Variation in Phenolic Compounds and Antioxidant Activity of Various Organs of African Cabbage (Cleome gynandra L.) Accessions at Different Growth Stages

Abstract

The presence of nutritional and health-benefiting compounds has increased awareness of orphan leafy vegetables such as Cleome gynandra (CG), whose phytochemicals vary among accessions and organs during growth. This study investigated the polyphenol accumulation and antioxidant activities (AOA) of eight CG accessions from the vegetative stage to the seed set stage. Plants were separated into leaves and stem (LS), flowers, and silique organs, and extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC), rutin and astragalin content, and AOA using 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). There were significant interaction effects of growth stages and accessions that contributed to changes in compounds content and AOA. TPC accumulated in plant generative parts, whereas flavonoids accumulated in young plant organs. HPLC profiling revealed that rutin was the most abundant compound in all organs, with flowers having the highest levels, while astragalin was only found in flowers. Silique extracts, particularly accession KF-14, recorded the highest TPC, which corresponded to the strongest radical scavenging activity in ABTS and DPPH assays and a strong linear correlation. The germplasm contained accessions with significantly different and varying levels of bioactive compounds and AOA. These findings potentiate the exploitation of CG organs such as siliques for AOA, flowers for rutin and astragalin, and young shoots for flavonoids. Moreover, the significant accumulation of the compounds in particular accessions of the germplasms suggest that such superior accessions may be useful candidates in genetic breeding programs to improve CG vegetable.

Hieracium waldsteinii (Asteraceae) and Onosma stellulata (Boraginaceae) as a Source of Antioxidant and Antimicrobial Agents

“…In general, there are some limitations for spectrophotometrical assays. Also, some data in literature suggest that TFC are mainly concentrated in the green parts of young plant as well as in the fully mature flowers leading to the higher values for TFC compared to TPC [26] . The results for soluble sugars and starch, given in Table 1 confirmed the highest amount for flower of H. waldsteinii (165.6 mg/g of glucose) thereby, supporting the highest content for total phenolics observed for this plant part.…”

“…Also, some data in literature suggest that TFC are mainly concentrated in the green parts of young plant as well as in the fully mature flowers leading to the higher values for TFC compared to TPC. [26] The results for soluble sugars and starch, given in Table 1 confirmed the highest amount for flower of H. waldsteinii (165.6 mg/g of glucose) thereby, supporting the highest content for total phenolics observed for this plant part. Namely, it is possible that sugars significantly contributed to the Folin-Ciocalteu reaction, making the results for the flower of H. waldsteinii the highest.…”

Volatile Compounds and Total Phenolic Content of Perilla frutescens at Microgreens and Mature Stages

“…Instead, the increase in TPC values in Perilla leaves during plant growth could be explained considering that the plants, after the microgreens stage, come out of a protected growth phase into a transplanted greenhouse environment with natural cycles of light and temperature, and periodical irrigation; therefore, leaves of mature Perilla plants are somehow "hardened" in comparison to microgreens. Thus, the increase in TPCs is related to a different developmental stage and different growth conditions as for example recently demonstrated by other authors for Amaranthus caudatus [30] or for African Cabbage [31].…”

Antioxidant Activity and Anti-Nutritional Factors of Selected Wild Edible Plants Collected from Northeastern Ethiopia

“…The overall phenolic content of the studied WEPs is lower than that of African Cabbage ( Cleome gynandra ) [ 23 ], lower than Amaranthus caudatus grain (257 mg GAE/100 g) in Ethiopia [ 24 ] and lower than the total phenolic contents of Chinese wild Passiflora foetida [ 25 ]. The higher phenolic substance in WEPs has been illustrated to be valuable in the avoidance of various chronic diseases [ 26 ].…”