Abstract
Context: During the last few decades, the prevalence of obesity in the western world has dramatically increased with epidemic proportions. Hand in hand with this statistic, the incidences of obesity-linked diseases such as diabetes are increasing with pandemic rate. The search for novel drugs and nutritional intervention approaches for obesity is now of significant importance.
Objective: The anti-obesity potential of eriodictyol (ERD) and its close structural analogue, sigmoidin A (SGN), were evaluated. SGN was isolated from Erythrina abyssinica Lam. ex DC. (Fabaceae).
Materials and methods: Concentrations between 300 and 0.1 µM of test samples and reference drugs made in three-fold dilutions were tested for enzyme inhibitory effects. The major obesity target, pancreatic lipase, was used to test the anti-obesity potential while the selective effects of the compounds were determined through assessments of effects on α-glucosidase.
Results: The inhibitory effect of SGN on pancreatic lipase (IC50, 4.5 ± 0.87 µM) was 30-times greater than that of ERD (IC50, 134 ± 19.39 µM) while their effect on α-glucosidase enzyme was comparable (IC50 value of 62.5 ± 9.47 and 57.5 ± 13.15 µM). The anti-obesity drug, orlistat, inhibited pancreatic lipase with an IC50 value of 0.3 ± 0.04 µM, while the anti-diabetic drug, acarbose, inhibited α-glucosidase with an IC50 value of 190.6 ± 16.05 µM.
Discussion: Although less active than the standard anti-obesity drug, orlistat, the observed activity indicated that prenylation of the flavonoid skeleton potently enhances anti-lipase activity.
Conclusion: Such groups of flavonoids need to be further investigated for their therapeutic and nutritional benefit in combating obesity problems.
Acknowledgement
The author wishes to thank Professor Ermias Dagne for the kind gift of sigmoidin A.
Declaration of interest
The author declares that there is no conflict of interest.