Gold nanoparticles (GNP) were bio-fabricated utilizing the methanolic extract of the endophytic isolate Aspergillus terreus. The biosynthesised gold nanoparticles (GNP023) were characterised using UV-visible spectroscopy (UV-Vis); transmission electron microscopy (TEM), Fourier-transform nfrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies. The bio-fabricated GNP023 displayed a sharp SPR peak at 536 nm, were spherically shaped, and had an average size between 10–16 nm. The EDX profile confirmed the presence of gold (Au), and XRD analysis confirmed the crystalline nature of GNP023. The antimicrobial activity of GNP023 was investigated against several food-borne and phytopathogens, using in vitro antibacterial and antifungal assays. The maximum zone of inhibition was observed for S. aureus and V. cholera at 400 μg /mL, whereas inhibition in radial mycelial growth was observed against Fusarium oxysporum and Rhizoctonia solani at 52.5% and 65.46%, respectively, when challenged with GNP023 (200 μg/mL). Moreover, the gold nanoparticles displayed significant antioxidant activity against the ABTS radical, with an IC50 of 38.61 µg/mL, and were non-toxic when tested against human kidney embryonic 293 (HEK293) cells. Thus, the current work supports the application of myco-synthesised gold nanoparticles as a versatile antimicrobial candidate against food-borne pathogens.
Microbial pathogens with antibiotic resistance have become challenging to manage in the last few decades. The situation is alarming and a threat to humankind. Despite emerging new drug candidates, there are numerous strategies for efficient antibiotic delivery for treating such infections; antibiotic-resistant bacteria are still not eradicated adequately from the infected hosts. Recently, antimicrobial peptides (AMPs) have emerged as saviors in overcoming antibiotic resistance against bacteria. AMPs are being produced naturally as well as synthetically. Irrespective of the source of production, AMPs have shown higher specificity and lower toxicity to the host. Such functions have been attributed to distinct structures, functions, and varied mechanisms of action. This review highlights sources, structural and physiological characteristics, action mechanisms, and biological potency towards clinical applications. Most recently, AMPs have also been explored in treating cancers and tumors. Despite the entry of a few AMPs into clinical trials, there are limitations associated with their usage, like shorter half-life, protease cleavage, and toxicity. There is an urgent need to produce AMPs with intensified activity, biocompatibility, and lesser toxicity. This review sheds light on these aspects and the future of AMPs for the betterment of the human race.
Coronavirus disease-2019 (COVID-19) has emerged as an aggressive viral infection in the last few years. Initially reported in the Wuhan area of the People’s Republic of China, it soon emerged across the globe. Researchers confront a worrying situation to rapidly develop effective strategies to combat this novel infection and its long-term aftereffects. To date, there have been myriad reports ranging from the repurposing of the classical antimalarial drug hydroxychloroquine to several other antiviral and anti-bacterial agents like remdesivir, favipiravir, and most recently azithromycin, which has entered clinical use in many countries for combating COVID-19 infections. Several studies have highlighted the nexus between COVID-19-associated morbidity and diabetes in a wide-ranging class of subjects ranging from pediatric cases to adults and patients with other co-morbidities. Metformin is a mainstay in the treatment of type 2 diabetes (T2D). It is safe, inexpensive, and effective and does more than merely control blood sugar levels. Important metabolites that encourage blood clotting and inflammation are also suppressed by metformin. Pro-inflammatory molecules are linked to obesity and T2D. Both are major risk factors for aggravated COVID-19. These characteristics gave rise to a hypothesis that metformin may find use as an efficacious treatment for COVID-19 especially if it decreases the inflammatory molecules that fuel the COVID-19 virus-induced effects. In this review, we attempt to elucidate the role of classical anti-diabetic medicine metformin in the treatment of COVID-19 infections by highlighting the pharmacological role of this drug during elevated glucose levels and insulin resistance. We examine how COVID-19 has correlations to diabetic physiology and thereby the possibility of repurposing metformin for COVID-19 treatment.
The incorporation of nucleoside analogs into DNA by polymerases, followed by their removal through base excision repair (BER), represents a promising strategy for cancer chemotherapy. In this study, we investigated the incorporation and cytotoxic effects of several nucleoside analogs—some of which are epigenetic reprogramming intermediates—in the U87 glioblastoma cell line. We found that two analogs, 5-hydroxymethyl-2′-deoxyuridine (5HmdU) and trifluorothymidine (TFT), are both cytotoxic and are efficiently incorporated into genomic DNA. In contrast, the 5-carboxy analogs—5-carboxy-2′-deoxyuridine (5CadU) and 5-carboxycytidine (5CadC)—showed no cytotoxicity and were not incorporated into DNA. Interestingly, 5-hydroxymethyl-2′-deoxycytidine (5HmdC) was cytotoxic but was not directly incorporated into DNA. Instead, it was deaminated into 5HmdU, which was then incorporated and likely responsible for the observed toxicity. 5HmdU is actively removed from DNA through the BER pathways. In contrast, TFT remains stably incorporated and is neither excised by BER nor does it hydrolyze into 5CadU—a known substrate for the DNA glycosylase SMUG1. We also found that N6-benzyladenosine (BzAdo), an inhibitor of the enzyme 2′-deoxynucleoside 5′-phosphate N-hydrolase (DNPH1), enhances the cytotoxicity of 5HmdU. However, the thymidine phosphorylase inhibitor tipiracil hydrochloride (TPI) does not increase the cytotoxic effect of TFT in U87 cells. Together, these findings highlight 5HmdU and TFT as promising chemotherapeutic agents for glioblastoma, each with distinct mechanisms of action and cellular processing.
In cancer biology, the microbiome has emerged as a revolutionary field, revealing host–microbe interactions that drive cancer initiation, development, metastasis, and therapeutic response. The microbiome plays a mechanistic role in carcinogenesis by directly regulating host cell proliferation, apoptosis, and genomic stability, and indirectly through immune regulation and chronic inflammation. Depending on the microbial genetic makeup and host environment, microbial genotoxins, metabolites, and signaling molecules can either induce tumor growth or exert beneficial anticancer effects. Infectious agents are estimated to trigger a significant proportion of cancers globally, although the mechanistic pathways of the broader microbiome remain less well quantified. Likewise, it has been shown that microbiomes modulate the toxicity and efficacy of cancer treatments—specifically immunotherapy and chemotherapy—by mediating anti-tumor reactions and altering drug metabolism. Microbiome-based diagnostics, predictive markers, and therapeutic strategies like dietary modifications, probiotics, synthetic microbes, and fecal microbiota transplantation have collectively benefited from these breakthroughs. Despite rapid progress, integrating microbiome research into oncology is hindered by patient variability, methodological hurdles, and the difficulty of identifying definitive causal links. Large-scale clinical trials are essential for verifying the functional impact of microbiome-targeted treatments. The current review evaluates the mechanistic influence of microbiomes on cancer diagnosis and therapeutics.