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Year : 2010  |  Volume : 42  |  Issue : 6  |  Page : 388--391

Effects of Phyllanthus reticulatus on lipid profile and oxidative stress in hypercholesterolemic albino rats

V Maruthappan1, K Sakthi Shree2,  
1 Department of Zoology, Unit of Endocrinology, Bharathiar Univeristy, Coimbatore - 641 046, India
2 PG and Research Center, Government Arts College (Autonomous), Coimbatore - 641 018, India

Correspondence Address:
V Maruthappan
Department of Zoology, Unit of Endocrinology, Bharathiar Univeristy, Coimbatore - 641 046
India

Abstract

Objective: This study was designed to investigate the effect of Phyllanthus reticulatus on lipid profile and oxidative stress in hypercholesterolemic albino rats. Materials and Methods: Hypercholesterolemia was induced in albino rats by administration of atherogenic diet for 2 weeks. Experimental rats were divided into different groups: normal, hypercholesterolemic control and P. reticulatus treated (250 and 500 mg/kg body weight doses for 45 days). After the treatment period of 45 th day triglyceride, VLDL-cholesterol, HDL-cholesterol, total cholesterol (TC), LDL-cholesterol and oxidative stress (protein carbonyl) were assayed and compared with hypercholesterolemic control. Results: The aqueous extract of P. reticulatus (250 mg and 500 mg/kg) produced significant reduction (P < 0.05) in triglyceride, VLDL-cholesterol, total cholesterol (TC), LDL-cholesterol and oxidative stress (protein carbonyl) while increased HDL-cholesterol in atherogenic diet-induced hypercholesterolemic rats at the end of the treatment period (45 days). However, the reduction in the above parameters was comparable with hypercholesterolemic control. Thus, aqueous extract of P. reticulatus is effective in controlling TC, lipid profile and oxidative stress in hypercholesterolemic animals. Conclusion: The results suggest the aqueous extract of P. reticulatus can be utilized for prevention of atherosclerosis in hypercholesterolemic patients.



How to cite this article:
Maruthappan V, Shree K S. Effects of Phyllanthus reticulatus on lipid profile and oxidative stress in hypercholesterolemic albino rats.Indian J Pharmacol 2010;42:388-391


How to cite this URL:
Maruthappan V, Shree K S. Effects of Phyllanthus reticulatus on lipid profile and oxidative stress in hypercholesterolemic albino rats. Indian J Pharmacol [serial online] 2010 [cited 2020 Aug 13 ];42:388-391
Available from: http://www.ijp-online.com/text.asp?2010/42/6/388/71923


Full Text

 Introduction



Hypercholesterolemia is associated with serious health risks and increased mortality. Hypertension, hyperlipidemia, insulin resistance and glucose intolerance are known as cardiac risk factors that cluster in obese individuals. [1] The persistence of hypercholesterolemic state causes enhanced oxidative stress, leading to the development of atherosclerosis, coronary artery disease (CAD) and other complications of obesity. [2],[3]

In the recent years, there is growing interest in herbal medicines all over the world. Traditional medicinal plants having antilipidemic property can prove to be an useful source for the development of new oral hypolipidemic agents or simple dietary adjuvant to existing therapies. Ethnopharmacological surveys indicate that more than 1200 plants are used in traditional medicine for their hypolipidemic activity. [4],[5] The hypolipidemic activity of a number of plants/plant products has been evaluated and confirmed in animal models, [6],[7] as well as in human beings. [8],[9]

Phyllanthus reticulatus (Family-Euphorbiaceae) is a climbing shrub which grows all over India. [10] It has been shown to have hypotensive effects and its folklore use in gastric complaints including colic and constipation has been reported. [11] Phyllanthus niruri has been shown to possess significant hepatoprotective activity in fatal liver diseases such as liver cirrhosis and hepatocellular carcinoma. [12] Chemical studies demonstrated the presence of octacosanol, teraxerol acetate, friedeline, teraxerone, betulin, sitosterol, etc. [13] Although P. reticulatus has not been studied for significant chemical as well as biological studies, the plants of this genus were reported to contain lignins, flavonoids, triterpenoids, alkaloids and polyphenolic compounds. [14] Flavonoids and polyphenolic compounds have a potential role in the prevention of various diseases through their antioxidant activity. [15] The present work was designed to study the lipid profile and oxidative stress of the aqueous extract of the aerial parts of P. reticulatus in rat model.

 Materials and Methods



Animals

Adult albino rats (Wistar strain) weighing 180-200 g of either sex were used for this study. The animals were housed in polypropylene cages at controlled temperature (26 ± 2°C), relative humidity (60 ± 5%) with a 12-12 h light-dark cycle. The rats were fed with standard laboratory diet and water was provided ad libitum. The animals were maintained as per the CPCSEA guidelines and regulations and the study was approved by the Institutional Animals Ethics Committee at Bharathiar University, Coimbatore, India. The composition of atherogenic diet used during the study was given as in [Table 1].{Table 1}

Preparation of the extract

Aerial parts (stem and leaves) of P. reticulatus were collected in July-September from Maruthamalai Hill, Coimbatore (India). The plant was identified and authenticated with the help of Botanical Survey of India, Coimbatore (India). The plant material was dried under shade and powdered in a grinder. The powdered material (100 g) was extracted with double-distilled water by the hot continuous percolation method in a Soxhlet apparatus. The extract was evaporated to dryness under vacuum and dried in a vacuum desiccator to obtain a residue of 15.65 g.

Induction of experimental hypercholesterolemia

In order to induce hypercholesterolemia, the method reported by Bopanna et al. was followed. [16] The animals were divided into four groups of six rats each and they received the following diets with or without treatment for 45 days orally:

Group I: Normal diet.

Group II: Atherogenic diet containing 1% cholesterol.

Croup III: Atherogenic diet + aqueous extract of P. reticulatus (250 mg/kg b.w.).

Group IV: Atherogenic diet + aqueous extract of P. reticulatus (500 mg/kg b.w.).

At the end of the treatment, the rats were fasted overnight and killed by decapitation. Blood was collected and serum was separated and stored in a refrigerator (4°C) until assay.

Measurement of serum lipid profile

Total cholesterol (TC), [17] serum triglyceride, [18] high density lipoprotein (HDL), [19] and protein carbonyl levels, [20] were measured while very low density lipoprotein (VLDL) was calculated as triglyceride/5 and low density lipoprotein (LDL) was calculated using the equation: LDL = total cholesterol - (HDL + VLDL). The atherogenic index was calculated using the following formula:

[INLINE:1]

Drugs and chemicals

All the chemicals were used of analytical grade, obtained from M/s. SISCO Research Laboratories Pvt. Ltd, Mumbai.

Statistical analysis

Statistical analysis was carried out using Student's t-test. [21]

 Results



Phytochemical screening revealed the presence of lignins, flavonoids, triterpenoids, alkaloids, polyphenolic compounds and mucilage in the aqueous extract of P. reticulatus. Feeding of atherogenic diet increased serum cholesterol, triglyceride, LDL-cholesterol and HDL-cholesterol level, VLDL-cholesterol and protein carbonyl level when compared to normal group at over a period of 45 days. Administration of aqueous extract of P. reticulatus (250 and 500 mg/kg per day) showed statistically significant decrease in total cholesterol (P < 0.05), triglyceride (P < 0.001), LDL-cholesterol (P < 0.05), VLDL-cholesterol (P < 0.001) and protein carbonyl level (P < 0.05) while increase in HDL-cholesterol level (P < 0.05) as compared to hypercholesterolemic animals [Table 2]. The aqueous extract treated animals showed decrease in the atherogenic index and increased percentage of protection at both the doses, i.e. 250 and 500 mg/kg [Table 3].{Table 2}{Table 3}

 Discussion



The effect of P. reticulatus on lipid profile and oxidative stress in hypercholesterolemic albino rats was evaluated in this study. P. reticulatus, an Indian herbal plant, possesses cardioprotective and lipid lowering properties. Treatment with P. reticulatus extract produced a significant decrease in the serum lipid level in atherogenic diet-induced hypercholesterolemia in rats. Maruthappan and Sakthi Shree [22],[23] found that the feeding of Adenanthera pavonina and Terminalia chebula lowered the total cholesterol and its fractions in lipoproteins. They reported hypolipidemic activity of the saponins, flavonoids and polyphenolic compounds from A. pavonina. Beta-sitosterol, a phytosterol, is reported as useful in the treatment of hyperlipidemia. [16] Sudhessh et al.[24] reported that condensed tannins of Solanum melongena are reduced in hyperlipidemia. The aqueous extract of P. reticulatus contains lignins, flavonoids, triterpenoids, alkaloids, polyphenolic compounds and mucilage. The high amount of lignins, flavonoids present in P. reticulatus may be responsible for the hypocholesterolemic effect. Use of diet rich in saturated fats and an increase in coronary heart disorder (CHD) has been observed in the developing countries for the past few decades. [25]

Pretreatment of P. reticulatus reduced the atherogenic diet-induced hypocholesterol manifestations in multiple ways. Increase in the level of serum triglyceride, total cholesterol, LDL-cholesterol and VLDL-cholesterol in the P. reticulatus-treated group indicate that phytochemicals may be interfering with metabolism or biosynthesis of lipids. Pretreatment with P. reticulatus showed reduction in serum lipid levels with concomitant increase in HDL-cholesterol. Decrease in serum lipid profiles and increase in HDL-cholesterol in P. reticulatus-treated group may be due to the present of phytochemicals. Lipid lowering effect of P. reticulatus could be due to inhibition of hepatic cholesterol biosynthesis, increased fecal bile acid secretion and stimulation of receptor-mediated catabolism of LDL-cholesterol and increase in uptake of LDL from blood by liver. [26] The atherogenic index (TG/HDL-C ratio) used to predict risk of CHD and marker of small, dense LDL-C (an atherogenic lipoprotein) [27],[28] were significantly reduced by the P. reticulatus extract, indicating the beneficial effect of extract in cardiovascular diseases.

Oxidative stress is an important event in the development and maintenance of atherosclerosis. [29] Protein carbonyl is the most widely used biomarker for oxidative damage to proteins by multiple forms reactive oxygen species (ROS). [30] On the basis of the measurement of protein carbonyl, it has been suggested that the accumulation of oxidized proteins is associated with atherosclerosis. [31] However, the relationship between serum lipid levels and protein carbonylation is not clear.

 Conclusion



In this study, an increase in serum HDL-cholesterol with a concomitant decrease in other lipids was observed. It can be concluded from the present data that the levels of total cholesterol, triglyceride, LDL-cholesterol, VLDL-cholesterol and protein carbonyl which are raised in atherogenic diet are lowered significantly with the aqueous extract of P. reticulatus. Aqueous extract of P. reticulatus can be utilized for prevention of atherosclerosis in hypercholesterolemic patients.

References

1Anuradha CV, Ravikumar P. Restoration on tissue antioxidants by fenugreek seeds (Trigonella Foenum Graecum) in alloxan-diabetic rats. Ind J Physiol Pharmacol 2001;45:408-20.
2Hunt JV, Smith CC, Wolff SP. Autoxidation glycosylation and possible involvement of peroxides and free radicals in LDL modification by glucose. Diabetes 1990;39:1420-4.
3Oberly LW. Free radicals and diabetes. Free Radi Biol Med 1988;15:113-6.
4Grover JK, Yadav S, Vats V. Medicinal plants of India with anti-diabetic potential. J Ethnopharmacol 2002;81:81-100.
5Li WL, Zheng HC, Bukuru J, De Kimpe N. Natural medicines used in the traditional Chinese medical system for therapy of diabetes mellitus. J Ethnopharmacol 2004;92:1-21.
6Gupta RK, Kesari AN, Watal G, Murthy PS, Chandra R, Tandon V. Nutritional and Hypoglycemic Effect of Fruit pulp of Annona squamosa in Normal Healthy and Alloxan-Induced Diabetic Rabbits. Annals Nutri Meta 2005;49:407-13.
7Kesari AK, Gupta RK, Singh SK, Diwakar S, Watal G. Hypogycemic and antihyperglycemic activity of Aegle marmelos Seed Extract in Normal and Diabetic Rats. J Ethnopharmacol 2006;107:374-9.
8Herrera-Arellano A, Aguilar-Santamaria L, Garcia-Hernandez B, Nicasio-Torres P, Tortoriello J. Clinical trial of Cecropia obtusifolia and Marrubium vulgare leaf extracts on blood glucose and serum lipids in type 2 diabetics. Phytomedicine 2004;11:561-6.
9Jayawardena MH, De Alwis NM, Hettigoda V, Fernando DJ. A double blind randomized placebo controlled cross over study of herbal preparation containing Salacia reticulata in the treatment of type 2 diabetes. J Ethnopharmacol 2005;97:215-8.
10Ghani A. In: Medicinal Plants of Bangladesh, Chemical constituents and uses. Asiatic Society of Bangladesh. 2 nd ed. 2003. p. 345.
11Wells BG, Dipiro JT, Schwinghammer, TL, Hamilton CW. Pharmacotherapy Handbook. New York: Mc Graw-Hill; 2003. p. 216-24.
12Gneti KR, Agarwal S. Hepatoprotective studies on Phyllanthus niruri and quercetin. J Exptl Biol 1995;33:261-8.
13Rates SM. Plants as source of drugs. Toxicon 2001;39:603-13.
14Yoshida T, Seno K, Takama Y, Okanda T. Tannins and related polyphenol of Euphorbiaceous plants. Phytochem 1964;21:1180-1.
15Kaur G, Alam MS, Jabbar Z, Javed K, Athar M. Evaluation of antioxidant activity of Cassia siamea flowers. J Ethnopharmacol 2006;108:340-8.
16Bopanna KN, Bhagyalakshmi N, Rathod SP, Balaraman R, Kannan J. Cell culture derived Hemidesmus indicus in the prevention of hypercholesterolemia in normal and hyperlipidemic rats. Ind J Pharmacol 1997;29:105-6.
17Roeschlau P, Bernt E, Gruber W. Enzymatic determination of total cholesterol in serum. Z Klin Chem Klin Biochem 1974;12:226-7.
18Buccolo G, David H. Quantitative determination of serum triglycerides by the use of enzymes. Clin Chem 1973;19:476-82.
19Burstein M, Scholnick HR, Morfin R. Rapid method for the isolation of lipoprotein from human serum by precipitation with polyanions. J Lipid Res 1970;11:583-95.
20Levine RL, Garland D, Oliver CN, Amici A, Climent I, Lens AG, et al. Determination of Carbonyl content in oxidatively modified proteins. Methods Enzymol 1990;186:464-78.
21Bennet CA, Franklin NL. Statistical analysis in chemistry and chemical industry. New York: John Willey Sons; 1967. p.133-7.
22Maruthappan V, Sakthi Shree K. Hypolipidemic activity of Haritaki (Terminalia Chebula) in atherogenic diet induced hyperlipidemic rats. J Adv Pharm Tech Res 2010;1:229-35.
23Maruthappan V, Sakthi Shree K. Blood cholesterol lowering effect of Adenanthera pavonina seed extraction atherogenic diet induced hyperlipidemia rats. Int J Pharma Sci Res 2010;1:87-94.
24Sudhessh S, Vijay KS, Sandhya C, Vijayalakshmi NR. Toxic effects of condensed tannins from Solanum melongena on rats. J Ecotoxicol Environ Monit 1996;6:221-8.
25Kulkarni SK, Gurpreet Kaur. Obesity: An insight into its neurochemical basis and treatment. Ind J Pharmaco 1999;31:388-95.
26Khanna AK, Ramesh C, Kapoor NK. Terminalia arjuna: An Ayurvedic cardiotonic regulates lipid metabolism in hyperlipidemic rats. Phytother Res 1996;10:663-9.
27Hanak V, Munoz J, Teague J, Stanley A, Bittner V. Accuracy of the triglyceride to high-density lipoprotein cholesterol ratio for prediction of the low-density lipoprotein phenotype B. Am J Cardiol 2004;94:219-22.
28Packard C, Caslake M, Shepherd J. The role of small, dense low density lipoprotein (LDL): A new look. Int J Cardiol 2000;74:S17-22.
29Madamanchi NR, Vendrov A, Runge MS. Oxidative stress and vascular disease. Arterioscler Thromb Vasc Biol 2005;25:29-38.
30Dalle-Donne I, Rossi R, Colombo R, Giustarini D, Milzani A. Biomarkers of oxidative damage in human disease. Clin Chem 2006;52:601-23.
31Stadtman ER, Levine RL. Free radical-mediated oxidation of free amino acids and amino acid residues in proteins. Amino Acids 2003;25:207-18.