Modulatory effect of protocatechuic acid on cadmium induced nephrotoxicity and hepatoxicity in rats in vivo

Introduction: This study sought to investigate the effect of protocatechuic acid (PCA); a phenolic compound readily available in most plant foods on cadmium-induced nephrotoxicity and hepatoxicity in rats. Case description: Thirty six adult male rats weighing about 150–160 g were acclimatized for 2 weeks and subsequently divided into six groups: Group 1 rats received normal saline (control group), group 2 rats were administered 5 mg Cd/kg body weight in form of solution orally (induced group), groups 3 and 4 received cadmium solution and different doses of PCA (10 and 20 mg/kg body weight) respectively, while groups 5 and 6 were the normal rats administered different doses of PCA (10 and 20 mg/kg) respectively in an experiment that lasted for twenty one days. The animals were sacrificed, the blood was collected and the serum was subsequently prepared. Furthermore, the liver was excised, homogenized and centrifuged to obtain the tissue homogenate used for the analyses. The serum was used for the determination of the total protein, urea, creatinine and uric acid levels while the liver homogenate was used for the estimation of alanine aminotransferase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP). Discussion and evaluation: The result revealed that total protein level was reduced in cadmium induced toxicity rat group which was elevated upon treatment with PCA. Conversely, the elevated levels of urea, uric acid and creatinine in cadmium induced toxicity kidney rats were significantly (p < 0.05) reduced in PCA treated groups. Similarly, marked elevation in the ALT, AST and ALP activity were observed in cadmium induced toxicity rat group when compared with the control group. However, significant (p < 0.05) decrease in ALT, AST and ALP activity were noticed in groups administered different doses of PCA. Conclusions: The results from this study suggest that PCA may protect against cadmium-induced toxicity in the kidney and liver

Alterations of Na+/K+-ATPase, cholinergic and antioxidant enzymes activity by protocatechuic acid in cadmium-induced neurotoxicity and oxidative stress in Wistar rats

Staff PublicationBackground: This study assessed the possible protective mechanisms of protocatechuic acid (PCA) against cadmium (Cd)-induced oxidative stress and neurotoxicity in rats. Methods: Male wistar strain rats weighing between 150–160 g were purchased and acclimatized for two weeks. The rats were divided into seven groups of seven each; NC group received normal saline, CAD group received 6 mg/kg of Cd-solution, CAD + PSG group received Cd-solution and prostigmine (5 mg/kg), CAD + PCA-10 and CAD + PCA-20 groups received Cd-solution and PCA (10 mg/kg and 20 mg/kg) respectively, PCA-10 and PCA-20 groups received 10 mg/kg and 20 mg/kg PCA each. Animals were administered normal saline, Cd and PCA daily by oral gavage for 21 days. After which the animals were sacrificed, the brain excised, homogenized and centrifuged. The activities of enzymes (Na+/K+-ATPase, cholinesterases, catalase, glutathione peroxidase, superoxide dismutase) and levels of oxidative stress markers (lipid peroxidation and reduced glutathione) linked to neurodegeneration were subsequently assessed. Results: Significant (p < 0.05) alterations in the enzyme activities and levels of oxidative stress markers were observed in CAD group when compared to the NC group. However, the activities of the enzymes were reversed in CAD + PSG and CAD + PCA groups. Conclusions: PCA may protect against cadmium-induced neurotoxicity by altering the activities of Na+/K+- ATPase, acetylcholinesterase, butyrylcholinesterase and endogenous antioxidant enzymes

Distribution of Phenolic Contents, Antidiabetic Potentials, Antihypertensive Properties, and Antioxidative Effects of Soursop ( Annona muricata

Soursop fruit has been used in folklore for the management of type-2 diabetes and hypertension with limited information on the scientific backing. This study investigated the effects of aqueous extracts (1 : 100 w/v) of Soursop fruit part (pericarp, pulp, and seed) on key enzymes linked to type-2 diabetes (α-amylase and α-glucosidase) and hypertension [angiotensin-I converting enzyme (ACE)]. Radicals scavenging and Fe2+ chelation abilities and reducing property as well as phenolic contents of the extracts were also determined. Our data revealed that the extracts inhibited α-amylase and α-glucosidase and ACE activities dose-dependently. The effective concentration of the extract causing 50% antioxidant activity (EC50) revealed that pericarp extract had the highest α-amylase (0.46 mg/mL), α-glucosidase (0.37 mg/mL), and ACE (0.03 mg/mL) inhibitory activities while the seed extract had the least [α-amylase (0.76 mg/mL); α-glucosidase (0.73 mg/mL); and ACE (0.20 mg/mL)]. Furthermore, the extracts scavenged radicals, reduced Fe3+ to Fe2+, and chelated Fe2+. The phenolic contents in the extracts ranged from 85.65 to 560.21 mg/100 g. The enzymes inhibitory and antioxidants potentials of the extracts could be attributed to their phenolic distributions which could be among the scientific basis for their use in the management of diabetes and hypertension. However, the pericarp appeared to be most promising

In vitro antioxidant activities of African birch (Anogeissus leiocarpus) leaf and its effect on the α-amylase and α-glucosidase inhibitory properties of acarbose

Objective This study sought to determine the antioxidant activities of African birch leaf, to assess its interaction with key enzymes relevant to type 2 diabetes (α-amylase and α-glucosidase) and to evaluate its effect on acarbose in vitro. Methods One milligram per milliliter of aqueous extract of African birch and acarbose were separately prepared. At the same time, both the African extract and acarbose solution (50:50 v/v) were thoroughly mixed until homogeneity was attained. The phenolic phytoconstituents and antioxidant properties of African birch leaf were subsequently determined. Finally, the effects of African birch extract, acarbose solution and a mixture of acarbose and African birch extract on α-amylase and α-glucosidase activities were assessed in vitro. Results The results showed that African birch extract demonstrated a remarkable antioxidant effect, as exemplified by its radical scavenging abilities, Fe2+ chelating ability and prevention of lipid peroxidation. Acarbose had significantly (p < 0.05) higher α-amylase (IC50 = 11.77 μg/ml) and α-glucosidase (IC50 = 9.05 μg/ml) activities compared to African birch extract [α-amylase (IC50 = 242.17 μg/ml); α-glucosidase (IC50 = 196.35 μg/ml)]. However, the combination of acarbose and African birch extract showed an additive effect on α-amylase inhibition, while a resultant synergistic action was observed against α-glucosidase inhibition. Conclusion The additive and synergistic actions of the combination of African birch extract and acarbose solution suggest effective, complementary and alternative strategies towards the management/treatment of hyperglycaemia associated with type 2 diabetes

Modulatory Effects of Ferulic Acid on Cadmium-Induced Brain Damage

Staff PublicationStudies have shown the pharmacological relevance of phenolics like ferulic acid (FA) in promoting health. This study sought to investigate the modulatory effects of FA on cadmium-induced brain damage in rats. Brain damage was induced in Wistar strain rats by oral administration of cadmium (5 mg/kg body weight) for 21 days. Assays for malondialdehyde (MDA) content, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO), and Naþ/Kþ-ATPase activities were carried out. The study revealed significant (P < .05) increases in the MDA content and all enzymes’ (AChE, BChE, MAO, and Naþ/Kþ- ATPase) activity investigated following cadmium administration. However, rats administered FA (10 and 20 mg/kg body weight) alongside cadmium significantly (P < .05) protected the brain by reversing the level of lipid peroxidation as measured by the MDA content as well as the enzymes’ activity. This study, therefore, substantiates the neuroprotective potentials of FA especially in the management of cadmium-induced toxicity

Antioxidant and inhibitory properties of Clerodendrum volubile leaf extracts on key enzymes relevant to non-insulin dependent diabetes mellitus and hypertension

Objective: To characterize the interaction of phenolic (free and bound) extracts from white butterfly (Clerodendrum volubile P. Beauv) leaves with key enzymes relevant to non-insulin dependent diabetes mellitus (α-amylase and α-glucosidase) and hypertension (Angiotensin-I converting enzyme) and their antioxidant properties in vitro. Methods: The effects of the extracts on enzymes [α-amylase, α-glucosidase, Angiotensin-I converting enzyme (ACE)], some pro-oxidant (Fe2+- and sodium nitroprusside-induced lipid peroxidation in the pancreas (in vitro)) and antioxidant properties and HPLC analysis of the extracts were investigated. Results: The phenolic extracts inhibited α-amylase, α-glucosidase, ACE and some pro-oxidants (Fe2+- and sodium nitroprusside-induced lipid peroxidation in the pancreas (in vitro)). Bound phenolics had significantly higher (P  0.05) in their α-amylase inhibitory activities. The stronger inhibition of α-glucosidase and ACE compared to α-amylase by both extracts may be of pharmacological relevance. Reversed-phase HPLC analysis of the extracts revealed the presence of quercetin, rutin, kaempferol, and chlorogenic and caffeic acids as the main components of both the free and bound extracts. Conclusion: The inhibitory properties of phenolic rich extracts on α-amylase, α-glucosidase, ACE, and Fe2+- and sodium nitroprusside-induced lipid peroxidation in the pancreas could be attributed to the antioxidant properties of the extracts and their phenolic composition. The stronger action of the bound phenolic extract on α-glucosidase may provide the possible bioactivity at the brush border end of the intestinal wall. This study may thus suggest that leaves represent a functional food and nutraceutical in the management of non-insulin dependent diabetes mellitus and hypertension

Pasting alters glycemic index, antioxidant activities, and starch‐hydrolyzing enzyme inhibitory properties of whole wheat flour

This study was designed to compare the antioxidant and antidiabetic activities of raw and paste wheat flour. The raw flour was cooked, dried, and milled to obtain the paste flour. The glycemic index, starch, amylose, and amylopectin contents were determined. The inhibitory effects of the raw and paste flour on α‐glucosidase and α‐amylase activities as well as metal‐induced pancreatic damage were also determined. Pasting reduced the glycemic index (63.15%), starch (22.83 g/100 g), amylose (2.88 g/100 g), and amylopectin (17.74 g/100 g) contents. The raw (IC 50 = 0.50 and 1.20 mg/ml) and paste (IC 50 = 0.29 and 1.66 mg/ml) flours reduced the activities of α‐amylase and α‐glucosidase, respectively. The paste flour exhibited stronger inhibitory effects against Fe2+‐induced pancreatic damage compared to raw flour. The paste flour exhibited better antioxidant and antidiabetic properties and could be a good processing method to improve the medicinal properties of wheat flour

Distribution of Phenolic Contents, Antidiabetic Potentials, Antihypertensive Properties, and Antioxidative Effects of Soursop (Annona muricata L.) Fruit Parts In Vitro

Soursop fruit has been used in folklore for the management of type-2 diabetes and hypertension with limited information on the scientific backing. This study investigated the effects of aqueous extracts (1 : 100 w/v) of Soursop fruit part (pericarp, pulp, and seed) on key enzymes linked to type-2 diabetes ( -amylase and -glucosidase) and hypertension [angiotensin-I converting enzyme (ACE)]. Radicals scavenging and Fe 2+ chelation abilities and reducing property as well as phenolic contents of the extracts were also determined. Our data revealed that the extracts inhibited -amylase and -glucosidase and ACE activities dose-dependently. The effective concentration of the extract causing 50% antioxidant activity (EC 50 ) revealed that pericarp extract had the highestamylase (0.46 mg/mL), -glucosidase (0.37 mg/mL), and ACE (0.03 mg/mL) inhibitory activities while the seed extract had the least [ -amylase (0.76 mg/mL); -glucosidase (0.73 mg/mL); and ACE (0.20 mg/mL)]. Furthermore, the extracts scavenged radicals, reduced Fe 3+ to Fe 2+ , and chelated Fe 2+ . The phenolic contents in the extracts ranged from 85.65 to 560.21 mg/100 g. The enzymes inhibitory and antioxidants potentials of the extracts could be attributed to their phenolic distributions which could be among the scientific basis for their use in the management of diabetes and hypertension. However, the pericarp appeared to be most promising

NTPDase, 5′-nucleotidase and adenosine deaminase activities and purine levels in serum of sickle cell anemia patients

Sickle cell anemia (SCA) is a hereditary disorder that is characterized by tendency of hemoglobin molecules within the erythrocytes to polymerize under hypoxia conditions, deform the red cells, and promote vaso-occlusion and endothelial damage. This disease may be associated with the extracellular release of nucleotides, particularly ATP, ADP and adenosine into the circulation. The aim of this study was to investigate the possible changes in adenine nucleotides and nucleoside metabolizing enzymes as well as their levels in serum of SCA patients. NTPDase, 50-nucleotidase and adenosine deaminase activities were evaluated in serum obtained from blood samples of 15 SCA treated patients and 15 healthy subjects (control group). The results revealed that there were significant (P 0.05) alteration was observed in ATP, ADP and adenosine levels of both SCA treated and control groups. However, inosine level was significantly (P < 0.05) decreased and hypoxanthine level was higher in SCA treated patients (P < 0.001) when compared to the control group. The results suggest the involvement of purinergic signaling enzymes in the maintenance of the levels of extracellular nucleotides and nucleosides, thus preventing some pathophysiological conditions associated with SCA

Phenolic constituents and modulatory effects of Raffia palm leaf (Raphia hookeri) extract on carbohydrate hydrolyzing enzymes linked to type-2 diabetes

This study sought to investigate the effects of Raffia palm (Raphia hookeri) leaf extract on enzymes linked to type-2 diabetes mellitus (T2DM) and pro-oxidant induced oxidative stress in rat pancreas. The extract was prepared and its α-amylase and α-glucosidase inhibitory effects were determined. Radical [2,2-diphenyl-1-picrylhydrazyl (DPPH)] scavenging and Fe2+-chelating abilities, and inhibition of Fe2+-induced lipid peroxidation in rat pancreas homogenate were assessed. Furthermore, total phenol and flavonoid contents, reducing property, and high performance liquid chromatography diode array detector (HPLC-DAD) fingerprint of the extract were also determined. Our results revealed that the extract inhibited α-amylase (IC50 = 110.4 μg/mL) and α-glucosidase (IC50 = 99.96 μg/mL) activities in concentration dependent manners which were lower to the effect of acarbose (amylase: IC50 = 18.30 μg/mL; glucosidase: IC50 = 20.31 μg/mL). The extract also scavenged DPPH radical, chelated Fe2+ and inhibited Fe2+-induced lipid peroxidation in rat pancreas all in concentration dependent manners with IC50 values of 402.9 μg/mL, 108.9 μg/mL and 367.0 μg/mL respectively. The total phenol and flavonoid contents were 39.73 mg GAE/g and 21.88 mg QAE/g respectively, while the reducing property was 25.62 mg AAE/g. The HPLC analysis revealed the presence of chlorogenic acid (4.17 mg/g) and rutin (5.11 mg/g) as the major phenolic compounds in the extract. Therefore, the ability of the extract to inhibit carbohydrate hydrolyzing enzymes and protect against pancreatic oxidative damage may be an important mechanisms supporting its antidiabetic properties and could make Raffia palm leaf useful in complementary/alternative therapy for management of T2DM. However, further studies such as in vivo should be carried out