Introduction

Lipid profile or lipid panel, is the collective term given to estimation of, typically, total cholesterol, high density lipoprotein, low density lipoprotein, lipoprotein cholesterol, and triglycerides. This is used to identify hyperlipidaemia which may pose as recognized risk factors for cardiovascular diseases and sometimes pancreatitis.

A number of plant extracts have been effective in the remedy of diabetes. Most importantly, it has shown insulinogenic and hypoglycaemic activity. Cinnamon could have some effects in the treatment of type II diabetes mellitus and insulin resistance (khan et al., 2003). Recent studies in phytochemistry have indicated that cinnatannin B1 isolated from Cinnamomum verum bears possible therapeutic effect on type II diabetes with the exception on postmenopausal patients.

Materials and Methods

Plant

Cinnamon (C. zeylanicum) was obtained in dried form from G. Baldwin & Co., 171-173 Walworth Road, United Kingdom. Authentication was done in the Department of Botany, University of Port Harcourt, Rivers State, Nigeria.

Rats

Twenty-one (21) confirmed pedigree of wistar albino rats weighing between 130-150g  and 14-15 weeks old were obtained from the Animal Science Department, University of Nigeria, Nsukka. They were fed with pelleted feed and water ad libitum

Alloxan

The powdery alloxan, product of Sigma-Adrich, Germany,was purchased from Walmart Nigeria Limited, Surulere, Lagos State Nigeria.

Preparation of plant extract

Dried Cinnamon (100 grams) was soaked in ethanol for 24 hours and then placed in a mechanical shaker for 48 hours. Extraction was carried out by percolation several times using ethanol as solvent. The solvent was evaporated using a Rotary Evaporator which was connected to a vacuum pump. The semi-solid extract that was obtained was dried in a hot air oven.

Experimental design and rat grouping

The rats were divided into three (3) groups. The 1^st group served as control rats. The 2^nd group was the diabetic control group, while the 3^rd group was the diabetic group that the extract was administered. Diabetes was induced by subcutaneous injection of 150mg/ml of alloxan. Diabetic rats were confirmed with the aid of a glucometer (Life Scan, China) after four days of administration.

Blood Sampling

At the end of the exposure the rats were fasted overnight. Blood samples were collected via heart puncture under anaesthesia. Blood samples were left to clot and thereafter centrifuged at 3000rpm for 15minutes at room temperature. Serum samples collected were frozen until when they were needed for  biological analysis.

Sample Analysis:

Cholesterol: The principle of assay was based on hydrolysis of cholesterol esters to produce hydrogen peroxide from the oxidation of cholesterol by the enzyme cholesterol oxidase in a coupled reaction catalyzed by peroxidase. Red quinoneimine dye which absorbed maximally at 520nm was formed, and its intensity was directly proportional to the serum total cholesterol content.(Roeschlau, P. et al., 1974)

High density lipoprotein-cholesterol

HDL was determined by the quantitative precipitation of LDL, VLDL and chylomicron fractions by the addition of phototlungstic acid in the presence of Mg²⁺. HDL-cholesterol fraction was thereafter determined according to previous method.(Lopes 1977)

Low density lipoprotein-cholesterol

The values obtained using this assay method are reliable provided no chylomicrons are present in the sample, the triglyceride concentration does not exceed 400mg/dl and the sample does not show signs of any hyperlipoproteinaemia.(Friedewald, 1972)

Triglycerides

Serum triglyceride level was determined by enzymatic hydrolysis with lipases. Absorbance of the indicator quinoneimine formed from H₂O_2, 4-aminophenazone and 4-chlorophenol under catalytic influence of peroxidase was measured at546nm and the value was proportional to serum triglyceride level. (Tietz 1990)

Statistical analysis

Results of Biochemical estimations were reported as mean ± SEM and statistical analysis were performed using the students t-test of statistical significance at 95% confidence level (P≤ 0.05) (Brokes et al, 1979).  Data were also analyzed by one-way analysis of Variance (ANOVA) using SPSS/PC package and difference between means were compared using Duncan’s (1995) multiple range test. 

Results

The effect of oral administration of 200mg/ml ethanol extract of Cinnamon zeylanicum on the lipid profile of alloxan induced diabetic rats are shown:

Table 1: Influence of cinnamon zeylanicum extract on serum Total Cholesterol (mmol/l) of alloxan-induced diabetic rats. Animal group Time(days).

Control Group                     3.45±0.03^c                3.65±0.09^c                3.60±0.11^c

Diabetic Control                  7.90±0.24^a               8.02±0.24^a              7.94±0.24^a

c.zeylanicum treatment        7.67±0.24^a                5.60±0.21^b                 5.13±0.33^b

Values are expressed as mean ± SEM for 3rats/ group. Values with the same superscript letters are not statistically significant at 95% confidence level. The control group was given pelleted feed and water ad libitum. The diabetic group was given pellet feed and fed before and after diabetes has been induced while the c.zeylanicum treatment group were given the extract in addition to pelleted feed and water.

Oral administration of 200mg/ml cinnamon zeylanicum extract significantly (p<0.05) reduced cholesterol levels at the fourth day (7.67± 0.24), the eight day (5.60± 0.21), and the twelfth day (5.13± 0.33) as is shown on table 1.

Table 2: Effect of cinnamon zeylanicum extract on serum Triglyceride(mmol/l) of alloxan-induced diabetic rats.

Animal group                                                              Time(days)

Control Group                     1.10±0.06^c                1.17±0.34^c                1.30±0.06^c

Diabetic Control                  3.40±0.29^b               4.80±0.28^b                  5.32±0.38^d

c.zeylanicum treatment        2.33±0.18^a                1.27±0.18^c                1.86±0.09^a

Values are expressed as mean ± SEM for 3rats/ group. Values with the same superscript letters are not statistically significant at 95% confidence level. The control group was given pelleted feed and water ad libitum. The diabetic group was given pelleted feed and fed before and after diabetes has been induced while the c.zeylanicum treatment group were given the extract in addition food and water.

Triglyceride levels for diabetic rats which were administered cinnamon extract were (2.33± 0.18) for day 4, (1.27 ± 0.18) for day 8 and (1.86± 0.09) for day 12. This shows a decrease in triglyceride levels from day 4 to day 8 and slight increase on day 12.

Table 3: Influence of cinnamon zeylanicum extract on serum High density lipoprotein-cholesterol (mmol/l) of alloxan-induced diabetic rats.

Animal group                                                              Time(days)

Control Group                     0.30±0.06^c                0.30±0.06^c                0.40±0.06^c

Diabetic Control                  0.44±0.07^c              0.31±0.08                  0.12±0.03^d

c.zeylanicum treatment        1.43±0.32^b                0.73±0.12^b                1.13±0.15^c

Values are expressed as mean ± SEM for 3rats/ group. Values with the same superscript letters are not statistically significant at 95% confidence level. The control group was given pelleted feed and water ad libitum. The diabetic group was given pelleted feed and fed before and after diabetes has been induced while the c.zeylanicum treatment group were given the extract in addition to pelleted feed and water.

There was a decrease in high density lipoprotein-cholesterol level from the 4^th day (1.43± 0.32), to (0.73± 0.12) for the 8^th day. A slight increase was shown on the 12^th day (1.13 ± 0.15).

Table 4: Effect of  cinnamon zeylanicum extract on serum Low density lipoprotein-cholesterol(mmol/l) of alloxan-induced diabetic srats.

Animal group                                                              Time(days)

Control Group                     0.04±0.01^a                0.06±0.02^c                0.06±0.03^c

Diabetic Control                  0.66±0.07^b              0.81±0.08^b                  0.78±0.08s

c.zeylanicum treatment        0.60±0.06^b                0.58±0.40^d                0.37±0.16^c

Values are expressed as mean ± SEM for 3rats/ group. Values with the same superscript letters are not statistically significant at 95% confidence level. The control group was given normal rat food and water ad libitum. The diabetic group was given pelleted feed and fed before and after diabetes has been induced while the c.zeylanicum treatment group were given the extract in addition food and water.

The level of Low density lipoprotein(LDL) decreased from (0.60± 0.06) for the 4^th day, to (0.58± 0.40) for the 8^th and (0.37± 0.16) for 12^th day respectively. The decrease was statistically significant (p<0.05).

Discussion

The extract of cinnamom zeylanicum reduced significantly the levels of cholesterol, low-density lipoprotein and increased high density lipoprotein level. Phytochemical analysis of the leaf shows that it contains tannins, saponins, terpenoids, phenols, alkaloids and flavonoids (Ajay et al., 2009). Tanins are naturally occurring substances that fall under the category of plant polyphenols. They are believed to influence protein and lipid digestion, binding to molecules and leading to their excretion from the body. Thus intake of tannins may help those with high cholesterol in managing their blood cholesterol levels. (Yugarani 1992). A similar study using ficus racemosa shows that tannins reduces cholesterol low density lipoprotein (Velayutharu 2012). Also Saponins has hypolipidemic potential (Elekofehinti et al., 2012). Thus the extract of cinnamom zeylanicum has hypolipidemic potentials. As a result it can be used in managing hypercholesterolemia by diabetic patients.

Acknowledgments

The authors are grateful to G. Baldwin & Co. United Kingdom and the Department of Botany University of Port Harcourt Rivers State were the plant leaves were obtained and authenticated respectively.

References

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