RESUMO
BACKGROUND: Lamivudine and tenofovir disoproxil fumarate act against the replication of hepatitis B and human immunodeficiency viruses via inhibition of the reverse transcriptase enzyme activity, thereby preventing the synthesis of viral DNA. Chronic administration of these drugs has been associated with toxicities, including senescence, oxidative stress and premature death. A study of these toxicities in Drosophila melanogaster, which share 75% genomic similarity with humans could help to develop a pharmacologic intervention. METHODS: Susceptibility of D. melanogaster for lamivudine and tenofovir-induced toxicities were investigated. First, flies (≤3 days old) were fed with drugs-supplemented diet at varying concentrations (1mg to 300mg/10-gram diet) or distilled water for seven days to determine LD50. Secondly, five groups of 60 flies were fed with four concentrations of test drugs: 2.9mg, 5.82mg, 11.64mg and 23.28mg each per 10-gram diet for 28 days survival and lifespan assays. Then 5-day treatment plan was utilized to determine drugs toxicities on climbing ability and some biomarkers of oxidative stress. Finally, molecular docking was carried out using the Auto-dock vina mode to predict the biological interactions between the test drugs and D. melanogaster acetylcholinesterase (AChE) or glutathione-S-transferase (GST). RESULTS: The LD50 of lamivudine or tenofovir was 47.07 or 43.95mg/10g diet, respectively. Each drug significantly (P<0.05) reduced the survival rate, longevity and climbing performance of the flies dose-dependently. These drugs also altered levels of biochemical parameters: AChE, GST, superoxide dismutase (SOD), catalase (CAT), total thiol (T-SH), and malondialdehyde (MDA) of the flies significantly (P<0.05). In silico molecular analysis showed that the test drugs interacted with significantly (P<0.05) higher binding affinities at the same catalytic sites of D. melanogaster GST and AChE compared with substrates (glutathione or acetylcholine). CONCLUSION: The significant lamivudine and tenofovir-induced toxicities observed as increased mortality, climbing deficits and compromised antioxidant defence in D. melanogaster demands further research for possible pharmacological intervention.
Assuntos
Antioxidantes , Drosophila melanogaster , Animais , Humanos , Acetilcolina/metabolismo , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Antioxidantes/farmacologia , Biomarcadores , Catalase/genética , Catalase/metabolismo , DNA Viral/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Glutationa , Glutationa Transferase/metabolismo , Lamivudina/toxicidade , Lamivudina/metabolismo , Malondialdeído/metabolismo , Simulação de Acoplamento Molecular , Estresse Oxidativo , DNA Polimerase Dirigida por RNA/metabolismo , Compostos de Sulfidrila , Superóxido Dismutase/metabolismo , Tenofovir/toxicidade , Tenofovir/metabolismoRESUMO
The hypoglycemic effects of the fruit extract of C. metuliferus was investigated in normoglycemic and alloxan-induced hyperglycemic rats. The results showed that there was an insignificant (P > 0.05) decrease in the blood glucose concentration of normoglycemic rats treated with oral doses of 1000 and 1500 mg/kg of the extract. On the other hand, 500 mg/kg of the fruit extract produced an insignificant (P > 0.05) decrease in blood glucose levels of alloxan-treated rats, while 1000 and 1500 mg/kg oral dose points produced a significant (P < 0.05) decrease in the blood glucose concentration of hyperglycemic rats comparable to that produced by tolbutamide. From this study, the data suggested that the fruit extract did not alter the BGC level in normoglycemic rats, but had a potential hypoglycemic property in alloxan-induced hyperglycemic rats.
