Screening of Anti-Infectives against Leishmania donovani

Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Half Maximal Inhibitory Concentrations (IC50) were obtained using the broth dilution method. The IC50’s of the drugs which were active against L. donovani were used as reference values to prepare drug combinations for the modified microdilution checkerboard method. Results: Five (5) out of the fifty-six (56) drugs used showed activity (inhibition of cell growth) against L. donovani cells. They include Quinine sulphate (IC50 = 0.089 μg/ml), gentamicin (IC50 = 8.1 μg/ml), amodiaquine (IC50 = 138 μg/ml) and the two standard drugs: Amphotericin B (IC50 = 6.3 μg/ml) and Pentamidine (IC50 = 25 μg/ml). The remaining fifty-one (51) drugs did not show any inhibition within the range of concentrations used (1.25 - 160 μg/ml). The drug combinations of Pentamidine/Amodiaquine, Pentamidine/ Quinine sulphate, Pentamidine/Gentamicin, Amphotericin B/Quinine Sulphate, Amphotericin B/ Gentamicin, Amodiaquine/Quinine sulphate and Amodiaquine/Gentamicin showed synergistic effects against L. donovani whereas the Amphotericin B/Amodiaquine combination was antagonistic. Notable in the results obtained was the high effectiveness of quinine sulphate in inhibiting the growth of L. donovani. Quinine sulphate, though not indicated for leishmania treatment, was more effective than the two standard drugs and has a potential of playing a significant role in the treatment of leishmaniasis. Conclusion: This study has revealed five (5) anti-infective agents that by themselves or in combinations show activity against L. donovani. Some of the drug combinations which showed synergism should further be investigated. These results have to be confirmed by in vivo studies to define their roles in leishmaniasis treatment.

ATR–FTIR Spectroscopy Combined with the Invitro Antioxidant Activity and Chromaticity for Rapid Discrimination of Fig(Ficus carica L.)Cultivars

Vibrational spectroscopy analysis of full-ripened fig fruits(Ficus carica L.)was acquired using Fourier-transformed infrared(FTIR)spectroscopy by attenuated total reflectance(ATR).The objective of this study was to investigate accurate discrimination of 25 fig cultivars using chemometric analysis of both ATR-FTIR fingerprinting and in-vitro antioxidant activity along with chromatic coordinates color.In-vitro antioxidant activity was assessed through three methods and displayed statistically significant differences across cultivars and between the fruit parts,with promising antioxidant potency.Infrared spectra were measured separately on both peels and pulp to better know which fruit part provides high discrimination throughput between cultivars.The results showed vibration intensities of five fingerprint regions displaying statically significant differences.The highest vibration intensity occurred in the region of 1175-940 cm^(-1)including the phenols fingerprint.Principal components analysis based on integrated intensities corresponding to fingerprint regions,revealed two main groups in pulp samples,while five groups in peels samples.The pulp extracts of’Nabout’showed a typical vibration in 3000-2800 cm^(-1)and 1775-1725 cm^(-1)regions and,therefore was classified as single subset in cultivars scatterplot.This cultivar had a lightcolored fig and exhibited the highest antioxidant potency for all essays particularly in peel extracts.The biochemical assessment and FTIR fingerprinting data were involved in PCA analysis,and that displayed some dissimilarities in the classification patterns,given the fact that antioxidant activities and chromaticity together could not totally explain the classification based on FTIR fingerprinting between peel and pulp.Application of FTIR-ATR spectroscopy to discriminate fig cultivars seems to be a rapid,accurate and cost-effective alternative to laborious measurement techniques,in fig quality screening and preselection,such as chromatography analysis.This study suggests the use of fig peels for a high-level discrimination while using ATR-FTIR spectroscopy,since it provides high-throughput screening framework.