Salix babylonica L. mitigates pancreatic damage by regulating the Beclin-P62/SQSTM1 autophagy pathway in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Salix babylonica L. belongs to the genus Salix, family Salicaceae. It is traditionally used as an antipyretic, antirheumatic, antidiabetic and for the treatment of ulcers and parasite skin diseases. It also has a range of pharmacological effects, such as anti-inflammatory, anti-tumor, antioxidant, and antibacterial effects. However, there are no reports on the phytochemical profile and efficacy of its leaves extract to modulate dexamethasone induced pancreatic damage. AIM OF THE STUDY: The present study was performed to annotate the phytoconstituents of Salix babylonica leaf extract and explore whether and how it could modulate dexamethasone-induced pancreatic damage and the role of oxidative stress and autophagy in mediating its protective effects. MATERIALS AND METHODS: Wistar rats were used for this study. Salix babylonica in two dose levels (100 and 200 mg/kg) or metformin (50 mg/kg) was given by oral gavage concurrently with dexamethasone which was injected SC in a dose of 10 mg/kg for 4 consecutive days. RESULTS: LC-MS analysis furnished 84 secondary metabolites belonging to phenolic acids, salicinoids, proanthocyanidins, flavonoids, cyclohexanediol glycosides, and hydroxy fatty acids. S. babylonica at both dose levels and metformin decreased the elevated pancreatic beclin while elevated the decreased pancreatic P62/SQSTM1 content compared to dexamethasone. These effects were associated with improved histopathological changes, glycemic and lipid parameters indicating that there might be a connection between autophagy and dexamethasone-induced pancreatic damage. Given that the level of GSH was negatively correlated with the levels of beclin and positively correlated with P62/SQSTM1, while both MDA and NO levels were positively correlated with beclin and negatively correlated with P62/SQSTM1, it seems that dexamethasone induced autophagy may be attributed to dexamethasone induced pancreatic oxidative stress. CONCLUSION: Our results indicate that S. babylonica protects pancreatic tissues against dexamethasone-induced damage by decreasing oxidative stress and its associated autophagy. Our study reveals a new mechanism for dexamethasone effects on pancreas and shows the potential therapeutic role of S. babylonica in mitigating dexamethasone adverse effects on pancreas and establishes the groundwork for future clinical applications.

Phytoestrogen ß-Sitosterol Exhibits Potent In Vitro Antiviral Activity against Influenza A Viruses.

Influenza is a contagious infection in humans that is caused frequently by low pathogenic seasonal influenza viruses and occasionally by pathogenic avian influenza viruses (AIV) of H5, H7, and H9 subtypes. Recently, the clinical sector in poultry and humans has been confronted with many challenges, including the limited number of antiviral drugs and the rapid evolution of drug-resistant variants. Herein, the anti-influenza activities of various plant-derived phytochemicals were investigated against highly pathogenic avian influenza A/H5N1 virus (HPAIV H5N1) and seasonal low pathogenic human influenza A/H1N1 virus (LPHIV H1N1). Out of the 22 tested phytochemicals, the steroid compounds ß-sitosterol and ß-sitosterol-O-glucoside have very potent activity against the predefined influenza A viruses (IAV). Both steroids could induce such activity by affecting multiple stages during IAV replication cycles, including viral adsorption and replication with a major and significant impact on the virus directly in a cell-free status "viricidal effect". On a molecular level, several molecular docking studies suggested that ß-sitosterol and ß-sitosterol-O-glucoside exhibited viricidal effects through blocking active binding sites of the hemagglutinin surface protein, as well as showing inhibitory effects against replication through the binding with influenza neuraminidase activity and blocking the active sites of the M2 proton channel activity. The phytoestrogen ß-sitosterol has structural similarity with the active form of the female sex hormone estradiol, and this similarity is likely one of the molecular determinants that enables the phytoestrogen ß-sitosterol and its derivative to control IAV infection in vitro. This promising anti-influenza activity of ß-sitosterol and its O-glycoside derivative, according to both in vitro and cheminformatics studies, recommend both phytochemicals for further studies going through preclinical and clinical phases as efficient anti-influenza drug candidates.

Apple (Malus domestica Borkh) leaves attenuate indomethacin-induced gastric ulcer in rats.

Malus domestica Borkh, the apple tree, exhibited numerous pharmacological properties including antioxidant, neuroprotective, anti-inflammatory, anticancer and antimicrobial activities. The present work aimed to annotate the secondary metabolites from a butanol fraction of apple leaves (BLE), evaluate the gastro-protective and healing effects of this fraction against indomethacin-induced gastric ulcers in rats and to identify its mechanism of action. BLE (100, and 200 mg/kg) was orally administered in rats as an acute treatment against indomethacin-induced gastric ulcer in comparison with famotidine as reference anti-ulcer drug. The stomachs of rats were collected to determine the ulcer index, the preventive ratio, measure the activity of glutathione peroxidase (GPx), and estimate the expression of cyclooxygenase-2 (COX-2), and heat shock protein 70 (HSP70). Furthermore, we evaluated both inflammatory and oxidative stress markers in the gastric tissues. We also performed histopathological study of gastric mucosa using H&E stain and periodic Schiff base stain to evaluate both gastric injury scores and gastric mucus content respectively. Pretreatment with BLE markedly lowered the severity of gastric injury induced by indomethacin, decreased oxidative stress, inflammatory cytokines, and COX-2 expression in the examined gastric tissues. The gastric healing effect of BLE was associated with increased mucoglycoproteins, and HSP70 expression. Additionally, gastric healing effect of high dose of BLE was superior to that of famotidine in decreasing gastric injury scores, COX-2, inflammatory cytokines, lipid peroxidation and in increasing gastric mucin content, HSP70, and reduced glutathione. These findings indicate that BLE is effective in accelerating ulcer healing by boosting HSP70 expression, and decreasing COX-2 expression, oxidative stress, and gastric inflammation which might be related to the presence of 21 phytoconstituents.

Vasorelaxant Effects of Syzygium samarangense (Blume) Merr. and L.M.Perry Extract Are Mediated by NO/cGMP Pathway in Isolated Rat Thoracic Aorta.

Syzygium samarangense (Blume) Merr. and L.M.Perry is utilized widely in traditional medicine. We have reported previously a wide array of pharmacological properties of its leaf extract, among them anti-inflammatory, antioxidant, hepatoprotective, antidiabetic, antiulcer, and antitrypanosomal activities. We also annotated its chemical composition using LC-MS/MS. Here, we continue our investigations and evaluate the vasorelaxant effects of the leaf extract on aortic rings isolated from rats and explore the possible underlying mechanisms. S. samarangense extract induced a concentration dependent relaxation of the phenylephrine-precontracted aorta in the rat model. However, this effect disappeared upon removing the functional endothelium. Pretreating the aortic tissues either with propranolol or NG-nitro-L-arginine methyl ester inhibited the relaxation induced by the extract; however, atropine did not affect the extract-induced vasodilation. Meanwhile, adenylate cyclase inhibitor, MDL; specific guanylate cyclase inhibitor, ODQ; high extracellular KCl; and indomethacin as cyclooxygenase inhibitor inhibited the extract-induced vasodilation. On the other hand, incubation of S. samarangense extract with aortae sections having their intact endothelium pre-constricted using phenylephrine or KCl in media free of Ca2+ showed no effect on the constriction of the aortae vessels induced by Ca2+. Taken together, the present study suggests that S. samarangense extract dilates isolated aortic rings via endothelium-dependent nitric oxide (NO)/cGMP signaling. The observed biological effects could be attributed to its rich secondary metabolites. The specific mechanisms of the active ingredients of S. samarangense extract await further investigations.

Robust Antiviral Activity of Santonica Flower Extract (Artemisia cina) against Avian and Human Influenza A Viruses: In Vitro and Chemoinformatic Studies.

The evolution of drug-resistant viral strains following natural acquisition of resistance mutations is a major obstacle to antiviral therapy. Besides the improper prescription of the currently licensed anti-influenza medications, M2-blockers and neuraminidase inhibitors, to control poultry outbreaks/infections potentiates the emergence of drug-resistant influenza variants. Therefore, there is always a necessity to find out new alternatives with potent activity and high safety. Plant extracts and plant-based chemicals represent a historical antiviral resource with remarkable safety in vitro and in vivo to control the emerging and remerging health threats caused by viral infections. Herein, a panel of purified plant extracts and subsequent plant-derived chemicals were evaluated for their anti-avian influenza activity against zoonotic highly pathogenic influenza A/H5N1 virus. Interestingly, santonica flower extract (Artemisia cina) showed the most promising anti-H5N1 activity with a highly safe half-maximal cytotoxic concentration 50 (CC50 > 10 mg/mL) and inhibitory concentration 50 (IC50 of 3.42 µg/mL). To confirm the anti-influenza activity, we assessed the anti-influenza activity of the selected plant extracts against seasonal human influenza A/H1N1 virus and we found that santonica flower extract showed a robust anti-influenza activity that was comparable to the activity against influenza A/H5N1. Furthermore, the mode of action for santonica flower extract with strong inhibitory activity on the abovementioned influenza strains was elucidated, showing a virucidal effect. To go deeper about the activity of the chemometric component of the extract, the major constituent, santonin, was further selected for in vitro screening against influenza A/H5N1 (IC50 = 1.701 µg/mL) and influenza A/H1N1 (IC50 = 2.91 µg/mL). The oxygen of carbonyl functionality in the cyclohexene ring succeeded to form a hydrogen bond with the neuraminidase active site. Despite the fact that santonin revealed similarity to both reference neuraminidase inhibitors in forming hydrogen bonds with essential amino acids, it illustrated shape alignment to oseltamivir more than zanamivir according to Tanimoto algorithms. This study highlights the applicability of santonica flower extract as a promising natural antiviral against low and highly pathogenic influenza A viruses.

Black pepper oil (Piper nigrum L.) mitigates dexamethasone induced pancreatic damage via modulation of oxidative and nitrosative stress.

Dexamethasone acts as an immunosuppressive drug and has been used recently in the management of specific coronavirus disease 2019 (COVID-19) cases; however, various adverse effects could limit its use. In this work, we studied the mitigation effects of black pepper oil (BP oil) on glycemic parameters, dyslipidemia, oxidative and nitrosative stress and pancreatic fibrosis in dexamethasone-treated rats. Animals were divided into five groups that were treated with vehicle, dexamethasone (10 mg/kg, SC) or black pepper oil (BP oil, 0.5 mL, or 1 mL/kg) or metformin (50 mg/kg) plus dexamethasone for 4 consecutive days. Serum insulin, blood glucose, total cholesterol, triglycerides, and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) were higher in the dexamethasone group vs the control group and decreased in BP oil and metformin groups relative to the dexamethasone group. Pancreatic nitric oxide, inducible nitric oxide synthase and malondialdehyde levels were increased in the dexamethasone group vs the control group and decreased in BP oil and metformin groups relative to the dexamethasone group. Pancreatic endothelial nitric oxide synthase and reduced glutathione were declined in the dexamethasone group vs the control group. They were increased in BP oil and metformin groups relative to the dexamethasone group. Moreover, the pancreatic islets diameter and collagen deposition were assessed and found to be higher in the dexamethasone group vs the control group. BP oil and metformin groups showed to regress this effect. In conclusion, BP oil may alleviate hyperglycemia, hyperinsulinemia, insulin resistance, dyslipidemia and pancreatic structural derangements and fibrosis by suppressing oxidative stress, increasing endogenous antioxidant levels, modulating nitric oxide signaling, preventing pancreatic stellate cells transition and collagen deposition.

Pentagalloyl Glucose, a Major Compound in Mango Seed Kernel, Exhibits Distinct Gastroprotective Effects in Indomethacin-Induced Gastropathy in Rats via Modulating the NO/eNOS/iNOS Signaling Pathway.

Gastric ulcers are a common health disorder that affect up to 10% of the world's population. The gastroprotective potential of pentagalloyl glucose (PGG) against indomethacin-induced ulcer in rats and the possible underlying mechanisms were investigated. Gastric ulceration was induced by indomethacin (single dose, 60 mg/kg). Pretreatment with PGG (100 or 200 mg/kg, orally) for 8 days prior to the administration of indomethacin furnished significant reductions in gastric mucosal lesions as well as a significant increase in mucus concentration. Also, PGG significantly declined the elevations in gastric mucosal MDA, TNF-α, IL-6, PECAM-1, VEGF, and iNOS expression. It also mitigated the decrease in GSH and GPx and eNOS expression observed with indomethacin. The protective effects furnished by PGG were comparable to that of famotidine. The obtained results suggested that the anti-ulcer effects of PGG are mediated by increasing mucus production, scavenging free radicals, decreasing inflammation, and attenuating the NO/NOS signaling in favor of eNOS. To sum up, PGG could provide a potential therapy for gastric ulcer after evaluating its efficacy and effectiveness.

Syzygium aqueum (Burm.f.) Alston Prevents Streptozotocin-Induced Pancreatic Beta Cells Damage via the TLR-4 Signaling Pathway.

Although several treatments are available for the treatment of type 2 diabetes mellitus, adverse effects and cost burden impose the search for safe, efficient, and cost-effective alternative herbal remedies. Syzygium aqueum (Burm.f.) Alston, a natural anti-inflammatory, antioxidant herb, may suppress diabetes-associated inflammation and pancreatic beta-cell death. Here, we tested the ability of the bioactive leaf extract (SA) to prevent streptozotocin (STZ)-induced oxidative stress and inflammation in pancreatic beta cells in rats and the involvement of the TLR-4 signaling pathway. Non-fasted rats pretreated with 100 or 200 mg kg-1 SA 2 days prior to the STZ challenge and for 14 days later had up to 52 and 39% reduction in the glucose levels, respectively, while glibenclamide, the reference standard drug (0.5 mg kg-1), results in 70% reduction. Treatment with SA extract was accompanied by increased insulin secretion, restoration of Langerhans islets morphology, and decreased collagen deposition as demonstrated from ELISA measurement, H and E, and Mallory staining. Both glibenclamide and SA extract significantly decreased levels of TLR-4, MYD88, pro-inflammatory cytokines TNF-α, and TRAF-6 in pancreatic tissue homogenates, which correlated well with minimal pancreatic inflammatory cell infiltration. Pre-treatment with SA or glibenclamide decreased malondialdehyde, a sensitive biomarker of ROS-induced lipid peroxidation, and restored depleted reduced glutathione in the pancreas. Altogether, these data indicate that S. aqueum is effective in improving STZ-induced pancreatic damage, which could be beneficial in treating type 2 diabetes mellitus.

Syzygium jambos extract mitigates pancreatic oxidative stress, inflammation and apoptosis and modulates hepatic IRS-2/AKT/GLUT4 signaling pathway in streptozotocin-induced diabetic rats.

The protective effect of Syzygium jambos (SJ) bark extract against streptozotocin-induced diabetes was tested in rats. Animals were treated with 100 or 200 mg/kg of the extract or glibenclamide, 0.5 mg/kg per os, once daily: started 2 days before streptozotocin (STZ) injection and lasted for 14 days after STZ injection. The effect of the extract was also evaluated on normal rats in comparison with glibenclamide. Diabetic animals showed an elevated blood glucose level, positive glycosuria, elevated fructosamine, pancreatic malondialdehyde, pancreatic TNF-a, and pancreatic caspase-3 levels and decreased serum insulin, pancreatic IL-10, pancreatic BCL-2, reduced glutathione (GSH), liver insulin substrate-2, liver phosphorylated protein kinase B (p-AKT) and liver glucose transporter 4 (GLUT4) levels. Histopathological examination of diabetic rats revealed islets destruction and vacuolation and collagen fibers deposition. All these changes were mitigated dose dependently by the extract. The high dose of the extract exerted comparable effects with glibenclamide in most studied parameters. These results indicated the protective role of SJ against the STZ diabetogenic action. In the pancreatic and hepatic tissue of diabetic rats, SJ effectively recovered pancreatic cells by reducing hyperglycemia through activating endogenous antioxidants, dynamic insulin production, and suppressing inflammation and apoptosis. The observed results might be attributed to the existence of 10 secondary metabolites as annotated by LC-MS. Taken together, S. jambos is a potential candidate for further studies to confirm its activities as a therapeutic agent for diabetic patients.

Anti-Inflammatory, Antipyretic, and Analgesic Properties of Potamogeton perfoliatus Extract: In Vitro and In Vivo Study.

Natural antioxidants, especially those of plant origins, have shown a plethora of biological activities with substantial economic value, as they can be extracted from agro-wastes and/or under exploited plant species. The perennial hydrophyte, Potamogeton perfoliatus, has been used traditionally to treat several health disorders; however, little is known about its biological and its medicinal effects. Here, we used an integrated in vitro and in vivo framework to examine the potential effect of P. perfoliatus on oxidative stress, nociception, inflammatory models, and brewer's yeast-induced pyrexia in mice. Our results suggested a consistent in vitro inhibition of three enzymes, namely 5-lipoxygenase, cyclooxygenases 1 and 2 (COX-1 and COX-2), as well as a potent antioxidant effect. These results were confirmed in vivo where the studied extract attenuated carrageenan-induced paw edema, carrageenan-induced leukocyte migration into the peritoneal cavity by 25, 44 and 64% at 200, 400 and 600 mg/kg, p.o., respectively. Moreover, the extract decreased acetic acid-induced vascular permeability by 45% at 600 mg/kg, p.o., and chemical hyperalgesia in mice by 86% by 400 mg/kg, p.o., in acetic acid-induced writhing assay. The extract (400 mg/kg) showed a longer response latency at the 3 h time point (2.5 fold of the control) similar to the nalbuphine, the standard opioid analgesic. Additionally, pronounced antipyretic effects were observed at 600 mg/kg, comparable to paracetamol. Using LC-MS/MS, we identified 15 secondary metabolites that most likely contributed to the obtained biological activities. Altogether, our findings indicate that P. perfoliatus has anti-inflammatory, antioxidant, analgesic and antipyretic effects, thus supporting its traditional use and promoting its valorization as a potential candidate in treating oxidative stress-associated diseases.

Syzygium samarangense leaf extract mitigates indomethacin-induced gastropathy via the NF-κB signaling pathway in rats.

We previously profiled the chemical composition of wax apple, Syzygium samarangense, leaf extract using HR-LC-MS/MS and reported its antioxidant, hepatoprotective and antitrypanosomal activities. The plant is widely used in traditional medicine to cure several ailments like bronchitis, asthma, diabetes, fever, pathogenic infections, gut spasms, as well as renal diseases. However, neither the gastroprotective effects nor the underlying mechanisms were explored. Here, we investigated the gastroprotective potential of the leaf extract on indomethacin-induced gastric ulcer in rats and explored the involved mechanism(s) of action. Administration of indomethacin significantly increased the ulcer index, mucosal injury, the gastric levels of the inflammatory markers nuclear factor kabba B-p65(NF-κB p65), myeloperoxidase (MPO), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), lipid peroxidation product, malondialdehyde (MDA) and Caspase-3 expression. It reduced the gastric levels of the endogenous antioxidants glutathione as well peroxidase (GPx), reduced glutathione (GSH) and the gastric mucosal protective factors, mucus secretion and goblet cells. Pretreatment with the leaf extract displayed a prominent decrease in the ulcer index, inflammatory cell infiltration, inflammatory markers, MDA, protein expression of Caspase-3 and a significant increase in the gastric levels of the endogenous antioxidants, mucus content and goblet cell proliferation when compared to the indomethacin group. The individual secondary metabolites of the extract exhibited low binding energy when docked into the prostaglandin receptors EP3 and EP4. This study revealed the gastroprotective effect of S. samarangense on indomethacin-induced gastric ulcer in rats. The gastroprotective effects might be attributed to cytoprotective, antioxidant, anti-inflammatory and antiapoptotic activities with a possible potential of activating EP3 and EP4 receptors. In conclusion, S. samarangense has a promising potential in the prevention of NSAIDs-induced ulcers.

Phytochemistry, Pharmacology and Medicinal Uses of Plants of the Genus Salix: An Updated Review.

The Willows (genus Salix), with more than 330-500 species and 200 hybrids, are trees, shrubs or prostrate plants that are widely distributed in Africa, North America, Europe, and Asia. The genus is traditionally used in folk medicine and represents a valuable source of biologically active compounds among them salicin, a prodrug for salicylic acid. Altogether, 322 secondary metabolites were characterized in the genus including flavonoids 94) (flavonols, flavones, flavanones, isoflavones, flavan-3-ols (catechins and procyanidins), chalcones, dihydrochalcone, anthocyanins, dihydroflavonols), phenolic glycosides (76), organic acids (28), and non-phenolic glycosides (17), sterols and terpenes (17), simple phenolics 13) and lignans 7) in addition to volatiles and fatty acids (69). Furthermore, willows exert analgesic, anti-inflammatory, antioxidant, anticancer, cytotoxic, antidiabetic, antimicrobial, antiobesity, neuroprotective and hepatoprotective activities. The current review provides an updated summary of the importance of willows, their chemical composition and pharmacological activities.

Gastro-Protective Effects of Albizia anthelmintica Leaf Extract on Indomethacin-Induced Gastric Ulcer in Wistar Rats: In Silico and In Vivo Studies.

We have previously reported that the leaf extract of Albizia anthelmintica exhibited substantial antioxidant, anti-inflammatory, analgesic, and antipyretic properties in vivo. We also comprehensively characterized the active phytoconstituents and found several flavonoids and galloyl glucosides derivatives. In the current work, we explored the gastroprotective effects of the leaf extract in an indomethacin-induced ulcer model and the mechanisms involved. The rats being pretreated with the tested extract (100 and 200 mg kg-1) significantly prevented gastric lesions by 87.4% and 92.3%, respectively, and they had no structural derangements in the gastric mucosa. The extract significantly reduced the elevated levels of IKκB, NF-κB, TNF-α, IL-6, iNOS, and lipid peroxidation; increased the reduced level of glutathione peroxidase (GPx) activity; and reduced glutathione (GSH) in the indomethacin-induced ulcer model. The protective activities of the extract were similar in most aspects to those exerted by the known anti-ulcer drug famotidine. These activities might be attributed to the anti-inflammatory and antioxidant activities, and the reduction of iNOS levels. In conclusion, Albizia anthelmintica is a potential candidate for management of gastric ulcers with antioxidant properties.

Potamogeton perfoliatus L. Extract Attenuates Neuroinflammation and Neuropathic Pain in Sciatic Nerve Chronic Constriction Injury-Induced Peripheral Neuropathy in Rats.

Sciatic nerve injury is often associated with neuropathic pain and neuroinflammation in the central and peripheral nervous systems. In our previous work, Potamogeton perfoliatus L. displayed anti-inflammatory, antipyretic and analgesic properties, predominantly via the inhibition of COX-2 enzyme and attenuation of oxidative stress. Herein, we extended our investigations to study the effects of the plant's extract on pain-related behaviors, oxidative stress, apoptosis markers, GFAP, CD68 and neuro-inflammation in sciatic nerve chronic constriction injury (CCI) rat model. The levels of the pro-inflammatory marker proteins in sciatic nerve and brainstem were measured with ELISA 14 days after CCI induction. Pretreatment with the extract significantly attenuated mechanical and cold allodynia and heat hyperalgesia with better potential than the reference drug, pregabalin. In addition, CCI lead to the overexpression of prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), tumor necrosis alpha (TNFα), nuclear factor κB (NF-κB), cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), and NADPH oxidase-1 (NOX-1) and decreased the catalase level in sciatic nerve and brainstem. The observed neuro-inflammatory changes were accompanied with glial cells activation (increased GFAP and CD68 positive cells), apoptosis (increased Bax) and structural changes in both brainstem and sciatic nerve. The studied extract attenuated the CCI-induced neuro-inflammatory changes, oxidative stress, and apoptosis while it induced the expression of Bcl-2 and catalase in a dose dependent manner. It also decreased the brainstem expression of CD68 and GFAP indicating a possible neuroprotection effect. Taking together, P. perfoliatus may be considered as a novel therapy for neuropathic pain patients after performing the required clinical trials.

Thymus algeriensis and Thymus fontanesii exert neuroprotective effect against chronic constriction injury-induced neuropathic pain in rats.

We have previously demonstrated that the Thymus algeriensis and Thymus fontanesii extracts have powerful anti-inflammatory, antipyretic, and analgesic effects against acute pain models. We profiled their chemical composition and found many phenolic acids, flavonoids, and phenolic diterpenes. In this work, we investigated their antioxidant properties on HaCaT cells exposed to UVA-induced oxidative stress and examined their effects against chronic neuropathic pain and the underlying mechanisms. Through a rat chronic constriction injury (CCI) model, we induced chronic neuropathic pain by placing 4 loose ligatures around the right sciatic nerve for 14 days. Thermal and mechanical hyperalgesia in addition to cold and dynamic allodynia were tested on the day before surgery and on the 7th and 14th post-surgery days. Key markers of the nitrosative and oxidative stresses, in addition to markers of inflammation, were measured at day 14 post surgery. Histopathological examination and immunostaining of both synaptophysin and caspase-3 of sciatic nerve and brain stem were also performed. Results of this study showed that T. algeriensis extract suppresses UVA oxidative stress in HaCaT cells via activation of the Nrf-2 pathway. Both extracts attenuated hyperalgesia and allodynia at 7- and 14-days post-surgery with more prominent effects at day 14 of surgery. Their protective effects against neuropathic pain were mediated by inhibiting NOX-1, iNOS, by increasing the enzyme activity of catalase, and inhibition of inflammatory mediators, NF-κB, TNF-α, lipoxygenase, COX-2 enzymes, and PGE2. Furthermore, they improved deleterious structural changes of the brainstem and sciatic nerve. They also attenuated the increased caspase-3 and synaptophysin. The data indicate that both extracts have neuroprotective effects against chronic constriction injury-induced neuropathic pain. The observed protective effects are partially mediated through attenuation of oxidative and nitrosative stress and suppression of both neuroinflammation and neuronal apoptosis, suggesting substantial activities of both extracts in amelioration of painful peripheral neuropathy.

Phytochemical characterization and anti-inflammatory potential of Egyptian Murcott mandarin cultivar waste (stem, leaves and peel).

The stem (S), leaf (L) and fruit peel (P) of Murcott mandarins were separately extracted using 80% ethanol and then fractionated into dichloromethane (DCM) and ethyl acetate (ET). Their metabolic profiles were studied via HPLC-PDA-ESI-MS/MS and afforded a tentative characterization of 98 compounds, including free organic acids, phenolic acid derivatives, flavonoid aglycones, flavonoid glycosides, flavonoids containing 3-hydroxyl-3-methylglutaroyl (HMG) units, coumarin derivatives and limonoids. Column chromatography resulted in isolation of six metabolites for the first time that were identified as nobiletin (C1), isosinensetin (C2), limonin (C3), 4'-demethylnobiletin (C4), stigmasterol-O-glucoside (C5) and hesperidin (C6). In vitro studies of the anti-inflammatory activity of DCM-L against cyclooxygenases (COXs) and 5-lipoxygenase (5-LOX) enzymes revealed that DCM-L showed higher activity than the other tested fractions. The in vivo gastroprotective effects of that fraction were evaluated using alcohol-induced gastric ulcers in rats. The obtained findings validated the gastroprotective and anti-ulcerogenic activities of DCM-L through its anxiolytic, anti-inflammatory, antioxidant and anti-apoptotic effects. Therefore, we recommend the use of Murcott mandarin leaves as a part of a protection strategy for gastric ulcer.

Thymus algeriensis and Thymus fontanesii: Chemical Composition, In Vivo Antiinflammatory, Pain Killing and Antipyretic Activities: A Comprehensive Comparison.

This study aimed to investigate the chemical composition, and evaluate the antioxidant, anti-inflammatory, anti-pyretic, and the analgesic properties of methanol extracts from the leaves of Thymus algeriensis and Thymus fontanesii (Lamiaceae). Thirty-five secondary metabolites were characterized in both extracts using HPLC-PDA-ESI-MS/MS. Phenolic acids, mainly rosmarinic acid and its derivatives, dominated the T. algeriensis extract, while the phenolic diterpene carnosol and the methylated flavonoid salvigenin, prevailed in T. fontanesii extract. Molecular docking study was carried out to estimate the anti-inflammatory potential and the binding affinities of some individual secondary metabolites from both extracts to the main enzymes involved in the inflammation pathway. In vitro enzyme inhibitory assays and in vivo assays were used to investigate the antioxidant and anti-inflammatory activities of the extracts. Results revealed that both studied Thymus species exhibited antioxidant, anti-inflammatory, analgesic, and antipyretic effects. They showed to be a more potent antioxidant than ascorbic acid and more selective against cyclooxygenase (COX-2) than diclofenac and indomethacin. Relatively, the T. fontanesii extract was more potent as COX-2 inhibitor than T. algeriensis. In conclusion, Thymus algeriensis and Thymus fontanesii may be interesting candidates for the treatment of inflammation and oxidative stress-related disorders.

Haematoxylon campechianum Extract Ameliorates Neuropathic Pain via Inhibition of NF-κB/TNF-α/NOX/iNOS Signalling Pathway in a Rat Model of Chronic Constriction Injury.

: In this study, the phytochemical composition and the possible prophylactic effects of an aqueous ethanol extract of Haematoxylon campechianum flowers (HCF) on peripheral neuropathic pain in a chronic constriction injury (CCI) rat model are investigated. Rats with induced CCI were subjected to neuropathic pain behaviour tests and evaluated by chemical, thermal, and mechanical sensation tests and functional recovery of the brain stem and sciatic nerve at 7- and 14-day intervals. The effect of the extract on acute pain and inflammation is also investigated. The extract exerted both peripheral and central analgesic and anti-inflammatory properties in addition to antipyretic effects that are clear from targeting COX, LOX and PGE. It was found that CCI produced significant thermal and mechanical hyperalgesia, cold allodynia and deleterious structural changes in both sciatic nerve and brain stem. Treatments with HCF extract significantly improved cold and thermal withdrawal latency, mechanical sensibility and ameliorated deleterious changes of sciatic nerve and brain stem at different dose levels. The extract also ameliorated oxidative stress and inflammatory markers in brain stem and sciatic nerve. It suppressed the apoptotic marker, p53, and restored myelin sheath integrity. The effects of HCF extract were more potent than pregabalin. Fifteen secondary metabolites, mainly gallotannins and flavonoids, were characterized in the extract based on their retention times and MS/MS data. The identified phenolic constituents from the extract could be promising candidates to treat neuropathic pain due to their diverse biological activities, including antioxidant, anti-inflammatory and neuroprotective properties.

Polyphenols from Salix tetrasperma Impair Virulence and Inhibit Quorum Sensing of Pseudomonas aeruginosa.

Bacterial resistance represents one of the emerging obstacles in plants, animals, and humans that impairs treatment with antibacterial agents. Targeting of the bacterial quorum sensing system is one of the strategies to overcome this problem. Recently, research has been focused on natural and food components which can function as quorum sensing inhibitors. In this study, a methanol extract from Salix tetrasperma stem bark was phytochemically profiled by LC-MS analysis. This resulted in the identification of 38 secondary metabolites with (epi)catechin-(epi)catechin, epicatechin, tremulacin, salicortin, and trichocarposide as the major constituents. The extracts of both stem bark and the previously profiled flower of S. tetrasperma were tested for anti-quorum sensing activity in a common and widely distributed pathogen Pseudomonas aeruginosa. The natural products inhibited swimming and swarming motilities, as well as proteolytic and hemolytic activities in a dose-dependent manner. Molecular docking of the constituents from both extracts against the quorum sensing controlling systems Lasl/LasR, rhll/rhlR, and PQS/MvfR showed that epicatechin, (epi)catechin-(epi)catechin, p-hydroxy benzoyl galloyl glucose, p-hydroxy benzoyl protocatechuic acid glucose, and caffeoylmalic acid could be the main active components. This study supports the importance of secondary metabolites, especially polyphenols, as quorum sensing inhibitors.

Salix tetrasperma Roxb. Extract Alleviates Neuropathic Pain in Rats via Modulation of the NF-κB/TNF-α/NOX/iNOS Pathway.

Patients with neuropathic pain experience chronic painful tingling, burning, and prickling sensations accompanied with hyperalgesia and/or allodynia. In this study, 38 secondary metabolites of a methanol extract from Salix tetrasperma flowers were identified by liquid chromatography-mass spectrometry (HPLC-MS/MS). The extract showed substantial anti-inflammatory, central and peripheral anti-nociceptive, antipyretic, and antioxidant activities in vitro and in different animal models. In the chronic constriction injury (CCI) rat model, the extract was able to attenuate and significantly relieve hyperalgesia and allodynia responses in a dose dependent manner and restore the myelin sheath integrity and Schwann cells average number in the sciatic nerve. The enzyme-linked immunosorbent assay (ELISA) showed that the extract significantly reduced the expression of various pro-inflammatory biomarkers including nuclear factor kabba B (NF-κB), tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE2), 5-lipoxygenase (5-LOX), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and the oxidative stress biomarker NADPH oxidase 1 (NOX1), in brain stem and sciatic nerve tissues. These findings were supported by in vitro enzyme inhibition assays (COX-1, COX-2 and 5-LOX). Moreover, the extract significantly reduced p53 expression in the brain stem tissue. These findings support the use of S. tetrasperma in folk medicine to alleviate pain. It could be a promising natural product for further clinical investigations to treat inflammation, nociceptive pain and chronic neuropathic pain.