Pattern Recognition and Chemometrics for Qualitative Pharmacological Indication of Moringa Oleifera Lam. Leaves Commercial Products

Abstract

Background: Moringa oleifera Lam leaves are known for their nutritional, pharmacological, and related biological 3 characteristics across the Globe. Its commercial products are marketed across Pretoria, South Africa. The label claims portray 4 such products contain Moringa oleifera leaves powder, extracts, or compounds inherent in the plant, and that pharmacological 5 activities of such products are intrinsically linked to them. Methods: We investigated (n = 29) commercial products using affordable, spectrophotometric UVvis, high performance thin layer chromatography (HPTLC), high performance liquid chromatography finger printing and chemometrics principal component analysis. The aim of the investigation was to recognize the phytochemical patterns similarity between the plant extracts and commercial products, to ascertain which product contains quercetin-3-O-glycoside or kaempferol-3-O-glycoside marker compounds known to be present in M. oleifera leaves that should mitigate the pharmacological properties of the products. Results: The pattern of quercetin-3-O-glycoside and kaempferol-3-O-glycoside standards conform to a peak in the ethanol extract to suggest that both compounds are present in the ethanol but not in the dichloromethane extract. The HPTLC analysis also indicated the presence of the quercetin and kaempferol glycosides in the ethanol extract at Rf of 0.18 and 0.28 respectively. As for the commercial products, only n = 3 of the 29 (≈10%) revealed patterns that were like that of the ethanol extracts. A principal component analysis with R2 = 0.97 for the DCM extract and 0.89 for the ethanol extract highlighted that commercial products P1, P7 and P24 as indicating good quality. The good quality commercial products clustered together with the quercetin-3-O-glycoside, kaempferol-3-O-glycoside, ethanol, or dichloromethane extracts while the poor-quality products were placed in a separate cluster in the PCA analysis conducted. Conclusion: This implies that only these three products will exhibit expected pharmacological and other biological activities displayed on the product labels. Keywords: Pattern recognition, Moringa oleifera leaves, Commercial products, Quality indication