Evaluation on the traditional safe use of Kochiae Fructus oriented by antioxidant properties and oral safety of its ethanolic extract.

Kochiae Fructus (KF) is a traditional Chinese medicine, which has been used to delay aging and treat inflammation, such as rubella, eczema, cutaneous pruritus, etc. In order to fully understand the traditional medicinal value of KF, we evaluated the antioxidant properties and oral safety of its ethanolic extract. Considering flavonoids and phenolics in medicinal plants generally have strong antioxidant activity, we firstly detected the total flavonoids and phenolics contents of KFEE and its fractions. Secondly, we evaluated the antioxidant activities of KFEE and its fractions. Finally, we evaluated the oral safety of KFEE by the acute and 28-day subacute toxicities. The n-butanol fraction (ENBF) possessed the highest phenolics and flavonoids with values of 77.30 ± 3.17 mg gallic acid equivalents/g and 228.81 ± 7.56 mg rutin equivalents/g, respectively. The results of antioxidant tests showed that ENBF possessed potent antioxidant ability. Among them, the high antioxidation capacity observed in ENBF could be attributed to its rich content of flavonoids and phenolics. The results of toxicological studies showed that the LD50 value of KFEE was 6000 mg/kg BW, and the no observed adverse effect level (NOAEL) of KFEE was 600 mg/kg BW. According to the standards of the American Academy of Sciences for the classification of toxic substances, KFEE can be classified as practically non-toxic substance, which provided valuable evidence for the oral safety of KF as a natural aging delay medicine.

Antioxidant, Anti-Inflammatory and Anti-Diabetic Activities of Tectona grandis Methanolic Extracts, Fractions, and Isolated Compounds.

Tectona grandis is a traditional Dai medicine plant belonging to the Lamiaceae family, which can be used to treat malaria, inflammation, diabetes, liver disease, bronchitis, tumors, cholelithiasis, jaundice, skin disease and as an anti-helminthic. To find more novel therapeutic agents contained in this medicinal plant, the antioxidant, anti-inflammatory and anti-diabetic activities of T. grandis methanolic extract, fractions and compounds were evaluated. In this study, 26 compounds were isolated from the leaves and branches of T. grandis. Their structures were identified based on extensive spectral experiments, including NMR, ESI-MS and comparison with published spectral data. Among them, compounds 1-2, 4-6, 9-14 and 16-22 were reported for the first time for this plant. The antioxidant activity screening results showed that compounds 5, 15 and 23 had potent antioxidant capacities, with SC50 values from 0.32 to 9.92 µmol/L, 0.92 to 1.10 mmol Trolox/L and 1.02 to 1.22 mmol Trolox/L for DPPH, ABTS and FRAP, respectively. In addition, their anti-inflammatory effects were investigated by releasing TNF-α, IL-1ß and IL-6 through the use of mouse monocytic macrophages (RAW 264.7). Compounds 1, 13, 18 and 23 had the effects of reducing the expression of inflammatory factors. Compounds 13 and 18 were reported for the first time for their anti-inflammatory activities. Furthermore, the methanolic extract (ME), petroleum ether extract (PEE) and EtOAc extract (EAE) of T. grandis showed significant glucose uptake activities; compounds 21 and 23 significantly promoted glucose uptake of 3T3-L1 adipocytes at 40 µM. Meanwhile, compounds 4, 5 and 7 showed significant inhibitory activities against α-glucosidase, with IC50 values of 14.16 ± 0.34 µmol/L, 19.29 ± 0.26 µmol/L and 3.04 ± 0.08 µmol/L, respectively. Compounds 4 and 5 were reported for the first time for their α-glucosidase inhibitory activities. Our investigation explored the possible therapeutic material basis of T. grandis to prevent oxidative stress and related diseases, especially inflammation and diabetes.

Kochiae Fructus: Evaluation on the antioxidant properties and oral safety of its water decoction.

Kochiae Fructus (KF) was listed as 'top grade' medicinal material by the 'Shennong's Herbal Classic of Materia Medica' and has been used in traditional Chinese medicine to delay aging and treat inflammation, such as rubella, eczema, cutaneous pruritus, etc. Our research focused on the antioxidant capability of water decoction and fractions from KF based on 2,2-iphenyl-1-picrylhydrazyl (DPPH) free radical and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging assay, the ferric reducing antioxidant power assay, and inhibitory effects on DNA and protein oxidative damage. The results of total phenolics and flavonoids contents showed that ethyl acetate fraction (EAF) possessed the highest phenolics and flavonoids with values of 112.90 ± 9.58 mg gallic acid equivalents/g and 329.60 ± 20.93 mg rutin equivalents/g, respectively. At the same time, the results of antioxidant capacities showed that EAF possessed best antioxidant abilities. In addition, in this work, we evaluated the oral safety of the water decoction of KF (KFWD) via the 14-day acute and 28-day subacute toxicity tests. The results of in vivo toxicity assessment showed that KFWD did not cause significant changes in the general clinical symptoms, hematology and biochemical parameters, organ weights, or histopathological appearances in mice or rats. In summary, the reason why KF has the traditional effect on delaying aging may be related to the fact that its rich in flavonoids and phenolics. Simultaneously, no toxicity was detected after acute or subacute treatment of KFWD, providing valuable evidence for the traditional safe use of KF.

In Vitro and In Vivo Evaluation of Antidiabetic Properties and Mechanisms of Ficus tikoua Bur.

In folk medicine, Ficus tikoua (F. tikoua) has been used to treat diabetes for a long time, but there is a rare modern pharmacological investigation for its antidiabetic effect and mechanisms. Our study aimed to evaluate its hypoglycemic effect using in vitro and in vivo experimental models and then explore the possible mechanisms. In the ethanol extracts and fractions of F. tikoua, n-butanol fraction (NBF) exhibited the most potent effect on inhibiting α-glucosidase activity (IC50 = 0.89 ± 0.04 µg/mL) and promoting glucose uptake in 3T3-L1 adipocytes. Further animal experiments showed that NBF could play an antidiabetic role by ameliorating random blood glucose, fasting blood glucose, oral glucose tolerance, HbA1c level, and islets damage in diabetic mice. Then, the activities of the five subfractions of NBF (NBF1-NBF5) were further evaluated; NBF2 showed stronger α-glucosidase inhibition activities (IC50 = 0.32 ± 0.05 µg/mL) than NBF. Moreover, NBF2 also possessed the ability to promote glucose uptake, which was mediated via P13K/AKT and AMPK pathways. This study demonstrated that F. tikoua possesses antidiabetic efficacy in vitro and in vivo and provided a scientific basis for its folk medicinal use. NBF2 might be potential natural candidate drugs to treat diabetes mellitus. It is the first time the antidiabetic activity and the potential mechanisms of NBF2 were reported.

Hypoglycemic and Antioxidant Properties of Extracts and Fractions from Polygoni Avicularis Herba.

Our research focused on the hypoglycemic capability and the possible mechanisms of extract and fractions from Polygoni Avicularis Herba (PAH) based on α-glucosidase, α-amylase inhibition assays, glucose uptake experiment, HPLC-MS analysis, and molecular docking experiment. In addition, DPPH, ABTS, and FRAP assays were used for determining the antioxidant capability. The results of total flavonoids and phenolics contents showed that ethyl acetate fraction (EAF) possessed the highest flavonoids and phenolics with values of 159.7 ± 2.5 mg rutin equivalents/g and 107.6 ± 2.0 mg galic acid equivalents/g, respectively. The results of in vitro hypoglycemic activity showed that all samples had effective α-glucosidase inhibition capacities, and EAF possessed the best inhibitory effect with IC50 value of 1.58 ± 0.24 µg/mL. In addition, n-butanol fraction (NBF) significantly promoted the glucose uptake rate of 3T3-L1 adipocytes. HPLC-MS analysis and molecular docking results proved the interactions between candidates and α-glucosidase. The results of antioxidation capacities showed that EAF possessed the best antioxidation abilities with DPPH, ABTS, and FRAP. In summary, the hypoglycemic activity of PAH might be related to the inhibition of α-glucosidase (EAF > PEF > NBF) and the promotion of glucose uptake in 3T3-L1 adipocytes (NBF). Simultaneously, the antioxidation capacity of PAH might be related to the abundant contents of flavonoids and other phenolics (EAF > PEF > NBF).

Antioxidant, Hypoglycemic and Molecular Docking Studies of Methanolic Extract, Fractions and Isolated Compounds from Aerial Parts of Cymbopogon citratus (DC.) Stapf.

Traditionally, Cymbopogon citratus is used to treat a variety of ailments, including cough, indigestion, fever, and diabetes. The previous chemical and bioactive research on C. citratus mainly focused on its volatile oil. In this study, 20 non-volatile known compounds were isolated from the dried aerial part of C. citratus, and their structures were elucidated by MS, NMR spectroscopy, and comparison with the published spectroscopic data. Among them, 16 compounds were reported for the first time from this plant. The screening results for antioxidant and α-glucosidase inhibitory activities indicated that compounds caffeic acid (5), 1-O-p-coumaroyl-3-O-caffeoylglycerol (8), 1,3-O-dicaffeoylglycerol (9) and luteolin-7-O-ß-D-glucopyranoside (12) had potent antioxidant capacities, with IC50 values from 7.28 to 14.81 µM, 1.70 to 2.15 mol Trolox/mol and 1.31 to 2.42 mol Trolox/mol for DPPH, ABTS, and FRAP, respectively. Meanwhile, compounds 8 and 9 also exhibited significant inhibitory activities against α-glucosidase, with IC50 values of 11.45 ± 1.82 µM and 5.46 ± 0.25 µM, respectively, which were reported for the first time for their α-glucosidase inhibitory activities. The molecular docking result provided a molecular comprehension of the interaction between compounds (8 and 9) and α-glucosidase. The significant antioxidant and α-glucosidase inhibitory activities of compounds 8 and 9 suggested that they could be developed into antidiabetic drugs because of their potential regulatory roles on oxidative stress and digestive enzyme.

Antidiabetic potential of Catechu via assays for α-glucosidase, α-amylase, and glucose uptake in adipocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: Catechu is the dry water extract of barked branches or stems from Senegalia catechu(L. F.)P. J. H. Hurter & Mabb, which is used as a hypoglycemic regulator in recent researches. Potential anti-hyperglycemic components and the putative mechanisms were evaluated in this investigation. AIM OF THE STUDY: Evaluated the hypoglycemic activity of Catechu via α-glucosidase, α-amylase inhibition assays, and glucose uptake in 3T3-L1 adipocytes. MATERIALS AND METHODS: The effects of Catechu on α-glucosidase, α-amylase inhibition assays and glucose uptake experiment were tested after the ethanol extract of Catechu (EE) was sequentially partitioned with petroleum ether (PEE), ethyl acetate (EAE), and n-butanol fractions (NBE). Next, HPLC-MS and traditional Chinese medicine (TCM) database were used to detect and analyze the primary active ingredients presented in hypoglycemic fraction. In addition, in silico molecular docking study was used to evaluate the candidates' inhibitory activity against α-glucosidase and α-amylase. RESULTS: The results of α-glucosidase and α-amylase inhibition assays indicated that all fractions, with the exception of PEE, presented significant inhibitory effects on α-glucosidase and α-amylase. The inhibitory effect of NBE on α-glucosidase was similar to the positive control (NBE IC50 = 0.3353 ± 0.1215 µg/mL; Acarbose IC50 = 0.1123 ± 0.0023 µg/mL). Furthermore, the inhibitory kinetics of α-glucosidase revealed that all fractions except for PEE belong to uncompetitive type. In silico molecular docking analysis showed that the main compositions of NBE ((-)-epicatechin, cyanidin, and delphinidin) possessed superior binding capacities with α-glucosidase (3WY1 AutoDock score: 4.82 kcal/mol; -5.59 kcal/mol; -5.63 kcal/mol) and α-amylase (4GQR AutoDock score: 4.80 kcal/mol; -5.89 kcal/mol; -4.26 kcal/mol), respectively. The results of glucose uptake experiment indicated that EE, PEE, EAE, and NBE without significant promotion effect on glucose uptake rate of 3T3-L1 adipocytes (P > 0.05). CONCLUSION: This study revealed that the hypoglycemic effect of Catechu might be related to the inhibitory effects of phenols on digestive enzymes (α-glucosidase and α-amylase), and the possible active phenols were (-)-epicatechin, cyanidin, delphinidin and their derivatives, which provided scientific evidences for Catechu's traditional use to treat T2DM.