Crataegus pinnatifida is used to treat various diseases, including indigestion, congestive heart failure, hypertension, atherosclerosis, and myocardial dysfunction. We evaluated antioxidant and anti-α-glucosidase activities of various solvent extracts and major bioactive components from the fruit of C. pinnatifida. Ethyl acetate extracts showed potent antioxidant activities with IC₅₀ values of 23.26 ± 1.97 and 50.73 ± 8.03 μg/mL, respectively, in DPPH and ABTS radical scavenging assays. Acetone extract exhibited significant anti-α-glucosidase activity with IC₅₀ values of 42.35 ± 2.48 μg/mL. HPLC analysis was used to examine and compare the content of active components in various solvent extracts. We isolated four active compounds and evaluated their antioxidant and anti-α-glucosidase properties. Among the isolated compounds, chlorogenic acid and hyperoside showed potential antioxidant activities in ABTS and superoxide radical scavenging assays. Moreover, hyperoside also displayed stronger anti-α-glucosidase activity than other isolates. The molecular docking model and the hydrophilic interactive mode of anti-α-glucosidase assay revealed that hyperoside might have a higher antagonistic effect than positive control acarbose. The present study suggests that C. pinnatifida and its active extracts and components are worth further investigation and might be expectantly developed as the candidates for the treatment or prevention of oxidative stress-related diseases and hyperglycemia.

Portulaca oleracea is a well-known species for traditional medicine and food homology in Taiwan. In traditional medicine, P. oleracea is also used to treat gastrointestinal disorders, liver inflammation, fever, severe inflammation, and headaches. We investigated antioxidant, anti-tyrosinase, and anti-α-glucosidase activities of various solvent extracts and major bioactive components from P. oleracea. Ethanol and acetone extracts showed potent DPPH, ABTS, and hydroxyl radical scavenging activities. Chloroform and n-hexane extracts displayed significant superoxide radical scavenging activity. Furthermore, ethyl acetate and acetone extracts of P. oleracea showed potent anti-tyrosinase and anti-α-glucosidase activities. Examined and compared to the various solvent extracts for their chemical compositions using HPLC analysis, we isolated seven major compounds and analyzed their antioxidant, anti-tyrosinase, and anti-α-glucosidase activities. Seven active compounds of P. oleracea, especially quercetin, rosmarinic acid, and kaempferol, exhibited obvious antioxidant, anti-tyrosinase, and anti-α-glucosidase activities. The molecular docking model and the hydrophilic interactive mode of tyrosinase and α-glucosidase revealed that active compounds might have a higher antagonistic effect than commonly inhibitors. Our result shows that the active solvent extracts and their components of P. oleracea have the potential as natural antioxidants, tyrosinase and α-glucosidase inhibitors. Our results suggest that the active solvent extracts of P. oleracea and their components have potential as natural antioxidants, tyrosinase and α-glucosidase inhibitors.

Polygonatum sibiricum (Asparagaceae) is often used as an herbal drug in the traditional medicine of Southeast Asia. Its rhizome, called “Huang Jing”, is used in traditional Chinese medicine as an immune system stimulant, hypolipidemic agent, anti-aging agent, anti-fatigue agent, and cardiovascular protectant. We investigated the antioxidant, anti-acetylcholinesterase (AChE), anti-inflammatory, and anti-α-glucosidase effects of various solvent extracts and major bioactive components of Polygonatum sibiricum (PS) and processed Polygonatum sibiricum (PPS). Dichloromethane extract of PS showed stronger antioxidant effects by DPPH, ABTS, and FRAP assays, and EtOAc extract displayed relatively high antioxidant activity by a superoxide radical scavenging test. Moreover, acetone, EtOAc, and dichloromethane extracts displayed a significant anti-α-glucosidase effect. EtOH and CH₂Cl₂ extracts showed effective AChE inhibitory activity. In addition, dichloromethane extract showed the best inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) accumulation in RAW264.7 macrophages. HPLC analysis was used to investigate and compare the content of major active components of various solvent extracts of PS and PPS. Rutin showed the most effective scavenging of DPPH and ABTS free radicals, while scopoletin and isoquercetin displayed the strongest anti-α-glucosidase and anti-AChE effect, respectively. Rutin showed the best inhibition against LPS-induced NO production and also inhibited inducible nitric oxide synthase (iNOS) expression in Western blot. The molecular docking of AChE and iNOS revealed that active components could have a better antagonistic effect than positive controls (common inhibitors). This study shows that the active extracts and components of Polygonatum sibiricum have the potential to be further developed as a natural anti-AChE, anti-α-glucosidase, antioxidant and anti-inflammatory agent.

The root bark of Morus alba L. (Mori Cortex) is used to treat diuresis and diabetes in Chinese traditional medicine. We evaluated different solvent extracts and bioactive components from the root bark of Morus alba L. for their antioxidant, anti-α-glucosidase, antityrosinase, and anti-inflammatory activities. Acetone extract showed potent antioxidant activity, with SC₅₀ values of 242.33 ± 15.78 and 129.28 ± 10.53 µg/mL in DPPH and ABTS radical scavenging assays, respectively. Acetone and ethyl acetate extracts exhibited the strongest anti-α-glucosidase activity, with IC₅₀ values of 3.87 ± 1.95 and 5.80 ± 2.29 μg/mL, respectively. In the antityrosinase assay, the acetone extract showed excellent activity, with an IC₅₀ value of 7.95 ± 1.54 μg/mL. In the anti-inflammatory test, ethyl acetate and acetone extracts showed significant anti-nitric oxide (NO) activity, with IC₅₀ values of 10.81 ± 1.41 and 12.00 ± 1.32 μg/mL, respectively. The content of the active compounds in the solvent extracts was examined and compared by HPLC analysis. Six active compounds were isolated and evaluated for their antioxidant, anti-α-glucosidase, antityrosinase, and anti-inflammatory properties. Morin (1) and oxyresveratrol (3) exhibited effective antioxidant activities in DPPH and ABTS radical scavenging assays. Additionally, oxyresveratrol (3) and kuwanon H (6) showed the highest antityrosinase and anti-α-glucosidase activities among all isolates. Morusin (2) demonstrated more significant anti-NO and anti-iNOS activities than the positive control, quercetin. Our study suggests that the active extracts and components from root bark of Morus alba should be further investigated as promising candidates for the treatment or prevention of oxidative stress-related diseases, hyperglycemia, and pigmentation disorders.

The dried root of Ampelopsis japonica (Thunb.) Makino (A. japonica.) is a traditional medicine used to treat fever, pain, and wound healing. It exhibits anti-inflammatory, antitumor, antityrosinase, and antimelanogenic activities. In this paper, we used different solvent extracts from the root of A. japonica to determine their antioxidant activity. Acetone extract showed relatively strong antioxidant properties by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), superoxide radical scavenging activity, and ferric reducing antioxidant power (FRAP) assays. In addition, these extracts also showed significant α-glucosidase and acetylcholinesterase (AChE) inhibitory activities. Acetone extract significantly inhibited α-glucosidase with an IC₅₀ value of 8.30 ± 0.78 μg/mL, and ethanol extract remarkably inhibited AChE with an IC₅₀ value of 37.08 ± 7.67 μg/mL. Using HPLC analysis and comparison with the chemical composition of various solvent extracts, we isolated seven active compounds and assessed their antioxidant, anti-α-glucosidase, and anti-AChE activities. Catechin (1), gallic acid (2), kaempferol (3), quercetin (4), resveratrol (6), and epicatechin (7) were the main antioxidant components in the root of A. japonica. According to the results of DPPH, ABTS, and superoxide radical scavenging assays, these isolates showed stronger antioxidant capacity than butylated hydroxytoluene (BHT). Moreover, 1, 3, 4, euscaphic acid (5), 6, and 7 also expressed stronger anti-α-glucosidase activity than the positive control acarbose, and all the isolated compounds had a good inhibitory effect on AChE. Molecular docking models and hydrophilic interactive modes for AChE assays suggest that 1 and 5 exhibit unique anti-AChE potency. This study indicates that A. japonica and its active extracts and components may be a promising source of natural antioxidants, α-glucosidase, and AChE inhibitors.

The rhizome of Anemarrhena asphodeloides Bunge (AA, family Liliaceae) is a famous and frequently used herbal drug in the traditional medicine of Northeast Asia, under vernacular name “zhimu”. A. asphodeloides has been used as an anti-inflammatory, antipyretic, anti-platelet aggregation, anti-depressant, and anti-diabetic agent in traditional Chinese medicine. We examined the antioxidant, anti-acetylcholinesterase (AChE), and anti-α-glucosidase activities of various solvent extracts and the main bioactive compounds from the rhizome of A. asphodeloides. Acetone extract exhibited comparatively high antioxidant activities by 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric-reducing antioxidant power (FRAP) assays. A water extract exhibited relatively strong antioxidant activity by superoxide radical scavenging test. Furthermore, dichloromethane, chloroform, and n-hexane extracts showed significant anti-α-glucosidase activities. Finally, ethanol and dichloromethane extracts exhibited relatively strong AChE inhibitory activity. HPLC analysis was used to examine and compare various solvent extracts for their compositions of isolates. We isolated four major chemical constituents and analyzed their antioxidant, anti-α-glucosidase, and AChE inhibitory activities. The bioactivity assays showed that mangiferin displayed the most potential antioxidant activities via FRAP, ABTS, DPPH, and superoxide assays and also exhibited the most effective anti-AChE and anti-α-glucosidase activities among all the isolates. The present study suggests that A. asphodeloides and its active extracts and components are worth further investigation and might be expected to develop as a candidate for the treatment or prevention of oxidative stress-related diseases, AChE inhibition, and hyperglycemia.