Effets of Pistacia lentiscus Virgin Fatty Oil on Lipidemic Profile and Carcass Characteristics in Hyperlipidemic Oryctolagus cuniculus Rabbits

Corresponding Author: Zouhir Djerrou Department of Sciences of Nature and Life, Faculty of Sciences, University of August 20th 1955, Skikda, Algeria E-mail: z.djerrou@univ-skikda.dz zouhir21265@yahoo.fr Abstract: The study aimed to evaluate Pistacia Lentiscus Virgin Fatty Oil (PLVFO) effects on lipidemic profile and carcass characteristics in rabbits. 15 male adult rabbits were allocated in three groups of 5 each. The first was not treated and served as control (CRL), the second was gavaged by Egg Yolk (EY) at a dose of 7 mL kg −1 BW (6/7 days), the third was treated as EY and then PLVFO was applied at a dose of 1 mL kg −1 BW (6/7 days). At 28th day of experiment, the biochemical profiles were determined and then animals were sacrified for anatomopathological studies and carcass characteristics investigation. PLVFO has resulted in non significant decrease of total cholesterol, a significant decrease of LDL-C (PLVFO Vs EY, ANOVA, p<0.01) and a significant increase of HDL-C (PLVFO Vs EY, ANOVA, p<0.001) with a significant amelioration of atherogenic index (PLVFO Vs EY, ANOVA, p<0.01). This oil has also increased non significantly ALT with a significant increase of AST (PLVFO Vs EY, ANOVA, p<0.01). Anatomo pathological investigations have not shown significant disturbances by PLVFO, this later has reduced significantly dissectible fat (PLVFO Vs EY, ANOVA, p<0.05). The study concludes that PLVFO prevent hyperlipidemia and obesity at tested dose. However, its prolonged use may increase transaminases enzymes activities.


Introduction
Lentisk oil is a fatty oil extracted from berries of Pistacia lentiscus L. plant which is largely distributed in the Mediterranean area. In North African regions, this oil is used traditionally to treat burns and wounds, respiratory allergies and lombalgies (Boukef and Souissi, 1982). It is consumed also for its nutritive value. Some pharmacological properties of this oil were recently investigated as cicatrizing activity (Djerrou et al., 2010), protection of mercury intoxication (Tounes et al., 2008), investigation of hepatoprotective effect against carbontetrachloride (Maameri et al., 2015). To ascertain the safety of this vegetable oil for its consumers, some studies were conducted as effects on glycemic index, liver and renal functions in rabbits (Djerrou et al., 2011), acute toxicity in mice (Boukeloua et al., 2012), irritancy potential and subacute dermal toxicity in rabbits (Djerrou et al., 2013), subchronic oral toxicity in rabbits (Maameri et al., 2016).
In a previous report, we have studied the antihyperlipidemic effect of this oil in female rabbits following a hyperlipidemic diet; at a dose of 2 mL kg −1 BW, this oil has resulted in reducing total cholesterol, LDL-cholesterol and triglycerides after 6 weeks of treatment (Djerrou, 2014).
The aim of the present study is to evaluate the antihyperlipidemic effect of P. lentiscus virgin fatty oil at a lower dose (1 mL kg −1 BW) and to investigate its possible side effects on hepatorenal functions and carcass characteristics in male rabbits.

Pistacia lentiscus Virgin Fatty Oil
The fruits of Pistacia lentiscus L. were harvested from Tamalous region (Latitude: 36°50.2578′, Nord, Longitude: 6°38.4108′ Est.) in the second half of December 2015, during sunny days. The virgin fatty oil, extracted traditionally, was stored in well-filled glass bottle and well sealed. It was kept cool to protect from light until use.

Eggs
These eggs were purchased from the local market. The yellow of eggs were separated manually, grouped together in a clean container and mixed.

Animals and Housing Conditions
This study was conducted on 15 Oryctolagus cuniculus local rabbits, males, healthy adults, weighing between 1750 g and 2190 g at the beginning of the experiment. The animals were housed 2 or 3 per cage in a standardized environment at room temperature with a light-dark cycle of 12 h. Food and water were provided ad libitum. The study was approved by Faculty of sciences, University of Skikda, Algeria.

Experimental Design
The animals were divided into three groups of five rabbits each: • Normal control (CRL): This group received a normal diet • Hyperlipidemic control (EY): This group received a normal diet + 7 mL kg −1 body weight of egg yolk • Tested group (PLVFO): This group received a normal diet +7 mL kg −1 body weight of egg yolk + PLVFO at a dose of 1 mL kg −1 body weight Rabbits were gavaged using a stomach tube (egg yolk and oil), once daily, 6 days a week for 28 consecutive days. PLVFO was administered 15 min after administration of egg yolk to avoid interaction. All animals were controlled for their general state and were weighted weekly until 28th day.
At the end of the experiment, the animals were fasted overnight and for biochemical analysis, samples of blood from the marginal ear vein were collected into heparinized tubes.

Biochemical Assays
Blood samples were centrifuged at 4000 rpm for 4 min and then plasma was separated. Selected blood parameters were carried out by an automatic analyzer and included Total Cholesterol (TC), Triglycerides (TG), High Density Lipoprotein (HDL), Aspartateamino Transferase (AST), Alanine Transaminase (ALT), creatinine, urea and uric acid. Low Density Lipoproteins (LDL) was calculated using Friedewald equation, the atherogenic index was calculated as reported by Hua et al. (2009): Atherosclerosis index = (serum TC-HDL-C)/HDL-C.

Anatomo-Pathological Study and Carcass Characteristics
After slaughtering animals on the 29th day of the experiment, they were dissected to examine the internal organs: Liver, kidneys, lungs, spleen, adrenals and heart. These organs were subjected to a quantitative and qualitative macroscopic examination (external structure, color, consistency and texture). These organs were weighed immediately to avoid their desiccation. Other zoo technical and carcass quality parameters were investigated: Live weight, slaughter weight, dressed weight, dressing percentage, head and pelt with lambs weight, full gastrointestinal tract and dissectible fat weights.

Statistical Analysis
Statistical data were presented as mean with SD and analyzed by one-way analysis of variance (ANOVA). The level of significance was p<0.05.

Results
Throughout the trial period, no deaths have been reported and no serious clinical signs of toxicity were observed in animals. All rabbits remained healthy and were available for evaluation.

Body Weight
Weekly weighed rabbits have shown that the difference between the averages of the different groups was not significant.
The average weight of the control group (CRL) has evolved gradually from 1855±108.972 g to 2028.66±202.02 g towards the end of the experimental period.
The group fed by the Egg Yolk (EY) has shown a gradual increase until the 3rd week (1958±189.233 g to 2061.6±225.22 g); thereafter there was a slight decrease recording 2006±189.145 g on the 28th day. While the PLVFO group recorded an increase in weight during the first 3 weeks (1908.33±289.233 g on day 0 and 1974±268.813 g at 21st day) followed by a more interesting decrease compared to EY group, but this decrease was not significant by scoring a weight of 1904.66±356.875 g at the end of the experiment.

Biochemical Analysis Lipidemic Profile
Statistical analysis of biochemical parameters was represented in Fig. 1-5. The rabbits gavaged Egg Yolk (EY group) showed a very significant increase in cholesterol (TC) (P = 5,75678E −4 ) compared with CRL group. Hypercholesterolemia induced by egg yolk has been reduced, but not significantly in PLVFO group.
The HDL was increased very significantly in the PLVFO group compared to the CRL and EY groups (p = 6,50094E −7 and p = 7,46127E −4 respectively).
The LDL was increased very significantly in EY group compared to CRL group (p = 2,0814E −4 ). The administration of the vegetable oil in PLVFO group resulted in a significant decrease of this parameter (p = 0.0174), the difference between this group and CRL group was not significant. For triglycerides, there was no significant difference between all the three groups.
The atherogenic risk was significantly increased in rabbits from EY group compared to CRL group. In PLVFO group, this risk was significantly decreased (P = 0.00385) compared to the group fed with egg yolk, noting that the difference with CRL group was not significant.

Hepatorenal Profiles
The results of hepatic and renal functions were recorded in Table 1. Aspartate Aminotransferase (AST) showed a significant increase in PLVFO group compared to CRL and EY groups (p = 0.00339 and p = 0.00588 respectively), in the EY group a less significant increase in that of PLVFO group was noted.
Alanine Aminotransferase (ALT) was increased but not significantly among PLVFO rabbits compared to other animals of CRL and EY groups.
The two parameters, creatinine and urea marked a slight increase but not significantly in EY and PLVFO groups. However, uric acid showed a significant increase in the animals of both groups compared to CRL group (P˂0.001).

Anatomo-Pathological Study and Carcass Characteristics
The general appearance of rabbit's organs of different groups and their relative weights were normal. Statistical analysis (Table 2 and 3) did not show significant differences, except for abdominal dissectible fat, which was significantly decreased in the PLVFO group compared to CRL and EY groups (p<0, 01 and p<0, 05 respectively).    Testes (

Discussion
In the present study, the gavage of rabbits during 28 days by Pistacia lentiscus virgin fatty oil has resulted in a slight reduction of body weight at the end of experiment accompanied by a significant reduction of dissectible fat; which suggest that this vegetable oil may be consumed to prevent obesity. This natural product has recorded a non significant decrease of total cholesterol but a significant decrease of LDL-C and a significant increase of HDL-C with an important amelioration of atherogenic index. In our previous study (Djerrou, 2014), this oil has decreased significantly total cholesterol in female rabbits, when applied at a dose of 2 mL kg −1 BW during 6 weeks. We note that in the current study conducted on males rabbits, the dose tested was only 1 mL kg −1 BW during 28 days, the egg yolk was gavaged at a dose higher than the previous study (7 mL kg −1 BW). The vegetable oil extracted from the same region in 2014 has shown a high level of Monounsaturated Fatty Acids (MUFA: 55.76%), a 20.45% of Poly Unsaturated Fatty Acids (PUFA), a 23.53% of Saturated Fatty Acids (SFA) with a good ratio of PUFA/SFA (ratio = 0.86) (Djerrou, 2014). The unsaponifiable fraction of P. lentiscus fatty oil contains sterols (cholesterol, campesterol, stigmasterol and β-sitosterol), tocopherols and phenolic components (Djerrou et al., 2010;Trabelsi et al., 2012). Several components existing in this oil were investigated and confirmed to be implicated in preventing hyperlipidemia, LDL oxidation and prevention of atherosclerosis as: Oleic acid (C18:1), Omega-3 PUFAs, Conjugated Linoleic Acids (CLAs), α-tocopherol, squalenes and phenolic components (Harris et al., 1997;Newmark, 1997;Kohr et al., 1998;Kris-Etherton, 1999;Visioli et al., 2002).
The current study has also shown for the first time that the application of P. lentiscus fatty oil for 28 days may increase transaminases enzymes activities particularly AST; noting here that several hypolipidemic drugs were known to increase transaminases activities.

Conclusion
The study concludes that Pistacia lentiscus virgin fatty oil may be consumed to prevent hyperlipidemia and obesity. However, it should be taken with precaution because it may increase transaminases enzymes activities in prolonged use.