Gongronema latifolium Benth. leaf extract attenuates diabetes-induced neuropathy via inhibition of cognitive, oxidative stress and inflammatory response.

BACKGROUND: Gongronema latifolium (G. latifolium) Benth. leaves are traditionally used to treat diabetes mellitus (DM) and other diseases in Nigeria and West Africa. This study was performed to evaluate the neuroprotective effect of aqueous extract of G. latifolium leaf against DM. Antidiabetic activity of G. latifolium extracts (6.36, 12.72 and 25.44 mg kg-1 , i.p.) was determined in alloxan-induced diabetic rats. Fasting blood glucose level and oxidative stress markers catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and nitric oxide (NO) levels were measured. Cognitive biomarkers acetylcholinesterase (AChE), butyrylcholinesterase (BChE), dopamine (DOPA), serotonin, epinephrine and norepinephrine and cyclooxygenase (COX-2) were measured in the brain of controls and of G. latifolium-treated diabetic rats. RESULTS: Administration of G. latifolium leaf extract to diabetic rats significantly restored the alterations in the levels of fasting blood glucose (FBG). The MDA and NO levels were significantly reduced with an improvement in CAT, SOD, and GPx activity in the kidneys and brains of diabetic rats treated with G. latifolium. Gongronema latifolium also significantly decreased the levels of AChE, BChE, DOPA, serotonin, epinephrine, and nor-epinephrine in diabetic rats. G. latifolium effectively ameliorated COX-2 in diabetic rats. CONCLUSION: This study showed that leaf extract of G. latifolium improved antioxidant defense against oxidative stress. It displays a neuroprotective effect resulting in the modulation of brain neurotransmitters, which could be considered as a promising treatment therapy. © 2020 Society of Chemical Industry.

In vitro antioxidant and inhibitory activities of polyphenolic-rich extracts of Syzygium cumini (Linn) Skeels leaf on two important enzymes relevant to type II diabetes mellitus.

In this study, the effect of free and bound polyphenolic-rich extract of Syzygium cumini (Linn) Skeels leaf on antioxidant as well as α-amylase and α-glucosidase activities were determined using in vitro model. Polyphenolic-rich extract of Syzygium cumini (Linn) Skeels leaf was prepared accordingly and the capability of the extract to inhibit antioxidants as typified by ferric reducing power (FRAP) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) among other free radicals scavenging abilities were quantified spectrophotometrically, added to this, the activities of (α-amylase and α-glucosidase were also assessed. The bound phenolic extract exhibited more in vitro antioxidant properties as represented by their high radicals scavenging ability in all the free radicals evaluated. Also, the polyphenolic-rich extracts inhibited α-amylase and α-glucosidase, with bound phenolics showing significant (p<0.05) increase in a dose-dependent manner than free phenolics. Therefore, this study suggests the use of Syzygium cumini leaf as a nutraceutical in the management/ control of type II diabetes mellitus patients.

Effect of Zingiber officinale on some biochemical parameters and cytogenic analysis in lead-induced toxicity in experimental rats.

Exposure to toxic elements is greatly unavoidable in our daily activities due to several routes of coming in contact with these elements. Thus lead (Pb), is one of the major causes of health hazard in human. In this study, evaluation of Zingiber officinale as mitigating measure against Pb induced biochemical and cytogenic toxicity in albino rats was investigated. Experimental rats were grouped into five with five animals per group, group I serves as control and groups 2-5 were induced intraperitoneal with lead acetate dissolved in distilled water at 3 mg/kg body weight whereas group 3-5 were orally administered with 200 mg/kg vitamin C, 200 mg/kg, and 100 mg/kg of Z. officinale, respectively for 7 d. The obtained results show that aspartate aminotransferase (AST), alkaline phosphatase (ALP), lipid peroxidation, urea, creatinine, bilirubin, and gamma-glutamyl transferase (GGT) were significantly increased (p < 0.05) and catalase (CAT) were reduced progressively in Pb alone induced rats. Hematological parameters showed a progressive reduction (p < 0.05) in lead acetate alone rats. There were significant changes in micronuclei (MN), chromosomal aberrations (CA) frequency, and oxidative damages in the bone marrow cells from lead acetate alone induced rats, although, mitotic index scores in these cells were reduced gradually (p < 0.05). The altered parameters were significantly reversed toward the levels observed in normal control rats administered with vitamin C and aqueous extract of Z. officinale. Hence, these results suggest that Z. officinale roots might contain therapeutic potential that can ameliorate the hazard effect of lead acetate poison.

Investigation of the In Vitro Antioxidant Potential Of Polyphenolic-Rich Extract of Artocarpus heterophyllus Lam Stem Bark and Its Antidiabetic Activity In Streptozotocin-Induced Diabetic Rats.

Artocarpus heterophyllus Lam (Moraceae) stem bark has been used locally in managing diabetes mellitus with sparse scientific information. This study investigates the in vitro antioxidant potential of polyphenolic-rich extract of A heterophyllus stem bark as well as its antidiabetic activity in streptozotocin-induced diabetic rats. Fifty male Wistar rats were used with the induction of diabetes by a single intraperitoneal injection of streptozotocin (45 mg/kg body weight) and were orally administered 400 mg/kg free and bound phenols of A heterophyllus stem bark. The animals were sacrificed on the 28th day of the experiment using the cervical dislocation method; antihyperglycemia and anti-inflammatory parameters were subsequently assessed. The polyphenolic extracts demonstrated antioxidant potentials (such as hydrogen peroxide and diphenyl-1-picrylhydrazyl), as well as strong inhibitory activity against amylase and glucosidase. There was a significant (P < .05) increase in glycogen, insulin concentration, pancreatic ß-cell scores (HOMA-ß), antioxidant enzymes and hexokinase activities, as well as glucose transporter concentration in diabetic animals administered the extracts and metformin. Also, a significant (P < .05) reduction in fasting blood glucose, lipid peroxidation, glucose-6-phosphatase, and all anti-inflammatory parameters were observed in diabetic rats administered the extracts and metformin. The extracts demonstrated antidiabetic potential, which may be useful in the management of diabetes mellitus.

Neuromodulatory effects of ethyl acetate fraction of Zingiber officinale Roscoe extract in rats with lead-induced oxidative stress.

OBJECTIVE: This study investigated the ameliorative potential of Zingiber officinale Roscoe extract against lead-induced brain damage in rats. METHODS: Thirty male rats were divided into 5 groups of 6 rats each. Lead-acetate toxicity was induced by intraperitoneal injection (10 mg/kg body weight (b.w.)) in Groups B-E. Group A (control) and Group B (lead-acetate) were left untreated; vitamin C (200 mg/kg b.w.) was administered to Group C; ethyl acetate fraction from Z. officinale extract (200 and 100 mg/kg b.w.) was administered to Group D and E by oral gavage once daily for 7 days. Changes in the content of some key marker enzymes such as acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO), epinephrine, dopamine, Na+/K+-ATPase, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as malonaldehyde (MDA) levels were determined in serum. RESULTS: Exposure to lead acetate resulted in a significant decrease (P < 0.05) in the activities of BChE, AChE, Na+/K+-ATPase, SOD, CAT and GPx with a corresponding increase in the levels of MDA, xanthine oxidase, epinephrine, dopamine and MAO relative to the control group. Levels of all disrupted parameters were alleviated by co-administration of Z. officinale fraction and by the standard drug, vitamin C. CONCLUSION: These results suggest that ethyl acetate fraction of Z. officinale extract attenuates lead-induced brain damage and might have therapeutic potential as a supplement that can be applied in lead poisoning.

In vitro antioxidant and enzyme inhibitory properties of the n-butanol fraction of Senna podocarpa (Guill. and Perr.) leaf.

Background This study evaluates the antioxidant activity and enzyme inhibitory properties of the n-butanol fraction of Senna podocarpa leaves on α-amylase, α-glucosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, arginase, phosphodiesterase 5 (PDE-5), and angiotensin converting enzyme (ACE). Methods The total phenol and flavonoids, iron (Fe) chelation, and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging were used to determine the antioxidant activity, and the inhibitory activities of α-glucosidase, α-amylase, AChE, BChE, tyrosinase, arginase, PDE-5 and ACE were also assessed. Results The n-butanol fraction of S. podocarpa shows high total phenol and total flavonoid contents. The n-butanol fraction of S. podocarpa leaves also chelates Fe2+ and ABTS radicals. The n-butanol fraction of S. podocarpa leaves also inhibited α-glucosidase, α-amylase, AChE, BChE, tyrosinase, arginase, PDE-5, and ACE at the concentration tested. Chromatographic analysis displayed the presence of ß-elemene, phytol and caryophyllene oxide chrysophanol, 3-oxo-methyl ester, α-humulene, ß-caryophyllene, rhein, emodin, and α-copaene. Conclusions Hence, the n-butanol fraction of S. podocarpa leaves demonstrates encouraging feat in controlling and/or managing cognitive dysfunction such as Alzheimer's disease and also hypertension, diabetes, erectile dysfunction, endothelial dysfunction, and hyperpigmentation.

Spondias mombim L. (Anacardiaceae): Chemical fingerprints, inhibitory activities, and molecular docking on key enzymes relevant to erectile dysfunction and Alzheimer's diseases.

Due to the exceptional wide range in biochemical activities of natural plant products, Spondias mombim L. are attaining a new height because they present great prospects for drug advancement. This research was designed to analyze the pharmaceutical properties of S. mombim L. ethyl acetate fraction (SMEAF) on key enzymes relevant to erectile and cognitive dysfunction. SMEAF inhibitory activities of the specified enzymes were determined spectrophotometrically. Chemical profile of SMEAF were assessed by HPLC/MS analysis. Thereafter, molecular docking of the studied enzymes with chlorogenic acid, lutein, and zeaxanthin were carried out using PATCHDOCK. SMEAF had remarkable enzyme inhibitory effects against phosphodiesterase-5 (PDE-5), arginase, angiotensin I-converting enzyme (ACE), cholinesterase, monoamine oxidase A (MAO), ecto-5' nucleotidase (E-NTDase), tyrosinase, and stimulated sodium-potassium ATPase (Na+/K+-ATPase) activities. HPLC/MS analysis revealed that phenolics and carotenoids were major components in these fraction notably, chlorogenic acid, lutein, and zeaxanthin. Our results suggested that SMEAF could be explored as phytopharmaceuticals. PRACTICAL APPLICATIONS: Spondias mombim L. are cooked as green vegetable with enormous medicinal value probably due to its polyphenols with potent antioxidant activity. Furthermore, the leaves could also be useful for therapeutic purposes against erectile dysfunction and central nervous system disorders.

HPLC-DAD fingerprinting analysis, antioxidant activities of Tithonia diversifolia (Hemsl.) A. Gray leaves and its inhibition of key enzymes linked to Alzheimer's disease.

Tithonia diversifolia (Hemsl.) A. Gray leaves have long been used to manage neurodegenerative diseases without scientific basis. This study characterized the phenolic constituents, evaluated the antioxidant properties of phenolic extracts from T. diversifolia leaves used as traditional medicine in Africa and its inhibition of key enzymes linked to Alzheimer's disease. The extract was rich in phenolic acids (gallic acid, chlorogenic acid, caffeic acid and p-coumaric acid) and flavonoids (apigenin) and had 1,1-diphenyl-2-picryl-hydrazil radical scavenging abilities (IC50 = 41.05 µg. mL-1), 2,2-Azino-bis3-ethylbenthiazoline-6sulphonic acid radical scavenging ability (IC50 = 33.51 µg. mL-1), iron chelation (IC50 = 38.50 µg. mL-1), reducing power (Fe3+- Fe2+) (7.34 AAEmg/100 g), inhibited acetylcholinesterase (IC50 = 39.27 µg mL-1) and butyrylcholinesterase (IC50 = 35.01 µg mL-1) activities. These results reveal the leaf as a rich source of phenolic compounds with antioxidant and cholinesterase inhibitory activity.

Chromatographic fingerprint analysis, antioxidant properties, and inhibition of cholinergic enzymes (acetylcholinesterase and butyrylcholinesterase) of phenolic extracts from Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill bark.

BACKGROUND: Irvingia gabonensis stem bark is a medicinal plant used in most parts of Africa to manage a number of ailments including neurodegenerative diseases that occur without scientific basis. This work characterized the phenolic composition, evaluated the cholinergic enzymes (acetylcholinesterase, AChE and butyrylcholinesterase, BChE) inhibition, and assessed the antioxidant activity of phenolic extracts from I. gabonensis (Aubry-Lecomte ex O'Rorke) Baill bark. METHODS: Total phenol and flavonoids content was evaluated in addition to antioxidant activity as shown by Fe2+ chelation, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, and 2,2-azino-bis-(3-ethylbenthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability. Inhibitory activities on AChE and BChE were evaluated. RESULTS: The extract was found to be rich in phenolic acid (ellagic acid) and flavonoids (quercetrin, kaempferol, and apigenin). The phenolic extracts displayed DPPH radical scavenging ability (IC50=19.98 µg/mL), ABTS radical scavenging ability (IC50=18.25 µg/mL), iron chelation (IC50=113.10 µg/mL), and reducing power (Fe3+ to Fe2+) (5.94 mg ascorbic acid equivalent/100 g). Extracts of I. gabonensis inhibited AChE (IC50=32.90 µg/mL) and BChE (IC50=41.50 µg/mL) activities in concentration-dependent manner. CONCLUSIONS: Hence, possible mechanism through which the stem bark executes their anti-Alzheimer's disease activity might be by inhibiting cholinesterase activities in addition to suppressing oxidative-stress-induced neurodegeneration.