## 4 Biological Activities of Ginger Polysaccharides
### Anti-Oxidant Effects  
Oxygen free radicals have been proved to be associated with [PERSON]'s disease, atherosclerosis, diabetes, radiation damage, and other diseases. If anti-oxidants are carried out early, the occurrence of such diseases can be prevented [55; 56]. Scientific research has proved that ginger polysaccharide has an anti-oxidant effect. In a study on the anti-oxidant effects of ginger polysaccharide ZOP and ZOP-1 were evaluated in vitro by measuring the scavenging ability of DPPH\(\bullet\) and OH\(\bullet\), chelating ability of Fe\({}^{2+}\), and total reducing ability of ZOP and ZOP-1 with VC as positive control. The results showed that the scavenging activity of ginger polysaccharide on OH\(\bullet\) and DPPH\(\bullet\) increased with the increase of its concentration. When ZOP, ZOP-1, and VC were at the same concentration (1600 \(\mathrm{\SIUnitSymbolMicro\SIUnitSymbolMicro m}\)), the median maximum inhibitory concentration (IC\({}_{50}\)) for DPPH was 226.8, 93.6, and 37.0 \(\mathrm{\SIUnitSymbolMicro\SIUnitSymbolMicro m}\), respectively. When ZOP and ZOP-1 were 1600 \(\mathrm{\SIUnitSymbolMicro\SIUnitSymbolMicro m}\), the scavenging ability of OH\(\bullet\) was 33.6% and 99.1%, respectively. When the chelating ability of ZOP and ZOP-1 to Fe\({}^{2+}\) was measured, the activity of ZOP was 7.45 times that of ZOP-1 at the same concentration, and the difference was significant. The IC\({}_{50}\) values of ZOP, ZOP-1, and VC were 0.149, 0.020. and 0.023 \(\mathrm{\SIUnitSymbolMicro\SIUnitSymbolMicro m}\), respectively. In addition, its total reduction capacity also increased with the increase of polysaccharide concentration. In short, high concentrations of ZOP and ZOP-1 have strong anti-oxidant capacity [49]. Another study analyzed the anti-oxidant activity of ginger polysaccharides \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Source** & **Compound Name** & **Molecular Weights** & **Monosaccharide Composition** & **Ref.** \\ \hline \multirow{3}{*}{Stems and leaves} & Polysaccharides from ginger & & & \\  & stems and leaves (GSLP) by & & & Man:Rha:Glc:Sql:Xyl:Ara:GlcA GalA = 2.11:16.06:7.518:32.44:7.764:28.43:17.43:95 & \\  & ultrasound-assisted extraction & & & \\  & (UAE-GSLP) & & & \\ \hline \multirow{3}{*}{Stems and leaves} & Polysaccharides from ginger & & & \\  & stems and leaves (GSLP) by & & & \\  & alkaline solution extraction & & & \\  & (ASE-GSLP) & & & \\ \hline \multirow{3}{*}{Stems and leaves} & Polysaccharides from ginger & & & \\  & stems and leaves (GSLP) by & & & \\  & enzyme-assisted extraction & & & \\  & (EAE-GSLP) & & & \\ \hline \multirow{3}{*}{Rhizome} & A novel polysaccharide (ZOP) & 6040 kDa (7.17 \%) and & Glc:GalA:Glu:Gal:Ara = 1.97:1.15:94.33:14.8:1.07 & [49] \\  & was extracted from & 604 kDa (92.83 \%) & & Glc:GalA:Glc:GalA:Ara = 1.97:1.15:94.33:14.8:1.07 & [49] \\  & Zingiber officinal & 6040 kDa (7.17 \%) and & Glc:GalA:Glc:GalA:Ara = 1.97:1.15:94.33:14.8:1.07 & [49] \\ \hline \multirow{3}{*}{Rhizome} & Zingiber officinal & 6040 kDa (7.17 \%) and & Glc:GalA:Glc:GalAra = 1.97:1.15:94.33:14.8:1.07 & [49] \\  & polysaccharides (ZOP) & 5.42 kDa (92.83 \%) & & Glc:Gal:Ara = 1.00:95.09:2.26 & [49] \\ \hline \multirow{3}{*}{Rhizome} & Zingiber officinal & 6040 kDa (7.17 \%) and & & \\  & polysaccharides 1 (ZOP-1) & 837 kDa & Glc:Gal:Ara = 1.00:95.09:2.26 & [49] \\ \hline \multirow{3}{*}{Rhizome} & Ginger polysaccharides (GP) & 747.2 kDa & Man:Rha:Glc:GalA:Glc:Gal:Xyl:Ara:Fuc = 0.17:0.13:0.21:0.12:0.08:1.0.16:0.64:0.18 & [29] \\ \hline \multirow{3}{*}{Rhizome} & Ginger polysaccharides UGP1 & 1002 kDa & N/A & [54] \\ \cline{1-1}  & Rhizome & Ginger polysaccharides UGP2 & 1296 kDa & N/A & [54] \\ \hline \hline \end{tabular} N/A means not mentioned.  
\end{table} 
Table 2: _Cont._by measuring ABTS radical scavenging activity, DPPH radical scavenging activity, hydroxyl radical scavenging activity, superoxide radical scavenging activity, chelating activity, and reducing power assay.