Inhibition of carbohydrate hydrolyzing enzymes associated with type 2 diabetes and antioxidative properties of some edible seeds in vitro

This study sought to evaluate the antioxidant properties and effects of some edible wild seeds [Afzelia africana Sm. (AFZ), Cyperus esculentus L. (CYP), Eleusine coracana Gaertn. (ELE), Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill. (IRV), Monodora myristica Dunal. (MON) and Parinari curatellifolia Planch. ex Benth. (PAR)] on α-amylase and α-glucosidase activities. The phenolic content and antioxidant activities of aqueous extracts of the seeds as typified by 1,1-diphenyl-2 picrylhydrazyl (DPPH) and hydroxyl (OH) radicals scavenging abilities and inhibition of Fe²⁺-induced malondialdehyde (MDA) production in rat’s pancreas in vitro were also assessed. ELE had significantly (p < 0.05) higher total phenol content than the other seeds; however, AFZ had the highest flavonoid content. The extracts scavenged DPPH· and OH· in a dose-dependent manner with aqueous extracts of PAR having the highest DPPH· scavenging ability, while extracts from IRV had the highest OH· scavenging ability and inhibition of Fe²⁺-induced MDA production in rat’s pancreas. Furthermore, all the extracts inhibited α-amylase and α-glucosidase activities in a dose-dependent manner. The α-amylase inhibitory effect of MON (IC₅₀ = 0.48 mg/mL) was comparable to that of acarbose (IC₅₀ = 0.40 mg/mL), while the α-glucosidase inhibitory effect of AFZ (IC₅₀ = 0.45 mg/mL) was comparable to that of acarbose (IC₅₀ = 0.39 mg/mL). The results suggest the potential use of the seeds in the dietary management of blood glucose levels associated with type 2 diabetes.

     

Effect of feeding cassava root meal on reproduction and growth of rabbits

In an experiment designed to determine the effect of feeding cassava-based diets on reproduction of young rabbit does, 16 New Zealand White does, about 36 weeks old, were fed four diets containing 0, 15, 30 or 45% cassava root meal (CRM) daily plus 200 g of green herbage every other day. After being fed those diets for 42 days, the does were bred to bucks fed standard commercial diet. The does were bred two more times after the pups were weaned at 5 weeks of age. Offspring of the first breeding study were used in an 8-week growth trial by feeding them the same cassava-based diets as their dams. The number of pups per litter at birth, 14, 28 and 35 days postpartum and the live weight of pups at the same ages did not differ significantly between treatments. Similarly, the thiocyanate content of the urine and blood serum of the dams was similar for all treatments. Results of the growth study using the offspring of the first breeding showed the average rate of gain, feed consumption, efficiency of feed utilization, the fresh weight of skin, kidney, liver, heart, pancreas and visceral fat were not significantly different. Also the urine and serum thiocyanate concentrations were not different.     

Sorghum stem extract modulates Na<Superscript>+</Superscript>/K<Superscript>+</Superscript>-ATPase,ecto-5′-nucleotidase,and acetylcholinesterase activities

Sorghum stem (Sorghum bicolor) has been in use in traditional medicine systems for the management of neurodegenerative conditions. However, there is dearth of information on the scientific basis for its use in the treatment of such conditions. This study sought to assess the antioxidant activity and effects of phenolic extract from sorghum stem (Sorghum bicolor) on some cholinergic (acetylcholinesterase (AChE)) and purinergic (Na⁺/K⁺-ATPase and ecto-5′-nucleotidase) enzymes associated with neurological conditions. Phenolic-rich extract was prepared using methanol: 1 N HCl (1:1, v/v) mixture and characterized using high-performance liquid chromatography-diode array detector (HPLC-DAD). In vitro tests were used to investigate the effects of the phenolic extract on AChE, Na⁺/K⁺-ATPase, and ecto-5′-nucleotidase activities. Furthermore, the hydroxyl (OH) radical scavenging and Fe²⁺-chelating abilities of the extract were investigated. HPLC-DAD analysis revealed the presence of some phenolic acids such as caffeic acid (120.58 mg/g), ferulic acid (76.45 mg/g), gallic acid (17.48 mg/g), chlorogenic acid (16.25 mg/g), and flavonoids such as kaempferol (15.98 mg/g), rutin (51.07 mg/g), quercetin (263.16 mg/g), and quercitrin (89.21 mg/g) in the phenolic extract. The extract significantly inhibited AChE and ecto-5′-nucleotidase activities in a dose dependent manner with IC₅₀?=?24.88 μg/ml and IC₅₀?=?37.49 μg/ml, respectively, and increased Na⁺/K⁺-ATPase activity in a dose dependent manner. Furthermore, the phenolic extract also scavenged OH radicals and was able to chelate Fe²⁺ in a dose dependent manner with IC₅₀?=?54.27 μg/ml and 18.47 μg/ml, respectively. This study revealed the antioxidant and modulatory effects of phenolic extracts from sorghum stem on some cholinergic and purinergic enzymes.     

Black Seed (Nigella sativa): A Favourable Alternative Therapy for Inflammatory and Immune System Disorders

Inflammopharmacology - In the recent years, various food additives, medicinal plants, and their bioactive components have been utilized in anti-inflammatory and immunomodulatory therapy. Nigella...     

Rutin alleviates cadmium-induced neurotoxicity in Wistar rats: involvement of modulation of nucleotide-degrading enzymes and monoamine oxidase

Metabolic Brain Disease - Rutin is a flavonoid commonly found in many vegetables, fruits and other plant species. Thus, this study investigated the protective role of rutin on cognitive function...     

Shaddock peels (Citrus maxima) phenolic extracts inhibit α-amylase, α-glucosidase and angiotensin I-converting enzyme activities: A nutraceutical approach to diabetes management

In this study, the interactions of free and bound phenolic-rich extracts from shaddock peels (popular in folklore for the management of diabetes and hypertension) with α-amylase and α-glucosidase (key enzymes linked to type-2 diabetes) and angiotensin I-converting enzyme (ACE) (key enzyme linked to hypertension) were assessed. The free phenolics of shaddock (Citrus maxima) peels were extracted with 80% acetone, while the bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate; and their interaction with the enzymes were assessed. The phenolic extracts inhibited α-amylase, α-glucosidase and ACE enzyme activities in a dose-dependent manner; however, bound phenolics had significantly higher (P < 0.05) α-amylase inhibitory activities, than free phenolics, which had significantly higher (P < 0.05) ACE inhibitory activities. There was no significant difference (P > 0.05) in their α-glucosidase inhibitory activities. The stronger inhibition of α-glucosidase when compared to α-amylase is of great pharmaceutical importance. The phenolic inhibited sodium nitroprusside induced lipid peroxidation in pancreas in a dose dependent manner. Therefore, free and bound phenolic extracts from shaddock peels could be used as nutraceutical for the management of hypertension and type-2 diabetes.     

Inhibition of acetylcholinesterase activity and Fe2+-induced lipid peroxidation in rat brain in vitro by some citrus fruit juices

This study sought to characterize the effects of some citrus fruit juices (shaddock [Citrus maxima], grapefruit [Citrus paradisii], lemon [Citrus limoni], orange [Citrus sinensis], and tangerine [Citrus reticulata]) on acetylcholinesterase activity in vitro. The total phenolic content, radical scavenging abilities, and inhibition of Fe(2+)-induced malondialdehyde (MDA) production in rats brain homogenate in vitro were also assessed. Orange had significantly (P<.05) higher phenolic content than the other juices. The juices scavenged 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals in a dose-dependent manner with orange having the highest scavenging ability. Furthermore, the juices inhibited Fe(2+)-induced MDA production in rat brain homogenate in a dose-dependent manner with shaddock having the highest inhibitory ability. Acetylcholinesterase activity was also inhibited in vitro by the juices in a dose-dependent manner. The inhibition of acetylcholinesterase activity and antioxidant properties of the citrus juices could make them a good dietary means for the management of Alzheimer's disease.     

Hypocholesterolemic properties of grapefruit (Citrus paradisii) and shaddock (Citrus maxima) juices and inhibition of angiotensin-1-converting enzyme activity

Grapefruit (Citrus paradisii) and shaddock (Citrus maxima) juices are used in folk medicine for the management of hypertension and other cardiovascular diseases, but the mechanism of action by which they exert their therapeutic action is unclear. The aim of this study was to investigate the effect of grapefruit and shaddock juices on angiotensin-1-converting enzyme (ACE) activity in vitro and the hypocholesterolemic properties of the juices in rats fed a high-cholesterol diet. Grapefruit juice had higher total phenol and flavonoid contents than shaddock juice, while both juices inhibited ACE activity in a dose-dependent manner. Furthermore, administration of the juices to rats fed a high-cholesterol diet caused a significant reduction in plasma total cholesterol, triglyceride, and low-density lipoprotein–cholesterol levels and an increase in high-density lipoprotein–cholesterol levels. The inhibition of ACE activity in vitro and in vivo hypocholesterolemic effect of the juices could explain the use of the juices in the management of cardiovascular diseases.     

Orange peels modulate antioxidant markers and key enzymes relevant to erection in the penile tissue of paroxetine‐treated rats

In comparison to other antidepressant drugs, erectile dysfunction (ED) is more pronounced in paroxetine use. On the other hand, orange (Citrus sinensis) peels commonly consumed in various forms are used in folkloric medicine for ED management. Thus, this study evaluated the effect of orange peels infusion on sexual behaviour, nitric oxide (NO) level and some enzymes (arginase, phosphodiesterase‐5 [PDE‐5], acetylcholinesterase [AChE] and adenosine deaminase [ADA]) in paroxetine‐treated rats. Erectile dysfunction was induced with paroxetine (10 mg/kg body weight). The animals were grouped into five (n = 6): normal rats; paroxetine‐induced rats; paroxetine‐induced rats treated with sildenafil citrate (5 mg/kg); paroxetine‐induced rats treated with orange peels infusion (50 mg/kg); Paroxetine induced rats treated with orange peel infusions (100 mg/kg). The results revealed a significant decrease in sexual behaviour, NO level and the activities of antioxidant enzymes, while there was a significant increase in arginase, PDE‐5, AChE and ADA activities in paroxetine‐induced rats. However, orange peel infusions ameliorated erectile dysfunction in paroxetine‐treated rats. This study showed some possible biochemical basis underlying the use of orange peels infusion in erectile dysfunction management.