Artesunate the most potent antimalarial is widely used for the treatment of multidrug-resistant malaria. The antimalarial cytotoxicity of artesunate has been mainly attributed to its selective, irreversible and iron- radical-mediated damage of parasite biomolecules. In the present research, iron oxide nanoparticle fortified artesunate was tested in P. falciparum and in an experimental malaria mouse model for enhancement in the selectivity and toxicity of artesunate towards parasite. Artesunate was fortified with nontoxic biocompatible surface modified iron oxide nanoparticle which is specially designed and synthesized for the sustained pH-dependent release of Fe2+ within the parasitic food vacuole for enhanced ROS spurt. Antimalarial efficacy of Iron oxide nanoparticle fortified artesunate was evaluated in wild type and artemisinin-resistant Plasmodium falciparum (R539T) grown in O + ve human blood and in Plasmodium berghei ANKA infected swiss albino mice. Internalization of nanoparticles, the pH-dependent release of Fe2+, production of reactive oxygen species and parasite biomolecule damage by iron oxide nanoparticle fortified artesunate was studied using various biochemical, biophysical, ultra-structural and fluorescence microscopy. For determining the efficacy of ATA-IONP+ART on resistant parasite ring survival assay was performed. The nanoparticle fortified artesunate was highly efficient in the 1/8th concentration of artesunate IC50 and led to retarded growth of P. falciparum with significant damage to macromolecules mediated via enhanced ROS production. Similarly, preclinical In vivo studies also signified a radical reduction in parasitemia with ~8-10-fold reduced dosage of artesunate when fortified with iron oxide nanoparticles. Importantly, the ATA-IONP combination was efficacious against artemisinin-resistant parasites. Surface coated iron-oxide nanoparticle fortified artesunate can be developed into a potent therapeutic agent towards multidrug-resistant and artemisinin-resistant malaria in humans. FUND: This study is supported by the Centre for Study of Complex Malaria in India funded by the National Institute of Health, USA.

Pyrano[3,2-c]pyranone is an important structural motif present in many natural products exhibiting diverse biological activities. Two series of carbohydrate fused pyrano[3,2-c]pyranone derivatives (n = 20) were efficiently synthesized starting from 2-C-formyl galactal and 2-C-formyl glucal, reacting with various 4-hydroxycoumarins in a very short reaction time (10 min) under microwave assisted conditions. The anticancer activity of these synthesized pyrano[3,2-c]pyranones was determined in detail through cellular assays against MCF-7 (breast), MDA-MB-231 (breast) and HepG2 (liver) cancer cell lines. The newly synthesized pyrano[3,2-c]pyranones were screened for their cell-viability and anti-proliferative activity against MCF-7, MDA-MB-231 and HepG2 cell lines. Compounds 12, 13 and 14 exhibited high growth inhibitory potencies selectively against MCF-7 cells with half-maximal inhibitory concentration (IC₅₀) values of 19.9, 14.5 and 10.9 μM respectively. Compounds 12, 13, 14, 15 and 19 inhibited the growth of MDA-MB-231 cells (breast) by 43, 44, 37, 31 and 45% respectively. However, no inhibitory effect was observed for these compounds in the human liver cancer cell line (HepG2) and normal cell lines (HEK293, human embryonic kidney cells). Mechanistic studies showed that these compounds alter the cell morphology and cause G2/M arrest in MCF-7. Further studies showed that compounds 12, 13 and 14 significantly inhibited cell migration which was accompanied by altered microtubule distribution. An enhanced accumulation of these compounds in cells was observed as compared to the 4-hydroxycoumarins precursor in the intracellular uptake assay. These findings confirm that carbohydrate fused pyrano[3,2-c]pyranones are better candidates for anticancer activity.

Prevailing drug resistance in malaria imposes the major roadblock for the existing interventions necessitating the timely need to search for alternative therapies. Ants in Solenopsis spp, termed ’Fire ants’, are well known for their aggressive behavior, which leads to the release of toxic venom. Notably, the tribal natives of the malaria-laden densely forested Bastar region, Chhattisgarh, India, use fire ant sting-based therapy to cure malaria-like high fever. Inspired by this, we have collected the fire ants from the forest of Bastar and extracted peptide and alkaloid fractions from ant venom using HPLC and analyzed them by LC/MS-based applications. Evaluation of the anti-malarial efficacy of these peptide fractions demonstrated a significant reduction in the growth of Plasmodium falciparum (Pf 3D7) in vitro, whereas the alkaloid fraction showed a negligible effect. in vitro hemolytic activity confirmed the venom peptide fraction to be non-hemolytic. Additionally, the venom peptide fraction is purely non-toxic to HepG2 cells. Anti-malarial efficiency of the same in Plasmodium berghei ANKA infected mice models showed a drastic reduction in parasitemia representing promising anti-malarial activity. Overall, our study has unraveled the scientific rationale underlying fire ant sting therapy used as a tribal naturotherapy for curing malaria-like fever, thus, introducing a way forward to develop nature-inspired anti-malarial chemotherapeutics.

Bacterial populations can display different susceptibilities to antibiotics among individual cells, even though they originate from the same parent cell. This variability can lead to treatment failure and the emergence of resistant bacteria. Understanding the factors influencing this variability is crucial for developing effective antibiotic treatments. The underlying cause of variation in susceptibility distribution within bacterial populations remains unclear, necessitating the development of new tools for measurement. Here, we use a droplet microfluidic single-cell antibiotic susceptibility assay and focus on antibiotic resistance conveyed by the TEM β-lactamases family. We investigate how the catalytic activity of β-lactamase, and the genetic characteristics of the host strains affect the susceptibility distribution within bacterial populations at the single-cell level. For this purpose, we selected TEM-1 with the least catalytic activity against cefotaxime, followed by its two variants, R164S and G238S, exhibiting moderate and significant catalytic activity, respectively. The results showed that increasing the catalytic activity causes an increase in the population’s mean level of antibiotic resistance. While the type of β-lactamase influences the susceptibility distribution of the strains, this effect is independent of the catalytic activity of the strains. Besides, the genetic characteristics of the strains receiving the β-lactam resistance gene is an important factor that plays a role in the distribution of susceptibility.