Experimental Study on Inhibitory Effect of Niacinamide on Tumor Necrosis Factor-alpha-induced Matrix Degradation of Annulus Fibrous Tissue in vitro

The inhibitory effect of niacinamide on tumor necrosis factor-α （TNF-α） induced annulus fibrous （AF） degradation was assessed, and the mechanism of the inhibition was investigated. Chiba＇s intervertebral disc （IVD） culture model was established. Forty-eight IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups （12 IVDs in each group）, and various concentrations of niacinamide and TNF-α were added to the medium for intervention： negative control group, niacinamide control group （0.5 mg/mL niacinamide）, degeneration group （10 ng/mL TNF-α）, and treatment group （0.5 mg/mL niacinamide and 10 ng/mL TNF-α）. After one week＇s culture, AFs were collected for glycosaminoglycan （GS） content measurement, safranin O-fast green staining, and immunohistochemical staining for type Ⅰ , Ⅱ collagen and cysteine containing aspartate specific prote- ase-3 （Caspase-3）. It was found that the GS content in treatment group was increased by about 48% as compared with degeneration group （t=16.93, P〈0.001）, and close to that in niacinamide control group （t=0.71, P=0.667）. Safranine O-fast green staining exhibited higher staining density and better histological structure of AF in the treatment group as compared with the degeneration group. Immunohistochemical staining for both TypeⅠ and Ⅱ collagen demonstrated that lamellar structure and continuity of collagen in treatment group were better reserved than in degeneration group. Positive staining rate of Caspase-3 in AFs of negative control group, niacinamide control group, degeneration group and treatment group was 3.4%, 4.3%, 17.9% and 10.3% respectively. The positive rate in treatment group was significantly lower than in degeneration group （P〈0.01）. It was concluded that niacinamide could effectively alleviate TNF-α induced destruction and synthesis inhibition of matrix ingredients in AFs. The inhibition may be related with reduction of expression of Caspase-3. Thus, niacinamide is of potential for IVD degeneration clinical treatment.

Protective Effect of Niacinamide on interleukin-1β-induced Annulus Fibrosus Type Ⅱ Collagen Degeneration in vitro

The protective effect of niacinamide on interleukin-1β （IL-1β）-induced annulus fibrosus （AF） type Ⅱ collagen degeneration in vitro and the mechanism were investigated, Chiba＇s intervertebral disc （IVD） culture models in rabbits were established and 48 IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups： normal control group, niacinamide-treated group, type Ⅱ collagen degneration group （IL-1 β） and treatment group （niacinamide＋IL-1 β）, After culture for one week, AFs were collected for inducible nitric oxide synthase （iNOS）, cysteine containing aspartate specific protease-3 （Caspase-3） and type Ⅱ collagen immunohistochemical examination, and type Ⅱ collagen reverse transcription polymerase chain reaction （RT-PCR）. The results showed that rate of iNOS positive staining AF cells in the 4 groups was 17.6%, 10.9%, 73.9% and 19.3% respectively, The positive rate in treatment group was significantly lower than in the type Ⅱ collagen degeneration group （P〈0.01）. Rate of Caspase-3 positive staining AF cells in the 4 groups was 3.4%, 4.2%, 17.6% and 10.3% respectively. The positive rate in treatment group was lower than in the type Ⅱ collagen degeneration- group （P〈0.01）. Type Ⅱ collagen staining demonstrated that lamellar structure and continuity of collagen in treatment group was better reversed than in the degeneration group. RT-PCR revealed that the expression of type Ⅱ collagen in treatment group was significantly stronger than that in type Ⅱ collagen degeneration group （P〈0.01）, It was concluded that niacinamide could effectively inhibit IL-1β stimulated increase of iNOS and Caspase-3 in AF, and alleviate IL-1β-caused destruction and synthesis inhibition of type Ⅱ collagen, Niacinamide is of potential for clinical treatment of IVD degeneration.

Up-regulation of Niacinamide in Intervertebral Disc Aggrecan in vitro

The regulatory effects of niacinamide （Nia） on intervertebral disc （IVD） aggrecan in vitro was investigated. Chiba＇s 10 ng/mL interleukin-1 （IL-1）-induced rabbit IVD degeneration model in vitro was established. 0.5, 0. 25 and 0.05 mg/mL Nia was added to normal and degenerated IVDs for intervention. On the first and second week after intervention, safranin O-fast green staining intensity and glycosaminoglycan （GS） content were measured. The expression of aggrecan core protein was detected by RT-PCR. The results showed： （1） After treatment with 0. 5 mg/mL Nia for one week, the GS content in nucleus pulposus （NP） was increased by 44.80% as compared with control group （P〈0. 01） ; The GS content in IL-1 induction groups was increased with the increase of Nia concentrations： After treatment with 0. 5 mg/mL for one week, the GS content in NP was increased by 68.30% as compared with control group （P〈0. 01）. After two weeks, GS content in NP and fibrous rings was still higher than in control group at the same period （P〈0. 01） and untreated group （P〈0.01）. （2） Safranin O-fast green staining revealed that with the increase of Nia concentrations, staining density in NP and fibrous rings was increased and histological structure damage to IVDs by IL-1β was alleviated. （3） RT-PCR showed that the expression of core protein gene in IL-1β-induced degenerated IVDS was increased with the increase of Nia concentrations. It was concluded that under conditions in vitro, Nia could up-regulate the expression of aggrecan in IVDs and protect IVDs from IL-1β-induced degeneration at least partially, which offers a potential choice for IVD degeneration clinical therapy.

Mechanism of Niacin Induced Hot Flushes and Suppression of Cholesterol

Niacin or nicotinic acid is a form of B3 vitamin prescribed at higher concentrations for the suppression of cholesterol levels. Supplemental doses may cause very little or no side effects. However, higher concentrations of niacin cause hot flushes for most people. Here we propose a biochemical mechanism of niacin induced hot flushes. Orally taken prescription doses of niacin are converted to NAD with the liberation of excess pyrophosphate which in turn releases energy in the form of heat (hot flushes through capsaicin receptor) by the action of pyrophosphatases. The excess pyrophosphate may suppress cholesterol biosynthesis through feedback mechanism. The pathways of NAD and cholesterol biosynthesis were discussed with refence to the production and function of pyrophosphate.

A Double-Blind, Placebo Controlled Clinical Trial Evaluating the Efficacy and Safety of a New Skin Whitening Combination in Patients with Chloasma

Melasma (or chloasma) is a hyperpigmentation disorder predominantly affecting sun-exposed skin in women, and is often refractory to treatment. The objective was to evaluate the efficacy and safety of a new whitening formula for the treatment of chloasma. This?single centre, double-blind, placebo controlled, bilateral (split-face) comparison, was conducted on 44 Chinese subjects with chloasma during the winter season. The test formula was applied twice a day, for 12 weeks on left side of the face and a placebo formula on the right side of the face. Assessments included the use of the hemi-MASI (split-face Melasma Area Severity Index), both ultraviolet and standard photography, together with clinical evaluations of efficacy and safety at T0, T6 and T12 weeks. A significant difference between the 2-hemi-MASI was noticed after 6 and 12 weeks of treatment. This result was confirmed by the clinical evaluation of the dermatologists who recorded a significant improvement in the half-face treated with the new whitening formula compared with that treated with placebo (p = 0.003). The tolerance of the new formula was recorded as excellent by 82% of subjects and found to be cosmetically appealing. In this study, the new whitening formula containing ferulic acid, Ginkgo Biloba, lipohydroxyacid (LHA), niacinamide and thermal spring water was safe and significantly improved chloasma after a 3-month-treatment period compared with placebo.

Effects of Nicotinamide on Mouse Skin Tumor Development and Its Mode of Action

Nicotinamide (NA), a naturally occuring vitamin and a protease inhibitor, has been shown to be effective in treating some skin ailments. It inhibits cell proiferaion and induces cell differentiation. This report shows the effects of NA on mouse skin tumor development and on the critical events involved in this process. NA reduced tumor growth, inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ornithine decarboxylase activity, but induced the transglutaminare activity which was inhibited by TPA under different experimental conditions.The effects of NA on ornithine decarboxylare (ODC) and transglutaminase (TG) indicated that nicotinamide (NA) probably programmmed the cells for their death in the natural course of time, i.e. programed cell death. This observation indicates that NA might be a better agent for the detailed study and for the better use in prevention of cancer alone or in combination with other drugs.

More than skin deep? Potential nicotinamide treatment applications in chronic kidney transplant recipients

Non-melanoma cutaneous carcinomas, or skin cancers, predominantly squamous cell carcinomas(SCCs), are the most common malignancies occurring in kidney transplant recipients(KTRs). Squamous cell carcinoma risk is dramatically elevated in KTRs, occurring at rates of up 45-250 times those reported in general populations. New non-melanoma skin cancers in KTRs with a prior non-melanoma skin cancer also develop at 3-times the rate reported in non-KTRs with the same clinical history. The unique aggressiveness of SCCs in KTRs increases patient morbidity, due to the high rate of new lesions requiring treatment, frequently surgical excision. Oral nicotinamide shows promise in the chemoprevention of the especially aggressive non-melanoma skin cancers which occur in KTRs. This benefit might be conferred via its inhibition of sirtuin enzymatic pathways. Nicotinamide's concurrent hypophosphatemic effect may also partially ameliorate the disturbed calcium-phosphorus homeostasis in these patients-a putative risk factor for mortality, and graft failure. Conceivably, a phase 3 trial of nicotinamide for the prevention of non-melanoma skin cancers in KTRs, lasting at least 12-mo, could also incorporate imaging and laboratory measures which assess nicotinamide's impact on subclinical cardiovascular and chronic kidney disease risk, and progression.