Antioxidant and acetylcholinesterase-inhibitory properties of long-term stored medicinal plants

Abstract

BackgroundMedicinal plants are possible sources for future novel antioxidant compounds in food and pharmaceutical formulations. Recent attention on medicinal plants emanates from their long historical utilisation in folk medicine as well as their prophylactic properties. However, there is a dearth of scientific data on the efficacy and stability of the bioactive chemical constituents in medicinal plants after prolonged storage. This is a frequent problem in African Traditional Medicine.MethodsThe phytochemical, antioxidant and acetylcholinesterase-inhibitory properties of 21 medicinal plants were evaluated after long-term storage of 12 or 16 years using standard in vitro methods in comparison to freshly harvested materials.ResultsThe total phenolic content of Artemisia afra, Clausena anisata, Cussonia spicata, Leonotis intermedia and Spirostachys africana were significantly higher in stored compared to fresh materials. The flavonoid content were also significantly higher in stored A. afra, C. anisata, C. spicata, L. intermedia, Olea europea and Tetradenia riparia materials. With the exception of Ekebergia capensis and L. intermedia, there were no significant differences between the antioxidant activities of stored and fresh plant materials as measured in the β-carotene-linoleic acid model system. Similarly, the EC50 values based on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay were generally lower for stored than fresh material. Percentage inhibition of acetylcholinesterase was generally similar for both stored and fresh plant material. Stored plant material of Tetradenia riparia and Trichilia dregeana exhibited significantly higher AChE inhibition than the fresh material.ConclusionsThe current study presents evidence that medicinal plants can retain their biological activity after prolonged storage under dark conditions at room temperature. The high antioxidant activities of stable bioactive compounds in these medicinal plants offer interesting prospects for the identification of novel principles for application in food and pharmaceutical formulations.

HPTLC Finger-Printing and Cholinesterase Inhibitory and Metal-Chelating Capacity of Various Citrus Cultivars and Olea europaea

“…According to our literature survey, AChE inhibitory eff ects of the leaf extracts of the stored and fresh samples of O. europaea were (69.2±6.0) and (85.4±3.4) % at 1 μg/mL, respectively (30). Nevertheless, the leaf and bark extracts from O. europaea used in this study had insignifi cant eff ect on both AChE and BChE as compared to that of the reference (galanthamine).…”

Investigation of the antiobesity and antioxidant properties of wild Plumbago europaea and Plumbago auriculata from North Palestine

“…In another investigation conducted by Amoo et al [48] in South Africa, the total phenolic and flavonoid contents in P. auriculata were 15.0 mg GAE/g and 5.5 mg QUE/g, respectively. This means that wild-growing P. auriculata used in our study had much better total phenolic and flavonoid contents than South African P. auriculata [48].…”

Antioxidative Phytochemicals and Anti-Cholinesterase Activity of Native Kembayau (Canarium Odontophyllum) Fruit of Sabah, Malaysian Borneo

“…Meanwhile, anticholinesterase inhibition activity in the present study showed a strongly positive correlation with DPPH assay with an r value of 0.913. Previous work by Amoo et al [39] indicated positive relationship between antioxidant activity and AChE inhibitory properties of some selected long-term stored African medicinal plants, whilst the study by Jo et al [40] also reported positive correlation between acetylcholinesterase and antioxidant activity of seed and pericarp of Camellia sinensis L.…”