Microscopic Characteristics, Chromatographic Profiles and Inhibition of Peroxidase Activity of the Leaves of Manihot esculenta and Manihot glaziovii , Consumed as Traditional Vegetables

Methanolic extracts from the leaves of Manihot esculenta (Two cultivars) and Manihot glaziovii, consumed as traditional vegetables in DR. Congo was chemically characterized by Thin layer Chromatography and High Performance Liquid Chromatography. In vitro biochemical activities of extracts against Radical Oxidative Species (ROS) production were assessed in cellular models, on enzymes, Myeloperoxidase (MPO) and Horseradish Peroxidase (HRP) involved in inflammation. The microscopic analysis of the powder of leaves showed that each species displays specific and discriminating botanical microscopic features. Varieties of M. esculenta had a chemical fingerprint different from M. glaziovii. The majority of compounds were polyphenols, represented mainly by rutin, kaempferol-3-O-rutinoside, amentoflavone, phenolic acids such as gallic acid. All extracts exhibited high cellular antioxidant activity in the range of 0.1 to 10 μg·mL-1 using lucigenin with neutrophils, but a moderate cellular antioxidant activity ranging between 10 and 100 μg·mL-1 with DCFDA on HL60 monocytes. Extracts from Manihot leaves showed a pronounced inhibitory effect on the production of extracellular ROS, on HRP and myeloperoxidase activity. Cellular antioxidant activities, the inhibitory effect on HRP of extracts from M. glaziovii, M. esculenta cultivar Mwambu were significantly higher, but their inhibitory effect on the activity of MPO was lower than those of M. esculenta cultivar TEM 419. The biological activities of Manihot esculenta and Manihot glaziovii were well correlated to their phytochemicals that could justify their traditional use as vegetables, potential functional foods or nutraceutical resources and medicines.