Neurotransmitter Metabolic Enzymes and Antioxidant Status on Alzheimer's Disease Induced Mice Treated with Alpinia galanga (L.) Willd

Abstract

Amyloid β₂₅₋₃₅ (Aβ) peptide may be neurotoxic during the progression of Alzheimer's disease by eliciting reactive oxygen species. The use of folklore medicine is prevalent and plants which possess a rejuvenating property are a large source of natural antioxidants that might afford leads for the development of novel drugs in neurodegenerative disorders. The study was designed to investigate the effect of an ethanol extract of Alpinia galanga (L.) Willd (EAG) on oxidative stress induced Alzheimer's type amnesia in mice. Mice were treated with an experimental extract at 200 mg/kg and 400 mg/kg dose for 14 days and injected with neurotoxic Aβ and the doses were continued for 21 days. Behavioural studies with open field, step-down inhibitory avoidance and a water maze after treatment indicated the acceleration in cognitive function. The elevated levels of acetylcholinesterase and monoamine oxidase enzymes in amnesia induced mice were attenuated by treatment with EAG. The generation of free radicals was decreased due increased activity of antioxidant enzymes after treatment with EAG. These findings suggested that EAG exerts an antiamnesiac effect in Aβ induced neurodegeneration through an antioxidant property.

The Role of Reactive Oxygen Species in the Pathogenesis of Alzheimer’s Disease, Parkinson’s Disease, and Huntington’s Disease: A Mini Review

“…Boyd-Kimball et al [66] reported that glutathione upregulation protected neuron against oxidative stress and neurotoxicity induced by A(1-42) in the AD affected brain. Hanish Singh et al [67] reported that ethanolic extract of Alpinia galangal improved the antioxidant status and inhibited the acetylcholine esterase activity in AD mice. Our research group from Oman reported the beneficial effects of natural products including pomegranate and figs on AD transgenic mice models [62, 68–77].…”

Antioxidant capacities and total phenolic contents of 20 polyherbal remedies used as tonics by folk healers in Phatthalung and Songkhla provinces, Thailand

“…Reported active constituents, including total oligomeric flavonoid fractions, nootkatone, aristolone, solavetivone, and orientin obtained from Cyperus rotundus , have protective effects against lipid peroxidation, DNA damage, antihemolytic activity, and anticancer treatment for erythroleukaemia cells, which might be correlated with their high antioxidant activities [ 34 ]. Earlier experiments have also demonstrated that Alpinia galangal exerts in vitro antimelanogenesis activity [ 35 ] and in vivo antiamnesiac activity through its antioxidant properties [ 36 ]. In addition to their well-described in vitro antioxidant activities, several in vivo studies demonstrated that consumption of Allium sativum [ 37 ], Zingiber officinale [ 38 ], Terminalia arjuna [ 39 ], and Tinospora crispa [ 40 ] extracts led to significant increases in antioxidant enzymes, such as superoxide dismutase, glutathione peroxidase, and catalase, and suppressed glutathione depletion and lipid peroxidation.…”

A Mechanistic Evaluation of Antioxidant Nutraceuticals on Their Potential against Age-Associated Neurodegenerative Diseases

“…The antioxidant enzymes of SOD were increased to 7.17 ± 0.51 vs. 1.82 ± 0.44 U/min/mg in negative control. In addition, GPX (33.41 ± 1.48, vs. 21.84 ± 0.66 U/min/mg) and CAT (2.16 ± 0.18 vs. 0.90 ± 0.10 U/mg) were also elevated, along with non-enzymatic antioxidant vitamin C (0.92 ± 0.03 vs. 0.55 ± 0.03 μg/mg after treatment with A. galanga ( Table 3 ) [ 184 ]). Extracts of A. galanga could also inhibit MAO A and B activity at a low dose with a stronger inhibitory effect at a higher dose.…”

“…MAO is an enzyme that catalyzes the oxidative deamination of neurotransmitters including norepinephrine, serotonin, and dopamine, which have been suggested to increase H 2 O 2 generation in the neurons. Collectively, the attenuation of free radicals by the enhanced endogenous antioxidant system and the inhibition of MAO enzymes by A. galanga improved cognition in AD mice [ 184 ].…”