Comparative assessment of antioxidant and antiglycation properties of Leucas species

Abstract BACKGROUND: The genus Leucas is an aromatic plant and belongs to the Lamiaceae family. They are rich in secondary metabolites. The benefits of Leucas in curing many ailments such as coughs, colds, diarrhea, diabetes, inflammation, and skin diseases have made it an Ayurvedic component. Hence, the present study aims to evaluate the phytochemical, antioxidant, and antiglycation properties of methanol and aqueous extract from three Leucas species, viz , Leucas aspera Link, Leucas zeylanica (L.) W.T.Aiton, and Leucas longifolia Benth. METHODS: Dry powders of the whole part of three species of Leucas were extracted with methanol and aqueous solution. Qualitative analysis of secondary metabolites such as flavonoids, phenolics, alkaloids, glycosides, terpenoids, and tannins was performed by using standard phytochemical procedures. Total phenol, flavonoid, and alkaloid contents were estimated by spectrophotometric methods. The superoxide radical scavenging activity, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, hydrogen peroxide radical scavenging activity, and ferric-reducing power methods are in vitro models. Bovine serum albumin glycation assay was used to evaluate the in vitro antiglycation activity of extracts. RESULTS: The highest percentage of extraction yield was observed in the methanolic extract of all Leucas species compared to the aqueous extract. The preliminary phytochemical tests reveal the presence of various bioactive secondary metabolites such as phenols, flavonoids, alkaloids, steroids, terpenoids, and glycosides. These extracts show that L. aspera has high DPPH activity, superoxide radical scavenging activity, hydrogen peroxide radical scavenging activity, and ferric-reducing antioxidant power compared to L. zeylanica and L. longifolia . The methanolic and aqueous extract of L. aspera exhibited more significant inhibitory (96.70 ± 1.78 and 90.33 ± 1.65%) effects on advanced glycation end products formation in bovine serum albumin glycation systems compared to standard aminoguanidine (99.45 ± 1.37%) than L. zeylanica and L. longifolia. The methanol extract of L. aspera is rich in phenols, flavonoids, and alkaloids and has strong antiglycation and antioxidant properties. CONCLUSION: The strong antiglycation and antioxidant activity of all three Leucas species suggests its possible role in combating diseases associated with diabetic complications and oxidative stress.