Phenylpropanoids from red kohlrabi sprouts inhibits nitric oxide production in RAW 264.7 macrophage cells

Biological Investigation and Chemical Study of Brassica villosa subsp. drepanensis (Brassicaeae) Leaves

Brassica villosa subsp. drepanensis (Caruel) Raimondo & Mazzola, belonging to the Brassica oleracea complex, is a wild edible plant endemic to western Sicily and a relative of modern cultivated Brassica crops. In this study, the antioxidant properties, anti-inflammatory activities, enzymatic inhibition, and cytotoxicity in cancer cells of B. villosa subsp. drepanensis leaf ethanolic extract were analysed for the first time. In addition, its chemical profile was investigated partitioning the total 70% ethanol extract among ethyl acetate, n-butanol, and water to obtain three residues that were subjected to chromatographic separation. Two flavonol glycosides, a phenol glucoside, two amino acids, and purine/pyrimidine bases were obtained. The presence of the glucosinolate glucoiberin was detected in the water extract by UHPLC-MS analysis. The total polyphenol and flavonoid content of the 70% ethanol extract showed good antioxidant capacities and anti-inflammatory properties by reducing nitric oxide release and reactive oxygen species levels and increasing glutathione in lipopolysaccharide-stimulated RAW 264.7 cells. The extract inhibited the enzymatic activity of α-amylase, α-glucosidase, and, significantly, of lipase. The MTT assay showed that the extract did not affect the viability of normal HFF-1 and RAW 264.7 cells. Among the cancer cell lines tested, an antiproliferative action was only observed in CaCo-2. The cytotoxicity of the extract was further confirmed by LDH release assay and by the destabilization of the oxidative balance. Results confirmed the antioxidant properties of the crude extract responsible for the anti-inflammatory effect on healthy cells and cytotoxicity in cancer cells.

The Impact of Kohlrabi Sprouts on Various Thyroid Parameters in Iodine Deficiency- and Sulfadimethoxine-Induced Hypothyroid Rats

Brassica sprouts, as the rich source of dietary glucosinolates, may have a negative effect on thyroid function. In this study, kohlrabi sprouts diet, combined with two models of rat hypothyroidism, was tested. TSH, thyroid hormones and histopathology analysis were completed with the evaluation of immunological, biochemical, haematological parameters, cytosolic glutathione peroxidase, thioredoxin reductase in the thyroid, and plasma glutathione peroxidase. A thermographic analysis was also adapted to confirm thyroid dysfunction. The levels of TSH, fT3 and fT4, antioxidant enzyme (GPX) as well as histopathology parameters remained unchanged following kohlrabi sprouts ingestion, only TR activity significantly increased in response to the sprouts. In hypothyroid animals, sprouts diet did not prevent thyroid damage. In comparison with the rats with iodine deficiency, kohlrabi sprouts diet decreased TNF-α level. Neither addition of the sprouts to the diet, nor sulfadimethoxine and iodine deficiency, caused negative changes in red blood cell parameters, glucose and uric acid concentrations, or kidney function. However, such a dietary intervention resulted in reduced WBC levels, and adversely interfered with liver function in rats, most likely due to a higher dietary intake of glucosinolates. Moreover, the possible impact of the breed of the rats on the evaluated parameters was indicated.

Pharmacological and therapeutic applications of Sinapic acid-an updated review

Phenolic compounds, present in plants, are considered to be indispensable parts of human dietary sources. Sinapic acid, is a natural herbal compound containing phenolic acid. It is found in oranges, grapefruits, and cranberries and in herbs like canola, mustard seed and rapeseed. Sinapic acid is chemically studied as a cinnamic acid derivative that contains 3, 5-dimethoxyl and 4-hydroxyl substitutions in the phenyl group of cinnamic acid. Sinapic acid has been pharmacologically evaluated for its potent antioxidant, anti-inflammatory, anti-cancer, hepatoprotective, cardioprotective, renoprotective, neuroprotective, anti-diabetic, anxiolytic and anti-bacterial activities. In this review we have summarized the potential pharmacological and therapeutic effects of Sinapic acid in various models.

Health Promoting vs Anti-nutritive Aspects of Kohlrabi Sprouts, a Promising Candidate for Novel Functional Food

Kohlrabi sprouts are just gaining popularity as the new example of functional food. The study was focused on the influence of germination time and light conditions on glucosinolates, phenolic acids, flavonoids, and fatty acids content in kohlrabi sprouts, in comparison to the bulbs. The effect of kohlrabi products on SW480, HepG2 and BJ cells was also determined. The length of sprouting time and light availability significantly influenced the concentrations of the phenolic compounds. Significant differences in progoitrin concentrations were observed between the sprouts harvested in light and in the darkness, with significantly lower content for darkness conditions. Erucic acid was the dominant fatty acid found in sprouts (14.5-34.5%). Sprouts and bulbs were less toxic to normal than to cancer cells. The sprouts stimulated necrosis (56.4%) more than apoptosis (34.1%) in SW480 cells, while the latter effect was predominant for the bulbs. Both sprouts and bulbs caused rather necrosis (45.5 and 63.9%) than apoptosis (32 and 32.5%) in HepG2 cells.

Methyl 3,4,5-trimethoxycinnamate suppresses inflammation in RAW264.7 macrophages and blocks macrophage-adipocyte interaction

Methyl 3,4,5-trimethoxycinnamate (MTC) is a bioactive natural phenylpropanoid. We evaluated anti-inflammatory effects of synthetic MTC in RAW264.7 macrophages and RAW264.7–3T3-L1 adipocytes co-culture. Levels of cytokines and chemokines, as well as NO and PGE₂ in cell supernatants were analysed using ELISAs, Griess assay and enzyme immunoassays, respectively. In-cell cytoblot was used to assess levels of proteins; while DNA binding and reporter gene assays were used to measure transcription factor DNA binding and transcriptional activities, respectively. Glucose uptake in adipocytes was evaluated with 2‐deoxy‐2‐[(7‐nitro‐2, 1, 3‐benzoxadiazol‐4‐yl) amino]‐d‐glucose uptake. MTC (5–20 µM) suppressed LPS + IFNγ-induced release of TNFα, IL-6 and IL-1β, as well as NO/iNOS and PGE₂/COX-2 levels in RAW264.7 cells. Furthermore, there was a reduction in phospho-IκB and phospho-p65 proteins, accompanied by a reduction in total IκB in RAW264.7 cells. Further studies showed that MTC also produced a reduction in NF-κB DNA binding and luciferase activity. Treatment of RAW264.7 cells with MTC (5–20 µM) resulted in enhanced DNA binding of Nrf2 and an increase in ARE-luciferase activity. In a macrophage–adipocyte co-culture, the compound reduced the release of TNFα, IL-6, IL-1β, MCP-1 and RANTES, while enhancing glucose uptake and activation of AMPKα. Our results suggest that MTC produced anti-inflammatory and antioxidant activities in macrophages. MTC also prevented inflammation in macrophage–adipocyte co-culture. The effect of MTC on glucose uptake in adipocytes is proposed to be linked to activation of AMPK.

Potential in vitro anti-allergic, anti-inflammatory and cytotoxic activities of ethanolic extract of Baliospermum montanum root, its major components and a validated HPLC method

Background

The root of Baliospermum montanum has been used as an ingredient of traditional Thai medicines for the treatments of several diseases including itching eczema, muscle and joint inflammation, and cancer. Few studies have been done on phytochemical components of this root. In this study, we isolated major compounds of the crude ethanolic extract of B. montanum root and developed and validated a high performance liquid chromatographic (HPLC) method for the determination of its major components. We then investigated anti-allergic, anti-inflammatory and cytotoxic activities of the extract.

Methods

The aims of this study were to investigate in vitro activities including inhibitory effect of β-hexosaminidase released from RBL-2H3 cells, inhibition of nitric oxide (NO) production from RAW 264.7 cells and cytotoxic activity against cancerous liver cell lines (HepG2 and KKU M156) by using sulforhodamine B (SRB) assay. Isolation of major components was conducted by using column chromatographic method. Isolated major compounds were analyzed by using high performance liquid chromatography (HPLC).

Results

The crude extract exhibited the highest cytotoxic activity, with IC₅₀ less than 1 μg/mL, while its anti-allergy and anti-inflammation were also potent with IC₅₀ less than 6 μg/mL. Three propiophenones isolated from B. montanum root exhibited moderate cytotoxic activities (IC₅₀ > 20 μg/mL). Two of the propiophenones found were major components that can be detected by HPLC. The developed and validated HPLC method showed good accuracy, precision, and linearity.

Conclusion

The results of this study suggested that ethanolic extract of of B.montanum root can be a potential source of anti-allergy, anti-inflammation, and anti-cancer compounds. The isolated compounds can serve as markers when B. montanum is used in herbal remedies but not as overall responsive markers. The HPLC method developed may be useful for quality control in the production of the extract and for further formulation developments. However, investigation of several associated biological activities is necessary before the development can proceed further. Minor active compounds should be isolated and a more sensitive analytical method should be developed to detail the key responsive components of the ethanolic extract of B. montanum root.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2449-0) contains supplementary material, which is available to authorized users.