Development of a validated RP-HPLC/DAD method for the quantitative determination of methyl jasmonate in an insect repellent semi-solid formulation.

A simple and efficient reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed for the first time for the estimation of a mosquito repellent, methyl jasmonate in a cream formulation, and validated as per the International Conference on Harmonization guidelines. Acetonitrile and water (75:25 v/v) were used as the mobile phase and the flow-rate of the mobile phase was kept constant at 1.0 mL/min. The analysis was performed isocratically on a C18 analytical column (250 × 4.4 mm, 5 µm) using a Diode Array Detector for the detection of methyl jasmonate at 214 nm. The presence of excipients did not interfere with the quantification of methyl jasmonate. The calibration curve was linear in the concentration range of 25-300 µg/mL. The relative standard deviations for intra-day and inter-day precision, and repeatability were less than 2%. The recovery ranged from 88.5% to 90.7% with relative standard deviations not higher than 2%. The limit of detection and quantification were 9.4 µg/mL and 28.5 µg/mL, respectively. System suitability parameters were within the accepted range. The proposed method was also robust. Thus, the present report puts forward a novel analytical method for the estimation of an emerging mosquito repellent, methyl jasmonate by using the RP-HPLC technique.

Integrative Approaches to Understand the Mastery in Manipulation of Host Cytokine Networks by Protozoan Parasites with Emphasis on Plasmodium and Leishmania Species.

Diseases by protozoan pathogens pose a significant public health concern, particularly in tropical and subtropical countries, where these are responsible for significant morbidity and mortality. Protozoan pathogens tend to establish chronic infections underscoring their competence at subversion of host immune processes, an important component of disease pathogenesis and of their virulence. Modulation of cytokine and chemokine levels, their crosstalks and downstream signaling pathways, and thereby influencing recruitment and activation of immune cells is crucial to immune evasion and subversion. Many protozoans are now known to secrete effector molecules that actively modulate host immune transcriptome and bring about alterations in host epigenome to alter cytokine levels and signaling. The complexity of multi-dimensional events during interaction of hosts and protozoan parasites ranges from microscopic molecular levels to macroscopic ecological and epidemiological levels that includes disrupting metabolic pathways, cell cycle (Toxoplasma and Theileria sp.), respiratory burst, and antigen presentation (Leishmania spp.) to manipulation of signaling hubs. This requires an integrative systems biology approach to combine the knowledge from all these levels to identify the complex mechanisms of protozoan evolution via immune escape during host-parasite coevolution. Considering the diversity of protozoan parasites, in this review, we have focused on Leishmania and Plasmodium infections. Along with the biological understanding, we further elucidate the current efforts in generating, integrating, and modeling of multi-dimensional data to explain the modulation of cytokine networks by these two protozoan parasites to achieve their persistence in host via immune escape during host-parasite coevolution.