Akram Shah

Silver and gold nanoparticles from Sargentodoxa cuneata: synthesis, characterization and antileishmanial activity

Leishmaniasis remains one of the fatal diseases worldwide and the conventional antileishmanial therapies are associated with several drawbacks. Therefore, there is a need to develop new antileishmanial strategies. Biogenic silver and gold nanoparticles possess broad-spectrum antimicrobial activities and could be future alternatives to current antimicrobial agents. In this report, we present a simple and green approach to synthesize silver and gold nanoparticles with efficient biological activities. Phytochemicals from Sargentodoxa cuneata were used to reduce and stabilize the silver and gold ions into metallic nanoparticles. The synthesized nanoparticles were characterized by UV-visible spectroscopy (surface plasmon resonance), X-ray diffraction analysis (crystallinity), high-resolution transmission electron microscopy (size and morphology), energy dispersive X-ray (elemental composition) and FTIR (surface functionalities). Under optimized conditions, the synthesized silver nanoparticles were spherical in shape, of small sizes (3–8 nm) and well dispersed. However, the gold nanoparticles were mostly hexagonal in shape with approximate sizes from 15 to 30 nm. Promising antileishmanial activity was shown by silver and gold nanoparticles with an IC50 value of 4.37 and 5.29 μg mL−1 respectively. Silver nanoparticles also exhibited significant antibacterial activity against Staphylococcus aureus (32 ± 3 mm), Pseudomonas araginosis (16 ± 2 mm), and Bacillus subtilis (18 ± 2 mm). The depicted biological activities of nanoparticles are not simply due to the capped silver and gold atoms but also to their surface macromolecules. Thus, the use of Sargentodoxa cuneata as a reducing and capping agent will retain its biological activity even after the depletion of maintained silver and gold. The findings of this study indicate that these nanoparticles could be an alternative, safe, and effective source of antileishmanial agents.

Cutaneous Leishmaniasis in Khyber Pakhtunkhwa Province of Pakistan: Clinical Diversity and Species-Level Diagnosis

This study primarily aimed to identify the causative species of cutaneous leishmaniasis (CL) in the Khyber Pakhtunkhwa Province of Pakistan and to distinguish any species-specific variation in clinical manifestation of CL. Diagnostic performance of different techniques for identifying CL was assessed. Isolates of Leishmania spp. were detected by in vitro culture, polymerase chain reaction (PCR) on DNA extracted from dried filter papers and microscopic examination of direct lesion smears from patients visiting three major primary care hospitals in Peshawar. A total of 125 CL patients were evaluated. Many acquired the disease from Peshawar and the neighboring tribal area of Khyber Agency. Military personnel acquired CL while deployed in north and south Waziristan. Leishmania tropica was identified as the predominant infecting organism in this study (89.2%) followed by Leishmania major (6.8%) and, unexpectedly, Leishmania infantum (4.1%). These were the first reported cases of CL caused by L. infantum in Pakistan. PCR diagnosis targeting kinetoplast DNA was the most sensitive diagnostic method, identifying 86.5% of all samples found positive by any other method. Other methods were as follows: ribosomal DNA PCR (78.4%), internal transcribed spacer 2 region PCR (70.3%), culture (67.1%), and microscopy (60.5%). Clinical examination reported 14 atypical forms of CL. Atypical lesions were not significantly associated with the infecting Leishmania species, nor with “dry” or “wet” appearance of lesions. Findings from this study provide a platform for species typing of CL patients in Pakistan, utilizing a combination of in vitro culture and molecular diagnostics. Moreover, the clinical diversity described herein can benefit clinicians in devising differential diagnosis of the disease.

In-vitro sensitivity of Pakistani Leishmania tropica field isolate against buparvaquone in comparison to standard anti-leishmanial drugs

In this study, in vitro anti-leishmanial activity of buparvaquone was evaluated against promastigotes and intracellular amastigotes of Pakistani Leishmania tropica isolate KWH23 in relation to the current standard chemotherapy for leishmaniasis (sodium stibogluconate, sodium stibogluconate, amphotericin B and miltefosine). For buparvaquone, mean % inhibition in intracellular amastigotes at four different concentrations (1.35 µM, 0.51 µM, 0.17 µM and 0.057 µM) was 78%, 44%, 20% and 14% respectively, whereas, against promastigotes it was 89%, 77%, 45% and 35% respectively. IC50 values calculated to estimate the anti-leishmanial activity of buparvaquone against intra-cellular amastigotes and promastigotes was 0.53 µM (95% C.I. = 0.32-0.89) and 0.15 µM (95% C.I. = 0.01-1.84) respectively. Amphotericin B was the most potent in-vitro drug tested, with an IC50 of 0.075 µM (95% C.I. = 0.006-0.907) against promastigotes, and 0.065 µM (95% C.I. = 0.048-0.089) against intra-cellular amastigotes. Amphotericin B was more cytotoxic against THP1 cells, with an IC50 of 0.15 µM (95% C.I. = 0.01-0.95) and an apparent in-vitro therapeutic index of 2.0, than was buparvaquone, with an IC50 of 12.03 µM (95% C.I. = 5.36-26.96) against THP1 cells and a therapeutic index of 80.2. The study proposes that buparvaquone may be further investigated as a candidate drug for treatment of cutaneous leishmaniasis.

Whole exome sequencing identifies a novel dominant missense mutation underlying leukonychia in a Pakistani family

Hereditary leukonychia (also known as porcelain nails or white nails) is a genetic disorder. It may exist as an isolated feature or associated with other cutaneous or systemic disorders. Although a number of genes have been described to cause leukonychia, still the underlying genetic etiologies of many cases remain unknown. Here, we report a Pakistani family presenting leukonychia and koilonychia nails in mother and five of her kids. All the affected individuals had white to pale nails in appearance exhibiting complete and partial leukonychia, respectively. Similarly, nails of finger and toe appeared brittle and concave, showing the characteristics features of koilonychia. Whole exome sequencing and subsequent Sanger sequencing identified a pathogenic novel missense mutation (c.1390G>A, p.Glu464Lys) in PLCD1, co-segregating with the disorder in an autosomal dominant pattern. In silico prediction tools supported the pathogenicity of the identified mutation. Literature review determined that mutations in PLCD1 only cause leukonychia. Therefore, our findings add another pathogenic variant to the PLCD1 mutation pool causing leukonychia that would help to understand the underlying molecular mechanism.