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.

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.

Chemical Fingerprint and Anti-Sickling Activity of Rosmarinic Acid and Methanolic Extracts from Three Species of Ocimum from DR Congo

The aim of this study was to characterize the polyphenolic composition by determination of chemical fingerprints of Methanolic extracts of Ocimum canum Sims, Ocimum basilicum L. and Ocimum gratissimum L. from Democratic Republic of Congo and to compare their antisickling activity of that of rosmarinic acid, the major compound to those of methanolic extracts. Phytochemical analysis performed by TLC and HPLC analysis, showed that rosmarinic acid is the most abundant phenolic acid in these Ocimum species according to the following order O. basilicum L., O. gratissimum L. and O. canum Sims. Methanolic extracts of these three species and pure rosmarinic acid showed significant antisickling activities with minimal concentration of normalization values of 0.18 ± 0.03, 0.23 ± 0.04, 0.26 ± 0.04 and 0.31 ± 0.05 mg/mL for rosmarinic acid, O. basilicum L., O. gratissimum L. and O. canum Sims methanolic extracts respectively. The antisickling activity order is the same as that of the rosmarinic acid content, indicating that this polyphenolic acid would be among the main active molecules in these extracts.

Microscopic Features, Antioxidant and Antibacterial Capacities of Plants of the Congolese Cosmetopoeia, Raw Materials of Cosmeceuticals

Cosmeceuticals are the fastest growing products in the cosmetics field and represent a hybrid between cosmetics and drugs. The main benefits reported for cosmeceutical herbal extracts, used in skin care, include antioxidant and antimicrobial activities and the tyrosinase inhibiting effect. The aim of this study was to evaluate the antioxidant and antibacterial activities of extracts from Chromolaena odorata, Mitracarpus villosus, Senna alata, Tetradenia riparia, Cannabis sativa and Pterocarpus soyauxii used traditionally in the management of skin and skin annexes pathologies;additionally to determine their microscopical characteristics and their chromatographic fingerprints. Microscopic analyses showed the specific botanical microscopic characters for each plant that constitute the database useful for the identification and authentication of these botanicals. To the best of our knowledge, our work is the first to describe the microscopic histological characters of studied plants except for Cannabis sativa. The results of the TLC chromatographic analysis revealed the richness in phenolic compounds, terpenes in all extracts and Pterocarpus soyauxii contained coumarins. All extracts displayed high ABTS and DPPH radical-scavenging activities connected with their IC50 values at the concentration range of 1 - 125 μg/mL with Cannabis sativa and Pterocarpus soyauxii as the most active. All plant extracts exhibited antibacterial activity on Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus to varying degrees. Cannabis sativa exhibited strong effect on Staphylococcus aureus and Escherichia coli. Chromolaena odorata and Tetradenia riparia showed a marked effect on Escherichia coli. Although certain crude extracts from studied botanicals have been shown to be inactive, fractionation studies are needed to determine the active fractions. Obtained biological activities could be related to phytochemicals present in the organic extracts like phenolic compounds and terpenoids. The antioxidant and antibacterial activities of the studied species may have potential therapeutic interest and could justify their use in traditional medicine and local cosmeceutical resources, but further studies are needed, especially in vivo studies, to demonstrate the benefit of these extracts on skin and skin appendages care.