Ecotoxicological Assays of Selected and Potentiated Antiretroviral and Antibiotics

Abstract The effects of active pharmaceutical ingredients (APIs) in the environment are not fully characterized, hence the need for comprehensive evaluation. In this study Allium cepa, Daphnia magna, and Salmonella typhimurium were employed in three bioassays to investigate the eco-toxicities of lone APIs, namely lamivudine (L) (an antiretroviral), ciprofloxacin (C) and sulfamethoxazole (S) (antibiotics), and cocktails of their mixtures at environmental concentration range between 10 and 100 ppb. Study results showed that exposure of daphnids to lone APIs; L, C, and S, had fatal impacts, with mortality rates of 100, 75, and 95%, respectively, after 48 hr. Sulfamethoxazole showed mutagenic tendency, with mutation ratio (background/sample ratio) of 2.0. Lamivudine had lethal impact on the root length of Allium cepa (P>0.05, P = 3.60E-3). Further microscopic examination of the Allium cepa root tip exposed to each of the 3-APIs revealed chromosomal aberrations. The ecotoxicology bioassays result of the LCS-mix indicated a synergistic effect on the daphnids, probably due to potentiation. While the LCS mix had a cytotoxic effect (evidenced by the absence of bacteria colonies) on exposed TA 98 P450 Salmonella typhimurium strain, this effect was not observed in other bacterial strain. Microscopic examination of Allium cepa exposed to the LCS-mix, revealed an aberration in the mitotic stage of the cell cycle. In general, the impact of the combined 3-API mix was greater than observed for tested individual pharmaceutical.