There was positive correlation between levels of protection of intestinal cells from cytopathic effects of RV (crystal violet assay) with coincubation and preincubation and enhancement of polarity (TER) of H4, CLAB, and CIEB cells by T. esculentum extracts and Combivir ( Table 3) . Survival of CLAB and H4 cells was moderately to highly correlated to release of nitric oxide (r = 0.79 and r = 0.43, resp.); similarly very high positive correlation was observed in levels of nitric oxide release from H4 and CLAB cells (r = 0.9) exposed to T. esculentum extracts (Table 3 ). These findings show that there is a positive link between effects of T. esculentum extracts (pre-and coincubated) against rotavirus on the different species of cells and the release of nitric oxide. Coincubation of RV and marama seed coat ethanolic extract (MSCE), cotyledon ethanolic extract (MCE), or tuber water extract (MTW) on H4 cells resulted in generally higher enhancement of TER than Combivir throughout 67hour test period. Enhancement of polarity across intestinal epithelial cells can be an important mechanism to control entry of RV across the intestinal epithelial barrier. Rotaviruses are known to disrupt tight junctions, resulting in loss of transepithelial resistance (TER) [13] , but without cell death during viral replication [35] ; hence T. esculentum bean seed coat and cotyledon ethanolic extracts (MSCE and MCE, resp.) and T. esculentum tuber water extract (MTW) can reduce entry of RV across the intestinal barrier in vitro. Effects of T. esculentum extracts on transepithelial resistance of H4 cells, however, could not be linked to survival of H4 cells, as shown by negative correlation between survival of cells and TER in presence of the extracts.