Microscopic Characteristics, Chromatographic Profiles and Inhibition of Peroxidase Activity of the Leaves of <i>Manihot esculenta</i>and <i>Manihot glaziovii</i>, 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.

Cellular Antioxidant Activity and Peroxidase Inhibition of Infusions from Different Aerial Parts of <i>Cassia occidentalis</i>

Cassia occidentalis L. is widely used in the world in traditional medicine and especially in some African countries for the treatment of various diseases. The aim of this study was to report the microscopic features, the chromatographic fingerprints and the cellular antioxidant activity and the peroxidase inhibition of infusions from different parts of this plant. Microscopically, leaf can be characterized by cells of the spongy mesophyll and parenchyma numerous cluster crystals of calcium oxalate, paracytic stomata, isolated calcium oxalate cluster crystals, covering and glandular trichomes, scalariform vessels, polyedric starch granules, lignified fibers;flowers by abundant covering and glandular trichomes, spirally thickened vessels and associated parenchyma, abundant pollen grains. Seeds were characterized by pluricellular non-glandular trichomes, epidermis of the testa with underlying oil cells, parenchymatous layers of the testa, thicker-walled cells of the endosperm, pollen grain. Phytochemical analysis revealed the presence of phenolic acids, flavonoids, iridoids, tannins and terpenes. TLC fingerprints of different parts were different and characteristic. They showed the presence of glycosylated flavonoids and phenolic acids as main phytochemicals for flowers, leaves and seedpods. ABTS and DPPH assays showed that infusion extracts have the ability to scavenge free radicals connected with their IC50 values ranging from 21.43 ± 1.25 to 566.24 ± 176.7 mg·mL-1. All extracts showed a weaker capacity to scavenge DPPH radical. Aqueous extracts displayed high cellular antioxidant activity at the concentrations range of 1 - 20 μg·mL-1 using LO-12 on monocytes HL 60. Flower and leave extracts showed more efficient effects on extracellular ROS production. Phenolic compounds could be major contributors to antioxidant activity of infusions of Cassia parts. In MPO (Myeloperoxidase) direct technique, all infusion extracts exhibited a dose-dependent inhibitory effect on MPO activity in the range concentrations of 1 to 20 μg·mL-1 with the leaves and flowers the most active. Obtained results support the potential therapeutic interest of all aerial parts of Cassia and could justify their use in traditional medicine and local nutraceutical resources.