Caffeic acid attenuates memory dysfunction and restores the altered activity of cholinergic, monoaminergic and purinergic in brain of cadmium chloride exposure rats

Objectives This study aims to evaluate the neuroprotective effect of caffeic acid (CAF) against cadmium chloride (CdCl2) in rats via its effect on memory index as well as on altered enzymatic activity in the brain of CdCl2-induced neurotoxicity. Methods The experimental rats were divided into seven groups (n=6 rats per group) of healthy rats (group 1), CdCl2 -induced (CD) (3 mg/kg BW) rats (group 2), CD rats + Vitamin C (group 3), CD rats + CAF (10 and 20 mg/kg BW respectively) (group 4 & 5), and healthy rat + CAF (10 and 20 mg/kg BW respectively) (group 6 & 7). Thereafter, CdCl2 and CAF were administered orally to the experimental rats in group 2 to group 5 on daily basis for 14 days. Then, the Y-maze test was performed on the experimental rats to ascertain their memory index. Results CdCl2 administration significantly altered cognitive function, the activity of cholinesterase, monoamine oxidase, arginase, purinergic enzymes, nitric oxide (NOx), and antioxidant status of Cd rats (untreated) when compared with healthy rats. Thereafter, CD rats treated with vitamin C and CAF (10 and 20 mg/kg BW) respectively exhibited an improved cognitive function, and the observed altered activity of cholinesterase, monoamine oxidase, arginase, purinergic were restored when compared with untreated CD rats. Also, the level of brain NOx and antioxidant status were significantly (p<0.05) enhanced when compared with untreated CD rats. In the same vein, CAF administration offers neuro-protective effect in healthy rats vis-à-vis improved cognitive function, reduction in the activity of some enzymes linked to the progression of cognitive dysfunction, and improved antioxidant status when compared to healthy rats devoid of CAF. Conclusions This study demonstrated the neuroprotective effect of CAF against CdCl2 exposure and in healthy rats.

Caffeic and chlorogenic acids modulate altered activity of key enzymes linked to hypertension in cyclosporine-induced hypertensive rats

OBJECTIVES

This study aimed to explore the protective mechanism of caffeic acid (CAA) and chlorogenic acid (CHA) on cyclosporine (CSA) induced hypertensive rats.

METHODS

Effect of CAA and CHA on diastolic blood pressure (DBP), mean arterial pressure (MAP), angiotensin-converting enzyme (ACE), e-nucleotide triphosphate dephosphorylase (e-NTPDase), 5' nucleotidase and adenosine deaminase (ADA) activity in CSA-induced hypertensive rats were determined.

RESULTS

CAA and CHA administration stabilized hypertensive effect caused by CSA administration. Also, altered activity of ACE (lung), e-NTPDase, 5' nucleotidase, ADA as well as elevated malondiadehyde (MDA) level was restored in all the treated hypertensive rats in comparison with the untreated hypertensive rats.

CONCLUSION

Hence, these observed results could underlie some of the mechanisms through which CAA and CHA could offer antihypertensive effect.

Effect of diet supplemented with P. ostreatus and L. subnudus on memory index and key enzymes linked with Alzheimer's disease in streptozotocin-induced diabetes rats

Mushrooms have been reported in folklore for the management of Alzheimer's disease (AD) and diabetes with limited scientific prove. This study aims to unravel the effect of diets supplemented with P. ostreatus and L. subnudus on diabetic encephalopathy (DE) in streptozotocin (STZ)-induced diabetic rats. The memory index, brain cholinesterase, arginase activity, and markers for oxidative stress were evaluated. STZ-induced diabetic rats exhibited memory deficits, elevated brain cholinesterase, arginase activity in comparison with nondiabetic rats. Also, markers for oxidative stress were altered in the brain of diabetic rat when compare with nondiabetic rats. Meanwhile, diabetic rats fed with supplemented-diets exhibited better memory index, reduced cholinesterase, arginase activity in comparison with untreated diabetic rats placed on a basal diet. Also, supplemented-diets restored altered markers of oxidative stress. Our findings indicated that P. ostreatus and L. subnudus-supplemented diets could prevent DE. Nevertheless, diets supplemented with L. subnudus had better nutraceutical potential than P. ostreatus. PRACTICAL APPLICATIONS: Diabetes mellitus is one of the most chronic diseases in the world. Also, it is a risk factor for several complications such as cognitive dysfunction, hypertension, and other health issues. Mushrooms are commonly consumed as food or as food supplements in many countries of the world and are a rich source of protein, chitin, and vitamins. Diet supplemented with P. ostreatus and L. subnudus were able to restore memory deficit in diabetic rats, proven to be a dietary intervention in the management of memory deficit linked with diabetes mellitus. Findings from this study show that consumption of P. ostreatus and L. subnudus as food or supplement could help in a diabetic state.

Pleurotus ostreatus and Lentinus subnudus supplemented diets restore altered acetylcholinesterase and butyrylcholinesterase activities and improve antioxidant status in transgenic Drosophila melanogaster model

Pleurotus ostreatus (P. ostreatus) and Lentinus subnudus (L. subnudus) have been used by the locals for the management of Alzheimer's disease (AD) but with scant scientific sources. The aim of this study is to assess the neuroprotective properties of P. ostreatus and L. subnudus using transgenic Drosophila melanogaster flies (TDMF). The activity of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), as well as the antioxidant status of TDMF raised on a diet supplemented with P. ostreatus and L. subnudus were determined. The flies were raised on a diet devoid of supplements or supplemented with P. ostreatus or L. subnudus (1% and 5% inclusion) for 7 days. Afterward, AChE and BChE activities, as well as catalase and total thiol level, were determined. The reactive oxygen species (ROS) and malondialdehyde (MDA) levels were also determined in the flies raised on a diet devoid of supplement and on supplemented diets. Meanwhile, flies raised on P. ostreatus- and L. subnudus-supplemented diets exhibited a significant reduction in the activity of AChE and BChE in comparison with the controls. Also, supplemented diets significantly (p < 0.05) enhance catalase activity and improve total thiol level, while ROS and MDA levels were observed to be reduced in all the flies raised on the supplemented diets in comparison with the controls. In summary, reduction in the activity of AChE and BChE, as well as improved antioxidant status in TDMF, could be some of the mechanisms through which P. ostreatus and L. subnudus exhibit anti-AD properties. Nevertheless, L. subnudus exhibits a better neuroprotective effect than P. ostreatus.

Inhibitory Effect of Garlic, Purple Onion, and White Onion on Key Enzymes Linked with Type 2 Diabetes and Hypertension

Spices are used in soup preparation in many homes and serve as ingredients in the preparation of several traditional delicacies endowed with natural antioxidants such as polyphenols. The aim of this study is to evaluate the effect of aqueous extract of garlic, white onion, and purple onion on angiotensin-converting enzyme, α-amylase, and α-glucosidase activity in vitro and determine their antioxidant properties via various antioxidant assays such as OH^*, Fe²⁺ chelation, and 2, 2'-azino-bis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical-scavenging assays. The results reveal that aqueous extract of garlic, purple onion, and white onion inhibited angiotensin-converting enzyme, α-amylase, and α-glucosidase in a concentration-dependent manner (0-4 mg/ml). However, purple onion (IC₅₀ = 0.59 mg/ml) had higher inhibitory effect on angiotensin-converting enzyme than white onion (IC₅₀ = 0.66 mg/ml) and purple onion (IC₅₀ = 0.96 mg/ml). Furthermore, white onion had significantly (p < .05) stronger inhibitory effect on α-amylase (IC₅₀ = 3.93 mg/mL) than garlic (IC₅₀ = 8.19 mg/ml) and purple onion (IC₅₀ = 8.27 mg/ml). Conversely, garlic (IC₅₀ = 4.50 mg/ml) had no significantly higher inhibitory effect on α-glucosidase activity than white onion and purple onion. In addition, the aqueous extracts were able to scavenge 2,2- diphenyl-1-picrylhydrazyl (DPPH^*) free radical and reduce Fe³⁺ to Fe²⁺ in a dose-dependent manner. Therefore, a possible mechanism by which garlic, white onion, and purple onion exert antidiabetes and antihypertensive properties could be through the inhibitory effect on ACE, α-amylase, and α-glucosidase coupled with their ability to prevent lipid peroxidation in the pancreas and heart, which justify their strong antioxidant properties.

Caffeic and chlorogenic acids inhibit key enzymes linked to type 2 diabetes (in vitro): a comparative study

BACKGROUND

Chlorogenic acid is a major phenolic compound that forms a substantial part of plant foods and is an ester of caffeic acid and quinic acid. However, the effect of the structures of both chlorogenic and caffeic acids on their antioxidant and antidiabetic potentials have not been fully understood. Thus, this study sought to investigate and compare the interaction of caffeic acid and chlorogenic acid with α-amylase and α-glucosidase (key enzymes linked to type 2 diabetes) activities in vitro.

METHODS

The inhibitory effect of the phenolic acids on α-amylase and α-glucosidase activities was evaluated. Thereafter, their antioxidant activities as typified by their 1,1-diphenyl-2 picrylhydrazyl radical scavenging ability and ferric reducing antioxidant properties were determined.

RESULTS

The results revealed that both phenolic acids inhibited α-amylase and α-glucosidase activities in a dose-dependent manner (2-8 μg/mL). However, caffeic acid had a significantly (p<0.05) higher inhibitory effect on α-amylase [IC50 (concentration of sample causing 50% enzyme inhibition)=3.68 μg/mL] and α-glucosidase (IC50=4.98 μg/mL) activities than chlorogenic acid (α-amylase IC50=9.10 μg/mL and α-glucosidase IC50=9.24 μg/mL). Furthermore, both phenolic acids exhibited high antioxidant properties, with caffeic acid showing higher effects.

CONCLUSIONS

The esterification of caffeic acid with quinic acid, producing chlorogenic acid, reduces their ability to inhibit α-amylase and α-glucosidase activities. Thus, the inhibition of α-amylase and α-glucosidase activities by the phenolic acids could be part of the possible mechanism by which the phenolic acids exert their antidiabetic effects.