Antioxidant, Antiglaucoma, Anticholinergic, and Antidiabetic Effects of Kiwifruit ( Actinidia deliciosa ) Oil: Metabolite Profile Analysis Using LC-HR/MS, GC/MS and GC-FID

**Background:** Kiwifruit (Actinidia deliciosa) is a widely consumed fruit known for its health benefits, attributed to bioactive phytochemicals such as polyphenols, carotenoids, and organic acids. Oxidative stress, caused by an imbalance between reactive oxygen species (ROS) and antioxidant defenses, contributes to various chronic diseases including cataracts, cardiovascular disorders, diabetes, glaucoma, and Alzheimer's disease (AD). Natural antioxidants from plants are preferred over synthetic ones due to safety concerns. This study aimed to evaluate the chemical composition, antioxidant, anticholinergic (anti-Alzheimer), antiglaucoma, and antidiabetic properties of kiwifruit oil using advanced analytical techniques.

**Methods:** Kiwifruit oil was prepared by steam distillation of fresh fruits. Polyphenolic composition was analyzed using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) with a Troyasil C18 column and a Thermo Orbitrap Q-Exactive mass spectrometer. Essential oil composition was determined by gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detection (GC-FID) on a DB-5 capillary column. Antioxidant capacity was assessed through reducing ability assays (Fe3+ reduction, Cu2+ reduction, and Fe3+-TPTZ (FRAP) reduction) and radical scavenging assays (DPPH and ABTS). Enzyme inhibition assays were performed for acetylcholinesterase (AChE, from Electrophorus electricus) using Ellman's method, α-amylase using a starch substrate method, and human carbonic anhydrase II (hCA II) purified from human blood via affinity chromatography. IC50 values were calculated from dose-response curves. All experiments were performed in triplicate, and statistical analysis used one-way ANOVA with Tukey's post hoc test (p < 0.05).

**Key Results:** LC-HRMS identified 26 phenolic compounds in kiwifruit oil. The most abundant were apigenin (74.24 mg/L oil), epigallocatechin (12.89 mg/L), caryophyllene oxide (12.89 mg/L), luteolin (5.49 mg/L), salicylic acid (4.84 mg/L), ascorbic acid (4.57 mg/L), quillaic acid (4.57 mg/L), rutin (4.54 mg/L), and naringenin (3.62 mg/L). GC-MS/FID revealed six volatile components, with squalene (53.04%), linoleoyl chloride (20.28%), linoleic acid (2.67%), and palmitic acid (1.54%) as major constituents. In reducing ability assays at 30 μg/mL, kiwifruit oil showed absorbance values of 0.835 ± 0.035 (Fe3+ reducing, λ700), 0.765 ± 0.031 (Cu2+ reducing, λ450), and 0.583 ± 0.017 (FRAP, λ593), which were lower than standards like BHA, BHT, Trolox, and ascorbic acid but comparable to α-tocopherol. For radical scavenging, kiwifruit oil had IC50 values of 48.55 μg/mL (DPPH, r²=0.9977) and 77.00 μg/mL (ABTS, r²=0.9890), while standards ranged from 5.82 μg/mL (ascorbic acid, DPPH) to 49.50 μg/mL (BHT, DPPH). In enzyme inhibition, kiwifruit oil inhibited AChE with IC50 12.80 μg/mL (r²=0.9680) compared to tacrine (IC50 8.82 μg/mL), α-amylase with IC50 421.02 μg/mL (r²=0.9080) compared to acarbose (IC50 7.54 μg/mL), and hCA II with IC50 505.83 μg/mL (r²=0.9249) compared to acetazolamide (IC50 9.96 μg/mL).

**Clinical Implications:** The study demonstrates that kiwifruit oil possesses moderate antioxidant activity and notable enzyme inhibitory effects against targets relevant to Alzheimer's disease (AChE), diabetes (α-amylase), and glaucoma (hCA II). The presence of high levels of apigenin, epigallocatechin, and other phenolics may contribute to these bioactivities. While the oil's antioxidant capacity is lower than some synthetic standards, its natural origin and multi-target potential make it a candidate for further research in functional foods or nutraceuticals. The hCA II inhibition suggests possible antiglaucoma applications, though the IC50 is much higher than acetazolamide. Similarly, α-amylase inhibition indicates potential for postprandial glucose control, but the effect is weak compared to acarbose. The AChE inhibition is relatively potent, suggesting possible neuroprotective benefits. These findings support the traditional use of kiwifruit and highlight the need for in vivo studies to confirm efficacy and safety.