Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Dec 15, 2016; 7(20): 605-614
Published online Dec 15, 2016. doi: 10.4239/wjd.v7.i20.605
Evaluation of extraction protocols for anti-diabetic phytochemical substances from medicinal plants
Stanley Irobekhian Reuben Okoduwa, Ismaila A Umar, Dorcas B James, Hajara M Inuwa, James D Habila
Stanley Irobekhian Reuben Okoduwa, Directorate of Research and Development, Nigerian Institute of Leather and Science Technology, Zaria 810004, Nigeria
Stanley Irobekhian Reuben Okoduwa, Ismaila A Umar, Dorcas B James, Hajara M Inuwa, Department of Biochemistry, Ahmadu Bello University, Zaria 811104, Nigeria
James D Habila, Department of Chemistry, Ahmadu Bello University, Zaria 811104, Nigeria
Author contributions: Okoduwa SIR and Umar IA got the concept and design of the study; Okoduwa SIR and Habila JD perform the study and data analysis; James DB, Inuwa HM and Habila JD participated in the interpretation of data; Okoduwa SIR wrote the first version of the manuscript; Umar IA, James DB, Inuwa HM and Habila JD critically revised the manuscript for important intellectual content; all the authors read and gave a final approval of the revised version of the manuscript to be published.
Institutional review board statement: Ethics of the study involving the use of animals were reviewed and approved by Institutional Animal Care and Use Committee of the Ahmadu Bello University and the Research Ethics Committee of Nigerian Institute of Leather and Science Technology, Zaria-Nigeria where the research was conducted.
Institutional animal care and use committee statement: The experimental protocol was review and approved by the Research Ethics Committee of the Institute. All experimental protocol was in conformity with the Institutional guidelines that are in compliance with National and International Laws and Guidelines for Care and Use of Laboratory Animals in Biomedical Research.
Conflict-of-interest statement: The authors declare no conflict of interest related to this study and publication.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Stanley Irobekhian Reuben Okoduwa, Researcher, Directorate of Research and Development, Nigerian Institute of Leather and Science Technology, P.M.B. 1034, Zaria 810004, Nigeria. siroplc@gmail.com
Telephone: +234-909-9640143
Received: June 28, 2016
Peer-review started: July 1, 2016
First decision: September 5, 2016
Revised: September 16, 2016
Accepted: October 17, 2016
Article in press: October 18, 2016
Published online: December 15, 2016
Processing time: 163 Days and 14.3 Hours
Abstract
AIM

To examine the efficacy of three extraction techniques: Soxhlet-extraction (SE), cold-maceration (CM) and microwave-assisted-extraction (MAE) using 80% methanol as solvent.

METHODS

The study was performed on each of 50 g of Vernonia amygdalina (VA) and Occimum gratissimum (OG) leaves respectively. The percentage yield, duration of extraction, volume of solvent used, qualitative and quantitative phytoconstituents present was compared. The biological activities (hypoglycemic effect) were investigated using albino wistar rat model of diabetes mellitus (n = 36) with a combined dose (1:1) of the two plants leaf extracts (250 mg/kg b.w.) from the three methods. The extracts were administered orally, once daily for 21 d.

RESULTS

In this report, the percentage VA extract yield from MAE was highest (20.9% ± 1.05%) within 39 min using 250 mL of solvent, when compared to the CM (14.35% ± 0.28%) within 4320 min using 900 mL of solvent and SE (15.75% ± 0.71%) within 265 min using 500 mL of solvent. The percentage differences in OG extract yield between: MAE vs SE was 41.05%; MAE vs CM was 46.81% and SE vs CM was 9.77%. The qualitative chemical analysis of the two plants showed no difference in the various phytoconstituents tested, but differs quantitatively in the amount of the individual phytoconstituents, as MAE had significantly high yield (P > 0.05) on phenolics, saponins and tannins. SE technique gave significantly high yield (P > 0.05) on alkaloid, while CM gave significant high yield on flavonoids. The extracts from CM exhibited a significantly (P > 0.05) better hypoglycemic activity within the first 14-d of treatment (43.3% ± 3.62%) when compared to MAE (36.5% ± 0.08%) and SE methods (33.3% ± 1.60%). However, the percentage hypoglycemic activity, 21 d post-treatment with 250 mg/kg b.w. extract from MAE was 72.6% ± 1.03% and it was more comparable to 10 mg/kg b.w. glibenclamide treated group (75.0% ± 0.73%), unlike the SE (69.5% ± 0.71%) and CM (69.1% ± 1.03%).

CONCLUSION

CM technique produces extract with better hypoglycemic activity, whereas; MAE is a better option for high yield of phytoconstituents using less solvent within a short time.

Keywords: Extraction techniques; Microwave-assisted-extraction; Maceration; Phytoconstituents; Medicinal plants; Soxhlet; Anti-diabetes

Core tip: Extraction of active phytoconstituents from medicinal plants rely mostly on the use of appropriate extraction method. Different extraction techniques affect the yield and biological activity of phytocomponents. In this study, we observed that microwave assisted extraction produces significantly higher overall extract yield as well as in phenolic, saponin and tannin content. Cold maceration and soxhlet extraction produced higher flavonoid and alkaloid yield respectively. Maceration extracts exhibited significantly better hypoglycemic activities in diabetic rats compared to extracts from soxhlet and microwave assisted extraction. This study reveals that the choice of extraction protocol should depend primarily on the purpose of interest.