Sains Malaysiana 49(10)(2020): 2433-2442

http://dx.doi.org/10.17576/jsm-2020-4910-09

High-Dose Edible Bird’S Nest Extract (EBN) Upregulates LDL-R via Suppression of HMGCR Gene Expression in HepG2 Cell Lines

(Sarang Burung Walet (EBN) Berdos Tinggi Meningkatkan LDL-R melalui Perencatan Gen HMGCR dalam Sel HepG2)

MOHD NOOR AKMAL¹, ABDUL RAZAK INTAN-SHAMEHA¹, ROZAIHAN MANSOR^1,2,3, AINI IDERIS^1,2,3, ABDUL RAHMAN OMAR^1,2,3, JALILA ABU^1,3 MOHD FAIZ IDRIS⁴ & MOKRISH AJAT^1,2,3*

¹Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia

²Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia

³Center of Excellence on Swiftlets, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia

⁴Pusat Bahasa dan Pengajian Umum, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak Darul Ridzuan, Malaysia

Diserahkan: 22 Januari 2020/Diterima: 7 Mei 2020

ABSTRACT

Edible bird’s nest (EBN) is an ancient food that had been consumed by Chinese people for well-being purposes. Nevertheless, the effect of EBN on cholesterol metabolism is poorly studied. Since the cholesterol is primarily being metabolized in the liver, HepG2 cell lines was selected as the model for in-vitro preliminary assessment. Our EBN extract (EBNE) showed 71% cell viability in HepG2 cell lines, even at the highest dose (1.5 mg/mL). Simultaneously, EBNE was significantly up-regulated the LDL-R gene expression via suppression of HMGCR at the highest concentration. Besides that, ACAT2 was up-regulated significantly to allow exogenous cholesterol storage. Expression analysis of these genes were correlated with high immunofluorescence distribution of the LDL-R and LDs compared to other treatment groups. Consistent with gene expression and immunofluorescence staining, intrahepatocellular cholesterol concentration was increased significantly at the highest dose of EBNE. The EBNE had significantly improved cholesterol metabolism in the HepG2 cell line via suppression of the HMGCR gene and subsequently up-regulated LDL-R gene expression at the highest dose. Therefore, this study provides an insight to understand the effect of EBNE in improving cholesterol metabolism.

Keywords: 3-hydroxy-3-methylglutharaldehyde CoA reductase (HMGCR); cholesterol metabolism; edible bird’s nest (EBN); HepG2; low-density lipoprotein receptor (LDL-R)

ABSTRAK

Sarang burung Walet (EBN) merupakan makanan tradisi yang diamalkan oleh masyarakat China bagi tujuan kesihatan. Dalam pada itu, kesan EBN ke atas metabolisme kolesterol masih belum dikaji dengan terperinci sehingga kini. Organ hati memainkan peranan sebagai organ utama di dalam tubuh badan manusia yang melibatkan metabolisme kolesterol terutamanya pada hati. Justeru, sel HepG2 iaitu sel hepatosit hati dipilih sebagai model kajian rintis terhadap peranan EBN pada organ hati secara in-vitro. Menerusi kajian yang telah dijalankan terhadap ekstrak EBN (EBNE) menemukan bahawa, walaupun dos tersebut paling tinggi (1.5 mg/mL) digunakan, namun kelangsungan sel HepG2 hidup adalah sebanyak 71%. Pada masa yang sama, EBNE telah meningkatkan pengekspresan gen LDL-R dengan ketara melalui perencatan gen HMGCR pada EBNE berkepekatan tertinggi. Manakala, ACAT2 turut jelas sekali meningkat dalam memainkan peranan ia membolehkan penyimpanan kolesterol eksogenus di dalam sel. Analisis ekspresi gen-gen ini berkait dengan taburan imunopendarfluor LDL-R dan LD yang tinggi berbanding dengan kumpulan rawatan seumpamanya. Rentetan kajian pengekspresan gen dan pewarnaan imunopendarfluor, didapati kepekatan kolesterol intrahepatosel telah meningkat pada dos EBNE yang tertinggi nyata sekali. EBNE telah menambahbaik metabolisme kolesterol di dalam sel HepG2 melalui perencatan gen HMGCR serta meningkatkan pengekspresan gen LDL-R pada dos tertinggi. Lantaran itu, kajian ini memberikan pemahaman mengenai kesan EBNE dalam menambahbaikkan metabolisme kolesterol di dalam tubuh badan manusia.

Kata kunci: 3-hidroksi-3-metilglutharaldehid CoA reduktase (HMGCR); metabolisme kolesterol; sarang burung walet (EBN); HepG2; reseptor lipoprotein berketumpatan rendah (LDL-R)

RUJUKAN

Al-Naqeb, G., Ismail, M., Bagalkotkar, G. & Adamu, H.A. 2010. Vanillin rich fraction regulates LDLR and HMGCR gene expression in HepG2 cells. Food Research International 43(10): 2437-2443.

Chan, D.C., Barrett, P.H.R. & Watts, G.F. 2014. The metabolic and pharmacological bases for treating atherogenic dyslipidaemia. Best Practice and Research: Clinical Endocrinology and Metabolism 28(3): 369-385.

Chang, T.Y., Li, B.L., Chang, C.C.Y. & Urano, Y. 2009. Acyl-coenzyme A: Cholesterol acyl transferase. American Journal of Physiology, Endocrinology and Metabolism 297(1): E1-E9.

Charlton-Menys, V. & Durrington, P.N. 2007. Human cholesterol metabolism and therapeutic molecules. Experimental Physiology 93(1): 27-42.

Chong, S.C., Dollah, M.A., Chong, P.P. & Maha, A. 2011. Phaleria macrocarpa (Scheff.) Boerl fruit aqueous extract enhances LDL receptors and PCSK9 expression in-vivo and in-vitro. Journal Ethnopharmacology 137(1): 817-827.

Chua, Y.G., Chan, S.H., Bloodworth, B.C., Li, S.F.Y. & Leong, L.P. 2014. Identification of edible bird’s nest with amino acid and monosaccharide analysis. Journal of Agriculture and Food Chemistry 63(1): 279-289.

Colombo, J.P., Garcia-Rodenas, C., Guesry, P.R. & Rey, J. 2003. Potential effects of supplementation with amino acids, choline or sialic acid on cognitive development in young infants. Acta Paediatrica Supplement 92(442): 42-46.

Gartner, L.P. 2017. Textbook of Histology. 4^th ed. New York: Elsevier.

Gradinaru, D., Borsa, C., Ionescu, C. & Prada, G.I. 2015. Oxidized LDL and NO synthesis-biomarkers of endothelial dysfunction and aging. Mechanism of Ageing and Development 151: 101-113.

Haghani, A., Mehrbod, P., Safi, N., Aminuddin, N.A., Bahadoran, A., Omar, A.R. & Ideris, A. 2016. In-vitro and in-vivo mechanism of immunomodulatory and anti-viral activity of Edible Bird’s Nest (EBN) against Influenza A virus (IAV) infection. Journal of Ethnopharmacology 185: 327-340.

Haghani, A., Mehrbod, P., Safi, N., Kadir, F.A.A., Omar, A.R. & Ideris, A. 2017. Edible bird’s nest modulate intracellular molecular pathways of influenza A virus infected cells. BMC Complementary and Alternative Medicine 17(1): 22-34.

Ladeiras-Lopes, R., Agewall, S., Tawakol, A., Staels, B., Stein, E., Mentz, R.J., Leite-Moreira, A., Zannad, F. & Koenig, W. 2015. Atherosclerosis: Recent trials, new targets and future directions. International Journal of Cardiology 192: 72-81.

Lindbohm, N., Gylling, H. & Miettinen, T.A. 2000. Sialic acid content of LDL and its relation to lipid concentration and metabolism of LDL and cholesterol. Journal of Lipid Research 41: 1110-1117.

Leng, E., Xiao, Y., Mo, Z., Li, Y., Zhang, Y., Deng, X., Zhou, M., Zhou, C., He, Z., Xiao, L., Li, J. & Li, W. 2018. Synergic effect of phytochemical on cholesterol metabolism and lipid accumulation in HepG2 cells. BMC Complementary and Alternative Medicine 18(1): 122-132.

Looi, Q.H. & Omar, A.R. 2016. Swiftlet and edible bird’s nest industry in Asia. The Pertanika Journal of Scholarly Research Reviews 2(1): 32-48.

Ma, F. & Liu, D. 2012. Sketch of edible bird’s nest and its important bioactivities. Food Research International 48(2): 559-567.

Marcone, M.F. 2005. Characterization of edible bird’s nest the ‘Caviar of the East’. Food Research International 38(10): 1125-1134.

Martin, S. & Parton, R.G. 2006. Lipid droplets: A unified view of a dynamic organelle. Nature Reviews: Molecular Cell Biology 7(5): 373-378.

Millar, J.S. 2001. The sialylation of plasma lipoproteins. Atherosclerosis 154(1): 1-13.

Nielsen, L.V., Krogager, T.P., Young, C., Ferreri, C., Chatgilialoglu, C., Jensen, O.N. & Enghild, J.J. 2013. Effect of elaidic acid on lipid metabolism in HepG2 cells, investigated by integrated approach of lipidomics, transcriptomics and proteomics. PLoS ONE 8(9): e74283.

Rogers, M.A., Liu, J., Song, B.L., Li, B.L., Chang, C.C.Y. & Chang, T.Y. 2015. Acyl-CoA: Cholesterol acyltransferase (ACATs/SOATs): Enzymes with multiple sterol sterols substrate and as activators. Journal Steroid Biochemistry and Molecular Biology 151: 102-107.

Shimano, H. & Sato, R. 2017. SREBP-regulated lipid metabolism: Convergent physiology- divergent pathophysiology. Nature Reviews Endocrinology 13(12): 710-730.

Steinberg, D. 2006. The thematic review series: The pathogenesis of atherosclerosis. An interpretive history of the cholesterol controversy, part V: The discovery of the statins and the end of the controversy. Journal of Lipid Research 47(7): 1339-1351.

Yida, Z., Imam, M.U., Ismail, M., Ooi. D-J., Sarega, N., Azmi, N.H., Ismail, N., Chan, K.W., Hou, Z. & Yusuf, N. 2015a. Edible bird’s nest prevents high fat diet-induced insulin resistance in rats. Journal of Diabetes Research 2015: 760535.

Yida, Z., Imam, M.U., Ismail, M., Hou, Z., Abdullah, M.A., Ideris, A. & Ismail, N. 2015b. Edible bird’s nest attenuates high fat diet-induced oxidative stress and inflammation via regulation of hepatic antioxidant and inflammatory genes. BMC Complementary and Alternative Medicine 15(1): 310-316.

Yida, Z., Imam, M.U. & Ismail, M. 2014. In-vitro bioaccessibility and antioxidant properties of edible bird’s nest following simulated human gastro-intestinal digestion. BMC Complementary and Alternative Medicine 14: 468-474.

Yu-Qin, Y., Liang, X., Hua, W., Hui-Xing, Z., Xin-Fang, Z. & Bu-Sen, L. 2000. Determination of edible bird’s nest and its products by gas chromatography. Journal of Chromatographic Science 38(1): 27-32.

Zhao, L., Guo, X., Wang, O., Zhang, H., Wang, Y., Zhou, F., Liu, J. & Ji, B. 2016. Fructose and glucose combined with free fatty acids induce metabolic disorders in HepG2 cells: A new model to study the impacts on high fructose/sucrose and high-fat diets in-vitro. Molecular Nutrition and Food Research 60(4): 909-921.

*Pengarang untuk surat-menyurat; email: mokrish@upm.edu.my