Saussurea lappa Exhibits Anti-Oncogenic Effect in Hepatocellular Carcinoma, HepG2 Cancer Cell Line by Bcl-2 Mediated Apoptotic Pathway and Mitochondrial Cytochrome C Release.

Amal A Alotaibi,Sreenivasa Nayaka,Meghashyama Prabhakara Bhat,Rasha Assad Assiri,Shashiraj Kareyellapa Nagaraja,Asmatanzeem Bepari,Shaik Kalimulla Niazi,Muthuraj Rudrappa

doi:10.3390/cimb43020079

Abstract

Background and Objectives: Saussurea lappa (S. lappa) is an important species of the Asteraceae family with several purposes in traditional medicine. This study intended to explore the cytotoxic effect of S. lappa on HepG2 cancer cell proliferation. Materials and Methods: The effects of an S. lappa n-butanol extract on the induction of apoptosis were investigated by flow cytometry and mitochondrial cytochrome C-releasing apoptosis assay. Additionally, real-time PCR was employed to confirm apoptosis initiation. Further, qualitative estimation of the active constituent of S. lappa was done by gas chromatography–mass spectroscopy (GC–MS). Results: The cell viability study revealed that the n-butanol extract of S. lappa demonstrated potent cytotoxicity against HepG2 cancer cells, with an IC50 value of 56.76 μg/mL. Cell morphology with dual staining of acridine orange (AO)-ethidium bromide (EB) showed an increase in orange/red nuclei due to cell death by S. lappa n-butanol extract compared to control cells. Apoptosis, as the mode of cell death, was also confirmed by the higher release of cytochrome C from mitochondria, the increased expression of caspase-3 and bax, along with down regulation of Bcl-2. Conclusion: These findings conclude that S. lappa is a cause of hepatic cancer cell death through apoptosis and a potential natural source suggesting furthermore investigation of its active compounds that are responsible for these observed activities.

Highlights

Hepato-cellular cancer (HCC) is one of the most prevalent lethal malignancies, accounting for 626,000 new cases per year worldwide [1]
We investigated the in vitro anti-cancer property of S. lappa extract against the hepatocellular carcinoma cell line, HepG2, along with its mechanism of cell death and qualitative estimation of its active constituent
We demonstrated their cell death analysis using nucleic acid-binding dyes, acridine orange and ethidium bromide, which cause fluorescence of cancer cells along with determining their effects on the mitochondrial membrane permeability by the cytochrome C-releasing apoptosis assay and regulation of activity level of genes of bax, bcl-2, and caspase-3

Summary

Introduction

Hepato-cellular cancer (HCC) is one of the most prevalent lethal malignancies, accounting for 626,000 new cases per year worldwide [1]. Sorafenib, which inhibits multiple receptor tyrosine kinases (RTKs), especially VEGF-R2/3 (vascular endothelial growth factor-receptor), plateletderived growth factor-β (PDGFR-β), and raf kinase, is the only useful chemotherapeutic agent in managing unresected HCC [4]. It increases the average survival time by three months in patients with late-stage HCC. The common adverse effects seen with sorafenib therapy are diarrhea, fatigue, weight loss, and hand–foot syndrome It lengthens the median survival time with limited side effects in these patients, the development of resistance to sorafenib is the bottleneck in extending the overall survival time for HCC patients along with its high cost, which are significant restrictions on its use [5]. Conclusion: These findings conclude that S. lappa is a cause of hepatic cancer cell death through apoptosis and a potential natural source suggesting investigation of its active compounds that are responsible for these observed activities

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Conclusion