestinal (GI) functions because food components affect inflammation and pain through their action on the GI immune and/or neural system and because many analgesics interact with the gut to alter its structure and function. Immunoglobulin G4 (IgG4) are food-specific antibodies resulting from exposure of the gut immune system to nutrients. High IgG4 levels have been found to be associated with inflammation. METHODS: IgG4 were determined (both with the rapid test and enzyme-linked immunosorbent assay, ELISA) in men and women outpatients with chronic pain. All subjects were asked to exclude for 4 weeks all foods to which they had high blood levels of IgG4 antibodies. Pain and quality of life questionnaires were administered before (visit 1) and after (visit 2) the personalized exclusion diet period. Visual analogue scale (VAS), Italian Pain Questionnaire (QUID) and Margolis (MA) questionnaires were administered to determine pain intensity, pain features and pain extent, while Short Form Health Survey (SF-36) and Profile of Mood States (POMS) were used to test the quality of life and mood state. The nutritional status was evaluated in all subjects. Subject groups were women of reproductive age (pre-MW), women in menopause for at least 1 year (MW) and men. RESULTS: Fifty-four subjects with chronic pain (n = 12 neuropathic, n = 14 diffuse pain, n = 11 headache, n = 17 low back pain) completed the two visits and the 1-month exclusion diet. At visit 1, 47 (87%) subjects showed medium/high levels of IgG4 to at least one food. The foods showing the highest IgG4 values were eggs, dairy products, cereals and dried fruit. At visit 2, IgG4 levels were decreased, increased or unchanged. In all groups, the 4-week exclusion diet resulted in a significant reduction in all pain measures and an improvement of quality of life parameters. In particular, at visit 2, the VAS score determined in the morning decreased by more than 50%. CONCLUSIONS: A food elimination diet based on IgG4 antibody levels may be effective in reducing pain and improving quality of life in patients with chronic pain.

New Insights on Formyl Peptide Receptor Type 2 Involvement in Nociceptive Processes in the Spinal Cord.

Formyl peptide receptor type 2 (FPR2/ALX) belongs to the formyl peptide receptors (FPRs) family clustered on chromosome 19 and encodes a family of three Class A of G protein-coupled receptors (GPCRs). A short N-terminal region, an NPXXY motif in transmembrane (TM) region 7 and an E/DRY motif that bridges TM3 and TM6 stabilizing inactive receptor conformations characterize this class of receptors. In recognizing pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), FPRs play a crucial role in innate immune responses. FPR2/ALX is highly expressed in myeloid cells, as well as in chondrocytes, fibroblasts, endothelial, epithelial and smooth muscle cells. FPR2/ALX mRNA expression was recently reported in the rat brainstem, spinal cord, thalamus/hypothalamus, cerebral neocortex, hippocampus, cerebellum and striatum. The central nervous system (CNS) distribution of FPR2/ALX suggests important functions in nociception. Thus, the present study was carried out to investigate the possible role of FPR2/ALX in nociception in mice. Intrathecal administration of the formyl peptide receptor type 1 (FPR1) agonist fMLF and the FPR2/ALX agonist BML-111 relieved nociception and these effects were reduced by contemporary administration of the FPR2/ALX antagonist WRW4. Furthermore, measurement of cytokines and brain-derived neurotrophic factor (BDNF) in the spinal cord of neuropathic mice demonstrated that the antinociceptive effects of BML-111 might depend on the reduction in cytokine release and BDNF in the spinal cord. These results suggest a possible role of FPR2/ALX for pain control in the spinal cord.

A Comparative Study on Phytochemical Fingerprint of Two Diverse Phaseolus vulgarisvar. Tondino del Tavo and Cannellino Bio Extracts.

Common bean (Phaseolus vulgaris) represents one of the most famous foods with antiobesity activity showing a significant efficacy against fat accumulation, insulin resistance and dyslipidaemia. In this work, two Italian varieties of common bean, i.e., Tondino del Tavo and Cannellino Bio, from the centre of Italy were studied to characterise their phenolic profile by HPLC-PDA in relation to different fractions after a straightforward extraction procedure. Antioxidant property and enzymatic inhibition power were also evaluated in order to delineate a possible biological profile. Results show a considerable phenolic content (0.79 and 1.1 µg/mg of 3-hydroxybenzoic acid for hexane extract of Tondino del Tavo and Cannellino Bio, respectively; 0.30 µg/mg p-coumaric acid for n-hexane extract of Tondino del Tavo) for both varieties, and a strong antioxidant activity according to the major phenolic concentration of the extracts. The anti-inflammatory activity of the decoction extracts was also investigated through a zymosan-induced edema formation assay, revealing a moderate ability for both of them. These preliminary data prompt us to further explore the nutrient components of these two varieties in the future.

A Study on Chemical Characterization and Biological Abilities of Alstonia boonei Extracts Obtained by Different Techniques.

In the quest for novel therapeutic agents from plants, the choice of extraction solvent and technique plays a key role. In this study, the possible differences in the phytochemical profile and bioactivity (antioxidant and enzyme inhibitory activity) of the Alstonia boonei leaves and stem bark extracted using water, ethyl acetate and methanol, and different techniques, namely infusion, maceration and Soxhlet extraction, were investigated. Data collected showed that methanol extracts of both A. boonei leaves (48.34-53.08 mg gallic acid equivalent [GAE]/g dry extract) and stem bark (37.08-45.72 mg GAE/g dry extract) possessed higher phenolic content compared to the ethyl acetate extracts (leaves: 30.64-40.19 mg GAE/g; stem bark: 34.25-35.64 mg GAE/g). The methanol extracts of A. boonei leaves showed higher radical scavenging and reducing capacity, and these findings were in accordance with phenolic content results. In general, water extracts of A. boonei leaves and stem bark obtained by infusion were poor inhibitors of acetylcholinesterase, α-amylase, α-glucosidase, and tyrosinase, except for butyrylcholinesterase. The chemical profiles of the extracts were determined by UHPLC-MS and the presence of several compounds, such as phenolic acids (caffeic, chlorogenic and ferulic acids, etc.), flavonoids (rutin and isoquercetin) and flavonolignans (Cinchonain isomers). Cell viability was tested using the human peripheral blood monocytic cell line (THP-1), and the extracts were safe up to 25 µg/mL. In addition, anti-inflammatory effects were investigated with the releasing of IL-6 TNF-α and IL-1ß. In particular, stem bark extracts exhibited significant anti-inflammatory effects. Data presented in this study highlight the key role of solvent choice in the extraction of bioactive secondary metabolites from plants. In addition, this study appraises the antioxidant and enzyme inhibitory action of A. boonei leaves and stem bark, which are extensively used in traditional medicine.