Sitara Bibi

Bio: Sitara Bibi is an academic researcher from Quaid-i-Azam University. The author has an hindex of 1, co-authored 1 publications receiving 27 citations.

The caspase-3/GSDME signal pathway as a switch between apoptosis and pyroptosis in cancer

Abstract: Apoptosis has long been recognized as a mechanism that kills the cancer cells by cytotoxic drugs. In recent years, studies have proved that pyroptosis can also shrink tumors and inhibit cells proliferation. Both apoptosis and pyroptosis are caspase-dependent programmed cell death pathways. Cysteinyl aspartate specific proteinase-3 (Caspase-3) is a common key protein in the apoptosis and pyroptosis pathways, and when activated, the expression level of tumor suppressor gene Gasdermin E (GSDME) determines the mechanism of tumor cell death. When GSDME is highly expressed, the active caspase-3 cuts it and releases the N-terminal domain to punch holes in the cell membrane, resulting in cell swelling, rupture, and death. When the expression of GSDME is low, it will lead to the classical mechanism of tumor cell death, which is apoptosis. More interestingly, researchers have found that GSDME can also be located upstream of caspase-3, connecting extrinsic, and intrinsic apoptotic pathways. Then, promoting caspase-3 activation, and forming a self-amplifying feed-forward loop. GSDME-mediated pyroptosis is correlated with the side effects of chemotherapy and anti-tumor immunity. This article mainly reviews the caspase-3/GSDME signal pathway as a switch between apoptosis and pyroptosis in cancer, to provide new strategies and targets for cancer treatment.

Facile green synthesis approach for the production of chromium oxide nanoparticles and their different in vitro biological activities

Abstract: Green synthesis of nanoparticles using plants has become a promising substitute for the conventional chemical synthesis methods. In the present study, our aim was to synthesize chromium oxide nanoparticles (Cr2 O3 NPs) through a facile, low-cost, eco-friendly route using leaf extract of Rhamnus virgata (RV). The formation of Cr2 O3 NPs was confirmed and characterized by spectroscopic profile of UV-Vis, EDX, FTIR, and XRD analyses. The UV-visible spectroscopy has confirmed the formation of Cr2 O3 NPs by the change of color owing to surface plasmon resonance. The bioactive functional groups present in the leaf extract of RV involved in reduction and stabilization of Cr2 O3 NPs were determined by FTIR analysis. Based on XRD analysis, crystalline nature of Cr2 O3 NPs was determined. The morphological shape and elemental composition of Cr2 O3 NPs were investigated using SEM and EDX analyses, respectively. With growing applications of Cr2 O3 NPs in biological perspectives, Cr2 O3 NPs were evaluated for diverse biopotentials. Cr2 O3 NPs were further investigated for its cytotoxicity potentials against HepG2 and HUH-7 cancer cell lines (IC50 : 39.66 and 45.87 μg/ml), respectively. Cytotoxicity potential of Cr2 O3 NPs was confirmed against promastigotes (IC50 : 33.24 μg/ml) and amastigotes (IC50 : 44.31 μg/ml) using Leishmania tropica (KMH23 ). The Cr2 O3 NPs were further evaluated for antioxidants, biostatic, alpha-amylase, and protein kinase inhibition properties. Biocompatibility assay was investigated against human macrophages which confirmed the nontoxic nature of Cr2 O3 NPs. Overall, the synthesized Cr2 O3 NPs are biocompatible and nontoxic and proved to possess significant biopotentials. In future, different in vivo studies are needed to fully investigate the cytotoxicity and mechanism of action associated with these Cr2 O3 NPs.

Green synthesis of zinc oxide nanoparticles using Elaeagnus angustifolia L. leaf extracts and their multiple in vitro biological applications.

Abstract: Due to their versatile applications, ZnONPs have been formulated by several approaches, including green chemistry methods. In the current study, convenient and economically viable ZnONPs were produced using Elaeagnus angustifolia (EA) leaf extracts. The phytochemicals from E. angustifolia L. are believed to serve as a non-toxic source of reducing and stabilizing agents. The physical and chemical properties of ZnONPs were investigated employing varying analytical techniques (UV, XRD, FT-IR, EDX, SEM, TEM, DLS and Raman). Strong UV-Vis absorption at 399 nm was observed for green ZnONPs. TEM, SEM and XRD analyses determined the nanoscale size, morphology and crystalline structure of ZnONPs, respectively. The ZnONPs were substantiated by evaluation using HepG2 (IC50: 21.7 µg mL-1) and HUH7 (IC50: 29.8 µg mL-1) cancer cell lines and displayed potential anticancer activities. The MTT cytotoxicity assay was conducted using Leishmania tropica "KWH23" (promastigotes: IC50, 24.9 µg mL-1; and amastigotes: IC50, 32.83 µg mL-1). ZnONPs exhibited excellent antimicrobial potencies against five different bacterial and fungal species via the disc-diffusion method, and their MIC values were calculated. ZnONPs were found to be biocompatible using human erythrocytes and macrophages. Free radical scavenging tests revealed excellent antioxidant activities. Enzyme inhibition assays were performed and revealed excellent potential. These findings suggested that EA@ZnONPs have potential applications and could be used as a promising candidate for clinical development.