Introduction: Sclerocarya birrea stem-bark is widely used for the treatment of many medical conditions. Advanced glycation end-products (AGEs) are implicated in the pathogenesis of vascular complications of diabetes mellitus. The study, other than phytochemical composition, evaluated the anti-glycation and AGEs-protein cross-link breaking effects of S. birrea stem-bark extracts. Methods: Different S. birrea extracts and aminoguanidine (used as control) were incubated with bovine serum albumin (BSA) and glucose/fructose at 37oC for 40 days. Amounts of fluorescent AGEs (FAGEs) and immunogenic AGEs formed were determined. Anti-glycation activity percentage of each extract and aminoguanidine was calculated. Their AGEs-protein cross-link breaking abilities were also assessed. Standard techniques were employed for phytochemical screening. Volatile compounds were identified by means of gas chromatography mass spectrometry (GC-MS). Results: S. birrea stem-bark n-hexane extract was statistically more effective than aminoguanidine against the formation of total immunogenic AGEs (P<0.05). For FAGEs, ethyl acetate, methanol, and water extracts exerted significantly higher anti-glycation effects than aminoguanidine (P<0.001). Methanol extract exhibited the highest anti-glycation effect with an average IC50 value of 0.142 mg/mL against FAGEs. All extracts were effective in releasing BSA from the preformed collagen-AGEs-BSA cross-links. GC-MS enabled the identification of many biologically important compounds, including campesterol, stigmasterol, and 1-heptatricontanol. Conclusion: S. birrea stem-bark has a potential for usage in the management of complications in uncontrolled glucose metabolism.

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Study and comparing the anti-glycation and cross-link breaking effects of Moringa oleifera leaf, seed and root extracts with aminoguanidine, a known inhibitor of advanced glycation end-products (AGEs). Their phytochemical composition and extraction yields were also assessed. All seed and root extracts demonstrated significantly higher anti-glycation effect than aminoguanidine against total immunogenic AGEs (p < 0.05). Both seed and root polar (methanol and water) extracts exhibited significantly higher anti-glycation effect against N′-(carboxymethyl)lysine than aminoguanidine (p < 0.05). Polar extracts of all M. oleifera tested parts demonstrated higher anti-glycation activity against fluorescent AGEs than aminoguanidine (p < 0.05). With exception to the aqueous root extracts, all leaf, seed and root extracts of M. oleifera demonstrated an ability to break AGE-protein cross-links. The highest cross-link breaking effect was exhibited by ethyl acetate extract of leaves.The methanol extract of seeds of M. oleifera showed the presence of all tested secondary metabolites.

One of the strategies proposed for combating advanced glycation end‐products (AGEs) and its devastating effects is the breaking of preformed AGEs‐protein cross‐links. AGEs are linked to the pathogenesis of late onset complications of diabetes mellitus, age‐related and neurodegenerative diseases. This study evaluated the AGEs‐protein cross‐link breaking effect of some medicinal plants used for managing diabetes mellitus. These plants, selected based on their blood glucose lowering property, include Sclerocarya birrea, Psidium guajava, Murraya koenigiiand Cinnamon cassia. Of the selected plants, the highest AGEs‐protein cross‐link breaking effect was observed with the hexane and ethyl acetate leaf extracts of Psidium guajava.Methanol extracts of both Psidium guajava leaf and Sclerocarya birrea stem‐bark also showed high cross‐link breaking effect. Chemical screening tests for the presence of phytochemicals and Gas Chromatography Mass Spectrometry (GC‐MS) analysis for the detection and identification of the phytoconstituents in the extracts were also carried out. Compounds detected in the hexane leaf extract of Psidium guajava, using GC‐MS, include I‐(+)‐Ascorbic acid 2,6‐dihexadecanoate, Octadecanoic acid (Stearic acid), Vitamin E (D‐alpha‐tocopherol), Alpha‐Tocopherol‐beta‐D‐mannoside and 2,6,10,14,18,22‐Tetracosahexaene, 2,6,10,15,19,23‐hexamethyl‐, (all‐E) (Squalene). The hexane leaf extract of Psidium guajava was subjected to column chromatography. Using Nuclear Magnetic Resonance and Infra‐red spectroscopy, the isolated compound from the hexane leaf extract of Psidium guajava was identified as a flavonoid. The results of the study indicate that present in these extracts are potent agents with the ability to break AGEs‐protein cross‐links which could be exploited for drug discovery.