The successful use of herbal combinations in managing diseases or conditions over a single herb has lead us to evaluate the anti-dyslipidemic properties of the combination of the artichoke leaves extract, turmeric extract, prickly pear dried leaves (PPL) and garlic extract versus each one alone in two different hyperlipidemic animal models. A two-week treatment of each of the natural extracts, combination 1 (artichoke, turmeric and PPL) or combination 2 (artichoke, turmeric, PPL and garlic) prior to a single intraperitoneal injection of Pluronic F-127 resulted in decreasing significantly serum LDL levels by garlic and PPL extracts and serum LDL/HDL ratios by turmeric, PPL, combination 1 and 2. In a 10-day high fat diet model, only the combination 1 and 2 lowered serum cholesterol, LDL by 8–12%, decreased significantly triglycerides, LDL/HDL ratio; and increased significantly HDL (
Dyslipidemia can be defined as the elevation of cholesterol, triglycerides, and low-density lipoprotein (LDL) cholesterol serum levels while maintaining low serum levels of high-density lipoprotein (HDL) cholesterol. This imbalance is considered a high-risk factor for inducing atherosclerosis and cardiovascular diseases (CVD). CVD is now considered the most common cause of death in both western and eastern countries [
Traditionally, natural remedies were used to overcome such imbalance in lipids metabolism and are claimed to be useful in controlling hyperlipidemia and associated pathologies [
Prickly pear cactus (
Garlic (
The successful use of herbal combinations in treating or managing diseases or conditions over a single herb [
Pluronic F-127, cholesterol and cholic, acid were obtained from Sigma-Aldrich, USA. Corn oil and Atorvastatin were supplied by the Jordanian Pharmaceutical Manufacturing Company (JPM). Artichoke leaves powdered extract (>2.5% caffeolquinic acid) was purchased from Finzelberg, Germany; cactus dried leaves (>35% edible fibers) from Bioserae, France; common turmeric extract (Curcumins >97.5%) from Xi'an Tianxing Natural Bio-Products Co Ltd, China, garlic powder extract (Alliin >3.4%) from Flachsmann, Canada. The natural extracts were used as supplied and no attempts were carried to evaluate their compositions.
Experiments were carried out on adult Spargue Dawley (SD) male rats weighing (200–250 g). The animals were housed in an air-conditioned environment under a daily photoperiod 12 h light/12 h dark cycle and received standard chow and tap water ad libitum. Animals were kept for 2 weeks to allow acclimatization to the animal facility before starting the experiments. All experiments on animals were performed following the standards of European Community Council Directive of November 24, 1986 (86/609/EEC). The study protocol was revised and approved (9/2008) by the Ethical Committee of the Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan.
Pluronic F-127 is a nontoxic, hydrophilic nonionic surfactant that is administered parenterally in rodents to induce reversible hyperlipidemia [
High-fat diet consisted of standard diet mixed with 10% corn oil, 1% cholesterol, and 0.2% cholic acid. For this method of induction, rats were divided in two groups; group 1: control, fed with the normolipidemic diet, and group 2: fed with the cholesterol based formula. All groups had free access to water. After 10 days of feeding, fasting rats were sacrificed under anesthesia. Blood samples were taken directly from the heart and processed as previously described.
To investigate the effect of the natural extracts to prevent the elevation of blood lipids, animals were divided into 8 groups with eight rats in each group. Each group received daily either water, atorvastatin 10 mg/kg, artichoke leaves extract 26 mg/kg, turmeric 80 mg/kg, prickly pear leaves (PPL) 22 mg/kg, garlic 17 mg/kg, combination 1 (artichoke, turmeric, and PPL), or combination 2 (artichoke, turmeric, PPL, and garlic). These doses correspond to the human recommended daily doses of 1.8, 5.6, 1.5, and 1.2 g/day for artichoke, turmeric, PPL, and garlic, respectively [
Serum total cholesterol, triglycerides, and LDL were determined by enzymatic method using Analyticon Biotechnologies AG, Germany kits, while HDL was measured by using Labkit, Chemelex, S.A. The absorbance was measured at 546 nm wavelength using RA-50 Chemistry Analyzer, Technicon, USA.
The effect of the natural extracts on the activity of HMG-CoA reductase was assayed using an enzymatic assay kit from Sigma-Aldrich, USA.
Results are expressed as mean ± S.E.M (standard error of the mean). Data obtained were analyzed by ANOVA followed by Dunnett as post hoc test using SPSS program, version 17.
Administration of Pluronic F-127 led to very high serum levels of triglycerides, cholesterol, and LDL, but not HDL in rats (Figure
Effects of high-cholesterol diet on the serum lipid profile of rats.
Parameter (mg/dL) | Control* |
High-cholesterol diet* |
---|---|---|
Total cholesterol | 61 ± 5 | 94 ± 3 a |
Triglyceride | 72 ± 5 | 92 ± 4b |
HDL | 19 ± 2 | 15 ± 2 |
LDL | 52 ± 4 | 82 ± 2a |
LDL/HDL | 2.9 ± 0.3 | 6.2 ± 0.7a |
Data presented as means ± SEM (standard error of the mean).
*Animals were fed high-cholesterol diet for 10 days.
Control animals received normal diet.
a
Changes in serum lipid levels at different times following a single i.p injection of 300 mg/kg Pluronic F-127. Values are presented as means ± SEM, with
A two-week treatment of PPL and garlic extracts prior to a single i.p injection of 300 mg/kg Pluronic F-127 resulted in decreasing significantly serum LDL levels (
The effect of the natural extracts and their combinations on serum lipid levels in Pluronic F-127 induced hyperlipidemia.
Groups | Serum Lipid Parameters (mg/dL) | ||||
---|---|---|---|---|---|
Cholesterol | Triglycerides | HDL | LDL | LDL/HDL | |
Normal | 75 ± 2 | 64 ± 6 | 39 ± 5 | 65 ± 1 | 1.9 ± 0.2 |
Control Pl. | 455 ± 30 | 2894 ± 206 | 33 ± 3 | 378 ± 23 | 11.5 ± 0.7 |
Atorvastatin | 460 ± 14 | 3021 ± 176 | 26 ± 2 | 377 ± 13 | 14.7 ± 1.1 |
Artichoke | 523 ± 44 | 3504 ± 160 | 41 ± 8 | 415 ± 39 | 11.7 ± 2.3 |
Turmeric | 487 ± 20 | 3365 ± 153 | 43 ± 2 | 387 ± 18 | 9.1 ± 0.8a |
PPL | 388 ± 17 | 2888 ± 190 | 50 ± 3 | 308 ± 15a | 6.2 ± 0.5b |
Garlic | 389 ± 17 | 3020 ± 198 | 25 ± 2 | 313 ± 14a | 12.9 ± 1.4 |
Comb. 1 | 573 ± 28 | 3723 ± 159 | 57 ± 4 | 472 ± 24 | 8.3 ± 0.4a |
Comb. 2 | 510 ± 37 | 3253 ± 204 | 54 ± 2 | 413 ± 33 | 7.7 ± 0.7a |
Data presented as means ± SEM with 6 rats in each group. Control Pl.: control group given only Pluronic F-127. PPL: prickly pear leaves. Comb. 1: combination 1 (artichoke, turmeric, and PPL). Comb. 2: combination 2 (artichoke, turmeric, PPL, and garlic). Statistical analysis was done using ANOVA, a
Treating the rats for 2 weeks either with a single product or with different combinations and then giving them High-Fat diet for only 10 days (with the treatment) gave the following results: none of the single product changed the level of any serum lipid profiles; the first combination (artichoke, turmeric and PPL) and the second one (artichoke, turmeric, PPL and garlic) lowered cholesterol and LDL levels by 8–12%; decreased significantly serum triglycerides, LDL/HDL ratio, and increased significantly HDL levels (
The effect of the two combinations on serum lipid levels in comparison with the single treatment. Atorva: atorvastatin 10 mg/kg. PPL: prickly pear leaves. Comb. 1: combination 1 (artichoke, turmeric, and PPL). Comb. 2: combination 2 (artichoke, turmeric, PPL, and garlic). Values are presented as means ± SEM, with
However, keeping the rats under High-Fat diet for another 25 days (i.e., 5 weeks in total) resulted in a drop of serum cholesterol level in the control group that abolishes the significance effect of Atorvastatin on cholesterol level. However, all the natural extracts, except for PPL, and Atorvastatin resulted in a significant decrease in triglycerides levels (
The effect of the natural extracts, separately, on serum lipid levels after 7-week period of treatment that included 5 weeks feeding high-fat diet.
Groups | Serum lipid parameters (mg/dL) | ||||
---|---|---|---|---|---|
Cholesterol | Triglycerides | HDL | LDL | LDL/HDL | |
Control | 85 ± 3 | 65 ± 7 | 16 ± 2 | 75 ± 2 | 5.2 ± 0.5 |
Atorvastatin | 86 ± 3 | 44 ± 2b | 24 ± 3 | 76 ± 3 | 3.5 ± 0.5a |
Artichoke | 79 ± 3 | 43 ± 3b | 21 ± 3 | 64 ± 3a | 3.5 ± 0.5a |
Turmeric | 75 ± 3 | 27 ± 1c | 29 ± 4b | 61 ± 2b | 2.5 ± 0.4c |
PPL | 72 ± 2b | 49 ± 1 | 28 ± 2b | 60 ± 3b | 2.2 ± 0.1c |
Garlic | 77 ± 3 | 35 ± 4c | 24 ± 2 | 62 ± 3b | 2.7 ± 0.2b |
Data presented as means ± SEM of 8 rats in each group. PPL
The effect of the natural extracts on the activity of HMG-CoA reductase is given in Figure
The effect of the natural extracts on HMG-CoA reductase activity at different concentrations. Atorva: Atorvastatin; PPL: prickly pear leaves. Values are presented as means ± S.D. Symbols mean statistically significant; *
In order to understand the relationship between disorders in cholesterol metabolism and atherogenesis and to test possible treatments for the reduction of serum lipid levels, various models are found to induce hyperlipidemia in rats [
As extrinsic inducer, 10-day high-fat diet caused a significant increase in serum cholesterol and LDL, triglycerides levels and decreased HDL. Pretreating the rats for 14 days with any of the single products did not prevent or decrease serum lipid profiles. On the other hand, the combinations artichoke, turmeric and PPL or artichoke, turmeric, PPL, and garlic decreased significantly serum triglycerides level, and LDL/HDL ratio; increased significantly HDL, and also mildly lowered cholesterol and LDL levels by 8–12%, respectively. Thus, such natural extracts combination for long-term use would give more significant normalization of dyslipidemia.
When the High-Fat diet continued for longer period (5 weeks), it did not increase the total serum cholesterol level but increased serum LDL and decreased HDL levels. It has been noticed that after 7–10 days of High-Fat diet feeding, serum cholesterol, triglyceride, and LDL levels increased significantly in comparison to baseline levels. During the next 4 weeks of High-Fat diet feeding to rats, it was noticed that the level of serum cholesterol and triglycerides started to decrease in the control group as well as the treated groups but the ratio of LDL/HDL stayed significantly high. This could be explained by that long-term High-Fat diet induces saturation in cholesterol synthesis inside hepatocytes, and thus LDL receptor expression is reduced justifying high LDL serum concentrations [
Englisch et al. (2000) have reported that the artichoke extract significantly lowered cholesterol and LDL (18.5% and 22.9%, resp.), in a randomized double-blinded placebo-control trial in which 143 hypercholesterolemic patients received either 1800 mg/day of the extracts or matched placebo for six weeks [
We have shown herein that turmeric decreased significantly serum triglyceride, LDL, LDL/HDL ratio, and increased serum HDL level. Although turmeric effect on serum cholesterol was not significant, it decreased its level by 12%. The hypocholesterolemic effect of turmeric has been widely investigated. In rats fed high-cholesterol diet for 7 days, Arafa (2005) investigated the hypolipidemic effect of curcumin (0.5% w/w) when added to diet and reported that curcumin decreased cholesterol by 21% and LDL by 42.5%, while HDL level was increased by 50% [
Prickly pear dried leaves significantly decreased serum cholesterol, LDL levels, and LDL/HDL ratio and significantly increased serum HDL levels. Although its effect on triglycerides level was not significant, PPL decreased serum triglycerides by 23.5%. Many authors mentioned that the cladodes of
Various extracts of garlic have been shown to lower serum cholesterol, triglycerides, and LDL in rodents and humans [
Since treating or managing dyslipidemia requires a life-long use of antihyperlipidemic drugs, it is necessary to use a combination of natural extracts that exert a similar outcome with multi-mechanism of action and have less adverse events. Such combination can be used alone as prophylactic, a booster to a known antihyperlipidemic drugs, or as life-long phytopharmaceuticals. As presented herein, neither of the artichoke leaves extract, turmeric extract, prickly pear dried leaves, and garlic extract showed any effect on short-term treatment in High-Fat diet model but the combination effect to normalize dyslipidemia is additive. Thus using the combination of artichoke leaves extract, turmeric extract, prickly pear dried leaves, and garlic extract for short-term, as well as long-term, treatment can prevent dyslipidemia; partially through inhibiting HMG-CoA reductase.
The authors have declared that there is no conflict of interests.
This work was supported by a grant from the Deanship of Scientific Research at Petra University, Amman, Jordan and by Delass Natural Products, Naor, Jordan.