Antiviral bioactivity of renewable polysaccharides against Varicella Zoster

Figures & data

Table 1. Representative description of the investigated PSs.

PS	Functional Groups	Branched/ Linear	Repeating unit	Side chains
ἰ	-OH, -OSO3^-	Linear	D-Gal-4-sulfate,3,6-anhydro-D-Gal-2-sulfate	-
κ	-OH, -OSO3^-	Linear	D-Gal-4-sulfate,3,6-anhydro-D-Gal	-
λ	-OH, -OSO3^-	Linear	D-Gal-2-sulfate, D-Gal-2,6 disulfate	-
P	-OH, -OSO3^- -COO^-	Branched	Not finally defined. A disaccharide aldobiouronic acid 3-O-(-d-glucopyranosyluronic acid)-l-galactopyranose and a larger linear composed of the same disaccharide were determined	Not available
G	-OH	Branched	β-(1→4)-linked D-mannose	single α-D-galactose at the C6 position of D-mannose at every second mannose
LB	-OH	Branched	β-(1→4)-linked mannose	single α-D-galactose at the C6 position of D-mannose and highly unevenly substituted
X	-OH -CH2OCOCH3 -COO^−	Branched	β-(1→4)-D-glucopyranose	a trisaccharide composed of d‐mannose (β‐1,4), d‐glucuronic acid (β‐1,2) and d‐mannose, which are attached to alternate glucose residues in the backbone by α‐1,3 linkages.

Figure 1. Cytotoxic effect of PSs. Vero cells (2x10⁵) were plated in 24 well plates and treated with different concentrations of the tested PSs. The cell viability was measured 3 days after the treatment. The results are presented as a percentage of the control untreated cells. Data are expressed as the mean ± SEM percentage (n = 5); *p < 0.05; **p < 0.001 vs. control untreated cells.

Figure 2. (a) Control untreated Vero cells. (b) Cells after 3 days of treatment with 1000 µg/mL κ.

Figure 3. Vero cells were infected with 0.01 m.o.i of VZV in the absence or presence of various doses of the tested PSs. The infected cells were treated with the PS during the infection and 2-days post infection. The effect is presented as inhibition percentage compared to the infected untreated cells. Data are expressed as the mean ± SEM percentage (n = 5); **p < 0.001 vs. the infected untreated cells.

Table 2. CC₅₀, IC₅₀ and SI values of different polysaccharides against VZV.

	Parameter Evaluation
Tested Molecule	CC50^a	IC50^b	SI^c
X	>5000	800	>6.25
LB	>5000	800	>6.25
G	>5000	1	>5,000
κ	1000	0.5	2,000
λ	>5000	0.1	>50,000
ἰ	>5000	0.8	>6,250
P	1000	1	1000
ACV	70	0.1	700

^aFifty percent cytotoxic concentration (µg/mL).

^bFifty percent inhibitory concentration (µg/mL).

^cSelective index (CC₅₀/IC₅₀).

Figure 4. Antiviral activity of i on VZV infection at different stages of the infection. Vero cells infected with 0.01 m.o.i of VZV and treated with 1 µg/mL of ἰ at different periods of time. Furthermore, direct effect of ἰ on the virus infectivity (direct incubation) and its effect on the endogenous virus production were examined (n = 5); **p < 0.001 vs. the infected untreated cells.