INTRODUCTION:

Mimosa pudica L. is common plant in moist waste ground belongs to family – Mimosaceae. It mainly contains tannins, steroids, triterpenes, alkaloids, glycosides, flavonoids, c-glycoside, flavones (Adikari, 2003).The extract of Mimosa pudica is used in the treatment of migraine, insomnia, headache, diarrhea, dysentery, fistula, piles, and fever (Rajendran, 2010).The decoction of M. pudica antagonized chemically induced seizures in mice. It significantly protected the mice in PTZ-induced seizures. Plant is also used as a blood purifier (Ghani, 1998). In Ayurvedic and Unani system of medicine, this plant has been used in diseases arising from corrupted blood and bile, heart disorders, bilious fever, piles, jaundice, leprosy, ulcers and small pox.

Hyperlipidemia contributes significantly in the manifestation and development of atherosclerosis and coronary heart diseases (CHD). Atherosclerosis, are the most common cause of mortality and morbidity worldwide. Although several factors, such as diet high in saturated fats and cholesterol, age, family history, hypertension and life style play a significant role in causing heart failure (Blackwelder, 1977).

The high levels of cholesterol particularly TC, TG and LDL cholesterol is mainly responsible for the onset of CHDs. A 20% reduction of blood cholesterol level can decrease about 31% of CHD incidence, and 33% of its mortality rate. The known lipid lowering drugs, such as fibrates, statins and bile acid sequestrants have many side effects in patients (Chattopadhyaya,1996). Thus, there is a considerable interest on development of lipid lowering drugs from natural products in the recent years.

As Mimosa pudica plant species have been traditionally claimed for the treatment of atherosclerosis; hence, in the present study, an attempt has been made to screen the herbal extract that is ethanol extract of Mimosa pudica leaves, for the hypolipidemic activity to prove its claim in folklore practice.

MATERIALS AND METHODS:

Collection of plant materials:

Mimosa pudica whole plants materials were collected from the fields of Thiruvarur in Tamilnadu.

Preparation of plant extract:

Mimosa pudica whole plants were dried at 40ºC for 7 days. Powdered using electric grinder’s server and stored in a container. This fine cured powder was used as herbal drug. Weighed amount of dried powdered of Mimosa pudica whole plant were taken and added 50 ml of 99.9% hot ethanol mixture and evaporated at 55ºC by using hot air oven, the collected were for hypolipidemic activity studies.

Preliminary Phytochemical analysis:

The ethanol extract of M.pudica was subjected to preliminary phytochemical analysis to assess the presence of various phytoconstituents; it revealed the presence of flavonoids, alkaloids and glycosides (Harborne,1984).

Healthy young male albino rats (130-150 gm) were purchased from animal house of St, Joseph arts and science college, Tirchy. The groups of rats were kept separately individual stainless steel hoppers. The test animals should be characterized by strain, source, sex, weight and age. The animals were kept individually for feeding in conventional laboratory diets with an unlimited supply of drinking water.

Diagnostics kits:

Diagnostics kits used for the estimation of lipid profile (Totalcholesterol, triglycerides, HDL, VLDL, LDL) were obtained from Eumic laboratory, Trichy.

Hyperlipidemic inducer:

Butter was used as the hyperlipidemic inducer in animal procured from Trichy.400mg of butter/Kg b.wt dissolved in 10ml of buffered saline was used for the induction of hypolipidemic rats.

Experimental Design:

Group I was considered as control which received 0.5% sodium carboxy methyl cellulose; Group II was considered as high fat diet group and received the butter diet; Group III was considered as test group and received the test extract that is ethanol extract of Mimosa pudica at the dose of 100 mg/ Kg body weight per oral along with the high fat diet and Group IV was considered as standard group which received the standard drug Lovastatin (dose of 75 mg/kg body weight per oral) along with the high fat diet.

Sample Collection:

At the end of 21^st day, blood serum was withdrawn from the retro orbital plexus after overnight fasting for the study of biochemical parameters. Serum was estimated for the total cholesterol, triglycerides, LDL, VLDL and HDL cholesterol.

Statistical Analysis:

Results were presented as mean ± SD. The significance of difference among the groups were assessed using one way analysis of variance (ANOVA) followed by Dunken’s Multiple Reliance test using SPSS software.P≤0.05 was considered significant.

RESULTS:

The preliminary phytochemical screening revealed the presence of phytoconstituents such as glycosides, alkaloids, flavonoids, tannins, saponins and phenolic compound in the ethanol extract of Mimosa pudica linn. (Table I)

Table 1: Phytochemical screening of ethanol extract of Mimosa pudica

S. No	Test	Constituents of Mimosa pudica
1.	Alkaloids	+
2.	Carbohydrates	-
3.	Saponins	+
4.	Tannins	+
5.	Terpenoids	-
6.	Flavanoids	+
7.	Phenol	+

+ indicates presence; - indicates absence

Hypolipidemic activity:

A marked increase in the level of serum cholesterol, triglycerides, LDL and VLDL were found in the animals which received high fat diet and HDL levels were decreased. Administrations of ethanol extract at the dose of 100 mg/kg showed significant reduction in the level of serum cholesterol, triglyceride, LDL, VLDL and increase in HDL level which was similar to the standard Lovastatin, and are almost near the levels of normal control.

A significant percentage reduction of serum cholesterol, triglyceride, LDL, VLDL and percentage increase in HDL in test extract was also comparable with the standard drug. A potent hypolipidemic effect of ethanol extract was evident by a significant reduction in the level of serum cholesterol, LDL, VLDL and triglycerides in the cholesterol treated animals and also marked increase in the HDL Cholesterol level (Table.2).

Table 2: Effect of Mimosa pudica on biochemical parameters

S. No

Groups

Total Cholestrol

(mg/dl)

Triglyceride

(mg/dl)

HDL

(mg/dl)

LDL

(mg/dl)

VLDL

(mg/dl)

Group I

(control)

148± 1.58

112.0±51.58

61.0 ±1.58

88± .42

22 ±1.47

Group II

(Butter Induced)

232.40±40.48

361.0± 1.58

38.0 ±1.58

161±1.69

72.15±1.58

Group III

(plant extract)

192.90±1.58

***

195.0± 1.58

***

42± 1.58

106±1.78

33.0±1.58

Group IV

(standard Lovastatin)

***

149.20± 1.92

***

164.52±1.58

***

37.58±1.31

***

123± .58

***

39 ±1.53

Values are expressed as mean ± SEM. Levels of significance- Group II compared with Group I,III and IV. **p≤0.01 and ***p≤0.001.

DISCUSSION:

Hyperlipidemia continues to be a health major problem in India and other developing countries, which lead to important risk factors like atherosclerosis, stroke etc. Hyperlipidemia evokes the damages in various tissue, which in turn, deregulates the cellular functions leading to damage to various pathological conditions (Chander et al.,2003).

The present studies were performed to assess the hypolipidemic activity and to prove its claim in folklore practice against various disorders. Probucol, a hypolipidemic drug is a potent lipophilic antioxidant and the ability to inhibit atherosclerosis has been attributed to its antioxidant properties (Balakrishnan et al., 2006). Probucol lowers the level of cholesterol in the bloodstream by increasing the rate of LDL catabolism. Additionally, probucol may inhibit cholesterol synthesis and delay cholesterol absorption. Probucol is a powerful antioxidant, which inhibits the oxidation of cholesterol in LDLs, this slows the formation of foam cells, which contribute to atherosclerotic plaques. Similarly, flavonoids present in the plant Mimosa pudica may be responsible for its hypolipidemic action and as already reported significant antioxidant activity of chloroform extract further confirms its significant hypolipidemic activity .

Cholesterol is synthesized in all animal tissue. It’s important relates to its role in the stabilization of membrane structures because of its rigid planar structure.It also as a precursor for the synthesis of steroid hormones . Increased amount of cholesterol leads to cardiovascular disease particularly coronary heart disease (CHD) (Aparna et al., 2003).

The plasma cholesterol was reduced remarkably on treating the HFD mice with ethanol extract of Mimosa pudica Linn.The lipid lowering effects may be due to the presence of plant sterol. Plant sterol reduces the absorption of cholesterol and thus increases the fecal excretion of steroids that results in decrease of body lipids

Reduction 1% cholesterol produces a 2% to 3% reduction in coronary heart disease risk (Ornish et al., 1985).

Triglycerides are mainly stored in the adipose tissue (Ahire,2005). The plasma lipoproteins are major sources of fatty acid to synthesis triacylglycerols. The excess of fat diet increased the TG level which is one of the causes of hardening of arteries (XU et al., 2005).

HDL is known as the good cholesterol it has reversed the transport function. It carries cholesterol away from the including the coronary categories and drops it off at the liver (Ginsberg and Annapurna,2004).

HDL is directly anti- androgenic and it is belived to remove cholesterol from the developing lesions (Sonnerberg et al., 1993).

LDL is a risk factor and plays a role at several steps of atherosclerosis (Witzum, 1994; Alexander, 1995). A decrease in oxidative stress and protection of LDL from oxidation might therefore be a strategy with great promise for prevention of atherosclerosis associated cardiovascular disease (Steinbreg and Gotto, 1999). The intense interest in this area stems in part from the generally low toxicity of antioxidants and the hope that treatment with antioxidants might be additive with cholesterol lowering regimes.

VLDL particles are smaller than the chylomicrons and also are rich triglycerides though to a lesser extent VLDL particles sizes vary widely ,with a concomitant variation of the chemical composition ;the larger particles are rich in triglycerides and in apo-c and the smaller particles depleted of TG andsurface materials result from the hydrolysis of VLDL by lipoprotein lipase activity. VLDL is the main carrier if triglycerides and it is less harmful than but still can damage the arterial lining .

VLDL production is directly related to the body fat (Kesavalu et al., 2001).Severe elevation in the VLDL cholesterol lead to hypercholesterolemia Triglycerides are mainly stored in the adipose tissue .The plasma lipoproteins are major sources of fatty acid to synthesis triacylglycerols. The excess of fat diet increased the TG level which is one of the causes of hardening of arteries (XU et al., 2005).

CONCLUSION:

In accordance with these results it may be confirmed that due to the presence of phytoconstituents such as flavonoids, alkaloids and glycosides in the ethanol extract, it could be responsible for the observed significant hypolipidemic activity. In conclusion, it can be said that the ethanol extract of Mimosa pudica exhibited a significant hypolipidemic activity.

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Received on 03.10.2011 Accepted on 21.10.2011

Asian J. Res. Pharm. Sci. 1(4): Oct.-Dec. 2011; Page 123-126