Vitamin D Induces Cyclooxygenase 2 Dependent Prostaglandin E2 Synthesis in HaCaT Keratinocytes.

The active metabolite of vitamin D calcitriol and its analogs are well-known for their anti-inflammatory action in the skin, while their main side effect associated with topical treatment of inflammatory disorders is irritant contact dermatitis. Prostaglandin E2 (PGE2 ) is pro-inflammatory at the onset of inflammation and anti-inflammatory at its resolution. We hypothesized that induction of PGE2 synthesis by calcitriol in epidermal keratinocytes may contribute both to its pro-inflammatory and anti-inflammatory effects on the skin. Treatment of human immortalized HaCaT keratinocytes with calcitriol (3-100 nM, 2-24 h) increased PGE2 production due to increased mRNA and protein expression of COX-2, but not to increase of COX-1 or release of arachidonic acid. The effect of calcitriol on COX-2 mRNA was observed also in primary human keratinocytes. The increase in COX-2 mRNA is associated with COX-2 transcript stabilization. Calcitriol exerts this effect by a rapid (2 h) and protein synthesis independent mode of action that is dependent on PKC and Src kinase activities. Treatment with a COX-2 inhibitor partially prevented the attenuation of the keratinocyte inflammatory response by calcitriol. We conclude that upregulation of COX-2 expression with the consequent increase in PGE2 synthesis may be one of the mechanisms explaining the Janus face of calcitriol as both a promoter and attenuator of cutaneous inflammation. J. Cell. Physiol. 231: 837-843, 2016. © 2015 Wiley Periodicals, Inc.

Two modes of ERK activation by TNF in keratinocytes: different cellular outcomes and bi-directional modulation by vitamin D.

Inflammation, elicited in the skin following tissue damage or pathogen invasion, may become chronic with deleterious consequences. Tumor necrosis factor (TNF) is a key mediator of cutaneous inflammation and the keratinocyte an important protagonist of skin immunity. Calcitriol, the hormonally active vitamin D metabolite, and its analogs attenuate epidermal inflammation and inhibit the hyperproliferation of keratinocytes associated with the inflammatory disorder, psoriasis. Since activation of extracellular signal-regulated kinase (ERK) promotes keratinocyte proliferation and mediates epidermal inflammation, we studied the effect of calcitriol on ERK activation in HaCaT keratinocytes exposed to the ubiquitous inflammatory cytokine TNF. By using the EGF receptor (EGFR) tyrosine kinase inhibitor, AG1487 and the Src family inhibitor, PP-1, we established that TNF activated ERK in an EGFR and Src dependent and an EGFR and Src independent modes. EGFR dependent activation resulted in the upregulation of the transcription factor, c-Fos, while the EGFR independent activation mode was of a shorter duration, did not affect c-Fos expression but induced IL-8 mRNA expression. Pretreatment with calcitriol, enhanced TNF-induced EGFR-Src dependent ERK activation and tyrosine phosphorylation of the EGFR, but abolished the EGFR-Src independent ERK activation. These effects were mirrored by enhancement of c-Fos and inhibition of IL-8 induction by TNF. Treatment with calcitriol increased the rate of the de-phosphorylation of activated ERK, accounting for the inhibition of EGFR-Src independent ERK activation by TNF. It is possible that effects on the ERK cascade contribute to the effects of calcitriol and its synthetic analogs on cutaneous inflammation and keratinocyte proliferation.

Phyto-Female Complex for the relief of hot flushes, night sweats and quality of sleep: randomized, controlled, double-blind pilot study.

OBJECTIVE: To determine the efficacy and safety of the herbal formula Phyto-Female Complex (SupHerb, Netanya, Israel; ingredients: standardized extracts of black cohosh, dong quai, milk thistle, red clover, American ginseng, chaste-tree berry) for the relief of menopausal symptoms. METHODS: A randomized, double-blind, placebo-controlled trial in 50 healthy pre and postmenopausal women, aged 44-65 years, to whom oral Phyto-Female Complex or matched placebo was prescribed twice daily for 3 months. A structured questionnaire on the frequency and intensity of menopausal symptoms was administered weekly from one week before throughout the 3-month treatment period, followed by biochemical tests, breast check, and transvaginal ultrasonography. RESULTS: The women receiving Phyto-Female Complex reported a significantly superior mean reduction in menopausal symptoms than the placebo group. The effect of treatment improvements in menopausal symptoms increased over time; by 3 months there was a 73% decrease in hot flushes and a 69% reduction of night sweats, accompanied by a decrease in their intensity and a significant benefit in terms of sleep quality. Hot flushes ceased completely in 47% of women in the study group compared with only 19% in the placebo group. There were no changes in findings on vaginal ultrasonography or levels of relevant hormones (estradiol, follicle-stimulating hormone), liver enzymes or thyroid-stimulating hormone in either group. CONCLUSION: Phyto-Female Complex is safe and effective for the relief of hot flushes and sleep disturbances in pre- and postmenopausal women, at least for 3 months' use.

Prospective, randomized trial of metformin and vitamins for the reduction of plasma homocysteine in insulin-resistant polycystic ovary syndrome.

One hundred and two women with insulin-resistant polycystic ovary syndrome were randomized to treatment with a vitamin B preparation, metformin, or both, in conjunction with standard infertility treatment. Plasma homocysteine levels were significantly reduced by both B vitamins and metformin, but to a greater degree by B vitamins, and higher pregnancy rates were associated with vitamin B treatment.

Vitamin D sensitizes breast cancer cells to the action of H2O2: mitochondria as a convergence point in the death pathway.

Calcitriol, the hormonal form of vitamin D3, sensitizes breast cancer cells to reactive oxygen species (ROS)-dependent cytotoxicity induced by various anticancer modalities. This effect could be due to increased generation of ROS and/ or to increased sensitivity of the target cells to ROS. This work examined the effect of calcitriol on the damage inflicted on breast cancer cells by the direct action of ROS represented by H2O2. Treatment of MCF-7 cells with H2O2 resulted in activation of caspase 7 as well as induction of caspase-independent cell death. Both were enhanced by 48-72 h of pretreatment with calcitriol. This effect was not due to modulation of H2O2 degradation or to a specific effect on *OH-mediated cytotoxicity. The H2O2-induced drop in mitochondrial membrane potential and release of cytochrome c were enhanced by calcitriol. These findings indicate that calcitriol sensitizes breast cancer cells to ROS-induced death by affecting event(s) common to both caspase-dependent and -independent modes of cell death upstream to mitochondrial damage.