الفهرس 
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Abstract
Acrylamide (ACR) is formed during thermal processing of carbohydrate-rich foods such as frying, baking and roasting. Human exposure to ACR is generally believed to occur only in workplaces or other environments with little relevance to public at large. However, ACR formation in many cooked starchy foods is of great concern in view of its possible neurotoxic and carcinogenic effect.
In experimental animals, ACR monomer is demonstrated to be neurotoxic, genotoxic, carcinogenic and also induces developmental and reproductive toxicity. In addition, ACR-induced lipid peroxidation and depletion of reduced glutathione (GSH) levels in various organs has been shown in rodents.
While the underlying mechanisms of ACR-induced neuropathy is not fully known, involvement of oxidative stress mechanisms and inflammatory responses have been speculated.
In view of the increased exposure of humans to ACR through consumption of various thermally processed foods, it is highly imperative to explore newer protective strategies to ameliorate ACR-induced neurotoxic effects and neuropathy.
Pomegranate is a fruit rich in polyphenols that include flavonoids, tannins and hydrolyzable tannins. It contains a complex mixture of gallotannins, ellagitannins, ellagic acid and anthocyanins. Separate studies showed pomegranate peel extracts to have both antioxidant and antimutagenic properties.
Particles with a minimum size of 100 nm in at least one dimension are referred to as nanoparticles (NPs). The greatest promise for in vivo applications exists for NPs with a size of 20 to 100 nm since they may circulate in the blood for prolonged periods of time. This size range of NPs is both big enough to avoid renal and lymphatic clearance and small enough to avoid opsonization. NPs are more likely to be taken up by cells than smaller or larger particles. Due to its availability, cheap cost, ease of gelation, and lack of toxicity, alginate is a biopolymer that is frequently utilized for the encapsulation of various substances.
The aim of the present study is to evaluate the potential prophylactic effect of pomegranate peel extract nanoparticles against acrylamide-induced brain injury in male rats.
Plan of the work
Preparation of pomegranate peel extract (PPE) nanoparticles:
1) Alg-PPE nanoparticles were prepared by the controlled gelification method.
2) Morphological characteristics of PPE nanoparticles were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Particle size analysis.
3) The active ingredients of PPE nanoparticles were investiga-ted by High performance liquid chromatography (HPLC): The PPE nanoparticles was be subjected to standard phytochemical analysis for different constituents such as alkaloids, totalphenolic, flavonoid, tannins and steroids.
In vivo studies
(A) Experimental design
Seventy five male Wistar albino rats were used in this study. Animals were divided equally and randomly into five main groups:
– group 1, Control Group: The animal in this group were injected intraperitoneally (i.p) with saline thrice a week for 5 consecutive weeks.
– group 2, Acrylamide group (ACR): Animals were injected i.p. with acrylamide (50 mg/kg bw) thrice a week for 2 consecutive weeks.
– group 3, (PPE): Rats were daily treated with the PPE nanoparticles (200 mg /kg bw) for two consecutive weeks and along with acrylamide intoxication (50 mg/kg bw/day) for 2 consecutive weeks.
– group 4, Alg-PPE nanoparticles group (Alg-PPE NPs): Rats were treated daily with 200 mg/kg bw of PPE nanoparticles by oral gavage for 2 weeks.
– group 5, (PPE + ACR): Rats were daily treated with PPE 200 mg/kg bw daily for two consecutive weeks and along with acrylamide intoxication (50 mg/kg bw/day) for 2 consecutive weeks.
– group 6, (Alg-PPE nanoparticles + ACR): Rats were daily treated with the PPE nanoparticles 200 mg/kg bw daily for two consecutive weeks and along with acrylamide intoxication (50 mg/kg bw/day) for 2 consecutive weeks.
(B) Biochemical studies
At the end of the experimental study, animals were be decapitated, brains were be excised and the following parameters were estimated in brain homogenates;
• The neurotransmitters norepinephrine (NE), dopamine (DA) and serotonin (5-HT), gamma-aminobutyric acid (GABA), glycine (Gly), aspartate (Asp) and glutamine (Glu) levels were assayed using HPLC.
• Acetylcholine esterase (AchE), total antioxidant capacity (TAC) and DNA fragmentation were assayed while the tumor necrosis factor-alpha (TNF-α) and brain derived neurotrophic factor (BDNF) levels were assayed using specific enzyme-linked immunesorbent assay (ELISA) rat kits.
(C) Histological studies
At the end of the experimental period, five brains from each group were gently excised, washed with normal saline and processed separately for hematoxylin and eosin staining. The sections were examined microscopically for histopathological changes.
Results revealed that ACR injection induced neurotoxicity manifested by the significant increase in tumor necrosis factor alpha, gamma aminobutyric acid, and DNA fragmentation level in brain tissues of treated animals. By contrast, the brain levels of brain-derived neurotrophic factor, total antioxidant capacity, acetylcholinesterase activity, dopamine, serotonin, norepinephrine, glutamine, glycine, and aspartate were significantly decreased. These changes in tissue biochemical parameters were associated with histopathological alternations in the architecture of brain tissues. Amelioration of the acrylamide-induced brain toxicity was observed following co-administration of either PPE or Alg-PPE NPs along with ACR neurotoxicity, with a higher degree of protection observed with the nanoparticles form as a result of increased bioavailability.
The protective effect of the studied extracts was ascribed mainly to the antioxidant potential of their phenolic and flavonoids components. In conclusion, Alg-PPE NPs can be regarded as a potential therapeutic agent that offers protection against acrylamide neurotoxicity, however, to fully understand the neuroprotective mechanism of Alg-PPE NPs at the molecular level, additional research must be done to characterize their active potential.