Standardization, Physicochemical, Elemental Analysis and Anti-diabetic activity of Powdered Leaves of Chromolaena odorata in Alloxan-induced diabetic Rats
Authors: Abdullahi Abdulrasheed Ajao , Aremu B. A. , Atunwa S.A. , Usman S.O. , Njinga N.S. , Attah F.A.U. , Lawal B.A 
Published: February 2020

BackgroundThe prevalence of diabetes is increasing worldwide, but more evidently in developing countries where there is higher incidence of the risk factors. Plants have offered an effective medicine for the treatment of illnesses since the dawn of mankind.The present study is aimed to standardize, determine the physicochemical parameters, element present and anti-diabetic activity of Chromolaenaodorata. Elemental analysis was done using Atomic Absorption Spectroscopy, while Alloxan-induced model was used to determine anti-diabetic activity.MethodologyThe leaves were cleaned and air dried for some days. The following macroscopic characters of the fresh leaves were noted; shape, length, colour, apex, margin, base, leaf arrangement and odour. The microscopy of the surface preparation and cross section of the fresh leaves and powdered leaves were carried out using a light Microscope connected to a standard camera.Alcohol soluble extractive was determined following the method used by Azwanida, (2015). Water soluble extractive was done on the powdered leavesThe moisture content was determined following the method used by Pimentel (2006). An evaporating dish was heated to a constant weight and allowed to cool in a desiccator. Elemental Analysis (K, Na, Mn, Mg and Ca) was carried out on the powdered leaves of Chromolaena odorata using the method of Association of Official Analytical Chemist (AOAC, 1980) with the aid of Atomic Absorption Spectrometer (AAS) GBC Avanta Model. Standards and digested samples were aspirated and the mean signal responses were recorded at each of the element respective wavelengths.The acute toxicity (LD50) test was determined following the method used by Jonsson et al. (2013) with little modification.Alloxan-induced model was used to determine the anti-diabetics activity following method by Rohilia and Ali, (2007) with slight modification.Twenty-Five Albino rats of both sexes weighing 150– 200g were used for the study.The data were expressed as mean ± standard error of mean (SEM). One-way analysis of variance (ANOVA) with Student-Newman-keuls tests was used to analyze the data and results were considered statistically significant at P < 0.05 when compared to the control.ResultsThe macroscopic evaluation reviewed a triangular shape, height of 6-10cm, pungent odour, acuminate apex, opposite leaf arrangement, dentate margin, hastate base and a green colour leaf. The microscopic study of both the fresh and powdered leaves of C. odorata showed the presence of anisocytic and anomocytic stomata, as well as multicellular uniseriate covering trichomes. The moisture content was 6.0 ±0.07%, the alcohol soluble extractive was 30±0.05%. while the water-soluble extractive was 40±0.05%. %. The elemental analysis of the powdered leaves of C. odorata showed that the leaves contains 29.00mg/L of K, 13.500mg/L of Na, 0.15mg/L of Mn, 4.78mg/L of Mg and 0.30mg/L of Ca.The powdered leaves showed a dose dependent anti-diabetic activity as 300 mg/kg significantly reduced the blood glucose level when compared to the negative control (p<0.05) on day 7, 14 and day 21. The 200 mg/kg dose showed significant reduction on day 14 and day 21 and the 100 mg/kg only on day 21.ConclusionThe presence of phytochemicals such as alkaloids, tannins, terpenoids and flavonoids, as well as elements such as Na, K, Mn and Mgin C. odorata could be responsible for an increase stimulate the production of insulin from the pancreas thus leading to reduction in the blood glucose level. The study suggest that the powdered leaves of C.odorata possess anti-diabetic activity