Identification and Quantification of Flavonoids in Okra (Abelmoschus esculentus L. Moench) and Antiproliferative Activity In Vitro of Four Main Components Identified.

Okra is a kind of flavonoid-rich food which was reported to have a variety of health functions. Flavonoids are the major polyphenolic compounds in okra and are thought to play a role in reducing the risk of disease. The aim of this study was to isolate and identify the flavonoids composition in okra pods and explore the activity of the main flavonoids components identified on inhibiting tumor cell proliferation in vitro. Six individual flavonoids were identified by HPLC-MS/MS: quercetin-3-gentiobioside (Q3G), quercetin-3-sambubioside (Q3S), rutin, quercetin-7-glucoside (Q7G), isoquercitrin (ISO) and quercetin-3-malonylglucoside (Q3M), which were all separated well within 30 min. The analytical method was validated by the recovery of spiked samples and so on. Moreover, four main flavonoids components, namely Q3G, Q3S, ISO and Q3M, exhibited significant (p < 0.05) inhibition of NCI-N87, A375, A549 cells proliferation (25−100 µmol/L) and of HFLS-RA (200−300 µmol/L) in different levels, according to MTT method, respectively. It is demonstrated that the flavonoids components of okra exhibited a noteworthy development prospect as a possible nutraceutical dietary supplement.

Effect of short-term high temperature on the accumulation of glucosinolates in Brassica rapa.

Glucosinolates, an important class of secondary metabolites in cruciferous vegetables, play a crucial role in protecting plants from stress-related damage. The mechanism of glucosinolate synthesis under short-term high temperature stress has not been sufficiently studied. In this work, we investigated the changes in transcription factors, synthetic genes, and related metabolites involved in glucosinolate synthesis by pakchoi seedlings under short-term high temperature stress (40 °C for 8 h). Short-term high temperature stress inhibited the primary sulfur assimilation and the contents of methionine, cysteine and glutathione. The contents of aliphatic and indolic glucosinolates were increased by short-term high temperature stress, whereas the content of 4-methoxy-glucobrassicin increased significantly. During the stress period, the transcript level of glucosinolate related MYB transcription factors had been basically significantly up-regulated, whereas the transcript level of aliphatic and indolic glucosinolate synthetic genes were predominantly up-regulated and down-regulated respectively. In the early recovery period, primary sulfur assimilation up-regulated rapidly, and decreased during the late recovery process. The glucosinolate content and synthesis gene expression act similar to the primary sulfur assimilation, a short up-regulated in early recovery, then all go down at 40 and 48 h after short-term high temperature treatment.