Detection of in vitro Inhibitory Effects of Boehmeria nivea Leaves Extracts on Influenza A Virus （H1N1）and Its Antioxidant Activity / 中国药房

OBJECTIVE： To study the in vitro inhibitory effects and antioxidant activity of different solvent extracts of Boehmeria nivea leaves against influenza A virus（H1N1）， and to expand the medicinal parts of B. nivea and develop natural antiviral and antioxidant drugs. METHODS： The leaves of B. nivea were extracted with 95％ ethanol. The ethanol extract was dissolved by water heating， and extracted with different solvents to obtain petroleum ether phase， trichloromethane phase， ethyl acetate phase， n-butanol phase and aqueous phase extracts of B. nivea leaves. The toxicity of aqueous extract of B. nivea leaves （50-400 μg/mL） on Madin-Darby canine kidney （MDCK） cell line was investigated. Using ribavirin as positive control， MDCK cells were attacked by influenza A virus（H1N1）. Western blotting assay was used to detect the expression of nucleoproteins （NP） in viral infected cells after treated with same concentrations of petroleum ether phase， trichloromethane phase， ethyl acetate phase， n-butanol phase and aqueous phase extracts of B. nivea leaves （100 μg/mL）， different concentrations of aqueous phase extract solution of B. nivea leaves （50， 100， 200， 400 μg/mL） and different concentrations of ribavirin solution （0.31， 0.63， 1.25 μg/mL）. Using vitamin C as a positive control， hydroxyl radical（·OH） scavenging test， DPPH radical scavenging test and reduction test were used to investigate in vitro antioxidant activity of the extracts. RESULTS： Aqueous phase extract of B. nivea leaves with concentration less than 400 μg/mL was nontoxic to MDCK cells. The petroleum ether phase， trichloromethane phase， ethyl acetate phase and aqueous phase extracts at 100 g/mL could significantly reduce the expression of NP protein in influenza A virus（H1N1） infected cells （P＜0.01）. Different concentrations （50-400 μg/mL） of aqueous extract could significantly reduce the protein expression of NP （P＜0.01） in concentration-dependent manner. The in vitro antioxidant activity of petroleum ether phase and ethyl acetate phase was similar to that of vitamin C. CONCLUSIONS： B. nivea leaves extract have better anti-influenza A virus（H1N1） effects in vitro， and the extracts of petroleum ether phase and ethyl acetate phase show good antioxidant activity in vitro.

Content Analysis of Rutin in the Leaves of Boehmeria nivea Harvested in Different Regions of South Korea by HPLC-UV

Phytochemical analysis of Boehmeria nivea (Bn) leaves by medium pressure liquid chromatography led to the isolation of a flavonoid glycoside identified by spectroscopic analysis as rutin. The amount of rutin in the leaves of Bn harvested from nine regions in South Korea (Bn 1–9) which were collected on the months of June, July, August, and September was determined by HPLC-UV analysis. A gradient elution program that utilizes a Discovery® C18 (4.6 × 250 mm, 5 µm) column and mobile phase composed of 1% acetic acid-water: acetonitrile (90:10 to 60:40 for min) was followed. The injection volume and flow rate were 10 µl and 1 mL/ min, respectively. UV detection was set at 350 nm. Results show that Bn-8 harvested in September reported the highest content of rutin among the samples analyzed. This study provides a basis for the optimal harvest time of Bn which maximizes the yield of rutin.

Phytochemical Identification from Boehmeria nivea Leaves and Analysis of (-)-Loliolide by HPLC

Phytochemicals were isolated from leaves of the fiber crop, ramie (Boehmeria nivea, Bn), using open column chromatography and medium pressure liquid chromatography. Their structures were identified as β-sitosterol, (-)-loliolide, rutin, and pyrimidinedione by MS, ¹H-, and ¹³C-NMR spectroscopic analysis. Among them, (-)-loliolide was isolated for the first time from B. nivea. A content analysis of (-)-loliolide in B. nivea collected from different regions and harvest times was conducted by HPLC. The highest content of (-)-loliolide was found in Bn-23 harvested in September. These results will be helpful to use the plant which harvest in September as a high content phytochemical additive in food, health supplements, and medicinal products.

Quantitative Analysis of the Flavonoid Content in the Leaves of Boehmeria nivea and Related Commercial Products

Content analysis of flavonoids (epicatechin, epicatechin gallate, and rutin) present in the leaves of Boehmeria nivea (originating from Geumsan-myeon, Biin-myeon, Hansan-myeon, and Baeksu-eup) and their commercial products (ramie tteok, ramie songpyeon, ramie bory-tteok, and ramie tea) was conducted by HPLC. The content of epicatechin, epicatechin gallate, and rutin was highest in the leaves of B. nivea from Geumsanmyeon (0.138 mg/g), Baeksu-eup (1.654 mg/g) and Geumsan-myeon (12.205 mg/g), respectively. With respect to commercial products, the content of epicatechin and epicatechin gallate was highest in ramie tea, with concentrations of 1.879 and 1.090 mg/g, respectively. Given these flavonoid concentrations, B. nivea leaf extracts have the potential to be used as additives in natural medicinal products, health supplements, and beverages.

Evaluation of antidiabetic, antihyperlipidemic and antioxidant effects of Boehmeria nivea (L.) Gaudich., Urticaceae, root extract in streptozotocin-induced diabetic rats

The potential role of 80 percent methanolic extract of Boehmeria nivea (L.) Gaudich., Urticaceae, root in the treatment of diabetes, along with its antihyperlipidemic and antioxidant effects, was studied in streptozotocin-induced diabetic male Wistar rats. Preliminary screening of the extract revealed the presence of polyphenolics and flavonoids. The animal study was conducted with variable doses of 125, 250 and 500 mg/kg of extract for 21 days in diabetic rats. A significant effect was observed at a dose of 500 mg/kg, which was comparable to the standard drug, glibenclamide. Administration of the extract at a 500 mg/kg dose resulted in a significant reduction of fasting blood glucose, total cholesterol, triglycerides, blood urea, alanine aminotransferase, aspartate aminotransferase, urine sugar and urine ketone levels in diabetic rats in comparison with the diabetic control group. Additionally, this dose significantly increased body weight, hemoglobin, plasma total protein, high density lipoprotein cholesterol, liver glycogen content, superoxide dismutase, reduced glutathione and catalase levels in diabetic rats at the end of 21 days of treatment. Therefore, dietary supplementation with Boehmeria nivea root extract could be beneficial for correcting hyperglycemia, hyperlipidemia and enhancing the antioxidant defense system.

Chemical constituents in roots of Boehmeria nivea / 中草药

Objective To investigate the chemical constituents in the roots of Boehmeria nivea.Methods The constituents were isolated by repeated column chromatography and their structures were elucidated by chemical properties and spectroscopic analyses.Results Seven compounds were isolated and their structures were identified to be daucosterol-10,13-eicosdienoate(Ⅰ),daucosterol(Ⅱ),?-sitosterol(Ⅲ),olein(Ⅳ),betulinic acid(Ⅴ),oleanolic acid(Ⅵ),19?-hydroxyursolic acid(Ⅶ).Conclusion Compound Ⅰ is a new compound named niveain A,compound Ⅳ is obtained from the plants of Boehmeria Jacq.for the first time.