Antidiabetes and antioxidant potential of Schiff bases derived from 2-naphthaldehye and substituted aromatic amines: Synthesis, crystal structure, Hirshfeld surface analysis, computational, and invitro studies.

Three Schiff bases were synthesised by the condensation reaction between 2-napthaldehyde and aromatic amines to afford (E)-N-mesityl-1-(naphthalen-2-yl)methanimine (L1), (E)-N-(2,6-dimethylphenyl)-1-(naphthalen-2-yl)methanimine (L2) and (E)-N-(2,6-diisopropylphenyl)-1-(naphthalen-2-yl)methanimine (L3). The synthesised compounds were characterised using UV-visible, NMR (13C & 1H), and Fourier transform infrared spectroscopic methods while their purity was ascertained by elemental analysis. Structural analysis revealed that the naphthalene ring is almost coplanar with the imine functional group as evident by C1-C10-C11-N1 torsion angles of 176.4(2)° and 179.4(1)° in L2 and L3, respectively. Of all the various intermolecular contacts, H⋯H interactions contributed mostly towards the Hirshfeld surfaces of both L2 (58.7 %) and L3 (69.7 %). Quantum chemical descriptors of L1 - L3 were determined using Density Functional Theory (DFT) and the results obtained showed that the energy band gap (ΔE) for L1, L2 and L3 are 3.872, 4.023 and 4.004 eV respectively. The antidiabetic potential of the three compounds were studied using α-amylase and α-glucosidase assay. Compound L1 showed very promising antidiabetic activities with IC50 values of 58.85 µg/mL and 57.60 µg/mL while the reference drug (Acarbose) had 405.84 µg/mL and 35.69 µg/mL for α-amylase and α-glucosidase respectively. In-silico studies showed that L1 docking score as well as binding energies are higher than that of acarbose, which are recognized inhibitors of α-amylase together with α-glucosidase. Further insight from the RMSF, RMSD and RoG analysis predicted that, throughout the simulation L1 showcased evident influence on the structural stability of α-amylase. The antioxidant potential of the compounds was carried out using nitric oxide (NO), ferric reducing ability power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The compounds exhibited good to fairly antioxidant properties with L1 as well as L3 having IC50 values of 70.91 and 91.21 µg/mL respectively for NO scavenging activities assay, which comparatively outshined acarbose (reference drug) with IC50 value of 109.95 µg/mL. Pharmacology and pharmacokinetics approximations of L1 - L3 showed minimal violation of Lipinski's Ro5 and this projects them to be less toxic and orally bioavailable as potential templates for the design of therapeutics with antioxidant and antidiabetic activities.

Lippia javanica (Burm. F.) Herbal Tea: Modulation of Hepatoprotective Effects in Chang Liver Cells via Mitigation of Redox Imbalance and Modulation of Perturbed Metabolic Activities.

Introduction: Hepatic oxidative injury is one of the pathological mechanisms that significantly contributes to the development of several liver diseases. In the present study, the hepatoprotective effect of Lippia javanica herbal tea was investigated in Fe2+- mediated hepatic oxidative injury. Methods: Using an in vitro experimental approach, hepatic oxidative injury was induced by co-incubating 7 mM FeSO4 with Chang liver cells that have been pre-incubated with or without different concentrations (15-240 µg/mL) of L. javanica infusion. Gallic acid and ascorbic acid served as the standard antioxidants. Results: The infusion displayed a reducing antioxidant activity in ferric-reducing antioxidant power (FRAP) assay and a potent scavenging activity on 2,2-diphenyl-2- picrylhydrazyl (DPPH) radical. Pretreatment with L. javanica infusion significantly elevated the levels of reduced glutathione and non-protein thiol, and the activities of superoxide dismutase (SOD) and catalase, with concomitant decrease in hepatic malondialdehyde levels, acetylcholinesterase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glycogen phosphorylase and lipase activities. The infusion showed the presence of phytoconstituents such as phenolic compounds, tannins, phenolic glycosides and terpenoids when subjected to liquid chromatography-mass spectrometry analysis. Molecular docking revealed a strong binding affinity of dihydroroseoside and obacunone with both SOD and catalase compared to other phytoconstituents. Conclusion: These results portray a potent antioxidant and hepatoprotective effect of L. javanica, which may support the local usage of the herbal tea as a prospective therapeutic agent for oxidative stress-related liver diseases.

Phytochemical Properties of Croton gratissimus Burch (Lavender Croton) Herbal Tea and Its Protective Effect against Iron-Induced Oxidative Hepatic Injury.

Oxidative stress plays a vital role in the pathogenesis and progression of various liver diseases. Traditional medicinal herbs have been used worldwide for the treatment of chronic liver diseases due to their high phytochemical constituents. The present study investigated the phytochemical properties of Croton gratissimus (lavender croton) leaf herbal tea and its hepatoprotective effect on oxidative injury in Chang liver cells, using an in vitro and in silico approach. C. gratissimus herbal infusion was screened for total phenolic and total flavonoid contents as well as in vitro antioxidant capacity using ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl-hydrazyl (DPPH) methods. Oxidative hepatic injury was induced by incubating 0.007 M FeSO4 with Chang liver cells which has been initially incubated with or without different concentrations (15-240 µg/mL) of C. gratissimus infusion or the standard antioxidants (Gallic acid and ascorbic acid). C. gratissimus displayed significantly high scavenging activity and ferric reducing capacity following DPPH and FRAP assays, respectively. It had no cytotoxic effect on Chang liver cells. C. gratissimus also significantly elevated the level of hepatic reduced glutathione (GSH), superoxide dismutase (SOD), and catalase activities as well as suppressed the malondialdehyde (MDA) level in oxidative hepatic injury. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis of the herbal tea revealed the presence of 8-prenylnaringenin, flavonol 3-O-D-galactoside, caffeine, spirasine I, hypericin, pheophorbide-a, and 4-methylumbelliferone glucuronide. In silico oral toxicity prediction of the identified phytochemicals revealed no potential hepatotoxicity. Molecular docking revealed potent molecular interactions of the phytochemicals with SOD and catalase. The results suggest the hepatoprotective and antioxidative potentials of C. gratissimus herbal tea against oxidative hepatic injury.

Senna petersiana (Bolle) leaf extract modulates glycemic homeostasis and improves dysregulated enzyme activities in fructose-fed streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Senna petersiana (Bolle) is a native South African medicinal shrub combined locally with other plant products to manage diabetes or used as a single therapy for several other ailing conditions. AIM OF THE STUDY: This study evaluated the antidiabetic and antilipidemic effects of S. petersiana leaf ethanol extract and its modulatory effects on dysregulated enzyme activities in fructose-fed streptozotocin-induced diabetic rats. MATERIALS AND METHODS: Six groups of 6-weeks old male Sprague Dawley rats were used in this study. Diabetes was induced in four of the groups by injecting (i.p.) 40 mg/kg of streptozotocin after a two-weeks feeding of 10% fructose via drinking water, while animals in the two normal groups were given similar volume of vehicle buffer and normal drinking water, respectively. After the confirmation of diabetes, treatment with 150 and 300 mg/kg body weight of the ethanolic leaf extract of S. petersiana proceeded for a period of 6 weeks. RESULTS: Oral administration of S. petersiana leaf extract significantly lowered blood glucose, food and liquid intake, glycosylhaemoglobin in blood, liver and cardiac biomarkers, and lipid profile in serum and atherogenic index (AIP) in both the low and high-dose treated animal groups. This was accompanied by a simultaneous increase in Homeostatic Model Assessment-beta (HOMA-ß) score, serum high-density lipoproteins cholesterol (HDL-c), and insulin levels. It also improved pancreatic and serum-reduced glutathione (GSH) levels, catalase, and superoxide dismutase (SOD) enzymes activities with a simultaneous reduction in malondialdehyde (MDA) and nitric oxide (NO) concentrations. Moreover, the extract modulated dysregulated α-amylase, lipase, cholinesterase, and 5' nucleotidase enzyme activities in pancreatic tissue as well as glycogen metabolism in the liver. Analysis of the phytochemicals in the S. petersiana extract showed the presence of phytol, 4a,7,7,10a-tetramethyldodecahydrobenzo[f]-chromen-3-ol, phytol acetate, solasodine glucoside, cassine, veratramine and solasodine acetate. Amongst these compounds, solasodine glucoside had the best binding energy (ΔG) with the selected diabetes-linked enzymes via molecular docking simulation. CONCLUSION: Data from this study demonstrate the antidiabetic effects of S. petersiana leaf extract via the modulation of the dysregulated indices involved in type 2 diabetes and its associated complications. Although it has been shown safe in animals, further toxicological studies are required to ensure its safety for diabetes management in humans.

Ferulic acid mitigates diabetic cardiomyopathy via modulation of metabolic abnormalities in cardiac tissues of diabetic rats.

Cardiovascular abnormalities have been reported as a major contributor of diabetic mortality. The protective effect of ferulic acid on diabetic cardiomyopathy in fructose-streptozotocin induced type 2 diabetes (T2D) rat model was elucidated in this study. Type 2 diabetic rats were treated by oral administration of low (150 mg/kg b.w) and high (300 mg/kg b.w) doses of ferulic acid. Metformin was used as the antidiabetic drug. Rats were humanely euthanized after 5 weeks of treatment, and their blood and hearts were collected. Induction of T2D depleted the levels of reduced glutathione, glycogen, and HDL-cholesterol and the activities of superoxide dismutase, catalase, ENTPDase, and 5'nucleotidase. It simultaneously triggered increase in the levels of malondialdehyde, total cholesterol, triglyceride, LDL-cholesterol, creatinine kinase-MB as well as activities of acetylcholinesterase, angiotensin converting enzyme (ACE), ATPase, glucose-6-phopsphatase, fructose-1,6-bisphophatase, glycogen phosphorylase, and lipase. T2D induction further revealed an obvious degeneration of cardiac muscle morphology. However, treatment with ferulic acid markedly reversed the levels and activities of these biomarkers with concomitant improvement in myocardium structural morphology, which had favorable comparison with the standard drug, metformin. Additionally, T2D induction led to the depletion of 40%, 75%, and 33% of fatty acids, fatty esters, and steroids, respectively, with concomitant generation of eicosenoic acid, gamolenic acid, and vitamin E. Ferulic acid treatment restored eicosanoic acid, 2-hydroxyethyl ester, with concomitant generation of 6-octadecenoic acid, (Z)-, cis-11-eicosenoic acid, tridecanedioic acid, octadecanoic acid, 2-hydroxyethyl ester, ethyl 3-hydroxytridecanoate, dipalmitin, cholesterol isocaproate, cholest-5-ene, 3-(1-oxobuthoxy)-, cholesta-3,5-diene. These results suggest the cardioprotective potential of ferulic acid against diabetic cardiomyopathy.

Harpephyllum caffrum fruit (wild plum) facilitates glucose uptake and modulates metabolic activities linked to neurodegeneration in isolated rat brain: An in vitro and in silico approach.

Alteration in brain glucose metabolism due to glucose uptake reduction has been described in the onset of certain neurodegenerative disorders. This study determined Harpephyllum caffrum fruit's potential ability to improve glucose uptake and its modulatory effects on intrinsic antioxidant, glucogenic, cholinergic, and nucleotide-hydrolyzing enzyme activities in isolated rat brain. Consequently, the bioactive compounds of the fruits were identified with LC-MS. The fruit significantly improved brain glucose uptake following coincubation with glucose and brain tissue. The fruit extract also elevated GSH level, SOD, catalase, glycogen phosphorylase, and ENTPDase activities while simultaneously suppressing NO and malonaldehyde levels and fructose-1,6-bisphosphatase, ATPase, acetylcholinesterase and butyrylcholinesterase activities. LC-MS analysis revealed S-methylcysteine sulfoxide, dihydroquercetin, 3,4-dimethyl-2,5-bis(3,4,5-trimethoxyphenyl) tetrahydrofuran (MTHF), nobiletin, puerarin, quercetin 3-rutinoside, 8-D-glucosyl-4',5,7-trihydroxyflavone, asperulosidic acid, 1,2,4,6-tetragalloylglucose, and phellamurin. This study suggests the neuroprotective effects of H. caffrum fruit due to its ability to enhance glucose uptake, attenuate glucose-induced oxidative stress while modulating glucogenic, cholinergic, and nucleotide-hydrolyzing enzyme activities in normal brain tissues. PRACTICAL APPLICATIONS: Available scientific evidence describes oxidative stress as one of the physiological processes contributing to aging-associated neurodegeneration in humans. In this regard, commonly consumed natural products from plants have attracted much interest due to their ability to mitigate redox imbalance-related pathologies that affect various organs in the body such as the brain. Harpephyllum caffrum or bush mango is an evergreen plant native to the South African vegetation. The fruit from the plant is consumed locally as food or specifically for improving the nutritional quality of meals as deserts or condiments. While previous findings described the high antioxidant properties of the fruits, this study reported possible mechanisms via which the plant may exhibit ameliorative effects against oxidative stress-related neurological disorders in the brain. Hence, findings from the current work present another justification for the significance of fruits as a safer nutraceutical alternative for therapy in neurological disease management.

Cannabidiol improves glucose utilization and modulates glucose-induced dysmetabolic activities in isolated rats' peripheral adipose tissues.

Reduced glucose uptake and utilization, with concomitant lipolysis in adipose tissues has been linked to the pathogenesis of obesity and its complications. The present study investigated the effect of cannabinoid-stimulated glucose uptake on redox imbalance, glucose and lipid metabolisms, as well as cholinergic and purinergic dysfunctions in isolated rats' adipose tissues. Freshly Isolated rats' adipose tissues were incubated with glucose and different concentrations of cannabidiol for 2 h at 37 °C. The negative control consisted of incubation without cannabidiol, while normal control consisted of incubations without glucose and/or cannabidiol and Metformin served as the standard drug. Cannabidiol caused an increase in adipose-glucose uptake, with concomitant elevation of glutathione, triglyceride level, superoxide dismutase, catalase and 5'nucleoidase activities. It also caused suppression in malondialdehyde and cholesterol levels, acetylcholinesterase, ENTPDase, fructose-1,6-biphosphatase, glucose 6-phosphatase, glycogen phosphorylase, and lipase activities. In silico studies revealed a strong molecular interaction of cannabidiol with adipose triglyceride lipase, hormone-sensitive lipase, and monoglyceride lipase. These results indicate that cannabidiol-enhanced glucose uptake in adipose tissues is associated with enhanced antioxidative activities, concomitant modulation of cholinergic and purinergic dysfunctions, and improved glucose - lipid homeostasis.

Vanillin modulates activities linked to dysmetabolism in psoas muscle of diabetic rats.

Skeletal muscles are important in glucose metabolism and are affected in type 2 diabetes (T2D) and its complications. This study investigated the effect of vanillin on redox imbalance, cholinergic and purinergic dysfunction, and glucose-lipid dysmetabolism in muscles of rats with T2D. Male albino rats (Sprague-Dawley strain) were fed 10% fructose ad libitum for 2 weeks before intraperitoneally injecting them with 40 mg/kg streptozotocin to induce T2D. Low (150 mg/kg bodyweight (BW)) and high (300 mg/kg BW) doses of vanillin were orally administered to diabetic rats. Untreated diabetic rats and normal rats made up the diabetic control (DC) and normal control (NC) groups, respectively. The standard antidiabetic drug was metformin. The rats were humanely put to sleep after 5 weeks of treatment and their psoas muscles were harvested. There was suppression in the levels of glutathione, activities of SOD, catalase, ENTPDase, 5'Nucleotidase and glycogen levels on T2D induction. This was accompanied by concomitantly elevated levels of malondialdehyde, serum creatine kinase-MB, nitric oxide, acetylcholinesterase, ATPase, amylase, lipase, glucose-6-phosphatase (G6Pase), fructose-1,6-biphophastase (FBPase) and glycogen phosphorylase activities. T2D induction further resulted in the inactivation of fatty acid biosynthesis, glycerolipid metabolism, fatty acid elongation in mitochondria and fatty acid metabolism pathways. There were close to normal and significant reversals in these activities and levels, with concomitant reactivation of the deactivated pathways following treatment with vanillin, which compared favorably with the standard drug (metformin). Vanillin also significantly increased muscle glucose uptake ex vivo. The results suggest the therapeutic effect of vanillin against muscle dysmetabolism in T2D as portrayed by its ability to mitigate redox imbalance, inflammation, cholinergic and purinergic dysfunctions, while modulating glucose-lipid metabolic switch and maintaining muscle histology.

Ocimum tenuiflorum mitigates iron-induced testicular toxicity via modulation of redox imbalance, cholinergic and purinergic dysfunctions, and glucose metabolizing enzymes activities.

Oxidative stress is a primary culprit in the pathophysiology of infertility conditions in males. This study investigated the effects of Ocimum tenuiflorum on redox imbalance, cholinergic and purinergic dysfunctions and glucose dysmetabolism in oxidative-mediated testicular toxicity using in vitro, ex vivo and in silico models. Induction of oxidative testicular injury was carried out by incubating normal testicular tissue with 0.1 mM FeSO4 and treated by co-incubating with different concentrations of O. tenuiflorum infusion for 30 min at 37°C. O. tenuiflorum displayed significant ferric reducing power activity while scavenging DPPH and hydroxyl (OH˙) free radicals in vitro. Oxidative testicular injury significantly reduced the glutathione level and superoxide dismutase and catalase activities with concomitant elevation of malondialdehyde and nitric oxide levels and acetylcholinesterase, ATPase, fructose-1,6-bisphosphatase and glycogen phosphorylase (GlyP) activities. Incubation with the infusion significantly reversed these levels and activities. The phytochemical constituent of the infusion was detected by gas chromatography-mass spectroscopy analysis and revealed favourable binding energies when docked with some of the studied proteins. These results suggest O. tenuiflorum exerts a protective effect against Fe2+ induced testicular toxicity via mitigation of redox imbalance while modulating metabolic dysfunctions linked to male infertility.

Vanillin exerts therapeutic effects against hyperglycemia-altered glucose metabolism and purinergic activities in testicular tissues of diabetic rats.

Testicular dysfunctions leading to male infertility has been reported in type 2 diabetes (T2D), with glucose dysmetabolism, cholinergic and purinergic dysfunction being major contributors. In the present study, the effect of vanillin on glucose metabolism, purinergic and cholinergic dysfunctions were investigated in testicular tissues of T2D rats. Male Sprague-Dawley rats were divided into 6 groups containing 5 rats each. T2D was induced in rats by administering 10 % fructose ad libitum for 14 days followed by a single intraperitoneal injection (40 mg/kg body weight) of streptozotocin. T2D rats were orally administered with vanillin at 150 and 300 mg/kg body weight (bw). Diabetic control (DC) consisted of untreated diabetic rats, while normal control (NC) consisted of normal rats and they were administered with distilled water only. Metformin was used as the standard antidiabetic drug. After 5 weeks treatment, the rats were sacrificed, and the testes were harvested. Induction of T2D led to significantly depleted testicular levels of glutathione, glycogen content, superoxide dismutase and catalase enzyme activities, with concomitantly elevated levels of nitric oxide, malondialdehyde, acetylcholinesterase, glucose-6-phosphatase, fructose-1,6-biphophastase, glycogen phosphorylase, amylase and lipase activities. These activities and levels were significantly reversed to near normal in rats treated with both doses of vanillin as compared with metformin. These results, when taken together, suggest the therapeutic effect of vanillin against hyperglycemia-mediated metabolic dysfunctions in testes of T2D rats. This is depicted by the ability of the phenolic to attenuate oxidative imbalance, purinergic and cholinergic dysfunctions, while suppressing glucose dysmetabolism.

Loperamide-induced cardiotoxicity in rats: Evidence from cardiac and oxidative stress biomarkers.

At therapeutic dose, loperamide is a safe over-the-counter antidiarrheal drug but could induce cardiotoxic effect at a supratherapeutic dose. In this study, we use cardiac and oxidative biomarkers to evaluate loperamide-induced cardiotoxicity in rats. Rats were orally gavaged with 1.5, 3, or 6 mg/kg body weight (BW) of loperamide hydrochloride for 7 days. The results after 7 days administration of loperamide, revealed dose-dependent increase (P < 0.05) in aspartate aminotransferase, lactate dehydrogenase, creatine kinase-MB, and serum concentration of cardiac troponin I, total homocysteine, and nitric oxide. A 50% decrease in antioxidant enzymes activity was observed at 6 mg/kg BW. Furthermore, malondialdehyde and fragmented DNA also increased significantly in the heart of the treatment groups. Loperamide provoked cardiotoxicity through oxidative stress, lipid peroxidation, and DNA fragmentation in rats. This study has provided a possible biochemical explanation for the reported cardiotoxicity induced by loperamide overdose.