Siti Hawa Ali Hassan (2014) Phytochemicals, antioxidants and acetylcholinesterase inhibition properties of selected underutilized fruits of Sabah. Masters thesis, Universiti Malaysia Sabah.
![[img]](https://eprints.ums.edu.my/style/images/fileicons/text.png) |
Text
24 PAGES.pdf Download (1MB) |
|
Text
FULLTEXT.pdf Restricted to Registered users only Download (4MB) |
Abstract
Sabah tropical rainforest consist of a rich biodiversity of fruits and vegetables which still remain underutilized. Fruits which have antioxidant properties are frequently related to anti-Alzheimer’s potential. Acetylcholinesterase is an enzyme known to break down the neurotransmitter acetylcholine which leads to Alzheimer’s disease. The aims of the present study was to determine the phytochemical content (total phenolic, total flavonoid, total anthocyanin and total carotenoid), antioxidant activity and acetylcholinesterase inhibition effect of five selected fruits of Sabah namely pengolaban (Litsea garciae), pidada (Sonneratia caseolaris), kembayau (Canarium odontophyllum), asam kandis (Garcinia parvifolia) and tamarillo (Cyphomandra betacea). All samples were separated into different parts (i.e edible and non-edible part) and extracted by using 80% methanol and distilled water. First, determination of total phenolic, flavonoid, anthocyanin and carotenoid contents were done spectrophotometrically. The total phenolic and flavonoid content for 80% methanolic and aqueous extract were significantly highest in the flesh of unripe S. caseolaris with the values of 67.67 ± 0.10 mg GAE/g and 37.06 ± 0.30 mg RE/g, respectively while the lowest phenolic was observed in the flesh of C. betacea (80% methanol) and peel of G. parvifolia (aqueous) with the values of 2.61±0.12 and 1.78±0.15 mg/g, respectively. The lowest flavonoid content were observed in the flesh of L. garciae (80% methanol) and flesh of C. betacea (aqueous) with the values of 2.05±0.21 and 1.15±0.01 mg/g, respectively. The flesh of C. odontophyllum displayed highest anthocyanin content while there was no anthocyanin detected in all parts of S. caseolaris. The flesh of C. betacea showed highest carotenoid content while the seed of C. odontophyllum displayed lowest carotenoid content in both extract. Evaluation of antioxidant activity was conducted using DPPH free radical scavenging assay, radical scavenging ABTS and ferric reducing power (FRAP) assay. Highest scavenging activity was found in unripe flesh S. caseolaris with the values of 98.32 ± 0.28% for DPPH, 91.24 mg AA/g in terms of AEAC (ascorbic acid equivalent antioxidant capacity) and 67.72 ± 0.74 mmol/g for FRAP assay. For acetylcholinesterase inhibition activity, the enzyme inhibition method and galanthamine was used as positive control. All the samples demonstrate dose dependant inhibition activity. Unripe flesh of S. caseolaris displayed highest acetylcholinesterase inhibition activity (47.18 ± 0.68% and 7.80 ± 0.94%) when tested at 250 μg/mL for both 80% methanol and aqueous extracts. As a conclusion, it might provide protection against oxidative damage in body and having a potential as acetylcholinesterase inhibitor.
| Item Type: | Thesis (Masters) |
|---|---|
| Keyword: | Phytochemical content, Antioxidant activity, Acetylcholinesterase inhibition, Alzheimer’s disease, Sabah tropical fruits, Litsea garciae |
| Subjects: | Q Science > QK Botany > QK1-989 Botany > QK710-899 Plant physiology |
| Department: | INSTITUTE > Institute for Tropical Biology and Conservation |
| Depositing User: | DG MASNIAH AHMAD - |
| Date Deposited: | 07 Feb 2025 11:32 |
| Last Modified: | 07 Feb 2025 11:32 |
| URI: | https://eprints.ums.edu.my/id/eprint/42728 |
Actions (login required)
 |
View Item |