Phytochemical Study and Evaluation of the Antiradical Activity of Extracts of Oleaginous Seeds of Panda oleosa and Isolona hexaloba from Gabon

Our study focused on phytochemical tests and evaluation of the anti-free radical activity of seed extracts of two oleaginous plants from Gabon used in traditional medicine or as condiments: Panda oleosa and Isolona hexaloba. The extraction was carried out by maceration with solvents of increasing polarity: cyclohexane, trichloroethylene, acetone, ethanol and finally distilled water. The total yields of the extracts are about 69.50% for Panda oleosa and 34.28% for Isolona hexaloba. The phytochemical tests carried out on the extracts of the seeds of Panda and Isolona highlight in both seeds the presence of alkaloids, polyphenols, triterpenes, carotenoids, reducing compounds, flavonoids, total sugars, coumarins, anthraquinones, free quinones, free anthracene derivatives, and terpenoids. Isolona seeds also contain leucoanthocyanins, sterols, cardiac glycosides and saponins. Phytochemical tests revealed the absence of tannins and mucilage in both seeds. The free radical scavenging activity was measured by scavenging the free radical cation of 2,2’-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid] (ABTS-+) with gallic acid as the reference antioxidant. The results of the free radical scavenging activity of the aqueous and ethanolic extracts of both seeds showed that the aqueous extracts were more active than the ethanolic extracts. The IC50s of the aqueous and ethanolic extracts of Panda seeds are 40 and 60 μg·mL-1 respectively, and those of the aqueous and ethanolic extracts of Isolona are 37.5 and 95 μg·mL-1 respectively. Gallic acid, the reference antioxidant (IC50 = 0.37 μg·mL-1) is about 10 times more active than the aqueous extracts of both seeds, 16 times more active than the ethanolic extract of Panda and 25 times more active than the ethanolic extract of Isolena.

Phytochemical Analysis and Antioxidant Activity of Crocus speciosus Leaves

The numerous studies indicate leaves of plants are a rich source of bioactive compounds that can be a valuable source of compounds used in the pharmaceutical and cosmetic industries.Aim of this study was to investigate the chemical composition and the antioxidant property of Crocus speciosus leaves.Primary phytochemical screening of C.speciosus leaves revealed the presence of some following compound categories such as phenolic compounds,aminoacids,saponins,proteins,tannins,triterpenoids,glycosides,polysaccharides.The total flavonoids and phenolic compounds content were determined spectrophotometrically and by HPLC-DAD and HPLC-MS.Antiradical activity was determined by ABTS radical-cation scavenging method,spectrophotometrically.The total amount of flavonoids in C.speciosus leaves was 1.07±0.02 mg RE/g(p<0.05),the total amount of phenolic compounds was 0.41±0.01 mg GAE/g(p<0.05).By HPLC-DAD-MS analysis the presence of the mangiferin,chlorogenic acid,isoorientin,kaempferol,hyperoside,and isoquercitin was established for the first time in Crocus leaves.The antiradical activity of C.speciosus leaves extracts was 150.08±4.5μmol/g(p<0.05)and its was mainly attributed to phenolic compounds content.The high amounts of flavonoids and antiradical activity in C.speciosus leaves suggests promising phytochemical and pharmacological study of this Crocus species.

Chemical Characterization and Anti-Radical Activity of Fruits and Vegetables Commonly Consumed in Brazzaville

The objective of this study was to analyze ten (10) species of edible vegetables and nine (9) fruit commonly found in Congo (Brazzaville) in order to determine their total polyphenol content (TPC) and total flavonoid content (TFC), and their antiradical activity by the method of 1,1-diphenyl-2-picrylhydrazyl (DPPH). The results obtained showed that the highest TPC and TFC were found, on the one hand, in the extracts of four species of vegetables, i.e. Ipomoea batatas L. (536.02 ± 0.01 mg of GAE/100 g DW;486.46 ± 0.10 mg of QtE/100 g DW), Cucurbita pepo (533.60 ± 0.05 mg of GAE/100 g DW;303.72 ± 0 mg of QtE/100 g DW), Hibiscus sabdariffa (421.02 ± 0.015 mg of GAE/100 g DW;243.49 ± 0.10 mg of QtE/100 g DW), Solanum negrum 1 (412.10 ± 0.05 mg of GAE/100 g DW;292.10 ± 0.14 mg of QtE/100 g of DW) and, on the other hand, in the extracts of two species of fruit, i.e. Chrysophyllum lacourtianum (532.79 ± 0.19 mg of GAE/100 g of DW;380.55 ± 0.10 mg of QtE/100 g of DW) and seeds of Aframomum alboviolaceum (469.38 ± 0.28 mg of GAE/100 g DW;107.27 ± 0.10 mg of QtE/100 g DW). The lowest TPC and TFC were obtained with the extracts of Brassica campestris and of Spinacia oleracea, respectively 97.78 ± 0.17 GAE mg/100 g DW and 27.52 ± 0.10 QtE mg/100 g DW. The extract of the Saba senegalensis pulp had the lowest TPC and TFC. In addition, the highest antiradical activity was observed with extracts from vegetables and fruit with high TPC and TFC. The results indicate that these vegetables and fruit could be potential sources of the phenolic compounds and the biomolecules having several biological activities. Thus, their consumption might be an alternative in the prevention of chronic diseases.