Effect of Bitters on the Body Weight, Lipid Profile, Catalase and Lipid Peroxidation in Experimental Animals

This study was designed to investigate the potential effect of bitters on body weight, lipid profile (total cholesterol, triglyceride, high density lipoprotein (HDL)-cholesterol and low density lipoprotein (LDL)-cholesterol), catalase and lipid peroxidation in the plasma and heart tissue of Albino rats. Three brands of bitters (Yoyo, Swedish and Living bitters) were administered daily for thirty-two days through oral rout to age matched twenty eight Albino rats of both sexes. The rats were grouped into four with seven rats per group. The control group was administered normal saline, the treatment groups were administered with Yoyo, Swedish and Living bitters respectively (15 mL kg^-1). The animals were sacrificed after thirty-two days. There was a significant (p<0.05) decrease in body weight, a reduction in cardiac total cholesterol, lipid peroxidation, triglyceride and LDL-cholesterol levels and an increase in catalase activity. There was also a significant reduction in plasma total cholesterol and triglyceride levels but significant increase in plasma catalase activity. Hence, bitters could be recommended to be taken as digestive, as it may help to reduced the body weight, cardiac total cholesterol, triglyceride, LDL-cholesterol levels, lipid peroxidation level and increase catalase activity.

INTRODUCTION

Bitters are prescription and natural remedies that are commonly used in developing countries as a cure for indigestion and other stomach ailments and for treatment of various diseases. Its use has been on the increase recently without investigations/examinations of the possible toxic effect or metabolic alteration. Studies or reports over the last two and a half decades have constantly demonstrate increasing use of herbal remedies in both developing countries and in developed countries where modern medicines are predominantly used medicine as the most common form of alternative medicine and is used by about 60-80% of the world (Bussmann et al., 2010). Bitters include but are not limited to: Gentian root (Gentiana spp.) (Jaeschke et al., 2010), Aloe (Aloe vera syn. A. arbadensis) (Reynolds and Dweck, 1999), Wormwood (Artemisia absinthium) (Kharoubi et al., 2008) from which absinthe was made, Dandelion root (Taraxacum officinale) (Choi et al., 2010), Angelica root (Angelica archangelica) (Sarker and Nahar, 2004), Senna leaves (Cassia senna) (El-Kamali and El-Amir, 2010), Zedoary root (Curcuma zedoaria) (Krishnamoorthy et al., 2009), Myrhh (Commiphora molmol) (Tariq et al., 1985), Cinchona bark (Cinchona spp.) (Schulz and Albroscheit, 1988), Turmeric (Curcuma longa syn. C. domestica) (Kim and Kim, 2010), Shitetta (Swertia chirata syn. Ophelia chirata) (Verma et al., 2008) and Saffron (Crocus sativa) (Motamedi et al., 2010). Bitters generally have been reported to prevent kidney and bladder infections, help to regulate blood pressure and dilate arteries, facilitate digestion, prevent disorder like ulcers, gastritis, insomnia, stress and depression and prevent overweight and excess body fat (Ogbonnia et al., 2010). The medicinal use of the extract from these plants are well documented but there exist little or no information as regard the effect on lipid profile (total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol), catalase and lipid peroxidation (thiobarbituric acid reactive substances (TBARS)) of the heart by the extract these plants when used in combination (Krishnamoorthy et al., 2009). The herbs are used in combination creates the desired synergistic effect (Krishnamoorthy et al., 2009). The aim of this study was to investigate the potential effect of bitters on the lipid profile (total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol), catalase and lipid peroxidation (TBARS) in the plasma and heart tissue of Albino rats.

MATERIALS AND METHODS

Food supplements: Yoyo bitters were obtained from Ablatt Pharmaceuticals Limited, Nigeria, Swedish Bitters was purchased from Swedish Bitters Herb Company, USA and Living bitters from African Angel, USA.

Reagents and chemicals: Bovine serum albumin, sodium hydroxide, copper sulphate, sodium potassium tartarate, potassium iodide, sodium dihydrogen phosphate, disodium hydrogen phosphate and sodium chloride were products of Aldric Chemicals, UK. All other chemicals are of analytical grade.

Animal: Age matched 28 Albino rats of both sexes which were purchased from the Physiology Department of the University of Ibadan, Ibadan, Oyo State, Nigeria. The rats were randomly grouped into four (YB-animal fed with Yoyo Bitters, SB-Swedish Bitters, LB-Living Bitters and CT as control) and kept in wooden cages, which were well ventilated. The animal were allowed to acclimatize to their new environment for two weeks and fed with normal rat chow (Guinea Feed Ltd, Nigeria) and water ad libitum. After two weeks of acclimatization, the four groups of animals were administered, Yoyo Bitters (YB), Swedish Bitters (SB), Living Bitters (LB) (15 mL kg^-1 b.wt.) and normal saline (CT) through oral rout once daily, in addition to the normal rat chow and water for 32 days (about 5 weeks).

Body weight: At least twice every week the body weight of each animal was measured.

Sample collection: After 32 days, the rats were sacrificed by cervical decapitation under the influence of diethyl ether anaesthesia. Blood samples were collected from each animal by cardiac puncture with sterile needle and transferred to heparinised tubes, centrifuged at 5,000 rpm for 10 min and the supernatant and plasma, was separated and stored at a temperature of -4°C until it is required for assaying. The heart was dissected out, washed in ice-cold saline, dried and weighed. The heart was then homogenized in normal saline solution in the ratio 1:4 (1 mg of heart tissue to 4 mL of normal saline solution) and the homogenate was centrifuge at 4000 rpm for 5 min while the supernatant was separated and stored at a temperature of -4°C until it is required for assaying.

Biochemical analysis: Triglyceride level was determined by the method of Mochin and Leyva (1984), total cholesterol and HDL-cholesterol levels were determined by the method of De Hoff et al. (1978) and LDL-cholesterol level was calculated by the method of Nauck et al. (2000). Catalase activity was determined by the method of Johansson and Borg (1988) and TBARS were determined by the method of Buege and Aust (1978).

Statistical analysis: All the results were expressed as Mean±Standard Error of Mean (SEM) for animal in each group. All the grouped data were statistically evaluated using SPSS 15.0 software. Hypothesis testing methods included One-way Analysis of Variance (ANOVA) and subsequent comparisons among groups were made using Duncan’s Multiple Range Test (DMRT). Statistical significance was set at p<0.05.

RESULTS

Effect of bitters on body weight: There was a significant decrease in body weight of the animal fed with Yoyo bitters whereas a significant reduction was observed in animal fed with Swedish and Living bitters from 15 days as shown in Fig. 1.

Effect of bitters on lipid profile: The lipid profile result (Table 1, 2) shows a significant reduction in the total cholesterol level of the plasma and heart tissue, respectively in all the animal fed with Yoyo bitters (162.78±2.19, 653.97±56.07), Swedish bitters (161.52±2.52, 703.50±35.98) and Living bitter (164.05±2.52, 668.54±29.80) when compared with the control (181.71±5.55, 1123.78±212.66) at p<0.05; a significant reduction in the triglyceride level of the heart tissue in animal fed with Yoyo bitters (1519.77±111.59), Swedish bitters (1999.34±43.51) and Living bitters (1964.09±116.67) when compared with the control (3219.67±583.12) at p<0.05 whereas no significant difference was observed in the plasma triglyceride level in the animal fed with Yoyo bitters (89.64±9.78), Swedish bitters (88.55±5.18) and Living bitter (89.66±3.79) when compared with the control (88.17±0.76) at p<0.05; a significant elevation in LDL-cholesterol level of the plasma and heart tissue, respectively in the animal fed with Yoyo bitters (39.32±2.22, 181.44±24.91), Swedish bitters (39.18±2.29, 135.72±25.57) and Living bitter (33.71±6.19, 114.10±25.35) when compared with the control (64.76±10.77, 282.99±54.82) at p<0.05; but no significant difference in HDL-cholesterol level of the plasma and heart tissue respectively in the animal fed with Yoyo bitters (105.53±2.44, 168.37±34.91), Swedish bitters (104.63±1.77, 167.91±35.09) and Living bitter (112.40±5.98, 162.26±37.46) when compared with the control (99.31±10.11, 196.86±23.74) at p<0.05.

Effect of bitters on catalase and lipid peroxidation: The catalase activity and lipid peroxidation results (Table 3, 4) also showed a significance increase in catalase activity of the plasma and heart tissue respectively in animal fed with Yoyo bitters (8.50±0.03, 8.48±0.11), Swedish bitters (8.34±0.06, 8.63±0.06) and Living bitter (8.60±0.05, 8.51±0.10) when compared with the control (8.07±0.03, 8.07±0.13) at p<0.05 but there was a decrease in TBARS level of the plasma and heart tissue, respectively in the animal fed with Yoyo bitters (12019.23±3582.25, 4.33±0.80), Swedish bitters (15000.00±1453.17, 4.74±0.83) and Living bitter (8226.49±1830.29, 4.17±0.64) when compared with the control (25213.68±2230.83, 3.63±0.94) at p<0.05.

Fig. 1:	Effect of Yoyo, Swedish and Living bitters on body weight of experimental animal when compared with control

Table 1:	Effect of bitters on plasma lipid profile
All value are expressed as Mean±SEM. Values with different superscript indicate significant difference at p<0.05

Table 2:	Effect of bitters on cardiac lipid profile
All value are expressed as Mean±SEM. Values with different superscript indicate significant difference at p<0.05

Table 3:	Effect of bitters on plasma catalase activity and lipid peroxidation
All value are expressed as Mean±SEM. Values with different superscript indicate significant difference at p<0.05

Table 4:	Effect of bitters on cardiac catalase activity and lipid peroxidation
All value are expressed as Mean±SEM. Values with different superscript indicate significant difference at p<0.05

DISCUSSION

The present study was designed to investigate the effect of bitters on the body weight, lipid profile (total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol), catalase and lipid peroxidation (TBARS) in the plasma and heart tissue of Albino rats.

The study showed that all experimental animals exerted a significant decrease in body weight in the experimental animal fed with bitters (Yoyo, Swedish and Living bitters) when compared with control. Intake of bitters was also shown to lower total cholesterol and LDL-cholesterol levels in the plasma and heart tissue; and triglyceride in the heart tissue. Lowering total cholesterol, triglyceride and LDL-cholesterol levels of the plasma and heart tissue reduces the risk of hypercholesterolemia and hyperlipidemia that may precipitate into coronary atherosclerosis and other related cardiovascular diseases (Witztum and Steinberg, 2001). This could be as a result of the fact that bitter helps in oxidation of total cholesterol and triglyceride plus reduction in LDL-cholesterol level. The study also showed an increase in catalase activity and a decrease in the level of lipid peroxidation products (TBARS) in both the plasma and the heart tissue. Oxidative stress is one of the causative factors that link hypercholesterolemia with atherogenesis. Malondialdehyde (MDA), the product of lipid peroxidation, is an index of the level of oxygen free radicals. The increased catalase activity help to scavenge oxygen free radicals (Jaeschke et al., 2010).

CONCLUSION

In conclusion, the present results show that moderate consumption of bitters may lower body weight, total cholesterol, LDL-cholesterol and lipid peroxidation and increase catalase activity.