Journal of Industrial and Engineering Chemistry 15 (2009) 281–284

Influence of bamboo oil supplementation on blood lipid concentration in serum

Hoon Cho a, Ki-An Cho b, Shiru Jia c, Seung Joo Cho d,e, DuBok Choi b,*a Department of Polymer Science & Engineering, Chosun University, Gwangju 501-759, Republic of Koreab Department of Environmental Health, Cho-dang University, Chonnam 534-800, Republic of Koreac Department of Biochemical Engineering, Tianjin University of Science and Technology, 300222 Tianjin, Chinad Department of Cellular and Molecular Medicine, College of Medicine, Chosun University, Gwangju 501-759, Republic of Koreae Research Center for Resistant Cells, Chosun University, Gwangju 501-759, Republic of Korea

A R T I C L E I N F O

Article history:

Received 31 August 2008

Accepted 17 December 2008

Keywords:

Bamboo oil

HMG-CoA reductase

Cholesterol

Triglyceride

Phospholipid

A B S T R A C T

The inhibitory activity of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase and the influence of

cholesterol reduction were studied to investigate the effects of bamboo oil on lipid metabolism. The

inhibitory activity of HMG-CoA reductase using Phyllostachys bambusoides oil was the highest among the

various bamboo oils tested. The inhibition rate of HMG-CoA reductase increased from 7.3 to 89.9% when

P. bambusoides oil concentration was increased from 10 to 90 mL/mL. However, when over 110 mL/mL of

bamboo oil was used, it was not increased. The total cholesterol and triglyceride concentrations in blood

decreased with the increase of bamboo oil concentration. Especially, when bamboo oil concentration

increased from 2.0 to 8.0%, the total cholesterol concentration decreased from 139.6 to 80.4 mg/dL,

which was a decrease of about 45% compared to the control. However, the phospholipid concentration

was an increase of about 30% compared to the control. HDL cholesterol concentration increased with the

increase of bamboo oil concentration. In particular, when bamboo oil increased from 2 to 8.0%, it was

increased from 25.7 to 40.2%, which was an increase of about 89% compared to the control. These results

suggest that bamboo oil is very effective at improving lipid metabolism and preventing hypercholes-

terolemia in high-cholesterol-fed rats.

� 2009 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights

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1. Introduction

Hypercholesterolemia is regarded as a major risk factor ofcardiovascular diseases such as atherosclerosis, myocardial infarc-tion, heart attacks, and cerebrovascular disease, which are leadingcauses of death in advanced countries [1]. Moreover, loweringcirculating cholesterol levels can reduce the risk of these diseases[2]. Hypercholesterolemia is related to increased levels of oxidativestress [3–5] and lipid metabolism, with low-density lipoproteingeneration being identified as a major contributor to the vasculardamage induced by high-cholesterol levels [6]. Drugs that lowercholesterol by inhibiting cholesterol biosynthesis such as the 3-hydroxy-3-methylglutary coenzyme A (HMG-CoA) reductase inhi-bitors, such as lovatatin and sinvatatin are used to treat hyperch-olesterolemia [7]. However, undesirable side effects of thesecompounds have raised concerns regarding their therapeutic use [8].

Bamboo extract has been used in traditional Chinese medicinefor treating fever and detoxification for over 1000 years. Its more

* Corresponding author. Tel.: +82 63 466 2984.

E-mail address: choidubok@yahoo.co.kr (D-B. Choi).

1226-086X/$ – see front matter � 2009 The Korean Society of Industrial and Engineer

doi:10.1016/j.jiec.2008.12.002

ancient use as a clinical traditional medicine was mainly to lessenor cure stomachache, diarrhea, vomiting, chest diaphragminflammation, restlessness, and excessive thirst [9]. In more recenttimes, the potential health value of some biologically activecomponents in bamboo leaves has been assessed. An ethanol orwater extract of bamboo leaf mainly containing flavone glycosides,phenolic acids, coumarone lactones, anthraquinones, and aminoacids has been utilized clinically in the treatment of hypertension,arteriosclerosis, cardiovascular disease, and certain forms of cancer[10]. However, there have been no reports concerning the effect ofbamboo oil supplementation on lipid metabolism. Previously, westudied the physicochemical characteristics and components ofbamboo oil [11]. Recently, we also examined the antioxidantactivity, phenolic compounds, glutathione production, glutathioneand catalase activities, and nitrite scavenging activity usingbamboo oil manufactured from Phyllostachys nigra var. henonis,which grows in the Damyang region of Korea [12].

In this study, we investigated the inhibitory activity of HMG-CoA reductase in vitro. In addition, to evaluate the bamboo oil aspotential agent for reducing high-cholesterol levels in rats fed ahigh-cholesterol diet, the concentration of cholesterol, phospho-lipid, cholesteryl ester, and triglyceride, and activities of glutamic

ing Chemistry. Published by Elsevier B.V. All rights reserved.

H. Cho et al. / Journal of Industrial and Engineering Chemistry 15 (2009) 281–284282

oxaloacetic transaminase and glutamic pyruvic transaminase wereinvestigated.

2. Experimental

2.1. Manufacture of bamboo oil

Phyllostachys bambusoides was used for the recovery of bamboooil. Fresh bamboo grown for 4–5 years was cut. The 40–50 cm-longvertically cut pieces were stored in water for 24 h, dried in theshade, and cut vertically again. The dried bamboo (30 kg) wasroasted at 900–1000 8C for 5 h. The crude bamboo oil obtainedthrough condenser cooling at 100–150 8C was saturated in astorage jar for 12 months. The saturated bamboo oil was refinedwith 200 mg of 200–250 mesh active charcoal (Yakuri PureChemical, Kyoto, Japan). The refined bamboo oil (1.0 L) was re-distilled at 108 8C.

2.2. Microsomal protein preparation

Saccharomyces cerevisiae ATCC 42949 was precultured in a500 mL flask containing 100 mL of a medium comprised of 1%glucose, 0.5% polypetone, and 1% yeast extract for 24 h at 30 8C.One percent of preculture was inoculated into another 500 mLflask containing 100 mL of a medium comprised of 3% glucose, 0.5%polypeptone, 0.5% yeast extract, 0.5% K2HPO4, and 0.5% KH2PO4

and cultured for 15 h at 30 8C. The culture broth was centrifugedfor 15 min at low speed and washed two times using distilledwater. The collected cells were resuspended in 20 mM ethylene-diaminetetraacetic acid (EDTA) containing 0.1 M triethanolaminebuffer (pH 7.4). After homogenization using cell homogenizer for5 min at 10,000 psi, the centrifugation was carried out for 15 minat 8000 rpm to remove mitochondria and the recovered super-natant was centrifuged for 90 min at 34,000 rpm for obtainmicrosomal protein.

2.3. Inhibitory activity of HMG-CoA reductase

The reaction containing 1.0 mg of Saccharomyces cerevisiae

microsomal protein, 150 nmol HMG-CoA, 2 mmol NADP+, 3 mmolglucose-6-phosphate, 2 units glucose-6-phosphate dehydrogen-ase, and 30–70 mL bamboo oil was prepared. After 30 min ofreaction at 37 8C, 20 mL sodium arsenite solution (10 mM) and0.1 mL citrate buffer (2 M, pH 3.5) containing 3% sodium tungstatewere added to 1 mL of the reaction mixture to stop the reaction for10 min. After centrifugation at 15,000 rpm for 5 min, theprecipitated protein was removed. One milliliter of supernatantand 50 mL sodium arsenite (0.4 M) were added to a test tubecontaining 0.2 mL Tris buffer (2 M, pH 10.6) and 0.1 mL Tris buffer(2 M, pH 8.0), and the reaction was carried out for 5 min. Onemilliliter of reaction mixture and 20 mL 5,50-dithiobis-(2-nitro-benzoic acid) (DTNB; 3 mM) were added and the absorbance wasmeasured at 412 nm.

2.4. Animals

White male Sprague–Dawley rats weighing 100 g were raised inthe same conditions for 8 weeks to acclimate to the 20 8C and 50%humidity conditions of the lab environment. Rats received solid feed(Samyang Foods, Pusan, Korea) for 2 weeks prior to supplementationof the diet of the test group of rats with bamboo oil.

2.5. Preparation of samples

Rats were fasted for 4 h prior to ether-induced anesthesia andsacrifice. Cardiac blood was obtained with a syringe, treated with

10% EDTA, and centrifuged at 1150 � g for 10 min to obtain serum,and kept at �80 8C until used for determination of lipid content.The liver was separated immediately after recovery of blood,washed with ice-cold 0.9% saline, dried, and weighed. The weighedliver was stored at �70 8C until being assayed for glutamicoxaloacetic transaminase and glutamic pyruvic transaminaseactivities.

2.6. Lipid concentration in serum and liver

The content of various serum lipids including triglyceride, totalcholesterol, and HDL-cholesterol were measured using a FDC 3000blood analyzer.

2.7. Glutamic oxaloacetic transaminase and glutamic pyruvic

transaminase activity

Glutamic oxaloacetic transaminase and glutamic pyruvictransaminase activities in blood were measured using an auto-matic blood analyzer using a diagnostic test kit and reagent.

3. Results and discussion

Dietary control is the most desirable avenue for the preventionand therapy of chronic degenerative diseases such as cardiovas-cular disease. The current study investigated the effect of bamboooil on antioxidant activity and nitrite scavenging activity [12].HMG-CoA reductase is the major regulatory enzyme of hepaticcholesterol biosynthesis in the liver, small intestine, renal gland,and sex glands. Activity of the enzyme is also controlled bycholesterol concentration, 26-hydroxycholesterol, and phosphor-ylation. Especially, elevated free cholesterol stimulates a decreasein the number of LDL-acceptor molecules and promotes choles-terol acyl transferase activity via inhibition of HMG-CoA reductasetranscription. Competitive inhibition of HMG-CoA reductase leadsto the abrogation of cholesterol synthese activity and increasedLDL-acceptor number. LDL-cholesterol concentration is controlledby the LDL-acceptor number. Therefore, HMG-CoA reductaseinhibition is important for reducing cholesterol concentration inserum [13].

In this study, we investigated various bamboo oils obtainedfrom Sasamorpha purpurascens Nakai var. boreailis Nakai, Phyllos-

tachys reliculata koch, Sasa coreana Nakai, Phyllostachys nigra var.

henonis, Phyllostachys nigra munro, Phyllostachys pubescens, andPhyllostachys bambusoides to select that which best inhibited HMG-CoA reductase in vitro. The inhibitory activity of HMG-CoAreductase using P. bambusoides oil was the highest among variousbamboo oils (data not shown). To investigate the effect of bamboooil concentration on the inhibitory activity of HMG-CoA reductasein vitro, 10, 30, 50, 70, 90, and 110 mL/mL P. bambusoides bamboooil were used. The results are shown in Fig. 1. HMG-CoA reductaseinhibition increased from 7.3 to 89.9% when the bamboo oilconcentration was increased from 10 to 90 mL/mL. However, whenconcentrations of bamboo oil exceeded 110 mL/mL, the inhibitiondid not increase further. These results indicate that bamboo oil isuseful as drugs that lower cholesterol by inhibiting cholesterolbiosynthesis such as HMG-CoA reductase inhibitor.

Table 1 summarizes the data on the concentration of totalcholesterol, triglyceride, phospholipids, and HDL cholesterol in ratsfed the experimental diets for 4 weeks. The total cholesterolconcentration in blood was decreased with the increase of bamboooil concentration. Especially, when bamboo oil concentration wasincreased from 2 to 8%, it was decreased from 139.6 to 80.4 mg/dL,which was a decrease of about 45% compared to the control groupwithout administration of bamboo oil. These results indicate thatthe symptoms of high-cholesterol were decreased by removal of

Fig. 2. Effect of bamboo oil concentration on the free cholesterol and cholesteryl

ester concentration in serum.

Fig. 1. Effect of bamboo oil concentration on HMG-CoA reductase inhibitory.

H. Cho et al. / Journal of Industrial and Engineering Chemistry 15 (2009) 281–284 283

the neutral lipid at the periphery tissue by biosynthesis of neutrallipid and by increased chylomicron secretion in the small intestine,biosynthesis increase of neutral lipid, LDL-cholesterol synthesisand secretion increase, synthesis decrease of high densitylipoprotein, and decrease of lipase activity in the liver, consistentwith previous observations [14]. The triglyceride concentration inblood was decreased with the increase of bamboo oil. Especially,when bamboo oil concentration was increased from 2 to 6%, it wassignificantly decreased from 67.3 to 41.8 mg/dL. However, above8% of bamboo oil, it was not decreased. These results indicate thatthe capillary lipoprotein lipase has high activity, which promotesthe decomposition of lipid as a transporter of triglyceride and very-low-density lipoprotein cholesterol. Phospholipid synthesis wasgenerally affected by the high lipid food. Composition ofphospholipids increased with the increased amount of bamboooil. Especially, when 8% bamboo oil was administrated, phospho-lipid concentration was 452.6 mg/dL, which was an increase ofabout 30% compared to the control group without administrationbamboo oil. Generally, LDL-cholesterol is a main carrier of bloodcholesterol. It is linearly related to the levels of serum cholesterol.Circulating HDL cholesterol is regarded as ‘good cholesterol’, whichcarries cholesterol from peripheral cells to the liver where thecholesterol is metabolized into bile acids. This pathway is crucialfor maintaining cholesterol homeostasis between blood andperipheral tissues. HDL cholesterol exerts a protective effectagainst coronary heart disease [15,16]. LDL-cholesterol concentra-tion was decreased with the increase of bamboo oil concentration(data not shown). On the other hand, HDL cholesterol concentra-tion increased with increasing bamboo oil concentration. Inparticular, when bamboo oil increased from 2 to 8.0%, HDLcholesterol concentration increased from 25.7 to 40.2%, which wasan increased of about 89% compared to control group withoutaddition of bamboo oil. These results indicate that increase of HDLcholesterol concentration using bamboo oil in the serum may beexploited for the prevention and treatment atherosclerosis.

Fig. 2 summarizes the data concerning the contents of freecholesterol and cholesteryl ester in serum of rats fed theexperimental diets for 4 weeks. The free cholesterol concentration

Table 1Effect of bamboo oil concentration on total cholesterol, triglyceride, and phospholipid

Variables Bamboo oil concentration (%)

0 2.0

Total cholesterol (mg/dL) 145.8 � 7.0 139.6 � 6.7

Triglyceride (mg/dL) 89.3 � 8.8 67.3 � 2.6

Phospholipid (mg/dL) 358.9 � 8.3 387.4 � 9.2

HDL cholesterol (mg/dL) 20.2 � 3.3 25.7 � 1.2

and cholesteryl ester in serum was decreased with the increase ofbamboo oil concentration. Especially, when 8.0% of bamboo oil wasadministrated, the free cholesterol concentration was 34.47 mg/dL, which was a decrease of about 50% compared to the controlgroup without administration of bamboo oil. These results suggestthat the cholesterol-lowering action of bamboo oil may be partiallyattributable to excretion of cholesterol via bile acid. Generally, thehypercholesterolemia was associated with cholesteryl esterconcentration. Therefore, it is very important for measuring thecholesteryl ester concentration in the management of liver disease.The cholesteryl ester in serum was decreased with the increase ofbamboo oil concentration. When 6.0% was administrated, it was92.6 mg/dL, representing a decrease of about 38% compared to thecontrol group. However, in the case of above 8.0% of bamboo oil, itwas not decreased.

Generally, increased activities of glutamic oxaloacetic transa-minase (GOT) and glutamic pyruvic transaminase (GPT) have beenshown in the liver injury. To evaluate liver functions, glutamicoxaloacetic transaminase and glutamic pyruvic transaminaseactivities were investigated. Fig. 3 summarizes the determinedglutamic oxaloacetic transaminase and glutamic pyruvic transa-minase activities in serum. The GOT and GPT activities weredecreased with the increase of bamboo oil concentration. Whenbelow 2.0% of bamboo oil was administrated, GOT activityremained similar to that of the control group. On the other hand,when above 4.0% of bamboo oil was administrated, it wasdecreased. Especially, when 8.0% of bamboo oil was administrated,it was 100.1 U/L, which was decreased of about 32% compared tocontrol without administration of bamboo oil. In the case of GPTactivity, it was decreased from 58.7 to 30.1 U/L when the bamboooil administrated was increased from 4.0 to 8.0%. These resultsindicate that bamboo oil is useful as a preventative and treatmentagent against damage of liver cells.

From these results, we suggest that the lipid-lowering effect ofbamboo oil dietary supplementation was potent in hypercholes-terolemic rats and appears to have benefit against oxidative stressby-regulating hepatic antioxidant enzyme activities. Bamboo oilsupplementation also significantly reduced hepatic cholesterol in

concentration in serum.

4.0 6.0 8.0

100.5 � 5.9 84.8 � 4.8 80.4 � 9.1

55.7 � 6.2 41.8 � 3.8 40.1 � 4.2

402.8 � 6.2 432.9 � 8.2 452.6 � 3.9

30.4 � 2.9 38.6 � 5.5 40.2 � 1.4

Fig. 3. Effect of bamboo oil concentration on glutamic oxaloacetic transaminase and

glutamic pyruvic transaminase activities in serum.

H. Cho et al. / Journal of Industrial and Engineering Chemistry 15 (2009) 281–284284

hepatic biosynthesis of cholesterol had been suppressed. It is wellknown that serum cholesterol concentrations can be regulated bycholesterol biosynthesis, cholesterol removal from the circulatorysystem, the absorption of dietary cholesterol, and the excretion ofcholesterol via bile and feces. Although the mechanism by whichbamboo oil reduces serum total cholesterol levels in hypercho-lesterolemic rats is not fully understood, the hyperlipidemic effectof bamboo oil could be due to a reduced activity of liver enzyme the3-hydroxy-3-methylglutary coenzyme A reductase, the rate-limiting enzyme of cholesterol biosynthesis. It is also possiblethat total cholesterol level suppression in serum by bamboo oilcould be related to increased 7-a-hydroxylase activity (a keyenzyme of cholesterol catabolism) and bile acid secretion and thesubsequent increased excretion of cholesterol through feces.Recently, we are investigating more fully recent observationswe made concerning the antimicrobial activities of bamboo oilagainst Propionibacterium acnes, Malassezia furfur, and Staphylo-

coccus epidermidis with the aim of developing a tonic solution forthe treatment of pustular acne.

4. Conclusion

These researches were performed to examine the effects ofbamboo oil on lipid accumulation and metabolism in rats fed thehigh-cholesterol diet. The total cholesterol, LDL-cholesterol, trigly-ceride and free cholesterol in serum were significantly decreased,whereas contents of HDL-cholesterol and phospholipid wereincreased. The hepatic contents of total cholesterol were loweredsignificantly than the control group without administration ofbamboo oil, but not in triglyceride. The GOT and GPT activities weredecreased with the increase of bamboo oil concentration. Theseresults suggest that bamboo oil supplementation can play animportant role in regulating lipid metabolism in rats fed a high-cholesterol diet. Therefore, it might be expected that bamboo oil isbelieved to be a possible protective or curative effects for fatty liversand arteriosclerosis induced by the high-cholesterol diet. However,further extensive studies are needed to elucidate the mechanismrelated to hepatic lipid-lowering effects of bamboo oil.

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