## 3 Results
### Cytotoxic Activities of Plant Polysaccharides in MCF-7 Cells  
Invasive breast ductal carcinoma, MCF-7, is one of the most common types of breast cancer; hence, it was used for the antiproliferative screening of the selected plant polysaccharides in this study by MTT. MCF-7 cells were incubated with different concentrations of the plant crude polysaccharide for 72 h (Figure 5a).  
Figure 4: (**a**) Cupric-Reducing Antioxidant Capacity of plant crude polysaccharides and (**b**) IC\({}_{0.5}\) of plant crude polysaccharides in Cupric-Reducing Antioxidant Capacity test; (**c**) IC\({}_{0.5}\) of the plant crude polysaccharides normalized to sugar contents. Results are illustrated as mean \(\pm\) S.D from 4 measurements. IC\({}_{0.5}\) results are significant at, \(p<0.05\). Mean values with the same letters are not statistically different (\(p>0.05\)); Mean values with different letters are statistically different at \(p<0.05\). Statistical analysis was carried out using one-way ANOVA and Bonferroni was used as a post hoc test.  
Figure 5: (**a**) Cytotoxic activities of crude polysaccharides extracted from selected plants (Snct-P, Gnkgo-P, ML-P, Dan-P, Onion-P, Garlic-P, MSP-50, MSP-80 and MSP-RT on human adenocarcinoma  
cell line MCF-7. MCF-7 cells were subjected to 0, 0.0625, 0.125, 0.25, 0.5, and 1 mg/mL of the crude polysaccharides from the selected plants for 72 h. Results are illustrated as mean \(\pm\) S.D of 4 measurements. Results are significant at \({}^{*}\)_p_ < 0.05 compared with control. Statistical analysis was carried out using one-way ANOVA and _t_-tests. (**b**) Dose-response curves for MSP-50, MSP-80, and MSP-RT on MCF-7 cells. (**c**) Dose-response curves for MSP-RT on MRC-5 and Vero Cell lines.  
It was discovered that five of all the investigated plant crude polysaccharides (Ginkgo-P, Dan-P, ML-P, Onion-P, and Garlic-P) showed no significant inhibition of MCF-7 viability. Snet-P reduced MCF-7 cell viability to 55% at a 1000 \(\mu\)g/mL concentration, while only MSP-50 and MSP-80 showed significant antiproliferative activities at the concentrations of 0.25 to 1 mg/mL. MSP-RT showed significant antiproliferative activities at all the concentrations tested. The decrease in MCF-7 cell viability caused by the _Moringa_ seed crude polysaccharide extracts occurred in a concentration-dependent manner. _Sanctum_ crude polysaccharide extract (Snet-P) was cytotoxic at 1 mg/mL, the highest concentration presented in this study, while lower concentrations produced no significant effect. However, at a higher concentration of 2 mg/mL, there was observed increased cytotoxicity in _sanctum_ polysaccharide; these data are not shown, which implies that Snet-P may show concentration-dependent cytotoxicity on the MCF-7 cells at concentrations higher than 1 mg/mL. The results of this study demonstrated that _Moringa_ beefera seed crude polysaccharides extracted through ethanol precipitation at 50% and 80% concentrations and room temperature were able to inhibit the growth of MCF-7 cells. The most significant antiproliferative activity against MCF-7 cells was exhibited by MSP-RT, with an IC\({}_{50}\) of 0.061 mg/mL, as shown in Figure 5b and Table 3.  
We, therefore, tested this extract on MRC-5 and Vero cell lines. The results showed that the MRC-5 and Vero cell lines were less responsive to MSP-RT than the MCF-7 cell line, with IC\({}_{50}\) values 2.6 folds (0.157 mg/mL and 0.159 mg/mL) higher than what was observed in MCF-7 cells (Figure 5c and Table 4).