Anti-inflammatory effect of natural and semi-synthetic phthalides

Synthesis and Anti-Inflammatory and Analgesic Potentials of Ethyl 2-(2,5-Dioxo-1-Phenylpyrrolidin-3-yl)-2-Methylpropanoate

Background/Objectives: Inflammation and analgesia are two prominent symptoms and often lead to chronic medical conditions. To control inflammation and analgesia, many marketed drugs are in practice but the majority of them have severe side effects. Methods: This study involved the synthesis of a pivalate-based Michael product and evaluated it for in vitro COX-1, COX-2, and 5-LOX inhibitory potentials using specific assays. Molecular docking studies were also assessed. Based on the in vitro results, the compound was also subjected to in vivo anti-inflammatory and antinociceptive studies. Results: The pivalate-based Michael product (MAK01) was synthesized by an organocatalytic asymmetric Michael addition of ethyl isobutyrate to N-phenylmaleimide with an isolated yield of 96%. The structure of the compound was confirmed through 1H and 13C NMR analyses. The observed IC50 values for COX-1, COX-2, and 5-LOX were 314, 130, and 105 μg/mL, respectively. The molecular docking studies on the synthesized compound showed binding interactions with the minimized pockets of the respective enzymes. In a carrageenan model, a percent reduction in edema when administered at 10 mg/kg (a reduction of 33.3 ± 0.77% at the second hour), 20 mg/kg (a reduction of 34.7 ± 0.74% at the second hour), and 30 mg/kg (a reduction of 40.58% ± 0.84% after the fifth hour) was observed. The compound showed a significant response at concentrations of 50, 100, and 150 mg/kg with latency times of 10.32 ± 0.82, 12.16 ± 0.51, and 12.93 ± 0.45 s, respectively. Conclusion: In this study, we synthesized a pivalate-based Michael product for the first time. Moreover, based on its rationality and potency, it was found to be an effective future medicine for the management of analgesia and inflammation.

The phthalide compound tokinolide B from Angelica sinensis exerts anti-inflammatory effects through Nur77 binding

BACKGROUND

Nur77, an orphan member of the nuclear receptor superfamily, regulates inflammatory diseases and is a therapeutic target for treating inflammation. Phthalides in Angelica sinensis exhibit anti-inflammatory activity.

PURPOSE

This study aimed to screen compounds from A. sinensis phthalide extract that could exert anti-inflammatory activity by targeting Nur77. To provide new theoretical support for better elucidation of Chinese medicine targeting mitochondria to achieve multiple clinical efficacies.

METHODS

The anti-inflammatory capacity of phthalides was assessed in tumor necrosis factor-alpha (TNF-α)-stimulated HepG2 cells using western blotting. The interaction between phthalides and Nur77 was verified by molecular docking, surface plasmon resonance, and cellular thermal shift assay. Co-immunoprecipitation, western blotting, and immunostaining were performed to determine the molecular mechanisms. The in vivo anti-inflammatory activity of the phthalides was evaluated in a lipopolysaccharide (LPS)/d-galactosamine (d-GalN)-induced acute hepatitis and liver injury mouse model of acute hepatitis and liver injury. Finally, the toxicity of phthalide toxicity was assessed in zebrafish experiments.

RESULTS

Among the 27 phthalide compounds isolated from A. sinensis, tokinolide B (TB) showed the best Nur77 binding capacity and, the best anti-inflammatory activity, which was induced without apoptosis. In vivo and in vitro experiments showed that TB promoted Nur77 translocation from the nucleus to the mitochondria and interacted with tumor necrosis factor receptor-associated factor 2 (TRAF2) and sequestosome 1 (p62) to induce mitophagy for anti-inflammatory functions. TB substantially inhibited LPS/d-GalN-induced acute hepatitis and liver injury in mice. TB also exhibited significantly lower toxicity than celastrol in zebrafish experiments.

CONCLUSION

These findings suggested that TB inhibits inflammation by promoting Nur77 interaction with TRAF2 and p62, thereby inducing mitophagy. These findings offer promising directions for developing novel anti-inflammatory agents, enhance the understanding of phthalide compounds, and highlight the therapeutic potential of traditional Chinese herbs.

LcSAO1, an Unconventional DOXB Clade 2OGD Enzyme from Ligusticum chuanxiong Catalyzes the Biosynthesis of Plant-Derived Natural Medicine Butylphthalide

Butylphthalide, a prescription medicine recognized for its efficacy in treating ischemic strokes approved by the State Food and Drug Administration of China in 2005, is sourced from the traditional botanical remedy Ligusticum chuanxiong. While chemical synthesis offers a viable route, limitations in the production of isomeric variants with compromised bioactivity necessitate alternative strategies. Addressing this issue, biosynthesis offers a promising solution. However, the intricate in vivo pathway for butylphthalide biosynthesis remains elusive. In this study, we examined the distribution of butylphthalide across various tissues of L. chuanxiong and found a significant accumulation in the rhizome. By searching transcriptome data from different tissues of L. chuanxiong, we identified four rhizome-specific genes annotated as 2-oxoglutarate-dependent dioxygenase (2-OGDs) that emerged as promising candidates involved in butylphthalide biosynthesis. Among them, LcSAO1 demonstrates the ability to catalyze the desaturation of senkyunolide A at the C-4 and C-5 positions, yielding the production of butylphthalide. Experimental validation through transient expression assays in Nicotiana benthamiana corroborates this transformative enzymatic activity. Notably, phylogenetic analysis of LcSAO1 revealed that it belongs to the DOXB clade, which typically encompasses genes with hydroxylation activity, rather than desaturation. Further structure modelling and site-directed mutagenesis highlighted the critical roles of three amino acid residues, T98, S176, and T178, in substrate binding and enzyme activity. By unraveling the intricacies of the senkyunolide A desaturase, the penultimate step in the butylphthalide biosynthesis cascade, our findings illuminate novel avenues for advancing synthetic biology research in the realm of medicinal natural products.

Integrating Chemical Profiling, In Vivo Study, and Network Pharmacology to Explore the Anti-inflammatory Effect of Pterocarpus dalbergioides Fruits and Its Correlation with the Major Phytoconstituents

The purpose of this study is to explore the anti-inflammatory activity of Pterocarpus dalbergioides fruit extract (PFE) and the underlying mechanism. Chemical profiling using ultraperformance liquid chromatography/mass spectrometry identified 28 compounds in PFE (12 flavonoids, 5 fatty acids, 4 phenolic compounds, 3 alkaloids, 2 sesquiterpenes, and 2 xanthophylls). PFE (2 g/kg) significantly inhibited carrageenan-induced rat paw edema after 4 h of administration (42% inhibition). A network-based strategy and molecular docking studies were utilized to uncover the anti-inflammatory mechanism. Out of the identified compounds, 16 compounds with DL ≥ 0.18 and F ≥ 30% were selected using bioavailability (F) and drug-likeness (DL) metrics. The network analysis revealed that 90 genes are considered key targets for the selected compounds and linked to the anti-inflammatory effect. Among all compounds, linoleic acid was found to be the top-most active constituent as it targets maximum genes. Four targets (TNF, IL6, AKT1, and CCL2) among the top 10 genes were found to be the main target genes that may contribute to the anti-inflammatory potential of PFE. Furthermore, KEGG (Kyoto encyclopedia of genes and genomes) pathway analysis revealed that PFE might regulate inflammation through five pathways: neuroactive ligand-receptor interaction, lipid and atherosclerosis, fluid shear stress and atherosclerosis, TNF signaling pathway, and rheumatoid arthritis. The docking study predicted the significant binding affinity between the top four active constituents (linoleic acid, 9-octadecenoic acid, 11,12,13-trihydroxy-9-octadecenoic acid, and rhamnetin-3-O-rhamnoside) and the selected target proteins (TNF and AKT1). The findings highlight PFE as a promising drug lead for controlling inflammation.

Synthesis and Antioxidant/Anti-Inflammatory Activity of 3-Arylphthalides

Phthalides are a group of compounds with relevant biological activities in different areas such as cytotoxicity, anti-stroke activity, neuroprotection, and inflammation, among others. In this study we designed and synthesized a series of 3-arylphthalide derivatives in order to identify their antioxidant and anti-inflammatory activities. The synthetic methodology was established in terms of atom and step economy through a dehydrative coupling reaction between 3-hydroxyphthalide and different properly functionalized arene rings. The evaluation of the antioxidant activity was performed by the ABTS assay and for the anti-inflammatory activity the inhibition of LPS-induced nitric oxide (NO) production in microglial cells Bv.2 and macrophage cells RAW 264.7 was measured. The synthesized compound 3-(2,4-dihydroxyphenyl)phthalide (5a) showed better antioxidant activity than the Trolox standard and caused strong inhibition of NO production in LPS-stimulated Bv.2 and RAW 264.7 cells. In addition, compound 5a reduced the expression of the pro-inflammatory cytokines Il1b and Il6 in RAW 264.7 cells. These results, which are the first account of the anti-inflammatory activity of 3-arylphthalides, suggest that compound 5a could be a promising candidate for more advanced anti-inflammatory studies.

Identification of a 3-(5-methyl-2-thiazolylamino)phthalide as a new minor groove agent

A new 3-(5-methyl-2-thiazolylamino)phthalide molecule, 3-((5-methylthiazol-2-yl)amino)isobenzofuran-1(3H)-one, was synthesized and characterized experimentally by FT-IR, NMR, UV-Vis, and single-crystal X-ray analysis and theoretically by quantum chemical calculations. The single-crystal X-ray studies revealed that the compound crystallizes in the monoclinic space group P-2_1/c with unit-cell parameters a = 8.0550(6) Å, b = 6.1386(3) Å, c = 23.3228(18) Å, β = 97.724(6)° and Z = 4. Optimized geometries and the vibrational frequencies were studied at the density functional theory (DFT) level by using the hybrid functional B3LYP with a 6-311 G (d,p) basis set. The title compound was evaluated for its anti-quorum sensing (anti-QS) activity on Chromobacterium violaceum 12472 and additionally for its antibacterial activity against Staphylococcus aureus 29213, Staphylococcus epidermidis 12228, Pseudomonas aeruginosa 27853, Escherichia coli 25922, and Proteus mirabilis 14153. The lowest MIC value was 0.24 μg/mL for S. aureus 29213 and the highest MIC value was 30.75 μg/mL for E. coli 25922. While anti-bacterial activity was observed in those other than the S. epidermidis and P. Mirabilis, anti-QS activity wasn't detected. Investigations on dsDNA binding affinity indicate that the title compound binds to dsDNA via the groove binding mode. Molecular docking calculations and molecular dynamics simulations results showed also that the title compound prefers binding to the minor groove of dsDNA and remains stable in the minor groove throughout the molecular dynamics simulation.Communicated by Ramaswamy H. Sarma.

Reviewing the Benefits of Grazing/Browsing Semiarid Rangeland Feed Resources and the Transference of Bioactivity and Pro-Healthy Properties to Goat Milk and Cheese: Obesity, Insulin Resistance, Inflammation and Hepatic Steatosis Prevention

The rangeland is an ecological resource that provides multiple benefits for environment and agriculture. Grazing/browsing on rangelands is a useful and inexpensive means to produce food derived from animal products. The aim of this study was to review the benefits of producing milk and cheese under this system in terms of bioactivity and the health benefits of their consumption in model animals. To conduct this review, we particularly considered the experiments that our research group carried out along the last fifteen years at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico. Firstly, we examined the forages consumed by goats on the rangelands in terms of plant bioactive compound occurrence and their concentration. Further, goat milk and cheese coming from (1) grazing animals, (2) animals managed indoors, and from (3) animals managed indoor supplemented with rich plant bioactive compounds, were analyzed. Milk was discussed to modulate the negative effects of high-fat diets in mice. Forages consumed by goats on the rangelands showed a close correlation between antioxidant activity assessed by the DPPH⁺ radical with total flavonoid and total polyphenol contents (TPC). Milk concentration of PUFA, MUFA, and n-3 fatty acids from grazing goats (4.7%, 25.2%, and 0.94% of FAME) was higher than milk from goats fed indoor diets (ID). Similar results were shown in cheese. TPC was higher in cheese manufactured with milk from grazing goats (300 mg of GAE/kg of cheese) when compared to cheese from milk goats fed ID (60 mg of GAE/of cheese). Acacia pods are a semiarid rangeland feed resource that transfers pro-healthy activity, inhibited in vitro lipid peroxidation (inhibition of TBARS formation) and diminished the damage induced by reactive oxygen species (ROS). Additionally, in vivo assessment revealed that Acacia species increased free radical scavenging (DPPH), oxygen radical absorbance capacity, and anti-inflammatory activity. The results highlight that grazing/browsing practices are superior to indoor feeding in order to promote the transference of bioactive compounds from vegetation to animal tissue, and finally to animal products. Grazing management represents a better option than indoor feeding to enhance bioactivity of milk and cheese. Supplementation with rich-bioactive compound forages increased total polyphenol, hydroxycinnamic acids, and flavonoid concentrations in milk and cheese. The consumption of goat milk prevents obesity, insulin resistance, inflammation, and hepatic steatosis while on a high-fat diet induced obesity in mice.

Mexican Plants and Derivates Compounds as Alternative for Inflammatory and Neuropathic Pain Treatment-A Review

Despite the availability of many anti-pain drugs, in the form of NSAIDs, steroids, gabapentinoids, opioids, and antidepressants, in this study we address the natural compounds belonging to the group of Mexican medicinal plants or "Mexican folk medicine", used for pain management in Mexico. Our interest in this subject is due to the growing idea that "natural is harmless" and to the large number of side effects exhibited in pharmacotherapy. The objective of this review was to document the scientific evidence about Mexican medicinal plants and their derivatives used for inflammatory and neuropathic pain treatment, as well as the mechanisms of action implicated in their antinociceptive effects, their possible adverse effects, and the main pharmacological aspects of each plant or compound. Our data review suggested that most studies on Mexican medicinal plants have used inflammatory experimental models for testing. The anti-pain properties exerted by medicinal plants lack adverse effects, and their toxicological assays report that they are safe to consume; therefore, more studies should be performed on preclinical neuropathic pain models. Moreover, there is no convincing evidence about the possible mechanisms of action involved in the anti-pain properties exerted by Mexican plants. Therefore, the isolation and pharmacological characterization of these plant derivatives' compounds will be important in the design of future preclinical studies.

Novel phthalide derivatives: Synthesis and anti-inflammatory activity in vitro and in vivo

Phthalide is a promising chemical scaffold and has been proved to show potent anti-inflammatory efficacy. In this study, three series, total of 31 novel phthalide derivatives were designed and synthesized, their anti-inflammatory activities were screened in vitro and in vivo. The anti-inflammatory activity of all the compounds were screened on LPS induced NO production to evaluating their inhibitory effects. Structure-activity relationship has been concluded, and finally 3-((4-((4-fluorobenzyl)oxy)phenyl)(hydroxy)methyl)-5,7-dimethoxyisobenzofuran-1 (3H)-one (compound 9o) was found to be the active one with low toxicity, which showed 95.23% inhibitory rate at 10 μM with IC₅₀ value of 0.76 μM against LPS-induced NO over expression. Preliminary mechanism studies indicated that compound 9o activated Nrf2/HO-1 signaling pathway via accumulation ROS and blocks the NF-κB/MAPK signaling pathway. The in vivo anti-inflammatory activity shown that compound 9o had obvious therapeutic effect against the adjuvant-induced rat arthritis model.

Anti-inflammatory, antioxidant, and gaso-protective mechanism of 3α-hydroxymasticadienoic acid and diligustilide combination on indomethacin gastric damage

The co-administration of 3α-hydroxymasticadienoic acid (3α-OH MDA) and diligustilide (DLG) generates a synergist gastroprotective effect on indomethacin-induced gastric damage. However, the related protective activities of the compounds alone (or in combination) remain unclear. In the present study, we evaluated the anti-inflammatory and antioxidative activities, as well as the potential modulation of important gasotransmitters of each compound individually and in combination using the indomethacin-induced gastric damage model. Male Wistar rats were treated orally with the 3α-OH MDA, DLG, or their combination (at a fixed ratio of 1:1, 1:3, and 3:1) 30 min before the generation of gastric mucosal lesions with indomethacin (30 mg/kg, p.o.). Three hours later, the gastric injury (mm²) was determined. Results from these experiments indicate, in addition to maintaining basal levels of PGE₂, the gastroprotective effect of the pre-treatment with 3α-OH MDA (70%), DLG (81%), and their combination (72%) which was accompanied by significant decreases in leukocyte recruitment, as well as decreases in TNF-α and LTB₄ gastric levels (p < 0.05). We also found that the pre-treatment maintains the basal antioxidant enzyme activities (SOD) and gastric NO and H₂S production even in the presence of indomethacin (p < 0.05). In conclusion, when 3α-OH MDA-DLG is given at a 1:1 combination ratio, the gastroprotective effect and the inflammatory, antioxidant, and gaso-modulation properties are not different from those of treatments using the maximum doses of each compound, revealing that this combination produces promising results for the treatment of gastric ulcers.

Synthesis, Bioevaluation, Structure-Activity Relationship and Docking Studies of Natural Product Inspired (Z)-3-benzylideneisobenzofuran-1(3H)-ones as Highly Potent antioxidants and Antiplatelet agents

For the first time, a series of highly potent natural product inspired substituted (Z)-3-benzylideneisobenzofuran-1(3H)-ones 28a-t, embraced with electron-withdrawing groups (EWG) and electron-donating groups (EDG) at site I and site II, were prepared and assessed for their in vitro antioxidant activities (DPPH free radical scavenging assay) and arachidonic acid (AA)-induced antiplatelet activities using ascorbic acid (IC₅₀ = 4.57 µg/mL) and aspirin (IC₅₀ = 21.34 µg/mL), as standard references, respectively. In this study, compounds 28f-g, 28k-l and 28q have shown high order of in vitro antioxidant activity. Infact, 28f and 28k were found to show 10-folds and 8-folds more antioxidant activity than ascorbic acid, respectively and was found to be the most active analogues of the series. Similarly, Compounds 28c-g, 28k-l, 28o and 28q-t were recognized as highly potent antiplatelet agents (upto 6-folds) than aspirin. Furthermore, in silico studies of the most active antioxidants 28f, 28k and 28l and very active antiplatelet molecules 28f, 28k, 28l and 28s were carrying out for the validation of the biological results. This is the first detailed study of the discovery of several (Z)-3-benzylideneisobenzofuran-1(3H)-ones as highly potent antioxidants and antiplatelet agents.

Pharmacodynamic interaction of 3α-hydroxymasticadienonic acid and diligustilide against indomethacin-induced gastric damage in rats

The aims of the study were to evaluate the pharmacodynamic interaction between 3α-hydroxymasticadienonic acid and diligustilide (DLG), isolated from the plants Amphiptherygium adstringens and Ligusticum porteri, respectively, using the indomethacin-induced gastric injury model, as well as their individual gastroprotective efficacy in this model. Male Wistar rats were orally administered with 3α-hydroxymasticadienonic acid, DLG or the mixture of 3α-hydroxymasticadienonic acid-DLG (at a fixed-ratio combination of 1:1, 1:3, and 3:1). Thirty minutes later, the gastric damage was induced by a single oral dose of indomethacin (30 mg/kg). Three hours later, the gastric injury (mm2 ) was determined. 3α-hydroxymasticadienonic acid and DLG as individual compounds showed a gastroprotective effect against indomethacin-induced gastric damage (p < .05). The effective dose (ED50 ) values for each compound were 6.96 ± 1.25 mg/kg for 3α-hydroxymasticadienonic acid and 2.63 ± 0.37 mg/kg for DLG. The isobolographic analysis performed showed that the combination exhibited super-additive interaction as the experimental ED50 values (Zexp) were lower than theoretical additive dose values (Zadd; p < .05). Our results identify the super-additive (synergist) interaction between 3α-hydroxymasticadienonic acid and DLG and the gastric safety of both compounds in the indomethacin-induced gastric injury model, suggesting their potential in the future as a strategy to decrease the gastric damage associated to the chronic use of nonsteroidal anti-inflammatory drugs (NSAIDs).

Chemistry and Biology of Selected Mexican Medicinal Plants

Herbal medicines are an integral element of alternative medical care in Mexico, and the best testimony to their efficacy and cultural value is their persistence in contemporary Mexican marketplaces where the highest percentages of medicinal and aromatic plants are sold. This chapter summarizes current trends in research on medicinal plants in Mexico, with emphasis on work carried out at the authors' laboratories. The most relevant phytochemical and pharmacological profiles of a selected group of plants used widely for treating major national health problems are described.From this contribution, it is evident that in the last five decades a significant amount of research on medicinal plants has been performed by Mexican scientists. Such efforts have led to the publication of many research papers in noted peer-reviewed journals and technical books. The isolation and structural characterization of hundreds of bioactive secondary metabolites have been accomplished, and most importantly, these studies have tended to support the ethnomedical uses of many different species. A multidisciplinary approach for investigating these plants has led to an increased emphasis on areas such as phytopharmacology, phytotoxicology, quality control, regulation, and conservation issues for these valuable resources. The medicinal plants analyzed so far have shown a very broad chemical diversity of their constituents, which have a high potential for exhibiting novel mechanistic effects biologically. The chapter shows also that there is need to conduct additional clinical studies on herbal drugs, in particular because the longstanding traditional evidence for their safety is not always sufficient to assure their rational use. There is also need to move to "omics" approaches for investigating the holistic effect and the influence of groups of phytochemicals on the whole organism. Mexican scientists may be expected to have bright prospects in this regard, which will imbue medicinal plant research with a new dynamism in the future.

Phenolic Compounds in Organic and Aqueous Extracts from Acacia farnesiana Pods Analyzed by ULPS-ESI-Q-oa/TOF-MS. In Vitro Antioxidant Activity and Anti-Inflammatory Response in CD-1 Mice

BACKGROUND

Acacia farnesiana (AF) pods have been traditionally used to treat dyspepsia, diarrhea and topically for dermal inflammation. Main objectives: (1) investigate the antioxidant activity and protection against oxidative-induced damage of six extracts from AF pods and (2) their capacity to curb the inflammation process as well as to down-regulate the pro-inflammatory mediators.

METHODS

Five organic extracts (chloroformic, hexanic, ketonic, methanolic, methanolic:aqueous and one aqueous extract) were obtained and analyzed by UPLC-ESI-Q-oa/TOF-MS. Antioxidant activity (DPPH•, ORAC and FRAP assays) and lipid peroxidation (TBARS assay) were performed. Assessment of anti-inflammatory properties was made by the ear edema induced model in CD-1 mice and MPO activity assay. Likewise, histological analysis, IL-1β, IL-6, IL-10, TNF-α, COX measurements plus nitrite and immunohistochemistry analysis were carried out.

RESULTS

Methyl gallate, gallic acid, galloyl glucose isomer 1, galloyl glucose isomer 2, galloyl glucose isomer 3, digalloyl glucose isomer 1, digalloyl glucose isomer 2, digalloyl glucose isomer 3, digalloyl glucose isomer 4, hydroxytyrosol acetate, quinic acid, and caffeoylmalic acid were identified. Both organic and aqueous extracts displayed antioxidant activity. All extracts exhibited a positive effect on the interleukins, COX and immunohistochemistry assays.

CONCLUSION

All AF pod extracts can be effective as antioxidant and topical anti-inflammatory agents.

Tyrosol and its metabolites as antioxidative and anti-inflammatory molecules in human endothelial cells

Novel biological activities for tyrosol metabolites on human endothelial cells.