Immunohistochemical analysis of substance P from cerebral ganglion of S. maculata and B. bengalensis

Abstract Background In agriculture, various chemicals and fertilizers are used to enhance the plant growth; however, their excessive use can cause environmental pollution and adversely affect both invertebrates and vertebrates. The present study was undertaken to investigate the effect of the phytoregulators Chlormequat chloride (CCC) and Paclobutrazol (PBZ) on Substance P immunoreactivity in the neuronal cells of the cerebral ganglion of Semperula maculata and Bellamya bengalensis after 96 hours of exposure. Substance P immunoreactivity was quantified as the percentage area of immunostaining to assess neurochemical alterations induced by these phytoregulators. Results Substance P immunoreactivity increased significantly in both gastropod species following exposure to CCC and PBZ compared with the control group. Among the two phytoregulators, PBZ induced a greater increase in Substance P immunoreactivity than CCC. In Semperula maculata , immunoreactivity increased by 14.35% following CCC exposure and by 16.77% following PBZ exposure. Similarly, in Bellamya bengalensis , immunoreactivity increased by 10.71% and 12.31% after CCC and PBZ exposure, respectively. Conclusion Comparative analysis showed that the relative increase in Substance P immunoreactivity was greater in Semperula maculata , whereas Bellamya bengalensis exhibited higher overall Substance P immunoreactivity under all experimental conditions. These findings indicate that CCC and PBZ induce significant neurochemical alterations in gastropods, suggesting their potential neurotoxic effects on non-target invertebrates. The study emphasizes the need to monitor the environmental impact of these phytoregulators in both terrestrial and aquatic ecosystems.