Gastroprotective potential of Pentahydroxy flavone isolated from Madhuca indica J. F. Gmel. leaves against acetic acid-induced ulcer in rats: The role of oxido-inflammatory and prostaglandins markers

Potential of natural products in inflammation: biological activities, structure-activity relationships, and mechanistic targets

A balance between the development and suppression of inflammation can always be found in the body. When this balance is disturbed, a strong inflammatory response can damage the body. It sometimes is necessary to use drugs with a significant anti-inflammatory effect, such as nonsteroidal anti-inflammatory drugs and steroid hormones, to control inflammation in the body. However, the existing anti-inflammatory drugs have many adverse effects, which can be deadly in severe cases, making research into new safer and more effective anti-inflammatory drugs necessary. Currently, numerous types of natural products with anti-inflammatory activity and distinct structural features are available, and these natural products have great potential for the development of novel anti-inflammatory drugs. This review summarizes 260 natural products and their derivatives with anti-inflammatory activities in the last two decades, classified by their active ingredients, and focuses on their structure-activity relationships in anti-inflammation to lay the foundation for subsequent new drug development. We also elucidate the mechanisms and pathways of natural products that exert anti-inflammatory effects via network pharmacology predictions, providing direction for identifying subsequent targets of anti-inflammatory natural products.

Madhuca indica: A Review on the Phytochemical and Pharmacological Aspects

Madhuca indica J.F. Gmel. (family: Sapotaceae), commonly known as Mahua in Indian dialects, occupies the importance as one of the fuel-efficient, energy-saving plant species. Extensive studies showed that the presence of phytochemicals e.g., carbohydrates, fatty acids, flavonoids, saponins, steroids, triterpenoids and glycosidic compounds in the extract of this species. Pharmacologically, it has been used against various disorders in indigenous system of medicine, inckuding antioxidant, anti-inflammatory, anticancer, hepatoprotective, anti-diabetic and wound healing activities. This review highlights various pharmacological activities, phytochemistry and importance of M. indica plant for medicine.

Quercetin-loaded chitosan nanoparticles ameliorate adjuvant-induced arthritis in rats by regulating anti-oxidant enzymes and downregulating pro- and inflammatory cytokines

Rheumatoid arthritis (RA) is an inflammatory condition and associated with the symmetrical synovitis of the joints and cause joint pain. The use of anti-rheumatic drugs is associated with many adverse effects. Quercetin, an important polyphenolic flavonoid, possess anti-inflammatory and anti-rheumatic effects. Quercetin use is limited due to poor absorption and bioavailability. Nanomedicines are used for the targeted drug delivery, hence it reduces the adverse effects of the drug. Based upon these factors, quercetin-loaded chitosan nanoparticles (Q-NPs) were prepared by solvent evaporation method, characterized and their better anti-rheumatic effect with mechanistic insights was validated in Freund's complete adjuvant (FCA)-induced arthritic rats along with safety studies. The animals were divided into five groups, each containing 5 animals. Group I was normal control, group II was arthritic control, while groups III, IV and V were administered with quercetin (15 mg/Kg) and Q-NPs (10 and 20 mg/Kg), respectively. The reduction in ankle diameter, serum oxidative stress markers as well as pro- and inflammatory cytokines, e.g., tumor necrosis factor (TNFα), interleukin (IL-6) were determined. The prepared Q-NPs showed hydrodynamic size of 83.9 nm, polydispersity index of 0.687, entrapment efficiency 90.5% as well as no interaction between quercetin and chitosan in Fourier transform infrared spectroscopy (FTIR). A significant reduction (p < 0.001) in ankle diameter was observed after administration of high-dose Q-NPs (4.32 ± 0.14 cm to 5.13 ± 0.62 cm). There was also reduction (p < 0.001) in levels of TNFα and IL-6 following high-dose Q-NPs (72.56 ± 2.30 and 308.19 ± 11.5 pg). The effect on biochemical tests, hematological parameters and oxidative stress parameters was also found to be significant. Histopathological changes of kidney, liver and ankle also confirmed the anti-rheumatic effect of high-dose Q-NPs. The study concludes that administration of Q-NPs (20 mg/Kg) may be used for the treatment of FCA-induced RA in rats.

Flavonols and Flavones as Potential anti-Inflammatory, Antioxidant, and Antibacterial Compounds

Plant preparations have been used to treat various diseases and discussed for centuries. Research has advanced to discover and identify the plant components with beneficial effects and reveal their underlying mechanisms. Flavonoids are phytoconstituents with anti-inflammatory, antimutagenic, anticarcinogenic, and antimicrobial properties. Herein, we listed and contextualized various aspects of the protective effects of the flavonols quercetin, isoquercetin, kaempferol, and myricetin and the flavones luteolin, apigenin, 3 $\prime$ ,4 $\prime$ -dihydroxyflavone, baicalein, scutellarein, lucenin-2, vicenin-2, diosmetin, nobiletin, tangeretin, and 5-O-methyl-scutellarein. We presented their structural characteristics and subclasses, importance, occurrence, and food sources. The bioactive compounds present in our diet, such as fruits and vegetables, may affect the health and disease state. Therefore, we discussed the role of these compounds in inflammation, oxidative mechanisms, and bacterial metabolism; moreover, we discussed their synergism with antibiotics for better disease outcomes. Indiscriminate use of antibiotics allows the emergence of multidrug-resistant bacterial strains; thus, bioactive compounds may be used for adjuvant treatment of infectious diseases caused by resistant and opportunistic bacteria via direct and indirect mechanisms. We also focused on the reported mechanisms and intracellular targets of flavonols and flavones, which support their therapeutic role in inflammatory and infectious diseases.

Structural characterization of a polysaccharide from Radix Hedysari and its protective effects against H2O2-induced injury in human gastric epithelium cells

The gastroprotective effects of polysaccharides had become a hot topic in the field of functional polysaccharides research. Three polysaccharides, namely HPS-80-1, HPS-80-2, and HPS-80-3 were purified by DEAE-52 column chromatography. The thermodynamic characteristics, scanning electron microscopy, and Congo red experimental results of the above polysaccharides were greatly distinctive. Then a mature GES-1 oxidative stress cell model induced by H₂O₂ was established to screen out subsequent research subjects. It turned out that HPS-80-1 had a desirable protective effect, which was confirmed by analyses of cell cycle & apoptosis, and oxidative stress-related factors in the cell culture media, and so on. Furthermore, Structural features demonstrated that the backbone of HPS-80-1 appeared to mainly consist of →4)-α-D-Glcp-(1→, →4,6)-β-L-Glcp-(1→, and →6)-α-D-Galp-(1→, with branches at O-1, O-4, and O-6 position consisting of →2,4)-β-D-Rhap-(1→, →1)-α-D-Galp-(4→, and →3,4)-α-D-Manp-(1→. It was speculated that the excellent gastric mucosal protective activity of HPS-80-1 may be due to the high amount of glucose in the backbone. In addition, it was also related to the anti-inflammatory activity and antioxidant bases such as (1 → 4)-Glcp and (1 → 6)-Galp in the structure of HPS-80-1. These findings provide a scientific basis for further utilization of polysaccharides from Radix Hedysari.

Pentahydroxy flavonoid isolated from Madhuca indica ameliorated adjuvant-induced arthritis via modulation of inflammatory pathways

Rheumatoid arthritis (RA) is an autoimmune disease associated with advanced joint dysfunction. Madhuca indica J. F. Gmel, from the family Sapotaceae, is an Indian medicinal plant reported to have an array of pharmacological properties. The aim of present investigation was to determine the anti-arthritic potential of an isolated phytoconstituent from methanolic leaf extract of Madhuca indica (MI-ALC) against FCA-induced experimental arthritis. Polyarthritis was induced in female rats (strain: Wistar) via an intradermal injection of FCA (0.1 mL) into the tail. Polyarthritis developed after 32 days of FCA administration. Then rats were treated orally with an isolated phytoconstituent from MI-ALC at doses of 5, 10, and 20 mg/kg. Findings suggested that High-Performance Thin-Layer Chromatography, Fourier-Transform Infrared Spectroscopy, and Liquid Chromatography-Mass Spectrometry spectral analyses of the phytoconstituent isolated from MI-ALC confirmed the structure as 3,5,7,3′,4′-Pentahydroxy flavone (i.e., QTN). Treatment with QTN (10 and 20 mg/kg) showed significant (p < 0.05) inhibition of increased joint diameter, paw volume, paw withdrawal threshold, and latency. The elevated synovial oxidative stress (Superoxide dismutase, reduced glutathione, and malondialdehyde) and protein levels of Tumor necrosis factor-α (TNF-α) and Interleukin (ILs) were markedly (p < 0.05) reduced by QTN. It also effectively (p < 0.05) ameliorated cyclooxygenase-2 (COX-2), Nuclear factor of kappa light polypeptide gene enhancer in B cells (NF-kβ) and its inhibitor-α (Ikβα), and ATP-activated P2 purinergic receptors (P2X7) protein expressions as determined by western blot analysis. In conclusion, QTN ameliorates FCA-induced hyperalgesia through modulation of elevated inflammatory release (NF-kβ, Ikβα, P2X7, and COX-2), oxido-nitrosative stress, and pro-inflammatory cytokines (ILs and TNF-α) in experimental rats.

Recent Progress in Environmental Toxins-Induced Cardiotoxicity and Protective Potential of Natural Products

Humans are unconsciously exposed to environmental toxins including heavy metals as well as various pesticides, which have deleterious effects on human health. Accumulating studies pointed out that exposure to environmental toxins was associated with various cardiopathologic effects. This review summarizes the main mechanisms of cardiotoxicity induced by environmental toxins (cadmium, arsenic and pesticides) and discusses the potential preventive effects of natural products. These findings will provide a theoretical basis and novel agents for the prevention and treatment of environmental toxins-induced cardiotoxicity. Furthermore, the limitations of current studies, future needs and priorities are discussed.

Neuroprotective potential of fisetin in an experimental model of spinal cord injury: via modulation of NF-κB/IκBα pathway

AIM

To evaluate neuroprotective efficacy of fisetin against the experimental model of spinal cord injury (SCI).

MATERIALS AND METHODS

SCI was induced in male Sprague-Dawley rats by placing an aneurysm clip extradurally. Rats were treated either with vehicle or fisetin for 28 days after SCI.

RESULTS

Treatment with fisetin significantly attenuated SCI-induced alternations in mechano-tactile and thermal allodynia, hyperalgesia and nerve conduction velocities. SCI-induced upregulated tumor necrosis factor-alpha, interleukins, inducible nitric oxide synthase, cyclooxygenase-II, Bcl-2-associated X protein and caspase-3 mRNA expressions in the spinal cord and these were markedly reduced by fisetin. Spinal nuclear factor kappa B and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha protein levels were also significantly downregulated by fisetin. Hematoxylin and eosin staining of spinal cord suggested that fisetin significantly ameliorated histological aberrations such as neuronal degeneration, necrosis and inflammatory infiltration induced in it.

CONCLUSION

Fisetin exerts neuroprotection via modulation of nuclear factor kappa B/nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha pathway by inhibiting release of inflammatory mediators (inducible nitric oxide synthase and cyclooxygenase-II), proinflammatory cytokines (tumor necrosis factor-alpha and interleukins), apoptotic mediators (Bcl-2-associated X protein and caspase-3).

Gastroprotective activity of Hypericum perforatum extract in ethanol-induced gastric mucosal injury in Wistar rats: A possible involvement of H+/K+ ATPase α inhibition

Hypericum perforatum (HP) is a plant native to Asia and Europe. It has been documented to enclose medical effects against many disorders such as anxiety, depression and burns. This experiment was performed to evaluate the gastro-protective effect of Hypericum perforatum leaf extract in ethanol induced gastric ulcer in rats as compared to esomeprazole (the drug of choice for stomach ulcers). The mechanism of action was performed by Auto Dock Vina method.

Ethanol ingestion up regulated the inflammatory reaction as demonstrated by rise of gastric proinflammatory TNF-α with a decline of IL-1β. On the other hand, the phytochemical screening of HP revealed the presence of alkaloids, flavonoids, tannins, phenols, steroids and saponins. The high dose of HP group shows mild injuries to the gastric mucosa which is comparable to the esomeprazole group, in contrast, severe damages are observed in the gastric mucosa of the ulcer control rats group. In silico results revealed that Amentoflavone and Quercitrin have highest affinity and very good interactions with H+/K+ ATPase α active site. This study showed that HP is nearly as effective as esomeprazole to prevent ethanol induced gastric ulcer the plant extract and it has more binding affinity than esomeprazole to gastric proton pumps.

Preventative and Therapeutic Potential of Flavonoids in Peptic Ulcers

Peptic ulcer disease is a common gastrointestinal tract disorder that affects up to 20% of the population of the world. Treatment of peptic ulcer remains challenging due to the limited effectiveness and severe side effects of the currently available drugs. Hence, natural compounds, owing to their medicinal, ecological, and other safe properties, are becoming popular potential candidates in preventing and treating peptic ulcers. Flavonoids, the most abundant polyphenols in plants, exhibit gastroprotective effects against peptic ulcer both in vivo and in vitro. In this review, we summarized the anti-ulcer functions and mechanisms, and also the bioavailability, efficacy, and safety, of flavonoid monomers in the gastrointestinal tract. Flavonoids exerted cytoprotective and rehabilitative effects by not only strengthening defense factors, such as mucus and prostaglandins, but also protecting against potentially harmful factors via their antioxidative, anti-inflammatory, and antibacterial activities. Although controlled clinical studies are limited at present, flavonoids have shown a promising preventable and therapeutic potential in peptic ulcers.

Effects of Paeonol and Gastroretention Tablets of Paeonol on Experimental Gastric Ulcers and Intestinal Flora in Rats

Paeonol, a major ingredient isolated from Moutan Cort, has various pharmacological effects. Our previous studies have shown that paeonol can exert antioxidant and anti-inflammatory therapeutic effects on ethanol-induced experimental gastric ulcer (GU). Therefore, in this study, we designed two GU models in rats induced by pyloric ligation (PL) and acetic acid and evaluated the protective effects of paeonol and gastroretention tablets of paeonol (GRT-Ps; 24, 48, and 96 mg/kg) on GU in rats and the effect of paeonol (48 mg/kg) on the intestinal flora. In vivo experiments showed that paeonol or GRT-Ps remarkably reduced gastric mucosal damage in a dose-dependent manner in the different types of models and improved the superoxide dismutase (SOD) activity and the malondialdehyde (MDA) content. And in fact, the sustained-release effect of GRT-Ps is more conducive to the improvement of GU compared with the rapid clearance of free drugs. In the PL-induced model, gastric secretion parameters, that is, pH and total acid, showed significant differences compared with the model group. In addition, paeonol treatment can improve the richness and diversity of the intestinal flora and increase the amount of beneficial bacteria, such as Lactobacillus. Paeonol and its stable sustained-release tablet GRT-Ps can promote ulcer healing by inhibiting oxidative stress and regulating the intestinal flora. This study can provide basis for the clinical treatment of GU with paeonol. Graphical Abstract.

Chrysin ameliorates ANTU-induced pulmonary edema and pulmonary arterial hypertension via modulation of VEGF and eNOs

Alpha-naphthylthiourea (ANTU), a rodenticide induces lung toxicity. Chrysin a flavonoid possesses antioxidant, anti-inflammatory, and antihypertensive potential. The aim of this study was to evaluate the efficacy of chrysin against ANTU-induced pulmonary edema (PE) and pulmonary arterial hypertension (PAH) in laboratory rats. Sprague-Dawley rats were used to induce PE (ANTU, 10 mg/kg, ip) and PAH (ANTU, 5 mg/kg, ip, 4 weeks). Animals were treated with chrysin (10, 20, and 40 mg/kg) and various biochemical, molecular, and histological parameters were evaluated. Acute administration of ANTU induces PE revealed by significant (P < 0.05) increase in relative lung weight, pleural effusion volume, lung edema, bronchoalveolar lavage fluid cell counts, total protein, 5-hydroxytryptamine (5-HT), lactate dehydrogenase (LDH), and γ-glutamyl transferase (GGT), whereas pretreatment with chrysin (20 and 40 mg/kg, ip) significantly (P < 0.05) attenuated these ANTU-induced biochemical and histological alterations. Repeated administration of ANTU caused induction of PAH evaluated by significant (P < 0.05) alterations in electrocardiographic, hemodynamic changes, and left ventricular function, whereas chrysin (20 and 40 mg/kg, p.o.) treatment significantly (P < 0.05) attenuated these alterations. ANTU-induced hematological and serum biochemical (aspartate transaminase, alanine transaminase, LDH, and creatinine kinase MB) alterations were significantly (P < 0.05) inhibited by chrysin. It also significantly (P < 0.05) decreased elevated levels of oxido-nitrosative stress in the right ventricle (RV) and lung. Chrysin significantly (P < 0.05) attenuated downregulated endothelial nitric oxide synthase and upregulated vascular endothelial growth factor messenger RNA and protein expressions both in the RV and pulmonary artery. Chrysin inhibited ANTU-induced PE and PAH via modulation of inflammatory responses (5-HT, LDH, and GGT), oxido-nitrosative stress, and VEGF and eNOs levels.

Diarylheptanoid, a constituent isolated from methanol extract of Alpinia officinarum attenuates TNF-α level in Freund's complete adjuvant-induced arthritis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Rheumatoid arthritis (RA) is a chronic inflammatory and destructive joint disease that affects the worldwide population. Alpinia officinarum Hance (Zingiberaceae), rhizomes are widely used ethnobotanically as an anti-inflammatory, analgesic, and antioxidant agent in traditional medicine.

AIM

To investigate the efficacy and possible mechanism of isolated phytoconstituent from the methanol extract of A. officinarum (MEAO) rhizomes against Freund's complete adjuvant (FCA)-induced arthritis in rats. Furthermore, molecular docking was performed to study the binding mode of this compound into the active site of TNF-α.

MATERIALS AND METHODS

Diarylheptanoid was isolated from MEAO, well characterized (HPTLC, ¹H NMR, ¹³C NMR, and ESI-MS) and evaluated for its antiarthritic activity in female Wistar rats (170-200 g). Diarylheptanoid (5, 10 and 20 mg/kg, p.o.) was administered starting from day 12. Various behavioral, biochemical, molecular and histopathology parameters were evaluated. Molecular docking study was performed using Glide module integrated into Schrodinger molecular modeling software.

RESULTS

The structure and molecular weight of the isolated compound (diarylheptanoid) were confirmed by 1D and mass spectral data and characterized as 1-phenyl-5-hydroxy-7- (4''-hydroxy-3''-methoxyphenyl) heptane-3-one (i.e., 5-HPH) with molecular formula C₂₀H₂₄O₄. Administration of 5-HPH (10 and 20 mg/kg) significantly inhibited (p < 0.05) FCA induced increases in paw volume, joint diameter, thermal hyperalgesia and tactile allodynia. It also significantly decreased oxido-inflammatory markers (SOD, GSH, MDA, and TNF-α). FCA induced a histological alteration in ankle joint also attenuated by 5-HPH. Its Glide docking score was found to be -9.702 with binding energy (Glide energy) of -37.033 kcal/mol.

CONCLUSION

5-HPH may exhibit its anti-arthritic potential via inhibition of elevated oxido-inflammatory markers thus restoring the elevated hyperalgesia, allodynia and reducing destruction in synovial membrane and cartilage. Therefore, 5-HPH is a potential moiety bearing antioxidant and with anti-inflammatory properties to inhibit FCA-induced arthritis in rats. The results of the present investigation should enable the design of potent small-molecule inhibitors that inactivate TNF-α with high affinity and specificity.

Phyllanthin and hypophyllanthin from Phyllanthus amarus ameliorates immune-inflammatory response in ovalbumin-induced asthma: role of IgE, Nrf2, iNOs, TNF-α, and IL's

Background: Asthma is a chronic airway immunoinflammatory disorder characterized by airway remodeling. Phyllanthus amarus has been reported to possess antioxidant and anti-inflammatory potential. Aim: To evaluate the possible mechanism of action of isolated phytoconstituents from P. amarus (PA) against ovalbumin (OVA)-induced experimental airway hyperresponsiveness (AHR). Material and method: Phyllanthin and hypophyllanthin were isolated and characterized (HPLC) from the methanolic extract of PA. AHR was induced in Sprague-Dawley rats by OVA-challenged, and animals were treated with PA (50, 100, and 200 mg/kg, p.o.) for 28 days. Results: The HPLC analysis showed the presence of phyllanthin and hypophyllanthin in methanolic extract of PA at RT of 25.243 and 26.832 min, respectively. OVA-induced alterations in hemodynamic parameters, lung functions test, peripheral blood oxygen level, total, and differential cell count in Bronchoalveolar Lavage Fluid was significantly attenuated (p < .05) by PA (100 and 200 mg/kg). It also significantly decreased (p < .05) the levels of total protein and albumin in serum, BALF, and lungs. OVA-induced increase in IgE (total and OVA-specific), and oxido-nitrosative stress (SOD, GSH, MDA, and NO) levels were significantly (p < .05) decreased by PA. RT-PCR analysis revealed that elevated oxido-nitrosative stress (Nrf2 and iNOs), immune-inflammatory makers (HO-1, TNF-α, IL-1β, and TGF-β1), Th2 cytokines (IL-4 and IL-6) levels were significantly attenuated (p < .05) by PA. PA also attenuated histological and ultrastructural aberrations induced by OVA. Conclusion: Results of the present investigation demonstrated that the presence of phyllanthin and hypophyllanthin in P. amarus alleviated Th2 response in OVA-induced AHR via modulation of endogenous markers in a murine model of asthma. Thus, phyllanthin and hypophyllanthin may be a new therapeutic approach for the management of asthma.

Hesperidin, a plant flavonoid accelerated the cutaneous wound healing in streptozotocin-induced diabetic rats: Role of TGF-ß/Smads and Ang-1/Tie-2 signaling pathways

Background: Delayed wound healing is a diverse, multifactorial, complex and inter-related complication of diabetes resulting in significant clinical morbidity. Hesperidin possesses potent antidiabetic and wound healing activity.

Aim: To evaluate the potential of hesperidin against experimentally induced diabetes foot ulcers.

Methods: Diabetes was induced experimentally by streptozotocin (STZ, 55 mg/kg, i.p.) in Sprague Dawley rats (180-220 g) and wounds were created on the dorsal surface of the hind paw of rats. Hesperidin (25, 50 and 100 mg/kg, p.o.) was administered for 21 days after wound stabilization. Various biochemical, molecular and histopathological parameters were evaluated in wound tissue.

Results: STZ-induced decrease in body weight and increase in blood glucose, food, and water intake was significantly (p < 0.05) inhibited by hesperidin (50 and 100 mg/kg) treatment. It showed a significant increase (p < 0.05) in percent wound closure and serum insulin level. The STZ-induced decrease in SOD and GSH level, as well as elevated MDA and NO levels, were significantly (p < 0.05) attenuated by hesperidin (50 and 100 mg/kg) treatment. Intraperitoneal administration of STZ caused significant down-regulation in VEGF-c, Ang-1, Tie-2, TGF-β and Smad 2/3 mRNA expression in wound tissues whereas hesperidin (50 and 100 mg/kg) treatment showed significant up-regulation in these mRNA expressions. STZ-induced alteration in would architecture was also attenuated by hesperidin (50 and 100 mg/kg) treatment.

Conclusion: Together, treatment with hesperidin accelerate angiogenesis and vasculogenesis via up-regulation of VEGF-c, Ang-1/Tie-2, TGF-β and Smad-2/3 mRNA expression to enhance wound healing in chronic diabetic foot ulcers.

Elucidation of protective efficacy of Pentahydroxy flavone isolated from Madhuca indica against arsenite-induced cardiomyopathy: Role of Nrf-2, PPAR-γ, c-fos and c-jun

BACKGROUND

Madhuca indica J. F. Gmel. (Sapotaceae) is widely used ethnobotanically as anti-diabetic, antipyretic, hepatoprotective, anti-inflammatory and analgesic. It was shown to possess potent anti-apoptotic property.

THE AIM OF THE STUDY

To evaluate the possible mechanism of action of isolated phytoconstituent from Madhuca indica Leaves methanolic extract (MI-ALC) on arsenic-induced cardiotoxicity in rats.

MATERIALS AND METHODS

The 3,5,7,3',4'-Pentahydroxy flavone (QTN) was isolated and characterized by using HPTLC, ¹H NMR, and LC-MS from MI-ALC. QTN (5, 10 and 20mg/kg, p.o.) was administered in arsenic intoxicated rats (5mL/kg, p.o.) for 28days and evaluated for various behavioral, biochemical, molecular and ultra-histological changes.

RESULTS

Treatment with QTN (10 and 20mg/kg, p.o.) significantly inhibited (p<0.05) arsenic-induced electrocardiographic, hemodynamic and left ventricular function alterations. Elevated levels of cardiac markers (LDH, CK-MB, AST, ALT, and ALP), altered lipid metabolism (total cholesterol, triglyceride, LDL, HDL, and VLDL) was significantly restored (p<0.05) by QTN. It also significantly inhibited (p<0.05) altered cardiac oxido-nitrosative stress, Na-K-ATPase level and mitochondrial enzymes (I-IV) activity after arsenite administration. QTN significantly increased (p<0.05) myocardial Nrf-2, PPAR-γ and significantly decreased (p<0.05) myocardial c-fos and c-jun mRNA expressions. Flow cytometric analysis showed that treatment with QTN (10 and 20mg/kg) significantly inhibited (p<0.05) arsenite-induce ROS and apoptosis. It also reduced ultra-histological aberrations induced by sodium arsenite.

CONCLUSION

Administration of 3,5,7,3',4'- Pentahydroxy flavone (i.e. Quercetin (QTN)) isolated from MI-ALC showed significant protection against arsenic-induced oxido-nitrosative stress and myocardial injury via modulation of Nrf2, PPAR-γ, and apoptosis.

Anti-inflammatory and antioxidant potential of Guaianolide isolated from Cyathocline purpurea: Role of COX-2 inhibition

BACKGROUND

Inflammation activated by oxidative stress can cause various diseases, such as asthma, rheumatoid arthritis, cancer, diabetes, etc. Plant constituents with sesquiterpene lactones possess antioxidant and anti-inflammatory properties.

AIM

To determine the antioxidant and anti-inflammatory potential of isolated phytoconstituent from Cyathocline purpurea Buch-Ham ex D (CP). Don in laboratory animals. Furthermore, to understand the interactions involved in the binding of this compound to cyclooxygenase-2 (COX-2) via computational docking.

METHODS

Phytoconstituent was isolated, purified and well characterized (using IR, NMR, and MS) from ethyl acetate fraction of CP methanolic extract. It was then evaluated for its in-vitro antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H₂O₂) and hydroxyl (OH) radical assays as well as in-vivo anti-inflammatory potential against carrageenan-induced paw edema model in rats. The molecular docking study was performed against the crystal structure of COX-2 to evaluate the binding potential of phytoconstituent towards this enzyme.

RESULTS

The isolated compound 6α-hydroxy-4 [14], 10 [15]-guainadien-8α, 12-olide (HGN) showed significant (p<0.001) antioxidant activity with IC₅₀ values of 76μg/mL. Administration of HGN (10 and 20mg/kg) significantly (p<0.001) reduced the increased paw volume after subplantar administration of carrageenan. It also exhibits good binding affinity towards with COX-2 with a docking score of -8.98 and Glide binding energy of -36.488kcal/mol shedding light on the potential mechanism of anti-inflammatory action.

CONCLUSIONS

The presence of hydroxyl group in HGN provides a credential to its in-vivo anti-inflammatory and in-vitro antioxidant activities. Furthermore, the good binding affinity of HGN for the active site of COX-2 may open novel vistas in therapeutic option with natural antioxidants like Cyathocline purpurea to treat various inflammatory disorders.

Neuroprotective effect of Azadirachta indica standardized extract in partial sciatic nerve injury in rats: Evidence from anti-inflammatory, antioxidant and anti-apoptotic studies

Chronic neuropathic pain is a common and widely recognized pain syndrome for patients and difficult to manage for physicians. Azadirachta indica (AI) possesses analgesic, anti-inflammatory, and antioxidant properties. To evaluate the neuroprotective effect of AI standardized extract in an animal model of peripheral neuropathy induced by partial sciatic nerve ligation (PSNL). PSNL was induced in male Wistar rats (180-200 g) with tight ligation of the nerve. Rats received treatment with either vehicle i.e. distilled water (PSNL control), Pyridoxine (100 mg/kg, p.o.) or AI (100, 200 and 400 mg/kg, p.o.) for 28 days. Various behavioral parameters, biochemical, molecular and histological parameters were evaluated. PSNL resulted in a significant decrease (p < 0.05) in allodynia, hyperalgesia, motor coordination and motor nerve conduction velocity (MNCV) whereas chronic treatment with AI (200 and 400 mg/kg) significantly attenuated (p < 0.05) these behavioral changes. Enhanced activity of oxidative-nitrosative stress, inflammatory mediators (TNF-α, IL-1β, and NF-κB) as well as mRNA expression of Bax, Caspase-3, and iNOs were significantly attenuated (p < 0.05) by AI treatment. It also significantly increased (p < 0.05) peripheral blood oxygen content and Bcl-2 mRNA expression. The flow cytometric analysis revealed that AI (200 and 400 mg/kg) treatment significantly attenuated neural apoptosis and reactive oxygen species levels. PSNL induced histological aberrations were also decreased by AI treatment. Azadirachta indica exerts its neuroprotection against PSNL induced neuropathic pain via inhibition of oxidative-nitrosative stress, the release of pro-inflammatory cytokines and apoptosis to improve MNCV (graphical abstract, Figure 1(Fig. 1)).