The purpose of this study was to investigate the contents of apigenin and luteolin in vegetables mainly distributed and consumed in Korea. In this study, the contents of apigenin, apigenin-7-O-glucoside, luteolin, and luteolin-7-O-glucoside in vegetables were surveyed by using liquid chromatography coupled to mass spectrometry (LC-MS/MS). According to the analysis of 27 items (91 samples) in vegetables, the content of total apigenin (the sum of apigenin and apigenin-7-O-glucoside) was quantified in 8 out of the 27 items in vegetables, followed by pepper leaves, parsley, celery, chamnamul, foremost mugwort, and perilla leaves. The content of total luteolin (the sum of luteolin and luteolin-7-O-glucoside) was found in 11 of the 27 items in vegetables, followed by pepper leaves, dandelion, celery, red lettuce, foremost mugwort, and perilla leaves. Celery was divided into stalks and leaves for comparing the contents of apigenin and luteolin. Celery showed higher contents of apigenin and luteolin in leaves than in stalks.

Oral squamous cell carcinoma (OSCC) is the most common type of oral malignancy. Numerous therapies have been proposed for its cure. Research is continually being conducted to develop new forms of treatment as current therapies are associated with numerous side-effects. Luteolin, a common dietary flavonoid, has been demonstrated to possess strong anti-cancer activity against various human cancer cell lines. Nevertheless, research into luteolin-based anticancer activity against oral cancer remains scarce. Thus, the objective of this study was to assess the effect of luteolin as an anti-cancer agent. After treatment with luteolin, Ca9-22 and CAL-27 oral cancer cells showed condensed nuclei and enhanced apoptotic rate with evidence of mitochondria-mediated apoptosis. Epithelial-mesenchymal transition (EMT) is closely related to tumor migration and invasion. Luteolin suppressed cancer cell invasion and migration in the current study. Elevated expression of E-cadherin, an adherens junction protein, was evident in both cell lines after luteolin treatment. Luteolin also significantly inhibited transcription factors (i.e., N-cadherin, Slug, Snail, Twist, and ZEB-1) that regulated expression of tumor suppressors such as E-cadherin based on Western blot analysis and quantitative PCR. Thus, luteolin could induce mitochondrial apoptosis and inhibit cancer cell invasion and migration by suppressing EMT-induced transcription factors.

Flavonoids have a range of biological activities, including anti-allergic, anti-inflammatory, anti-microbial, and anti-cancer activities, as demonstrated by in vitro studies. In this study, we investigated whether luteolin can be applied to suppression of lipopolysaccharide (LPS)-stimulated inflammatory responses in murine macrophages. Luteolin was found to reduce nitric oxide (NO) production in LPS-stimulated Raw 264.7 cells. In addition, expression of inducible nitric oxide synthetase (iNOS), cyclooxygenase-2 (COX-2), and pro-inflammatory cytokine tumor necrotic factor-α (TNF-α) at the mRNA and protein levels were decreased. These inhibitory effects were found to be caused by the blockade of nuclear factor kappa-light- chain-enhancer of activated B cells (NF-κB) activation and phosphorylation of mitogen-activated protein (MAP) kinase family, extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 MAP kinase. In addition, pre-treatment with luteolin resulted in reduced ganglioside expression levels and inhibited expression of GT1b in Raw 264.7 cells. On the basis of these observations, we suggest that luteolin has potential as an anti-inflammatory drug candidate, and ganglioside GT1b may play a role in the inflammatory process.

Luteolin is a flavonoid that exists in a glycosylated form in celery and green pepper. Flavonoids possess antioxidant and anti-inflammatory properties and can reduce the expression of key inflammatory molecules in macrophages and monocytes. It has been reported also that some flavonoids have effects on bone metabolism. The effects of luteolin on the function of osteoblasts were investigated by measuring cell viability, alkaline phosphatase activity, type I collagen production, osteoprotegerin secretion, Wnt promoter activity, BMP-2 and Runx2 expression and calcified nodule formation. Luteolin has no effects upon osteoblast viability but induced an increase in alkaline phosphatase activity, type I collagen production and a decrease in osteoprotegerin secretion in these cells. Luteolin treatment also upregulated BMP-2 mRNA expression. These results suggest that luteolin may be a regulatory molecule that facilitates the differentiation of osteoblasts.

The content of luteolin in the different parts of Lithospermum erythrorhizon was determined by high performance liquid chromatography (HPLC). Luteolin was quantified by a reverse-phase column with gradient solvent program (water : ACN = 90 : 10 to 77 : 23 for 60 min). UV detection was conducted at 330 nm. The content of luteolin was measured in the seeds (0.28 mg/g), stems (0.30 mg/g), and roots (0.16 mg/g) of L. erythrorhizon. The presence of luteolin in Lithospermum species is important in agricultural crop production for increasing the amounts of clinically available medicine and health supplements.

This studies was carried out to assess antioxidant activity between flavonoid compounds (rutin, qurcetin, luteolin) and maysin(2''-O-6-C-(6-deoxy-xylo-hexose-4ulosyl)luteolin) isolated from corn silks of Zea mays L. Maysin extracted by corn silks was the highest free radical scavenging among flavonoid compounds such as rutin, qurcetin, and luteolin. But, the other flavonoid compounds(luteolin) showed the strongest free radical scanverning activity. In the results of peroxidase activity(POD), maysin don't indicated the remarkable peroxidase inhibiton activities. At the lowest concentration, NBT(Nitro blue tetrazolium) reduction activity of rutin, qurcetin, and luteolin were the low inhibition activities but maysin showed the highest Nitro blue tetrazolium reduction activity. Lipid peroxidase inhibition activities using Thiobarbituric acid(TBA) method, maysin showed the highest lipid peroxidase inhibition in three concentration levels..

The influenza neuraminidase (E.C. 3.2.1.18) is an antiviral target of high pharmaceutical interest because of its essential role in cleaving sialic acid residues from surface glycoproteins and facilitating release of virions from infected cell. In this context, polyphenolic compounds including luteolin, rosmarinic acid, and apigenin from Perilla frutescens were evaluated for their inhibitory effect on recombinant virus H1N1 neuraminidase. Among the test compounds, luteolin and rosmarinic acid inhibited the rvH1N1 neuraminidase with an IC50 of 8.4 and 46.7 μM, respectively. The inhibition kinetics analyzed by Dixon plots indicates that luteolin and rosmarinic acid are noncompetitive inhibitor and inhibition constant, Ki, were established as 14.3 and 43.9 μM, respectively. Subsequently, we also analyzed the rosmarinic acid and luteolin contents of 383 accessions of perilla seed germplasms by high performance liquid chromatography (HPLC). The rosmarinic acid and luteolin contents of perilla seeds were ranged from 15.7 μg/g to 2,894.9 μg/g and from 1.6 μg/g to 949.1 μg/g, respectively.

The perilla [Perilla frutescens (L.)], which belongs to the family Lamiaceae, have been used as a not only important traditional source of oil but also used traditional herbal medicine for treating various disease including depression, anxiety, tumor, cough, bacterial and fungal infections, allergy, detoxication and some intestinal disorders in east asian countries. In this context, luteolin isolated from the P. frutescens inhibited the linoleic acid peroxidation catalyzed by soybean lipoxygenase-1 (EC 1.13.11.12, Type 1) with an IC50 of 5.0 μM. To investigate the inhibitory effect of luteolin on dioxygenase enzyme, we assayed soybean lipoxygenase-1 activity with the inhibitor. Soybean lipoxygenase-1 showed time-dependent inhibition in the presence of luteolin. Increasing luteolin concentrations led to the decrease in both the initial velocity (vi) and the steady-state rate (vs) in the progress curve. Thus luteolin showed a simple reversible noncompetitive slow-binding inhibition against soybean lipoxygenase-1 with kinetic parameter (k3 = 0.056 μM-1min-1, k4,= 0.006 μM-1min-1, Ki app = 0.106 μM).

Perilla frutescens, which belonging to the Labiatae family, is widely cultivated oil crop and have been used traditional herbal medicine in East Asia such as Korea, China, and Japan. Especially, the leaves and the seeds of this species are important in Korean traditional cooking, as one of the popular garnish and food colorants. Numerous studies have revealed that the beneficial health effects of perilla are due to its several phytochemicals contents, such as rosmarinic acid, caffeic acid, luteolin, and apigenin. For this reason, increasing the content of phytochemicals in perilla hasbecome a major breeding objective. The genetic diversity of the rosmarinic acid, caffeic acid, luteolin, and apigenin content in perilla seed is poorly documented. We analyzed the rosmarinic acid, caffeic acid, luteolin, and apigenin content of 203 accessions of perilla germplasm by high performance liquid chromatography (HPLC). The rosmarinic acid and luteolin contents ofgermplasms were ranged from 15.7 μg/g to 2717.1 μg/g and from 1.6 μg/g to 582.4 μg/g respectively.