Abdul Arif Khan

Recent developments in l-asparaginase discovery and its potential as anticancer agent

L-Asparaginase (EC3.5.1.1) is an enzyme, which is used for treatment of acute lymphoblastic leukaemia (ALL) and other related blood cancers from a long time. This enzyme selectively hydrolyzes the extracellular amino acid L-asparagine into L-aspartate and ammonia, leading to nutritional deficiencies, protein synthesis inhibition, and ultimately death of lymphoblastic cells by apoptosis. Currently, bacterial asparaginases are used for treatment purpose but offers scepticism due to a number of toxicities, including thrombosis, pancreatitis, hyperglycemia, and hepatotoxicity. Resistance towards bacterial asparaginase is another major disadvantage during cancer management. This situation attracted attention of researchers towards alternative sources of L-asparaginase, including plants and fungi. Present article discusses about potential of L-asparaginase as an anticancer agent, its mechanism of action, and adverse effects related to current asparaginase formulations. This article also provides an outlook for recent developments in L-asparaginase discovery from alternative sources and their potential as a less toxic alternative to current formulations.

Normal to cancer microbiome transformation and its implication in cancer diagnosis

Microbial communities coexisting with humans are collectively known as microbiome. It influences almost every aspect of an individuals body function. Microbiome is idiosyncratic for body condition and its alteration is indicative for several abnormalities. This article discusses about recent ideas for developing microbiology based cancer indicators using alterations in microbiome. It is noteworthy that large exploratory studies are required to identify cancer indicator microorganisms from complex and diverse microbiome constituents. This complexity also warrants that these markers should be used in conjunction with other routine cancer indicators. The present article concludes that such studies can spur development of novel microbiome based cancer diagnostics.

KINETIC STUDIES OF L-ASPARAGINASE FROM Penicillium digitatum

L-Asparaginase is an enzyme used in the treatment of acute lymphoblastic leukemia and other related malignancies. Its further use includes reduction of asparagine concentration in food products, which may lead to formation of acrylamide. Currently bacterial asparaginase is produced at industrial scale, but the enzyme isolated from bacterial origin is often associated with adverse reactions. These side effects require development of asparaginase from alternative sources. In the present study, Penicillium digitatum was explored for the production of extracellular L-asparaginase using modified Czapek–Dox media. The enzyme was purified about 60.95-fold and then kinetic study showed that the Km value of the enzyme was 1 × 10−5 M. The optimum pH and temperature for the enzyme were 7.0 and 30°C, respectively. The optimum incubation period for L-asparaginase was 15 min. This work concludes that this enzyme can be a suitable candidate due to its strong kinetic properties, and further research can usher into development of asparaginase formulation from fungal origin with less adverse effects.

Optimizing indomethacin-loaded chitosan nanoparticle size, encapsulation, and release using Box–Behnken experimental design

Indomethacin chitosan nanoparticles (NPs) were developed by ionotropic gelation and optimized by concentrations of chitosan and tripolyphosphate (TPP) and stirring time by 3-factor 3-level Box-Behnken experimental design. Optimal concentration of chitosan (A) and TPP (B) were found 0.6mg/mL and 0.4mg/mL with 120min stirring time (C), with applied constraints of minimizing particle size (R1) and maximizing encapsulation efficiency (R2) and drug release (R3). Based on obtained 3D response surface plots, factors A, B and C were found to give synergistic effect on R1, while factor A has a negative impact on R2 and R3. Interaction of AB was negative on R1 and R2 but positive on R3. The factor AC was having synergistic effect on R1 and on R3, while the same combination had a negative effect on R2. The interaction BC was positive on the all responses. NPs were found in the size range of 321-675nm with zeta potentials (+25 to +32mV) after 6 months storage. Encapsulation, drug release, and content were in the range of 56-79%, 48-73% and 98-99%, respectively. In vitro drug release data were fitted in different kinetic models and pattern of drug release followed Higuchi-matrix type.

Synthesis and anti-Candidal activity of N-(4-aryl/cyclohexyl)-2-(pyridine-4-yl carbonyl) hydrazinecarbothioamide.

Eighteen N-(4-aryl/cyclohexyl)-2-(pyridine-4-yl carbonyl) hydrazinecarbothioamide derivatives were synthesized, evaluated against ten clinical isolates of Candida spp. and compared with itraconazole. Introduction of p-chloro (2c), p-iodo (2q), m-chloro (2l) and o-nitro (2r) substitution at phenyl ring of thiosemicarbazide enhanced the anti-Candida activity. Compound (2c) bearing p-cholorophenyl ring was found to be the most effective against Candida albicans ATCC 66027, Candida spp. 12810 (blood) and Candida spp. 178 (HVS) with MIC value of 0.09-0.78 μg/mL, whereas itraconazole exhibits the inhibitory activity with MIC value of 0.04-1.56 μg/mL against all tested strains. There is a correlation between anti-Candidal activity and p-chloro substitution at phenyl ring of thiosemicarbazide. All synthesized compounds were investigated for their potential cytotoxicity against non cancer cell line MCF-10A. The active compounds 2c, 2r and 2a were further investigated for their cytotoxic effects on three cancer cell lines; HT1080 (skin), HepG2 (liver) and A549 (lung). The active compounds showed minimal cytotoxic activity against non cancer cell line and all three cancer cell lines. Moreover, compound 2c displaying better activity against C. albicans ATCC66027 and Candida spp. [blood] compared to reference drug (itraconazole), represents a good lead for the development of newer, potent and broad spectrum anti-Candidal agents.

Survivin, a molecular target for therapeutic interventions in squamous cell carcinoma

Squamous cell carcinoma (SCC) is the most common cancer worldwide. The treatment of locally advanced disease generally requires various combinations of radiotherapy, surgery, and systemic therapy. Despite aggressive multimodal treatment, most of the patients relapse. Identification of molecules that sustain cancer cell growth and survival has made molecular targeting a feasible therapeutic strategy. Survivin is a member of the Inhibitor of Apoptosis Protein (IAP) family, which is overexpressed in most of the malignancies including SCC and totally absent in most of the normal tissues. This feature makes survivin an ideal target for cancer therapy. It orchestrates several important mechanisms to support cancer cell survival including inhibition of apoptosis and regulation of cell division. Overexpression of survivin in tumors is also associated with poor prognosis, aggressive tumor behavior, resistance to therapy, and high tumor recurrence. Various strategies have been developed to target survivin expression in cancer cells, and their effects on apoptosis induction and tumor growth attenuation have been demonstrated. In this review, we discuss recent advances in therapeutic potential of survivin in cancer treatment.

Characteristics and Antibiotic Resistance of Urinary Tract Pathogens Isolated From Punjab, Pakistan

Background: Urinary tract infection (UTI) is deemed the most prevalent infectious disease in that it has now touched the overall incidence of 18/1000 persons per year in the general population. Objectives: This study sought to determine the characteristics of isolates from patients with UTI and their susceptibility to commonly used antibiotics in Punjab, Pakistan. Patients and Methods: Totally, 1429 urine samples were analyzed from UTI patients for the isolation of uropathogens at Chughtai’s Lahore Lab, Lahore, Pakistan, during a period of 14 months. The antimicrobial susceptibility test was performed via the disc diffusion method for the isolates obtained from 392 (26%) positive cultures. Results: The highest percentage (67%) of isolates was from females in comparison to males (33%). The frequency of Escherichia coli was the highest (62%) in culture-positive urine samples, followed by E. faecalis (15%), Candida (14%), Pseudomonas (6%), Klebsiella spp. (1%), Proteus (1%), and Staphylococcus aureus (1%). E. coli was highly resistant to antimicrobial drugs, viz. cephalexin (95%), cephradine (95%), pipemidic acid (92%), amikacin (91%), and nalidixic acid (91%). Most of the routine β-lactam antibiotics like amoxicillin/clavulanic acid, ampicillin, and aztreonam were also ineffective against E. coli, with resistance rates of 84%, 84%, and 72%, correspondingly. This pathogen showed maximum susceptibility (97%) against three drugs, namely imipenem, meropenem, and cefoperazone. Piperacillin and fosfomycin also provided significant results against E. coli with respective susceptibility rates of 96% and 90%. Conclusions: Our results showed that broad-spectrum antibiotics such as imipenem, meropenem, fosfomycin, cefoperazone/sulbactam, and vancomycin would be the first line and the most effective drugs for the empirical treatment of urinary tract pathogens due to their higher resistance rates against other drugs like cephalexin, cephradine, ciprofloxacin, levofloxacin, and norfloxacin.

Bacterial infections associated with cancer: possible implication in etiology with special reference to lateral gene transfer

Bacteria are capable of exchanging DNA between each other and even from other organisms including human, but what will be the fate of such exchange? Enigmatic association between bacterial infections and cancer is also demonstrated recently with unknown exact cause and effect mechanism. This enigma may be resolved not in all but in few cases with the view of horizontal DNA transfer. The present article tries to examine this association in the frame of new idea. This article concludes that knowledge of this association may aid in management of cancer in clinical settings.

In vitro evaluation of anticancer and biological activities of synthesized manganese oxide nanoparticles

This paper presents the results from a systematic study into the characterization and anticancer and biological activity of synthesized super-paramagnetic manganese oxide nanoparticles (Mn3O4-NPs). The Mn3O4-NPs showed an IC50 value of 666.44 μg mL−1 on the HT29 human colorectal cell line. Furthermore, we investigated the molecular mechanism of Mn3O4-NPs for the inhibition of Bcl-2 and Bcl-xL through an in vitro study. Bcl-2 and Bcl-xL are key signaling regulators of the programmed cell death pathway and ensure proper apoptosis and have been proposed as a novel target for anticancer therapy. The down-regulation of Bcl-2 and Bcl-xL on the HT29 cancer cell line showed that the NPs under study could be useful in the treatment of cancer. The down-regulation of the anti-apoptotic regulators Bcl-2 and Bcl-xL enhances cytotoxicity in colon carcinoma cells connected with the induction of apoptosis. Moreover, the in vitro haemolysis study antibacterial tests showed that Mn3O4-NPs have no significant toxicity and antibacterial activity, thereby exhibiting their biocompatibility and reliability in biomedical sciences.

Gut Microbiota and Probiotics: Current Status and Their Role in Cancer Therapeutics

Preclinical Research