RESUMO
The current investigation was carried out to assess the potential of fungi isolated from polluted soil samples in Al Jubail, Saudi Arabia, to degrade crude oil. In a minimal salt medium with 1% crude oil as the carbon source, the growth potential of various fungal isolates was examined. Among twelve fungal isolates, YS-6 and YS-10, identified as Cunninghamella echinulata and Mucor circinelloides based on multiple sequence comparisons and phylogenetic analyses, were selected as having superior crude oil degrading abilities. To the best of our knowledge, the isolated species have never been detected in polluted soil samples in the eastern province of Saudi Arabia. YS-6 and YS-10 have shown their capacity to metabolize crude oil by removing 59.7 and 78.1% of crude oil, respectively. Interestingly, they succeeded in reducing the surface tension to 41.2 and 35.9 mN/m, respectively. Moreover, the emulsification activity and hydrophobicity were determined to be 36.7, 44.9, 35.9, and 53.4%, respectively. The recovery assays included zinc sulfate, ammonium sulfate, acid precipitation, and solvent extraction techniques. All these approaches showed that the amount of biosurfactants correlates to the tested hydrocarbons. Furthermore, the enzyme activity of these two isolates generated significantly more laccase (Lac) than manganese peroxidase (MnP) and lignin peroxidase (LiP), as compared to the control. In conclusion, our study highlights new perspectives on the fungal resources found in persistently polluted terrestrial ecosystems. This knowledge will be useful for bioremediation, safe disposal of petroleum-oil contamination, and other industrial uses.
Assuntos
Petróleo , Biodegradação Ambiental , Petróleo/análise , Ecossistema , Filogenia , Hidrocarbonetos/metabolismo , SoloRESUMO
Leishmaniasis is a major vector-borne disease triggered by an obligate intracellular protozoan parasite of the genus Leishmania and transmitted by the bite of phlebotomine female sand flies. This parasite causes a wide range of human diseases, from localized self-healing cutaneous lesions to fatal visceral infections. The aim of this study was to investigate the cytotoxic, antiproliferative, and apoptotic effects of curcumin on Leishmania major promastigotes (MHOM/SA/84/JISH) and to assess these effects on the cell cycle of promastigotes. The MTT colorimetric assay was used to evaluate the cytotoxicity and proliferation of promastigotes. Additionally, flow cytometry was used to analyze the cell cycle. The Annexin V/propidium iodide staining technique followed by flow cytometry was used to study the cell death induced by curcumin. In this study curcumin showed a potent antileishmanial effect, exhibiting cytotoxicity against L. major promastigotes. At 80µM, the survival in curcumin treated promastigotes reached 22%; however, the median lethal concentration of curcumin (LC50) was 35µM. The drug exerted its cytotoxic effect by inducing apoptosis. Curcumin-induced cell death in promastigotes reached 82.5% at 80µM concentration. In addition, curcumin delayed the cell cycle in the S-phase inhibiting cell proliferation. Thus, curcumin was shown to be effective against L. major promastigotes. Therefore, curcumin merits further research studies to demonstrate its efficacy in treating cutaneous leishmaniasis.