Hypolipidemic activity of the lipids from bilineata (), an edible Shengjun Wu SHENGJUN WU HuaiHai Institute of Technology, School of Marine Science and Technology, 59 Cangwu Road, Xinpu, 222005, China

KEYWORDS: larvae; hypolipidemic activity; lipids.

ABSTRACT: The present work was carried out to determine the hypolipidemic activities of the lipids from Clanis bilineata larvae (Lepidoptera) (LCBL) in rats. Three groups of rats were fed diets containing either high fat or LCBL, or a normal fat for 6 weeks. Effective inhibition of body weight gain relative to high fat and normal fat groups was observed for the LCBL group. Compared with high fat and normal fat groups, LCBL group showed decreased plasma triacylglycerol (TG), total cholesterol (TC), as well as decreased plasma low-density lipoprotein cholesterol (LDL-C) level. Fecal fat and cholesterol of the LCBL group were lower than those of normal fat group and comparable to the HF group. The results suggest that LCBL may be a suitable alterative hypolipidemic source for humans.

INTRODUCTION According to DeFoliart some contain more essential fatty acids, like linoleic and/or linolenic acids, compared to Many studies indicate that edible insects are potential food meat (8). Therefore, high content of the linolenic acid in CBL resource for human beings (1, 2). Clanis bilineata (CB) Walker may have some physiological effect on human. is a member of the subfamily Ambulicinae (,

Functional food Lepidoptera) that usually grows on soybean leaves. It is an The body weight gain (WG), food intake (FI), and food edible insect, and ~ 6000 tones of CB larvae (CBL) are efficiency ratio (FER) consumed in China each year. WG, FI, and FER of rats after 6 weeks are shown in Table 1. In addition to be a food resource for human beings, many The rats in HF group showed a significant increase in WG edible insects including CBL were reported for their compared with the NF control (p < 0.05). At the same time, hypolipidemic activity without characterizing the active WG of the LCBL group decreased significantly (p < 0.05). ingredients in their samples (3). Polyunsaturated fatty acid, There was no significant difference in food intake among the which has hypolipidemic activity (4), was reported for the 3 groups (p > 0.05). The FER of rats in HF group was higher presence in the body of the edible insects (1, 2). than that of other 2 groups (p < 0.05). This suggested that In this paper, the fat content in CBL was determined, the LCBL was able to inhibit the increase of body weight of the fatty acids of the fat were characterised, and the rats fed high-fat diets. hypolipidemic activity of LCBL was studied.

RESULTS AND DISCUSSION

Total lipid content The total lipid content in CBL was 23.31percent g/100g dry weight, which was comparable to that of cicada (23.98 g/100g dry weight) and higher than those of June beetle (0.34 g/100g dry weight) (2). The different lipid content of

OOD Industry Hi Tech - January/February 2013 Vol. 24(1) edible insects could be ascribed to the different species. F Table 1. Body weight gain of rats (WG), Food intake (FI), food

gro efficiency ratio (FER) of rats fed on high fat, Clanis bilineata

A Fatty acid composition protein (CBP), and normal fat diets. The proportion of unsaturated fatty acids of CBL was 72.34 Values are expressed as mean ± SE (n=6). Means with different superscripts within a row indicate significant differences (p<0.05). percent (w/w). It is noteworthy that the linolenic acid content was 46.21 percent (w/w). Jensen et al. reported that infants who received formula with 3.2 percent (w/w) α-linolenic acid had higher plasma concentrations of the phospholipid docosahexaenoic acid (DHA) but lower concentrations of arachidonic acid at 21, 60, and 120 days of age (5). Peterson and Calder observed that spleen lymphocyte proliferation of rats in response to concanavalin A was significantly reduced (by 60 percent) by feeding them a diet containing higher levels of γ-linolenic acid (6). Dai et al. reported that both Table 2. Fecal fat and cholesterol excretion of rats. Values are expressed as mean ± SE (n=6). Means with different α-linolenic acid and γ-linolenic acid could decrease on superscripts within a row indicate significant differences (p<0.05). blood-lipid levels in hyperlipidemia people (7).

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Functional food 53 ad libitum with a commercial diet and water Table 4. The composition of the commercial diet. Other amino acids, vitamins and minerals in commercial diet all met the requirement of GB14924.3-2001. The fatty acid methyl esters were recovered after solvent after were recovered esters acid methyl The fatty methyl esters fatty acid (10). The vacuum under evaporation GC series gas using a Trace 2000 were analyzed SGE BPx70 spectrometer. A and Thermo mass chromatograph used. The film thickness) was m×0.25 mm, 0.25 mm column (60 of 1 mL/min. The oven was helium at a rate carrier gas to for 5 min and programmed was kept at 100°C temperature for 5 kept constant at 240°C rate of 4°C/min and 240°C at a source temperatures were 250°C andmin. The injection and interface temperature was 240°C. The220°C, respectively. MS 0.5 mL with a split ratio of 1:30. EI/MSinjection volume was ionization energy. Mass range was fromwere taken at 70 eV time was 0.5 s with a 0.1 interscanm/z 50 to 650 amu, scan was carried out using NIST and Wileydelay. The library search library. SupelcoTM 37GC/MS library and TÜBÍTAKUME (Catalogue no: 47885-U) was usedcomponents FAME mixture the GC chromatograms. The relativefor the comparison of compounds was calculated frompercentage of separated by the computerized integrator. Total Ion Chromatography Test ± 9 g , were used inMale Sprague-Dawley rats, weighing 113 in metabolicthe experiment. The rats were housed individually and fecescages fitted with glass separators for urine room maintained atcollection and kept in an air-conditioned All protocols22 ± 1°C with a 12-h light and dark cycle. care and usewere approved by the institutional animal (Jiangsu, China).committee of HuaiHai Institute of Technology water. Rats were allowed free access to food and 36 rats were fed into 3 groups (12for 5 days, and were then randomly grouped therats per group): normal fat group (NF), receiving GB14924.3; high-fatcommercial diet (Table 4) conformed to containing 10control group (HF), receiving high-fat diet yolk powder, 1percent (w/w) lard, 15 percent (w/w) egg diet to 100percent (w/w) cholesterol and commercial percent (w/w) high- percent (w/w); LCBL group, receiving 95 were prepared byfat diets plus 5 percent (w/w) LCBL. The diets with otherblending powdered commercial basal diet ingredients and with test materials then pelleting. . 4 SO 2 - 3 flow rate, 20 L/min; 2 were purchased from a local

Table 3. Plasma lipid concentrations of rats. with different Values are expressed as mean ± SE (n=6). Means (p<0.05). superscripts within a row indicate significant differences MeOH solution was added by a pipette through the condenser and the contents were boiled for 2 min, followed by 5 mL of heptane and further boiling for 1 min. The solutions were cooled, a saturated NaCl solution (5 mL) was added, and the fatty acid methyl esters were extracted with heptane (2×5 mL). The organic layer was dried over anhydrous Na pressure, 25 MPa; temperature, 35°C and time, 60 min. The LCBL was refluxed with 0.5 N sodium hydroxide solution in methanol (5 mL) for 10 min. Then 5 mL of 14 percent BF Materials Hibernating 5th instar CBL Characterization of LCBL The larvae were washed with tap water, killed with hot water (90°C), and dried at 60°C to a constant weight. The dried CBL was crushed into a fine paste. Lipid levels were determined using a Soxhlet extractor with diethyl ether as the solvent (sample of 2 g) (9). The CBL paste was defatted using a supercritical carbon dioxide extraction method (Model: HA 420-40-96, Jiangsu Huaan Scientific Instrument Co., Ltd., Jiangsu, China) with the following parameters: dried CBL, 20 g; approximate size of dried CBL, 0.53 mm; supercritical CO EXPERIMENTAL SECTION Dragon fish, Kerryagricultural market. Soybean oil (Golden from aOils & Grains, Shanghai, China) was obtained supermarket without any further treatment. Triacylglycerol (TG), total cholesterol (TC), and low- and high-density lipoprotein cholesterol (LDL-C and HDL-C) kits were purchased from Zhejiang Dongou Bioengineering Co. Ltd. (Wenzhou, China). Plasma lipid concentrations of rats concentrations of Plasma lipid in of the rats are shown lipid concentrations The plasma of high fat diets, the plasma TC and TGTable 3. After 6 weeks HF group increased compared withconcentrations of the (p < 0.05). However, the addition ofthose of the NF control decreased the TG and TC levels (p

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