Curcumin diethyl disuccinate, a prodrug of curcumin, enhances anti-proliferative effect of curcumin against HepG2 cells via apoptosis induction

Chawanphat Muangnoi,Luminita Paraoan,Ponsiree Jithavech,Pahweenvaj Ratnatilaka Na Bhuket,Pornchai Rojsitthisak,Suthiluk Patumraj,Wiwat Supasena

doi:10.1038/s41598-019-48124-1

Chawanphat Muangnoi, Luminita Paraoan + Show 5 more

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https://doi.org/10.1038/s41598-019-48124-1

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Abstract

Curcumin (Cur) has been reported to have anti-hepatocellular carcinoma activity but its poor oral bioavailability limits its further development as a chemotherapeutic agent. We synthesized previously a succinate ester prodrug of Cur, curcumin diethyl disuccinate (CurDD) with better chemical stability in a buffer solution pH 7.4. Here, we further investigated and compared the cellular transport and anti-proliferative activity against HepG2 cells of CurDD and Cur. Transport of CurDD across the Caco-2 monolayers provided a significantly higher amount of the bioavailable fraction (BF) of Cur with better cytotoxicity against HepG2 cells compared to that of Cur (p < 0.05). Flow cytometric analysis showed that the BF of CurDD shifted the cell fate to early and late apoptosis to a higher extent than that of Cur. The Western blot analysis revealed that CurDD increased Bax protein expression, downregulated Bcl-2 protein, activated caspase-3 and -9 and increased LC3-II protein level in HepG2 cells. Flow cytometric and immunoblotting results suggest that CurDD can induce HepG2 cell death via an apoptotic pathway. We suggest that CurDD can overcome the limitations of Cur in terms of cellular transport with a potential for further extensive in vitro and in vivo studies of anti-hepatocellular carcinoma effects.

Highlights

Curcumin (Cur, Fig. 1A) is a major bioactive curcuminoid found in turmeric (Curcuma Longa L.)
The bioavailable fraction (BF) of curcumin diethyl disuccinate (CurDD) induced apoptosis in HepG2 cells with the % cell population in the early and late of apoptosis of 14.61% and 42.98%, respectively. These results indicated that the BF of CurDD had anti-proliferation effect on HepG2 cells by apoptosis induction in HepG2 cells at significantly higher levels than that of Cur
Exposure of HepG2 cells to the BF of Cur and CurDD increased B-cell lymphoma 2 (Bcl-2) Associated X (Bax) protein by 13 and 40%, respectively, while decreasing Bcl-2 protein expression protein by 16 and 50% times, respectively (Fig. 6A,B). These results indicated that treatment of HepG2 cells with the BF of CurDD increased and respectively decreased the expression of Bax and Bcl-2 proteins, to a higher extent than in the case of the BF of Cur

Summary

Introduction

Curcumin (Cur, Fig. 1A) is a major bioactive curcuminoid found in turmeric (Curcuma Longa L.). Curcumin diethyl disuccincate (CurDD, Fig. 1B) is one of our Cur ester prodrugs with improved chemical stability in phosphate buffer pH 7.4 and increased anti-proliferative activity against colon and breast cancer cell lines[25,26]. Pharmacokinetic studies of CurDD showed that CurDD had superior tissue distribution in comparison with Cur and improved an area under the plasma concentration versus time curve of Cur after oral and intravenous administration[27,28] It possesses a promising analgesic activity in the peripheral and central anti-nociceptive models in mice[29]. We show that CurDD could improve the transport of Cur across the Caco-2 monolayers and anti-proliferative activity against HepG2 cells of Cur

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