| Gynostemma pentaphyllum(Thunb.)is a perennial climbing herb.It contains gypenosides,which has a wide range of biological activities,such as good anti-inflammatory,anti-tumor,hypolipidemic,hpyerglycemic,anti-oxidation,anti-aging,liver protection and other effects.In this paper,we evaluated the antioxidant,hypoglycemic and anti-inflammatory activities of saponins in vivo and in vitro.In this paper,the activity of 22 saponins was detected and 5 compounds with better activity were selected.They are(20R,23R)-3β,20-dihydroxydammar-24-en-21-oic acid21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl(1→3)]-6-O-acetyl-β-D-glucopyranoside(9),(20S,23S)-3β,20-dihydroxydammar-24-en-21-oic acid21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl(1→3)]-6-O-acetyl-β-D-glucopyranoside(10),(20R,23R)-19-oxo-3β,20-dihydroxydammar-24-en-21-oci acid21,23-lactone 3-O-[α-L-rhamnopyranosyl-(1→2)][β-D-xylopyranosyl(1→3)]-α-Larabinopyranoside(14),(20S)-3β,20,21-trihydroxydammar-23,25-diene3-O-{[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl(1→3)]-β-D-glucopyranosyl}-21-O-β-D-glucopyranoside(15)and(20S,23S)-3β,20-dihydroxydammar-24-en-21-oic acid21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl-(1→3)]-β-Dglucopyranoside(21).The antioxidant activity of G.pentaphyllum saponins was evaluated by four antioxidant methods: 1,1-diphenyl-2-trinitrophenylhydrazine free radical scavenging ability(DPPH),2-diamine-bis(3-ethylbenzothiazolyl-6-sulfonic acid)diammonium radical(ABTS+),superoxide free radical scavenging ability(PSC)and cellular antioxidant(CAA).The antioxidant activity of saponins was evaluated comprehensively in vitro and in vivo.The results showed that although the antioxidant capacity of compounds 9,10,14,15 and 21 were much lower than that of vitamin C positive control,it also showed a certain antioxidant capacity in a concentration-dependent manner.The inhibition experiments of α-glucosidase and PTP1 B were carried out on five compounds in vitro.The results showed that all the five compounds had strong inhibitory effects on α-glucosidase in a dose-dependent manner.Compounds 10,15 and 21 have the highest activity and are in a concentration-dependent manner.The IC50 values were 2.10,3.50 and 6.95 μM,respectively,which was higher than that of the positive control drug acarbose(12.46 μM).The results of inhibitory study on PTP1 B showed that compounds 9 and10 had strong inhibitory effect,and their IC50 values were 6.92,1.07 μM respectively,whichwas much higher than that of positive control sodium vanadate(14.73 μM).The type of enzyme inhibitor was judged by enzyme kinetics experiment,and the type of inhibitor was determined to be competitive inhibition.The spatial binding mode of 10 and PTP1 B was analyzed by molecular docking analysis.The results showed that 10 could almost completely fill the active pocket and inactivate the enzyme by closely binding to the amino acid residues of PTP1 B,thus achieving a good hypoglycemic effect.Mouse macrophage RAW264.7 induced by lipopolysaccharide(1 μg / m L)was used as inflammatory model.By detecting the cytotoxicity of saponins to normal RAW264.7 cells and RAW264.7 cells induced by lipopolysaccharide,it was determined that the concentration range of non-toxic and protective effect on RAW264.7 cells induced by lipopolysaccharide was 0-100 μ M(except 14),and 14 was 50 μM.The nitric oxide and inducible nitric oxide synthase were detected.Comparing with cells treated with LPS,the production of NO decreased significantly.And the inhibitory effect was significantly higher than that of the positive control group.At the same time,the secretion of common pro-inflammatory factors such as tumor necrosis factor TNF-α,IL-1 β and IL-6 decreased significantly,and the expression of TNF-α,IL-1 β and IL-6 m RNA decreased by 31%,83% and 40%.The anti-inflammatory and analgesic activities of the saponins were studied by animal experimental model.The results indicated that saponins in the range of 10-50 mg/kg bw could effectively reduce the writhing times of mice,increase the pain threshold of mice,and significantly inhibit the toe swelling caused by carrageenan.In addition,the related indexes of blood,liver,kidney and lung of LPS-induced model mice were analyzed,and the tissue sections of liver,kidney and lung were analyzed.The results showed that the saponins played an active role in anti-inflammation and protected liver,kidney and lung.This paper makes an in-depth study on the activity of G.pentaphyllum saponins saponins,which not only lays a theoretical foundation for fully developing and utilizing the hypoglycemic and anti-inflammatory effects of saponins,but also provides a reference for further determining the functional factors of G.pentaphyllum. |
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