Comparative Study of Chemical Composition, In Vitro Inhibition of Cholinergic and Monoaminergic Enzymes, and Antioxidant Potentials of Essential Oil from Peels and Seeds of Sweet Orange (Citrus Sinensis [L.] Osbeck) Fruits

Abstract

This study was designed to compare the chemical compositions and effect of essential oils from the peels and seeds of sweet orange on cholinergic (acetylcholinesterase [AChE], butyrylcholinesterase [BChE]) and monoaminergic (monoamine oxidase [MAO]) enzymes. The ability of the essential oils to protect the brain against Fe2+‐induced lipid peroxidation was also investigated. Forty and forty‐four compounds were identified in peels and seed essential oils, respectively, using gas chromatography. The essential oils inhibited AChE, BChE and MAO in dose‐dependent manner. However, essential oil from the peels had higher inhibition on cholinergic enzymes but lower inhibitory effect on MAO and Fe2+‐induced lipid peroxidation compared to the seed essential oils. This study also revealed the presence of volatile compounds. Conclusively, both essential oils could be used as therapeutic agents in the management of Alzheimer's disease. Practical Applications Sweet orange (Citrus sinensis) peels and seeds are waste materials in the production of orange juice and can be used as a source to produce essential oils which can be of use in the production of functional foods and nutraceuticals. This study provided reference information for the first time on the chemical composition and potential application of sweet orange peels and seed essential oils in the treatment and management of Alzheimer's diseases.

In vitro neuroprotective properties of some commonly consumed green leafy vegetables in Southern Nigeria

“…Considering the ex tracts inhibitory effectiveness as revealed by the EC 50 values (Table 1), there was no significant difference (P N 0.05) in the inhibitory effects of the extracts (editan = 1.03 ± 0.08 μg/mL; utazi = 0.13 ± 0.03 μg/mL; afang = 0.16 ± 0.04 μg/mL). These findings also agree with earlier studies on the MAO inhibitory properties of plant phyto chemicals; Zhi et al [6], reported that phytoconstituents from leaf of Desmodium elegans are potent MAO inhibitor, while Ademosun et al [33], reported MAO inhibitory properties of essential oils from peel and seed of sweet orange as part of their neuroprotective properties. Therefore, the ability of the extracts in this study to inhibit MAO activity could be another mechanism contributing to their neuroprotective properties, and could be essential for the prevention and management of neurodegeneration.…”

“…Therefore, it is of interest that the extracts showed higher BChE inhibitory effect than AChE. Previous findings have also reported the ability of plant extracts to inhibit BChE activity better than AChE (in vitro) [33,34]. Impairment of the monoaminergic neurotransmission through rapid oxidation of monoamine neurotransmitters by MAO has been implicat ed in the pathogenesis and progression of several neurodegenerative diseases, especially PD and AD [35].…”

Cognitive Enhancing and Antioxidative Potentials of Velvet Beans (Mucuna pruriens) and Horseradish (Moringa oleifera) Seeds Extracts: A Comparative Study

“…; Ademosun et al . ). Therefore, to achieve the holistic treatment/management of neurodegenerative disease and cognitive dysfunction, these enzymes should be co‐inhibited so as to restore ACh level and prevent indiscriminate hydrolysis of monoamine neurotransmitter with a positive increase in serotonergic and catecholaminergic compound in AD patient as reported by Ademosun et al .…”

Modulation of some markers of erectile dysfunction and malonaldehyde levels in isolated rat penile tissue with unripe and ripe plantain peels: identification of the constituents of the plants using HPLC

“…Penile homogenate was prepared according to the method of Belle et al (2004) and lipid peroxidation assay was determined using the method of Ademosun et al (2016). The rat penile homogenate (100 lL) was mixed with a mixture containing 30 lL of 0.1 M Tris-HCl buffer (pH 7.4), extract and 30 lL of 250 lM Fe 2þ .…”