Nicotinamide as a chemopreventive therapy of skin cancers. Too much of good thing?

Supramolecular salicylic acid combined with niacinamide in chloasma: a randomized controlled trial

BACKGROUND

Chloasma is a common skin hyperpigmentation condition, with treatment options ranging from topical agents to advanced interventions such as chemical peels and laser therapy. Salicylic acid, including its supramolecular form (SSA), has shown promise in managing chloasma. However, to date, no multicentre randomized controlled trial of SSA for chloasma is available.

OBJECTIVES

The purpose of this study was to assess the efficacy and safety of 30% SSA combined with 10% niacinamide in treating -chloasma.

METHODS

This multicentre (n = 15), randomized, double-blind, parallel placebo-controlled trial (Clinical trial registration number: ChiCTR2200065346) enrolled and randomized 300 participants (1 : 1) to either 30% SSA treatment or placebo, with 150 allocated to treatment and 150 to placebo in the full analysis set, and 144 to treatment and 147 to placebo in the per-protocol set. A Visia® Skin Analysis System was used at each visit to assess the degree of improvement in chloasma lesions. The primary endpoint was the effective rate after 16 weeks, assessed using the modified Melasma Area and Severity Index (mMASI) score [(pretreatment score - post-treatment score)/pretreatment score × 100%].

RESULTS

The total mMASI score, overall score on the Griffiths 10-point scale, and Griffiths 10 score for the left and the right sides of the face were significantly lower in the 30% SSA group than in the placebo group (all P < 0.001). One study of drug-related adverse events (AEs) and one study of drug-unrelated AEs were reported in the 30% SSA group. No AE was reported in the placebo group.

CONCLUSIONS

Among our patients, 30% SSA combined with 10% niacinamide was shown to be effective and safe for treating chloasma.

Compartmentalized regulation of NAD+ by Di (2-ethyl-hexyl) phthalate induces DNA damage in placental trophoblast

Di (2-ethyl-hexyl) phthalate (DEHP) is a wildly used plasticizer. Maternal exposure to DEHP during pregnancy blocks the placental cell cycle at the G2/M phase by reducing the efficiency of the DNA repair pathways and affects the health of offsprings. However, the mechanism by which DEHP inhibits the repair of DNA damage remains unclear. In this study, we demonstrated that DEHP inhibits DNA damage repair by reducing the activity of the DNA repair factor recruitment molecule PARP1. NAD+ and ATP are two substrates necessary for PARP1 activity. DEHP abated NAD+ in the nucleus by reducing the level of NAD+ synthase NMNAT1 and elevated NAD+ in the mitochondrial by promoting synthesis. Furthermore, DEHP destroyed the mitochondrial respiratory chain, affected the structure and quantity of mitochondria, and decreased ATP production. Therefore, DEHP inhibits PARP1 activity by reducing the amount of NAD+ and ATP, which hinders the DNA damage repair pathways. The supplement of NAD+ precursor NAM can partially rescue the DNA and mitochondria damage. It provides a new idea for the prevention of health problems of offsprings caused by DEHP injury to the placenta.

Mechanistic Basis and Clinical Evidence for the Applications of Nicotinamide (Niacinamide) to Control Skin Aging and Pigmentation

Vitamin B3 (nicotinic acid, niacin) deficiency causes the systemic disease pellagra, which leads to dermatitis, diarrhea, dementia, and possibly death depending on its severity and duration. Vitamin B3 is used in the synthesis of the NAD+ family of coenzymes, contributing to cellular energy metabolism and defense systems. Although nicotinamide (niacinamide) is primarily used as a nutritional supplement for vitamin B3, its pharmaceutical and cosmeceutical uses have been extensively explored. In this review, we discuss the biological activities and cosmeceutical properties of nicotinamide in consideration of its metabolic pathways. Supplementation of nicotinamide restores cellular NAD+ pool and mitochondrial energetics, attenuates oxidative stress and inflammatory response, enhances extracellular matrix and skin barrier, and inhibits the pigmentation process in the skin. Topical treatment of nicotinamide, alone or in combination with other active ingredients, reduces the progression of skin aging and hyperpigmentation in clinical trials. Topically applied nicotinamide is well tolerated by the skin. Currently, there is no convincing evidence that nicotinamide has specific molecular targets for controlling skin aging and pigmentation. This substance is presumed to contribute to maintaining skin homeostasis by regulating the redox status of cells along with various metabolites produced from it. Thus, it is suggested that nicotinamide will be useful as a cosmeceutical ingredient to attenuate skin aging and hyperpigmentation, especially in the elderly or patients with reduced NAD+ pool in the skin due to internal or external stressors.

Melanoma models for the next generation of therapies

There is a lack of appropriate melanoma models that can be used to evaluate the efficacy of novel therapeutic modalities. Here, we discuss the current state of the art of melanoma models including genetically engineered mouse, patient-derived xenograft, zebrafish, and ex vivo and in vitro models. We also identify five major challenges that can be addressed using such models, including metastasis and tumor dormancy, drug resistance, the melanoma immune response, and the impact of aging and environmental exposures on melanoma progression and drug resistance. Additionally, we discuss the opportunity for building models for rare subtypes of melanomas, which represent an unmet critical need. Finally, we identify key recommendations for melanoma models that may improve accuracy of preclinical testing and predict efficacy in clinical trials, to help usher in the next generation of melanoma therapies.

Oral nicotinamide: The role in skin cancer chemoprevention

The incidence of skin cancer has gradually increased in the last years and exposition to ultraviolet radiation remains the main risk factor. We performed a comprehensive review on the role of nicotinamide (NAM) in the chemoprevention of skin cancers. NAM, a water-soluble form of vitamin B3, interferes with skin carcinogenesis as it regulates immunosuppressor genes such as p53 and sirtuins and restores intracellular level of NAD+, a co-enzyme essential for energy production. Efficacy and safety of NAM was evaluated in a Phase III double-blinded control-placebo study (ONTRAC), thus demonstrating that the incidence of actinic keratoses and non-melanoma skin cancers was lower in the nicotinamide group than in placebo group. Further studies showed the efficacy of NAM also in transplanted patients and among inhabitants living in arsenic contamination areas. Despite the quick response to NAM supplementation, its intake need to be carried on chronically as the efficacy seems to vanish rapidly.