Effect of Ipomoea batatas leaf extract on the blastemal regeneration of Eudrilus eugeniae exposed to copper sulfate

Abstract

The ameliorating effect of sweet potato (Ipomoea batatas) leaf extract on the regenerative ability of the annelid species Eudrilus eugeniae exposed to copper sulfate was investigated. For this study, a sublethal concentration of 1x10-9 g/L CuSO4 for the test worms was estimated through a four-day contact filter paper test. Blastemal regeneration was examined in the following: Group 1, as the negative control, was treated with water only; Group 2 was exposed to 1x10-9 g/L CuSO4·5H2O; Group 3 was treated with 1% I. batatas leaf extract; Group 4 was exposed to a mixture of the CuSO4 with the leaf extract; Group 5 contained 0.005M ascorbic acid (Vit. C); and Group 6 was exposed to a mixture of the CuSO4 and Vit. C. The length of blastemal regeneration (LBR) of each worm was measured from the site of excision to the tip of the regenerated blastema under a calibrated microscope. Digital images of each specimen were used to estimate the volume of the blastemal mass (VBM) using ImageJ software. Statistical analysis revealed that the Group 3 worms had the highest mean overall LBR and mean VBM at values 125.91 µm/day and 5.3x105 µm3, respectively. Among the copper-exposed test groups, those treated in combination with the leaf extract or with Vit. C had higher mean LBR and VBM values than those treated with CuSO4 alone. The findings suggest that the I. batatas leaf extract is as effective as the positive control in enhancing tissue regeneration in the copper-exposed worms possibly due to its antioxidative properties. These results imply the potential of the I. batatas leaf extract as an important source of medicinal compounds for wound healing