Browsing by Author "On–Nom N."

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    Elucidation of phenolic profile and bioactive potential of Aeginetia indica L.: A comparative study between newly discovered yellow and native purple flowers
    (2025-08-01) Temviriyanukul P.; Thangsiri S.; Inthachat W.; On–Nom N.; Sahasakul Y.; Aursalung A.; Chupeerach C.; Suttisansanee U.; Temviriyanukul P.; Mahidol University
    Aeginetia indica L. is a wild plant, with scant information on its food and medicinal applications. This research investigated the phenolics, antioxidant properties, in vitro medicinal activities, and genotoxicity of the newly discovered yellow and native purple flowers of A. indica collected from diverse locations in Thailand. Purple A. indica harvested from Ubon Ratchathani Province (PU) exhibited 1.3–1.4-fold higher total phenolic content (TPC) and 1.1–1.4-fold higher total flavonoid content (TFC) than purple A. indica collected from Sakon Nakhon Province (PS) and yellow A. indica collected from Sakon Nakhon Province (YS), with apigenin and naringenin predominantly detected in PU by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The purple color of PU and PS led to 2.5–2.9-fold higher total anthocyanin content (TAC) than YS. Higher phenolic content in PU led to stronger antioxidant activities by 1.2–1.3- and 1.2–1.8-fold as determined by ferric ion reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays, respectively, while the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was not significantly different from PS. PU and PS exhibited 1.1-fold lower scavenging capacities (50 % of total radicals or SC50) than YS, suggesting their higher antioxidant strength. Higher inhibitory activities of most key enzymes relevant to obesity (lipase, 1.6–3.3-fold higher), type II diabetes (α-amylase, 1.3–1.6-fold higher), and Alzheimer's disease (acetylcholinesterase (AChE, 1.6–3.0-fold higher) and butyrylcholinesterase (BChE, 1.1-fold higher)) were also observed in PU. Further investigation of the PU extract with orlistat (a commercially available anti-obesity drug) and donepezil (a commercially available anti-Alzheimer's disease drug) suggested synergistic effects of PU with both drugs. PU did not induce gene mutations as assayed by the bacterial reverse mutation test. The results suggested that PU could be further developed as a future functional food or health ingredient.
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    The effect of pre- and post-harvesting techniques on phenolics, antioxidant activities and key enzyme inhibitions of commercially available ready-to-drink teas
    (2025-06-01) Khemthong C.; Thangsiri S.; Chathiran W.; Inthachat W.; Chupeerach C.; Temviriyanukul P.; On–Nom N.; Srichamnong W.; Suttisansanee U.; Khemthong C.; Mahidol University
    Tea, the world's most popular beverage, is prepared using different pre- and post-harvesting techniques, leading to its unique sensory characteristics and bioactive ingredients. However, knowledge about the impact of these processing methods on the phenolic compositions and health properties of commercially available ready-to-drink teas is limited. To fill this research lacuna, the phenolic compositions, antioxidant potentials, and inhibitory activities against the key enzymes relevant to non-communicable diseases including hyperlipidemia (lipase), type II diabetes (α-amylase, α-glucosidase, and dipeptidyl peptidase-IV), and Alzheimer's disease (acetylcholinesterase, butyrylcholinesterase, and β-secretase) of eleven commercially available ready-to-drink teas were investigated. The results indicated that pre-harvest shading led to higher contents of catechin, epicatechin gallate, chlorogenic acid, and 3,4-dihydroxybenzoic acid, while fermentation significantly increased rutin content, which, in turn, led to higher total phenolic contents. Antioxidants in shaded tea tended to follow a hydrogen atom transfer (HAT)-based mechanism, while the single electron transfer (SET)-based mechanism was a preferable reaction pathway for antioxidants in fermented teas. The ability to inhibit key enzymes was more pronounced in fermented teas than in shaded tea, potentially attributed to the biological activities of certain phenolics, either individually or working together as effective inhibitors. The addition of flavors (honey lemon, kyoho grape, watermelon, and roasted rice) led to higher contents of catechins than the original green tea (without added flavor), while the contents of other general phenolics varied, leading to similar or higher TPCs. Antioxidant potentials and enzyme inhibitions varied for different ready-to-drink tea varieties. The knowledge from this research will benefit the development of ready-to-drink teas with particular phenolics and health-related properties.