Hypoglycemic and Hypolipidemic Effects of Corchorus Olitorius Leaves As a Food Supplement on Rats with Alloxan-Induced Diabet
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ISSN 2409-4943. Ukr. Biochem. J., 2020, Vol. 92, N 4 UDC 616.379-008.64 doi: https://doi.org/10.15407/ubj92.04.063 HYPOGLYCEMIC AND HYPOLIPIDEMIC EFFECTS OF Corchorus olitorius LEAVES AS A FOOD SUPPLEMENT ON RATS WITH ALLOXAN-INDUCED DIABET G. N. ANYASOR, O. O. ADEKANYE, O. T. ADEYEMI, O. OSILESI D epartment of Biochemistry, Benjamin S. Carson School of Medicine, Babcock University, Ilisan-Remo, Ogun State, Nigeria; e-mail: [email protected] Received: 16 October 2019; Accepted: 15 May 2020 Corchorus olitorius is a species of shrub in the family Malvaceae known to have rich sources of chemical compounds. The leaves of this plant are locally consumed as a vegetable and as a remedy in Africa, Middle East and Southern Asia. This study was designed to evaluate the hypoglycemic and hypolipidemic effects of C. olitorius leaves sample given for 14 days as a food supplement to rats with alloxan-induced dia- betes. Twenty one male albino rats weighing 150-200 g were randomly assigned into three groups: 1 – control rats; 2 – diabetic rats; 3 – diabetic rats fed with C. olitorius leaves as supplement. Phytochemical analysis of C. olitorius leaves ethanolic extract revealed the presence of alkaloids, anthraquinone, cardiac glycosides, saponins, tannins, phenols, phlobatannins and flavonoids. Diabetic rats fed with C. olitorius leaves as a supplement were shown to have significantly (P < 0.01) decreased plasma glucose, LDL-cholesterol, total cholesterol and triglycerides levels when compared with untreated diabetic rats. The findings from this study indicated that C. olitorius leaf possesses hypoglycemic and hypolipidemic properties. K e y w o r d s: Corchorus olitorius, alloxan-induced diabetes, hypoglycemic and hypolipidemic effects, cho- lesterol, triglycerides. Corchorus olitorius L. is a vegetable plant of Diabetes mellitus is characterized by a hyper- the Family of Malvaceae, formerly called Tiliaceae, glycemic condition induced by insulin insensitivity which is commonly known as “Jews mallow”. It or inappropriate production of insulin by the beta is a tall, annual plant that thrives in any soil-type. cells of Islet of Langerhans found in the pancreas [5]. The jute fiber from Corchorus is the most widely Chronic diabetes have been shown to compromise cultivated vegetable fiber after cotton [1, 2]. The the integrity of organ architecture with an eventual leaves of C. olitorius have been a staple Egyptian loss of cellular function. Several synthetic drugs vegetable which is also used as cuisines in Africa, including sulfonylurea are been used clinically to Southern Asia, and Middle East. It has a mucilagi- manage the onset of diabetes, however, these drugs nous texture when cooked. The seeds are used as a are often associated with adverse effects to the body flavoring agent while the dried leaves are used for system [6], hence the need for an alternative source preparation of herbal tea [3]. In Nigerian cuisine, es- of treatment with minimal adverse effects. Data exist pecially amongst the South-Westerners, C. olitorius in literature on the care of diabetes using various leaves are commonly used as vegetable in prepara- extracted medicinal plant products. However , tion of stew based diet known as ‘ewedu’. In Sierra consuming plant material as food for therapeutic Leone it is known as krain krain (or crain crain) and purposes may play an important role in providing is cooked as stew. In the Philippines, C. olitorius is adequate health benefits to diabetic patients. Thus, known as “saluyot” and it is consumed as a leafy this study was designed to investigate the hypogly- vegetable together with bamboo shoots [3, 4]. cemic and hypolipidemic effects of compounded © 2020 Nduka A. G. et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 63 ISSN 2409-4943. Ukr. Biochem. J., 2020, Vol. 92, N 4 C. olitorius leave as food supplement fed to alloxan- Moisture content. The empty petri dish was induced diabetic rats. dried in the oven and cooled in a desiccator. The weight of the empty dish was recorded and 5 g of Materials and Methods the fresh leaf samples were weighed into the dish. Sample collection and identification The leaves were dried in a hot air-oven for 2 h at Fresh leaves of C. olitorious were procured 100 °C after which it was removed and allowed to from Awolowo market, Shagamu, Ogun State, Nige- cool in a desiccator for 30 min. The cooled dish to- ria. It was identified by Professor Edward B. Esan, a gether with its contents was weighed. The dish was plant scientist in the Department of Biosciences and returned into the oven and dried for another 30 min Biotechnology, Babcock University. after which it was cooled and weighed again. The Phytochemical evaluation. Ethanolic extract of process was repeated until a constant final weight C. olitorius leaf was screened for the presence of fla- was recorded and the moisture content was calcu- vonoid, saponin and tannins using method described lated as described below. Weight of empty dish = W1, by Trease and Evans [7], Harbone [8] and Sofowora Weight of dish + sample before drying = W2, Weight [9]. of dish + sample after drying = W3, Weight of sam- Plant extraction procedure. The plant extract ple only before drying = W2 – W1 = WA, Weight of used for phytochemical screening was obtained by sample only after drying = W3 – W1 = WB, Moisture soaking 100 g of the dry, pulverized plant sample in Content = WA – WB. 600 ml of 50% ethanol for 72 h after which it was % Moisture content = . filtered and the filtrate got was concentrated using the rotary evaporator (Buchi Rotavapor RE; Swit- Ash content. A clean, dry and empty crucible zerland) at 40 °C. The concentrate was gently evapo- was weighed. Dried leaf sample (2 g) was weighed rated over a water bath in order to obtain an ethanol- into the crucible. The crucible was put into the muf- free concentrate. This concentrate was used for the fle furnace and the leaves were incinerated at 600 °C phytochemical analysis. for 5 h. Thereafter, the furnace was allowed to cool Test for flavonoids. One millilitre of water was and the crucibles were brought out using safety added to 0.5 g of the sample and was subsequently tongs. The crucibles were cooled in a desiccator and filtered. Afterwards, 5 ml of dilute ammonia fol- the weight of the crucible and the ash inside was de- lowed by 1 ml of concentrated sulphuric acid was termined. The ash content was calculated as follows. added to the filtrate. A yellow colouration was taken Weight of the empty crucible = W1, Weight of the as an evidence for the presence of flavonoids. crucible and sample = W , Weight of sample only = Test for saponins. Extract (0.5 g) was shaken 2 W2 – W1, Weight of crucible and ash = W3, Weight of with 5 ml of water in a test tube. Frothing which per- ash only = W – W . sists on warming was taken as preliminary evidence 3 1 for the presence of saponin. % Ash Content = . Test tannins. About 0.5 g of pulverized sample was stirred with 1 ml of distilled water and filtered. Crude fat content. The crude fat content of the The 5 drops of 1% ferric chloride was added to the sample was determined using a Soxhlet extractor. filtrate. A blue-black, green or blue-green precipitate Two grams of the sample was weighed into a was taken as evidence for the presence of tannins. muslin cloth and the cloth was tied up. The cloth The Corchorus sample was screened qualitatively was then placed into the extracting chamber of Sox- for the presence of phytochemicals. The screening hlet extractor. A dried and empty boiling flask was was carried out using the ethanolic extracts of the weighed. Petroleum ether (400 ml) was put into the plants. boiling flask and placed into a heating mantle. The whole Soxhlet apparatus was set up and left to run Proximate analysis for 3-4 h until the colour of the solvent in the ex- The proximate moisture, carbohydrate, crude traction chamber of the Soxhlet extractor was clear. ash and fat content were determined following the Afterwards, the solvent in the flask was evaporated standard methods as described by Association of Of- leaving behind the fat. The weight of the flask con- ficial Analytical Chemist (AOAC) [10]. taining the fat was then determined and the crude fat 64 G. N. Anyasor, O. O. Adekanye, O. T. Adeyemi, O. Osilesi content calculated as shown below. Weight of sample % Crude Protein = % Nitrogen × 6.25, = W , Weight of the empty flask = W , Weight of the 1 2 where VS – volume of acid required to titrate the flask and fat = W , Weight of fat only = W – W . 3 3 2 sample (ml), VB – volume of the acid required to ti- trate the blank (ml), CA – concentration of the acid % crude fat = . (mol/dm3). Crude fibre content. Two grams of dried, defat- Carbohydrate determination. Carbohydrate ted sample was weighed. The sample was then boiled content was determined by subtracting the sum of in 200 ml of 1.25% sulphuric acid for 30 min then percentage moisture, ash, fat, fibre and protein con- filtered and rinsed with water in order to remove tent from 100% as shown below: the acid. The residue was then boiled in 200 ml of % carbohydrate = 100 – (% fibre + % moisture 1.25% sodium hydroxide for another 30 min, filtered + % protein + % fat + % ash). and rinsed with water to remove the alkali. The fi- Experimental feed preparation nal residue was then dried, weighed and ashed in the The experimental feed for this study was pre- muffle furnace at 600 °C for 4 h.