5 results on '"Daniel Emmanuel Ekpo"'
Search Results
2. Ethanol extract of Tephrosia bracteolata leaves and its fractions ameliorates alloxan-induced diabetes and its associated complications in Wistar rat model
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Daniel Emmanuel Ekpo, Precious Adejoh Idakwoji, Okwesilieze Fred Chiletugo Nwodo, Obioma U. Njoku, and Parker Elijah Joshua
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medicine.medical_specialty ,Ethanol ,biology ,Tephrosia ,business.industry ,Endocrinology, Diabetes and Metabolism ,Rat model ,Ethyl acetate ,030209 endocrinology & metabolism ,Pharmacology ,biology.organism_classification ,medicine.disease ,Metformin ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,chemistry ,Diabetes mellitus ,Alloxan ,Internal Medicine ,medicine ,Histopathology ,030212 general & internal medicine ,business ,medicine.drug - Abstract
Tephrosia bracteolata Guill. & Perr. (Leguminosae-Papilionoideae) is a traditional Nigerian medicinal plant used for the treatment of whitlow, toothache, wounds, and diabetes. This study investigated the biochemical and histopathological effects of the ethanol extract of T. bracteolata leaves (EETB) and its fractions on alloxan-induced diabetic rats. EETB was fractionated successively with n-hexane, chloroform, ethyl acetate, methanol, and water to yield the respective fractions (nHF, CF, EAF, MF, and AF). The antidiabetic activities of EETB and its fractions at 250 and 500 mg/kg body weight (groups 4–15) were investigated in comparison to the normal control (group 1), the diabetic control (group 2), and the standard (150 mg/kg b.w. metformin, group 3) on alloxan-induced diabetic Wistar rats (200–220 g) for 28 days. Alterations in some biochemical parameters and histopathology of major organs were assessed. Induction of diabetes triggered significant (p
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- 2021
3. UPLC-PDA-ESI-QTOF-MS/MS fingerprint of purified flavonoid enriched fraction of Bryophyllum pinnatum; antioxidant properties, anticholinesterase activity and in silico studies
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Joyce Oloaigbe Ogidigo, B. C. Nwanguma, Collins U. Ibeji, Chioma Assumpta Anosike, Parker Elijah Joshua, Daniel Emmanuel Ekpo, and O. F. C. Nwodo
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Antioxidant ,In silico ,medicine.medical_treatment ,Flavonoid ,Pharmaceutical Science ,Fraction (chemistry) ,RM1-950 ,030226 pharmacology & pharmacy ,01 natural sciences ,Lipid peroxidation ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Fingerprint ,Drug Discovery ,medicine ,Bryophyllum pinnatum ,Pharmacology ,chemistry.chemical_classification ,Chromatography ,biology ,Chemistry ,carlinoside ,docking studies ,lipid peroxidation ,acetylcholinesterase ,General Medicine ,biology.organism_classification ,0104 chemical sciences ,Crassulaceae ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,butyrylcholinesterase ,Molecular Medicine ,Therapeutics. Pharmacology ,alzheimer’s diseases - Abstract
Bryophyllum pinnatum (Lam.) Oken (Crassulaceae) is used traditionally to treat many ailments. This study characterizes the constituents of B. pinnatum flavonoid-rich fraction (BPFRF) and investigates their antioxidant and anticholinesterase activity using in vitro and in silico approaches. Methanol extract of B. pinnatum leaves was partitioned to yield the ethyl acetate fraction. BPFRF was isolated from the ethyl acetate fraction and purified. The constituent flavonoids were structurally characterized using UPLC-PDA-MS2. Antioxidant activity (DPPH), Fe2+-induced lipid peroxidation (LP) and anticholinesterase activity (Ellman’s method) of the BPFRF and standards (ascorbic acid and rivastigmine) across a concentration range of 3.125–100 μg/mL were evaluated in vitro for 4 months. Molecular docking was performed to give insight into the binding potentials of BPFRF constituents against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). UPLC-PDA-MS2 analysis of BPFRF identified carlinoside, quercetin (most dominant), luteolin, isorhamnetin, luteolin-7-glucoside. Carlinoside was first reported in this plant. BPFRF significantly inhibited DPPH radical (IC50 = 7.382 ± 0.79 µg/mL) and LP (IC50 = 7.182 ± 0.60 µg/mL) better than quercetin and ascorbic acid. Also, BPFRF exhibited potent inhibition against AChE and BuChE with IC50 values of 22.283 ± 0.27 µg/mL and 33.437 ± 1.46 µg/mL, respectively compared to quercetin and rivastigmine. Docking studies revealed that luteolin-7-glucoside, carlinoside and quercetin interact effectively with crucial amino acid residues of AChE and BuChE through hydrogen bonds. BPFRF possesses an excellent natural source of cholinesterase inhibitor and antioxidant. The material could be further explored for the potential treatment of oxidative damage and cholinergic dysfunction in Alzheimer’s disease.
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- 2021
4. Bioassay-guided fractionation, phospholipase A2-inhibitory activity and structure elucidation of compounds from leaves of Schumanniophyton magnificum
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Emmanuel Nnaemeka Uhuo, Daniel Emmanuel Ekpo, Rita Onyekachukwu Asomadu, Chizoba Joy Anosike, Parker Elijah Joshua, and O. F. C. Nwodo
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Bioassay guided fractionation ,medicine.drug_class ,gas chromatography ,Bacillus cereus ,Pharmaceutical Science ,RM1-950 ,Inhibitory postsynaptic potential ,030226 pharmacology & pharmacy ,01 natural sciences ,Schumanniophyton magnificum ,Anti-inflammatory ,03 medical and health sciences ,0302 clinical medicine ,Phospholipase A2 ,14-methyl pentadecanoic acid methyl ester ,Drug Discovery ,medicine ,enzyme inhibition ,rubiaceae ,anti-inflammatory ,Pharmacology ,Rubiaceae ,biology ,Traditional medicine ,Chemistry ,bacillus cereus ,General Medicine ,biology.organism_classification ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,Snake venom ,hexadecanoic acid, ethyl ester ,3-ethylhexane ,biology.protein ,Molecular Medicine ,lipids (amino acids, peptides, and proteins) ,Therapeutics. Pharmacology - Abstract
Context Schumanniophyton magnificum Harms (Rubiaceae) is used traditionally in Nigeria for the treatment of snake bites. Snake venom contains phospholipase A2 (PLA2) which plays a key role in causing inflammation and pain. Objective To assess the anti-inflammatory effect of the methanol extract of Schumanniophyton magnificum (MESM) leaves through the inhibition of PLA2 and investigate the compounds responsible for the effect. Materials and methods PLA2-inhibitory activity of MESM was assessed at concentrations of 0.1–0.8 mg/mL using human red blood cells as substrate. Prednisolone was used as the standard control. MESM was subsequently partitioned using n-hexane, dichloromethane, ethyl acetate and aqueous-methanol (90:10 v/v), after which PLA2-inhibitory activity of the partitions was determined. The best partition was subjected to chromatographic techniques and the fractions obtained were assessed for PLA2 inhibition at 0.4 mg/mL. Compounds in the most active fraction were determined using Fourier-transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS). Results MESM significantly inhibited PLA2 activity at 0.8 mg/mL (44.253%) compared to prednisolone (35.207%). n-Hexane partition (SMP1) proved more active with inhibition of 55.870% observed at 0.1 mg/mL. Fraction 1 (SMF1) showed the highest PLA2-inhibitory activity of 58.117%. FTIR studies revealed the presence of some functional groups in SMF1, and GC-MS confirmed the presence of 9 compounds which are first reported in this plant. Hexadecanoic acid, ethyl ester was identified as the major compound (24.906%). Discussion and conclusions The PLA2-inhibitory activity of MESM suggests that its compounds may be explored further in monitoring anti-inflammatory genes affected by the venoms.
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- 2020
5. High resolution UPLC-PDA-QTOF-ESI-MS/MS analysis of the flavonoid-rich fraction of
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Daniel Emmanuel Ekpo, Okwesilieze Fred Chiletugo Nwodo, Joyce Oloaigbe Ogidigo, and Parker Elijah Joshua
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0301 basic medicine ,Lasianthera africana P. Beauv ,Antioxidant ,Flavonoid-rich fraction ,DPPH ,medicine.medical_treatment ,Isolation and characterization ,Toxicology ,Polyphenolic phytochemicals ,Article ,Natural product ,Antioxidants ,03 medical and health sciences ,Rutin ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,Gallic acid ,lcsh:Social sciences (General) ,lcsh:Science (General) ,Carbon tetrachloride ,Isorhamnetin ,Cardiac enzymes ,Creatinine ,Multidisciplinary ,Chromatography ,Ascorbic acid ,Pharmaceutical science ,Biological sciences ,030104 developmental biology ,chemistry ,Oxidative stress ,Ethnopharmacology ,lcsh:H1-99 ,UPLC-PDA-QTOF-ESI-MS/MS ,Quercetin ,Reactive oxygen species ,030217 neurology & neurosurgery ,Renal function ,lcsh:Q1-390 - Abstract
Lasianthera africana P. Beauv. (Icacinaceae) is a traditional Nigerian medicinal plant used for treatment of ulcers, diarrhea, parasitic infections and diabetes. This study was aimed at characterizing the bioactive principles extractable from the flavonoid-rich fraction of L. africana leaves (LAFRF), and to evaluate its effects on renal and cardiac functions. Isolation, and purification of the LAFRF was achieved using standard methods. The in vitro antioxidant activity was evaluated on DPPH∗ and ferric reducing antioxidant potential (FRAP). The total flavonoids (281.05 ± 7.44 mg QE/g), were identified, structurally characterized and quantified using high resolution ultra-performance liquid chromatography, in tandem with quadrupole-time-of-flight electrospray ionization mass spectrometer (UPLC-PDA-QTOF-ESI-MS/MS). Fifty Wistar rats of both sexes (110–130 g), were distributed into 10 groups (n = 5). Groups 1 and 2 served as the normal and CCl4 controls respectively. Groups 3A-6B constituted the preventive and curative studies. The effects of the LAFRF at 3, 10, and 30 mg/kg body weight on urea and creatinine concentrations, lactate dehydrogenase (LDH), and creatine kinase (CK) activities of CCl4-intoxicated rats were assessed. The LAFRF displayed remarkable in vitro antioxidant property by scavenging the DPPH∗, with an IC50 of 5.40 ± 0.00 μg/ml which is more potent than the scavenging activity of the ascorbic acid (IC50 of 7.18 ± 0.00 μg/ml), and also effectively reduced Fe3+ to Fe2+ when compared to gallic acid. The UPLC-PDA-QTOF-ESI-MS/MS fingerprint of the LAFRF indicated presence of quercetin (758983.6 mg/kg), rutin (17540.4 mg/kg), luteolin (126524.3 mg/kg), isorhamnetin (197949.0 mg/kg), and other non-phenolic compounds. The LAFRF significantly (p < 0.05) improved renal function, and normalized cardiac enzyme activities in vivo. The ability of the LAFRF to scavenge the DPPH and Fe3+ radicals, improve renal and cardiac functions following CCl4 intoxication shows its potential in the development of alternative therapy for combating oxidative stress-related complications., Antioxidants; Cardiac enzymes; Carbon tetrachloride; Flavonoid-rich fraction; Isolation and characterization; Lasianthera africana P. Beauv.; Oxidative stress; Polyphenolic phytochemicals; Reactive oxygen species; Renal function; UPLC-PDA-QTOF-ESI-MS/MS; Biological sciences; Ethnopharmacology; Pharmaceutical science; Natural product; Toxicology.
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- 2020
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