Characterization of Structures and Antiviral Effects of Polysaccharides from Portulaca oleracea L.

Abstract

507Portulaca oleracea L. (Portulacaceae) is an annual plant widely distributed from the temperate to the tropical zones, and has a long history of use as a medicinal and edible plant. As a traditional Chinese medicine, it has been used for treating dysentery with bloody stools, eczema, erysipelas, and used as febrifuge and antiseptic. 1) Recent researches show that it exhibits a wide range of biological effects, including skeletal muscle relaxant effect, 2) analgesic and anti-inflammatory effects, 3) antifungal activity, 4) and antifertility effect. 5) Although P. oleracea has been applied in clinical treatment for viral infectious diseases in China, there is no report on the antiviral activity of this plant. 6) In the present paper, we report on the structures and antiviral activities of three polysaccharides isolated from P. oleracea. Results and DiscussionThe hot water extract from the defatted aerial part of Portulaca oleracea L. was dialyzed against H 2 O to obtain a crude polysaccharide. The non-dialyzed fraction was separated by anion-exchange chromatography on Toyopearl DEAE 650M to give two major fractions, RH1 and RH2, eluted with H 2 O and 0.5 M NaCl, respectively. Further separation of each fraction was carried out using a combination of ion-exchange column chromatography and gel filtration to yield a neutral polysaccharide (RN), an acidic polysaccharide (RA) and a pectic polysaccharide (RP).All of the isolated polysaccharides were eluted as a single and symmetrically sharp peak on HPLC chromatogram, and the apparent molecular weight of RN, RA and RP were estimated to be 8.3ϫ10 3 (M w /M n ϭ1.2), 5.8ϫ10 4 (M w /M n ϭ1.2) and 8.7ϫ10 4 (M w /M n ϭ1.7), respectively. In addition, RP was detected as a single band on the cellulose acetate membrane electrophoresis (data not shown). From these results, RN, RA and RP were regarded to be homogeneous polysaccharides. Total carbohydrate contents of RN, RA and RP were determined to be 98.1%, 54.7% and 57.0% by phenol-H 2 SO 4 method, respectively. Uronic acid contents of the samples were determined to be 2.8% (RN), 13.2% (RA), 90.7% (RP) using a m-hydroxydiphenyl method. In addition, three polysaccharides were estimated to contain trace amounts of protein, RN (0.7%), RA (1.5%) and RP (1.9%) by Bradford assay, respectively.Sugar composition analysis of RN revealed that it was mainly composed of glucose (Glc) (40.1%), mannose (Man) (38.8%) and arabinose (Ara) (13.7%) with small amounts of galactose (Gal) (5.3%). As shown in Table 1, methylation analysis showed that RN contained 1,4-linked mannopyranosyl (Manp) (34.9%), 1,4-linked glucopyranosyl (Glcp) (22.0%), and 1,2,4-linked Glcp (10.2%) residues with small amounts of 1,4,6-linked Manp (1.9%), 1,4,6-linked Glcp (0.5%) and terminal-linked galactopyranosyl (Galp) residues (1.8%). In addition, arabinofuranosyl (Araf ) residue was Characterization of Structures and Antiviral Effects of Polysaccharides from Portulaca oleracea L.Cai-Xia DONG, Kyoko HAYASHI, Jung-Bum LEE, and Toshimitsu HAYASHI* Three polysaccharides i...

Structures and anti-HSV-2 activities of neutral polysaccharides from an edible plant, Basella rubra L.

“…We also found several polysaccharides with antiviral characteristics such as a rhamnan sulfate from green alga Monostroma nitidum [8], a fucoidan from brown alga Undaria pinnatifida [9,10], acidic polysaccharides without a sulfate group isolated from the edible blue-green alga Nostoc flagelliforme [11] and Cordyceps militaris grown on germinated soybeans [12], and a pectin-type polysaccharide RP from Portulaca oleracea [13]. In the more recent paper, we reported that a pectin BRP-4 from an edible plant Basella rubra L. (Basellaceae) showed potential anti-HSV-2 and-IFV-A effects in vivo [14].…”

Polysaccharides from <i>Portulaca oleracea</i> L Improve Exercise Endurance and Decrease Oxidative Stress in Forced Swimming Mice

“…Recently, the bio-activities of polysaccharides from plants and fungi have attracted more and more attention in biochemistry and medicine [6][7][8][9]. In the last few decades, several studies have shown that polysaccharides from Portulaca oleracea L. (POP) exhibit strong antioxidant, anticancer, anti-microbial, anti-diabetic and antiinflammatory properties [10]. So far, there has been little reported work on the effects of POP on exercise endurance and oxidative stress induced by exercise.…”

Portulaca oleracea: An Untapped Bioactive Repository for Health Amelioration

“…Elkhayat et al (2008) conducted chromatographic fractionation of the chloroform extract of P. oleracea L. and reported the presence of diterpene portulene, lupeol, β-sitosterol and daucosterol. Dong et al (2010) isolated three polysaccharides including a neutral, an acidic and a pectic polysaccharide from the aerial part of P. oleracea L. Naeem and Khan (2013) reported the presence of steroids and saponins, among other nutrients. Ora and Anekwe (2013) analyzed the lipids of P. oleracea, chief components of which are quanitified to be linoleic acid (66.7 %) and triolene (26.7 %).…”

“…Strong inhibition was exerted towards Salmonella typhimurium and Proteus mirabilis. Dong et al (2010) showed that P. oleracea pectic polysaccharide had anti-herpes simplex virus type 2 (anti-HSV-2) activity. It was was elucidated to check the virus penetration into host cells.…”