Structural Elements and Cough Suppressing Activity of Polysaccharides from Zingiber officinale Rhizome

Abstract

Zingiber officinale is used for the management of fever, bronchial asthma and cough for thousands of years. While the link to a particular indication has been established in human, the active principle of the formulation remains unknown. Herein, we have investigated a water extracted polysaccharides (WEP) containing fraction from its rhizome. Utilizing a traditional aqueous extraction protocol and using chemical, chromatographic and spectroscopic methods a fraction containing a branched glucan and polygalaturonan in a ratio of 59:1 was characterized. This glucan, which has a molecular mass of 36 kDa, is made up of terminal-, (1,4)- and (1,4,6)-linked α-Glcp residues. Oral administration of WEP in doses of 25 and 50 mg/kg body weight significantly inhibited the number of citric acid-induced cough efforts in guinea pigs. It does not alter the specific airway smooth muscle reactivity significantly. Thus, traditional aqueous extraction method provides molecular entities, which induces antitussive activity without addiction.

Bioactive Compounds and Bioactivities of Ginger (Zingiber officinale Roscoe)

“…In addition, ginger ameliorated allergic asthma by reducing allergic airway inflammation and suppressed Th2-mediated immune responses in mice with ovalbumin-induced allergic asthma [105]. Moreover, the water-extracted polysaccharides of ginger could decrease times of coughing, which was induced through citric acid in guinea pigs [106]. Besides, ginger oil and its bioactive compounds, including citral and eucalyptol, inhibited rat tracheal contraction induced by carbachol in rats [104].…”

Research progress on ginger polysaccharides: extraction, purification and structure–bioactivity relationship

“…Thus, the advantages of the EAE method include less time, low cost, mild conditions, good reproducibility, few polysaccharide impurities and a high extraction rate. 9 However, the disadvantage is that the extraction temperature is difficult to control, because high or low temperatures can affect enzyme activity, thereby affecting the extraction of polysaccharides and their activity. 9 Therefore, the EAE method is better for obtaining polysaccharide samples with high bioactivity.…”

“…9 However, the disadvantage is that the extraction temperature is difficult to control, because high or low temperatures can affect enzyme activity, thereby affecting the extraction of polysaccharides and their activity. 9 Therefore, the EAE method is better for obtaining polysaccharide samples with high bioactivity.…”

“…4 Recently, researchers have shown increasing interest in ginger polysaccharides (GPs), one of the active ingredients of ginger, particularly in the pharmaceutical field. GPs exhibit various pharmacological activities, including antitumour, [5][6][7] anti-inflammatory, 8 cough suppressant, 9 hypoglycaemic, 10 thrombotic anticoagulant, 11 and immunomodulatory activities 12 (Fig. S1, ESI †).…”

“…Fig.2(a) GP's backbone structure;25 (b) GC-MS analysis of water-extracted polysaccharide (WEP)-derived partially methylated alditol acetates for definitive structural confirmation 9. …”