Category Archives: blood sugar regulation

Blueberin

Cancer: Colon, prostate, cervical., breast

Action: Anti-inflammatory, blood sugar regulation

Blueberin is isolated from Vaccinium arctostaphylos (L.).

Colon Cancer

Research has shown that diets rich in phenolic compounds such as those associated with blueberries such as blueberin may be associated with lower risks of several chronic diseases including cancer.

To probe this effect, the bioactivities of various components of blueberries were investigated and their potential anti-proliferation and apoptosis induction effects were investigated using two colon cancer cell lines, HT-29 and Caco-2. Polyphenols in three blueberry cultivars, Briteblue, Tifblue, and Powderblue, were extracted and freeze-dried. The extracts were further separated into phenolic acids, tannins, flavonols, and anthocyanins using an HLB cartridge and LH20 column. The phenolic acid fraction showed relatively lower bioactivities with 50% inhibition at 1000 µg/mL. The greatest anti-proliferation effect among all four fractions was from the anthocyanin fractions. Both HT-29 and Caco-2 cell growth was significantly inhibited by >50% by the anthocyanin fractions at concentrations of 15−50 µg/mL. Anthocyanin fractions also resulted in 2−7 times increase in DNA fragmentation, indicating the induction of apoptosis. The effective dosage levels are close to the reported range of anthocyanin concentrations in rat plasma. These findings suggest that blueberry intake may reduce colon cancer risk (Yi, 2005).

Prostate Cancer; AR+, AR-

The role of polyphenol fractions from both wild and cultivated blueberry fruit was probed in the inhibitory effects on the proliferation of LNCaP, an androgen-sensitive prostate cancer cell line, and DU145, a more aggressive androgen insensitive prostate cancer cell line. When 20µg/ml of a wild blueberry polyphenol fraction was added to LNCaP media, growth was inhibited to 11% of control with an IC50 of 13.3µg/ml. Two similar polyphenol-rich fractions from cultivated blueberries at the same concentration inhibited LNCaP growth to 57% and 26% of control with an IC50 of 22.7 and 5.8µg/ml, respectively. Differences in cell growth inhibition of LNCaP and DU145 cell lines by blueberry fractions rich in polyphenols indicate that blueberry proanthocyanidins have an effect primarily on androgen-dependent growth of prostate cancer cells. Possible molecular mechanisms for growth inhibition are reviewed (Schmidt, 2006).

Prostate Cancer

The mechanism(s) by which three flavonoid-enriched fractions from lowbush blueberry (Vaccinium angustifolium) down-regulate matrix metalloproteinase (MMP) activity in DU145 human prostate cancer cells were investigated. Regulation of MMPs is crucial to regulate extracellular matrix (ECM) proteolysis which is important in metastasis. Findings indicate that blueberry flavonoids may use multiple mechanisms in down-regulating MMP activity in these cells (Matchett, 2005).

Cervical Cancer, Breast Cancer

Blueberin, extracted with hexane, 50% hexane/ethyl acetate, ethyl acetate, ethanol, and 70% acetone/water at ambient temperature was tested for in vitro anti-cancer activity on cervical and breast cancer cell lines. Ethanol extracts strongly inhibited CaSki and SiHa cervical cancer cell lines and MCF-7 and T47-D breast cancer cell lines. An unfractionated aqueous extract of raspberry and the ethanol extract of blueberry significantly inhibited mutagenesis by both direct-acting and metabolically activated carcinogens (Wedge et al., 2001).

Anti-inflammatory

The reduction of fasting glucose was correlated with the reduction of serum CRP in the Blueberin group whereas in the Placebo group CRP levels were not significantly reduced. Furthermore, the Blueberin also significantly reduced the levels of plasma enzymes ALT, AST and GGT, indicating that, in addition to anti-diabetes effects, the Blueberin also possess pharmacologically relevant anti-inflammatory properties (Abidov et al., 2006).

References

Abidov M, Ramazanov A, Jimenez Del Rio M, Chkhikvishvili I. (2006). Effect of Blueberin on fasting glucose, C-reactive protein and plasma aminotransferases, in female volunteers with diabetes type 2: double-blind, placebo controlled clinical study. Georgian Med News, (141):66-72.

Matchett MD, MacKinnon, L, Sweeney MI, Gottschall-Pass KT, Hurta, RAR. (2006). Inhibition of matrix metalloproteinase activity in DU145 human prostate cancer cells by flavonoids from lowbush blueberry (Vaccinium angustifolium): possible roles for protein kinase C and mitogen-activated protein-kinase-mediated events. The Journal of Nutritional Biochemistry. doi: 10.1016/j.jnutbio.2005.05.014.

Schmidt BM, Erdman Jr JW, Lila MA. (2006). Differential effects of blueberry proanthocyanidins on androgen sensitive and insensitive human prostate cancer cell lines. Cancer Letters, 231(2):240-246. doi: 10.1021/jf049238n.

Wedge DE, Meepagala KM, Magee JB, et al. (2001). Anti-carcinogenic Activity of Strawberry, Blueberry, and Raspberry Extracts to Breast and Cervical Cancer Cells. Journal of Medicinal Food, 4(1):49-51. doi: 10.1089/10966200152053703.

Yi W, Fischer J, Krewer G, Akoh C. (2005). Phenolic Compounds from Blueberries Can Inhibit Colon Cancer Cell Proliferation and Induce Apoptosis. J. Agric. Food Chem, 53(18):7320–7329. doi: 10.1021/jf051333o.

Kaempferol

Cancer:
Pancreatic, osteosarcoma, metastasis, ovarian cancer

Action: Anti-oxidation, anti-inflammatory, cell-cycle arrest, blood sugar regulation, estrogen receptor modulator, metastasis

Kaempferol is a flavonol compound present in various plants and Chinese medicinal herbs, including Allium cepa (L.).

Blood Sugar Regulation

It has been found that kaempferol, a flavonol compound present in various Chinese medicinal herbs, has cyto-protective effects on cultured clonal beta-cells and pancreatic human islets. Kaempferol treatment dose-dependently promoted viability, inhibited cellular apoptosis, and reduced caspase-3 activity in beta-cells and human islets exposed to chronic high glucose, with 10 µM kaempferol exerting the maximum effect. In addition, kaempferol treatment improved the expression of anti-apoptotic proteins Akt and Bcl-2, that was significantly reduced in beta-cells and human islets chronically exposed to hyperglycemia.

Furthermore, exposure of beta-cells and human islets to kaempferol restored high glucose-attenuated intracellular cAMP and ATP production. Inhibition of protein kinase A or Akt activation ablated the anti-apoptotic effect of kaempferol. These cytoprotective effects of kaempferol were associated with improved insulin secretory function and synthesis in beta-cells and human islets.

These findings provide evidence that kaempferol may be a naturally occurring anti-diabetic compound through protecting pancreatic beta-cell survival and function in a hostile environment that would otherwise lead to type 2 diabetes (Zhang et al., 2011).

Ovarian Cancer

Recent studies indicate that apigenin, genistein, kaempferol, luteolin, and quercetin potently inhibit VEGF production and suppress ovarian cancer cell metastasis in vitro. Unlike NSAIDS (non-steroid anti-inflammatory drugs), well-documented clinical data for phyto-active compounds are lacking. In order to evaluate objectively the potential benefit of these compounds in the treatment of ovarian cancer, strategically designed, large scale studies are warranted (Chen et al., 2012).

Estrogen Receptor Modulator

Kaempferol is a dietary flavonoid that can function as a selective estrogen receptor modulator (SERM). Estrogen-related receptors alpha and gamma (ERR α and ERRγ) are orphan nuclear receptors that play important roles in mitochondrial biogenesis and cancer development. Wang, Gao, & Wang (2013) have shown that kaempferol can functionally antagonize the activities of ERRs based on both response element reporter systems and target gene analysis. Kaempferol modulation of mitochondrial function and suppression of cancer cell growth has been confirmed. These findings suggest that kaempferol may exert its anti-cancer activities through antagonizing ERRs activity.

Osteosarcoma; Metastasis

Kaempferol displayed inhibitory effects on the invasion and adhesion of U-2 osteosarcoma (OS) cells in a concentration-dependent manner and it also inhibited the migration of U-2 OS cells in a concentration-dependent manner. Kaempferol treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase plasminogen activator (uPA) and furthermore, kaempferol was able to reduce the protein phosphorylation of ERK, p38 and JNK. Results suggest a potential role for kaempferol in the therapy of tumor metastasis of OS (Chen et al., 2013).

Cell-cycle Arrest

Kaempferol decreased cell viability as determined by MTT assays and induced a G2/M phase cell-cycle arrest in a concentration-dependent manner. CDK1/cyclin B expression and the AMPK and AKT signaling pathways contributed to kaempferol-induced G2/M cell-cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells (Huang et al., 2013).

References

Chen SS, Michael A, Butler-Manuel SA. (2012). Advances in the treatment of ovarian cancer: a potential role of anti-inflammatory phytochemicals. Discov Med, 13(68):7-17.


Chen HJ, Lin CM, Lee CY, et al. (2013). Kaempferol suppresses cell metastasis via inhibition of the ERK-p38-JNK and AP-1 signaling pathways in U-2 OS human osteosarcoma cells. Oncol Rep, 30(2):925-32. doi: 10.3892/or.2013.2490.


Huang WW, Tsai SC, Peng SF, et al. (2013). Kaempferol induces autophagy through AMPK and AKT signaling molecules and causes G2/M arrest via down-regulation of CDK1/cyclin B in SK-HEP-1 human hepatic cancer cells. Int J Oncol, 42(6):2069-77. doi: 10.3892/ijo.2013.1909.


Wang H, Gao M, Wang J. (2013). Kaempferol inhibits cancer cell growth by antagonizing estrogen-related receptor α and γ activities. Cell Biol Int. doi: 10.1002/cbin.10152.


Zhang Y, Liu D. (2011). Flavonol kaempferol improves chronic hyperglycemia-impaired pancreatic beta-cell viability and insulin secretory function. Eur J Pharmacol, 670(1):325-32. doi: 10.1016/j.ejphar.2011.08.011.