A comparison of the antioxidant activity with the Total Phenolic and Total Flavonoid Contents of the leaves and stem-bark of Anogeissus leiocarpa (DC.) Guill& Pirr. (Combretaceae)

Background: Anogeissus leiocarpa is used in traditional medical practice for the treatment of many diseases such as asthma, malaria, diabetic ulcers, dysentery,  blood clots, cough, tuberculosis, parasitic infections and general body pain. Free radicals are known to play a major role in the aetiology of several these diseases. Thus, radical scavenging as well as antioxidant potentials of the plant are good indications of its effectiveness in disease management.Objective: This study evaluates the antioxidant activity of the extracts from the leaves and stem bark of Anogeissus leiocarpa..Materials and Methods: Dried powdered leaves and bark were extracted with  methanol. The extracts were subjected to DPPH Free Radical Scavenging Activity, Ferric Reducing Antioxidant Power (FRAP), Total Antioxidant Capacity (TAC), ABTS Cation Decolourization, Cupric Reducing Antioxidant Capacity (CUPRAC), and Metal Chelating (MC) assays. The Total Phenolic Content (TPC), Total Flavonoid Content (TFC), total anthocyanidin Content (tAC), and proanthocyanidin Content (pAC) were also determined.Results: The extract and ethyl acetate fraction of the stem bark had more  antioxidant potential. The stem bark extract had an IC50 of 12.44+2.32 in the  DPPH radical scavenging assay, the ferric reducing antioxidant power of 98.43+1.63 and ABTS radical decolourisation activity of 96.55+0.54 while the DPPH radical scavenging activity and the ABTS radical decolourisation effect for ascorbic acid and trolox were 39.25+ 1.11 and 379.24 + 0.08 respectively. The Total Antioxidant Capacity as well as the Total Phenolic Content and Total Flavonoid Content was highest in the ethyl acetate fraction of the bark.Conclusion: The extract of A. leiocarpa showed good antioxidant activity which  compares well with the high phenolic content and thus have potential for use in the management of several diseases.Keywords: Anogeissus leiocarpa. Antioxidant, Radical Scavenging, Total Phenolic, Total Flavonoi

Anticholinesterase and Antioxidant Activities of Spilanthes filicaulis Whole Plant Extracts for the Management of Alzheimer’s Disease

Background: Spilanthes filicaulis is a tropical herb implicated as a memory enhancer in ethnomedicine. Objective: The study investigated acetyl/butyryl cholinesterase inhibitory and antioxidant activities of different extracts of S. filicaulis whole plant and correlated them to its phytochemical constituents. Methods: The powdered whole plant was successively extracted with n-hexane, ethyl acetate and methanol. Acetyl cholinesterase (AChE) and Butyryl cholinesterase (BuChE) inhibitory activity were evaluated by Ellman colorimetry assay. Antioxidant activity was tested using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric reducing power and nitric oxide scavenging assays. Total phenolic, flavonoid and tannin were estimated using standard methods. Correlation was determined using Quest Graph™ Regression Calculator. Results: Various extracts exhibited concentration-dependent AChE and BuChE inhibitory activity with ethyl acetate extract being the highest with IC50 of 0.77 μg/mL and 0.92 μg/mL for AChE and BuChE respectively. The ethyl acetate extract also showed the highest reducing power when compared with the other extracts. The methanol extract had slightly higher phenolic and flavonoid content and showed the highest DPPH radical scavenging effect. DPPH scavenging, AChE and BuChE inhibition had high correlation with the total flavonoid content with R2 values of 1.00, 0.800 and 0.992 respectively while nitric oxide scavenging had high correlation with phenolics and tannins with R2 = 0.942 and 0.806 respectively. Conclusion: These results show that the extracts of the whole plant of S. filicaulis possess significant AChE/BuChE inhibitory and antioxidant properties, mostly due to its flavonoid content, suggesting the possible use of the plant in neurodegenerative diseases such as AD

Anticholinesterase activities of methanol extract and partitioned fractions of Acanthospermum hispidum DC

Age related memory loss is a common occurrence in traditional medical practice and several medicinal plants have been used over the years for managing it. Acanthospermum hispidum DC (Asteraceae) is a medicinal plant that has been included in traditional preparations used in the management of memory loss. In clinical practice however, anticholinesterases have remained relevant in managing memory and cognition dysfunction associated both with old age and certain neurodegenerative diseases. In vitro anticholinesterase activity of extracts and fractions of A. hispidum was done using Ellman’s colorimetric and TLC bioautography assay with eserine as control. The ethyl acetate fraction of A. hispidum showed highest inhibition to acetylcholinesterase and butyrylcholinesterase (91.11% and 64.31%, respectively) in a concentration-dependent manner. A. hispidum presents a good prospect in the development of cholinesterase inhibitors for the management of memory-related disorders.Keywords: Acanthospermum hispidum, Anticholinesterase, acetylcholinesterase, butyrylcholinesteras