1, 3, 4-Oxadiazole derivatives (4a-5f) were previously synthesized to investigate their anticancer properties. However, studies relating to their antioxidant potential and signal transducer and activator of transcription (STAT) inhibition have not been performed. We investigated previously synthesized 1, 3, 4-oxadiazole derivatives (4a-5f) for various radical scavenging properties using several in vitro antioxidant assays and also for direct inhibition of STAT3 through molecular docking. The data obtained from various antioxidant assays such as 2, 2,-diphenyl-1-picrylhydrazyl radical (DPPH), nitric oxide, hydrogen peroxide, and superoxide anion radical revealed that among all the derivatives, compound 5e displayed high antioxidant activities than the standard antioxidant L-ascorbic acid. Additionally, the total reduction assay and antioxidant capacity assay further confirmed the antioxidant potential of compound 5e. Furthermore, the molecular docking studies performed for all derivatives along with the standard inhibitor STX-0119 showed that binding energy released in direct binding with the SH2 domain of STAT3 was the highest for compound 5e (-9.91kcal/mol). Through virtual screening, compound 5e was found to exhibit optimum competency in inhibiting STAT3 activity. Compound 5e decreased the activation of STAT3 as observed with Western blot. In brief, compound 5e was identified as a potent antioxidant agent and STAT3 inhibitor and effective agent for cancer treatment.
Piperazine scaffolds or 2-azetidinone pharmacophores have been reported to show anti-cancer activities and apoptosis induction in different types of cancer cells. However, the mechanistic studies involve in induction of apoptosis addressing these two moieties for human cervical cancer cells remain uncertain. The present study emphasizes on the anti-proliferating properties and mechanism involved in induction of apoptosis for these structurally related azoles derivatives in HeLa cancer cells. 1-Phenylpiperazine clubbed with 2-azetidione derivatives (5a-5h) were synthesized, characterized using various spectroscopic techniques and evaluated for their in-vitro anti-proliferative activities and induction of apoptosis. Further, we also evaluated oxidative stress generated by these synthetic derivatives (5a-5h). Cell viability studies revealed that among all, the compound N-(3-chloro-2-(3-nitrophenyl)-4-oxoazetidin-1-yl)-2-(4-phenylpiperazin-1-yl) acetamide 5e remarkably inhibited the growth of HeLa cells in a concentration dependent manner having IC50 value of 29.44 ± 1.46 µg/ml. Morphological changes, colonies suppression and inhibition of migration clearly showed the antineoplasicity in HeLa cells treated with 5e. Simultaneously, phosphatidylserine externalization, DNA fragmentation and cell-cycle arrest showed ongoing apoptosis in the HeLa cancer cells induced by compound 5e in concentration dependent manner. Additionally, generation of intracellular ROS along with the decrease in mitochondrial membrane potential supported that compound 5e caused oxidative stress resulting in apoptosis through mitochondria mediated pathway. Elevation in the level of cytochrome c and upregulation in expression of caspase-3 clearly indicated the involvement of the intrinsic pathway of programmed cell death. In brief; compound 5e could serve as a promising lead for the development of an effective antitumor agent.
N-benzhydrylpiperazine and 1,3,4-oxadiazoles are pharmacologically active scaffolds which exhibits significant inhibitory growth effects against various cancer cells, however, antiproliferation effects and the underlying mechanism for inducing apoptosis for aforementioned scaffolds addressing HeLa cancer cells remains uncertain. In this study, N-benzhydrylpiperazine clubbed with 1,3,4-oxadiazoles (4a-4h) were synthesized, subsequently characterized using high resolution spectroscopic techniques and eventually evaluated for their antiproliferation potential by inducing apoptosis in HeLa cancer cells. The MTT assay screening results revealed that among all, compound 4d ( N-benzhydryl-4-((5-(4-aminophenyl)-1,3,4-oxadiazol-2-yl)methyl)piperazine) in particular, exhibited IC 50 value of 28.13 ± 0.21 μg/mL and significantly inhibited the proliferation of HeLa cancer cells in concentration-dependent manner. The in vitro anticancer assays for treated HeLa cells resulted in alterations in the cell morphology, reduction in colony formation, and inhibition of cell migration in concentration-dependent treatment. Furthermore, G2/M phase arrest, variations in the nuclear morphology, degradation of chromosomal DNA confirmed the ongoing apoptosis in treated HeLa cells. Increase in the expression of cytochrome C and caspase-3 confirmed the involvement of intrinsic mitochondrial pathway regulating the cell death. Also, elevation in reactive oxygen species level and loss of mitochondrial membrane potential signified that compound 4d induced apoptosis in HeLa cells by generating the oxidative stress. Therefore, compound 4d may act as a potent chemotherapeutic agent against human cervical cancer.