Association of plasma retinol levels with incident cancer risk in Chinese hypertensive adults: a nested case-control study

Enzymatic vitamin A2 production enables red-shifted optogenetics

Optogenetics is a technology using light-sensitive proteins to control signaling pathways and physiological processes in cells and organs and has been applied in neuroscience, cardiovascular sciences, and many other research fields. Most commonly used optogenetic actuators are sensitive to blue and green light, but red-light activation would allow better tissue penetration and less phototoxicity. Cyp27c1 is a recently deorphanized cytochrome P450 enzyme that converts vitamin A1 to vitamin A2, thereby red-shifting the spectral sensitivity of visual pigments and enabling near-infrared vision in some aquatic species.Here, we investigated the ability of Cyp27c1-generated vitamin A2 to induce a shift in spectral sensitivity of the light-gated ion channel Channelrhodopsin-2 (ChR2) and its red-shifted homolog ReaChR. We used patch clamp to measure photocurrents at specific wavelengths in HEK 293 cells expressing ChR2 or ReaChR. Vitamin A2 incubation red-shifted the wavelength for half-maximal currents (λ50%) by 6.8 nm for ChR2 and 12.4 nm for ReaChR. Overexpression of Cyp27c1 in HEK 293 cells showed mitochondrial localization, and HPLC analysis showed conversion of vitamin A1 to vitamin A2. Notably, the λ50% of ChR2 photocurrents was red-shifted by 10.5 nm, and normalized photocurrents at 550 nm were about twofold larger with Cyp27c1 expression. Similarly, Cyp27c1 shifted the λ50% of ReaChR photocurrents by 14.3 nm and increased normalized photocurrents at 650 nm almost threefold.Since vitamin A2 incubation is not a realistic option for in vivo applications and expression of Cyp27c1 leads to a greater red-shift in spectral sensitivity, we propose co-expression of this enzyme as a novel strategy for red-shifted optogenetics.

Associations of serum carotenoids with the severity of sunburn and the risk of cancer: A cross-sectional analysis of 1999-2018 NHANES data

Background

Sunburn is a common problem for outdoor workers and casual outdoor walkers. Carotenoids are important elements in normal function of skin tissue and skin metabolism and are critical in the development of some cancers. However, the possible relationships between sunburn sensitivity, carotenoids and the risk of cancers remain unknown.

Objectives

To explore the associations of serum carotenoids with sunburn severity and the risk of cancers.

Methods

A cross-sectional study from the National Health and Nutrition Examination Survey from 1999 to 2018 were conducted. The relationship between sunburn and serum carotenoids, cancers were investigated by unconditional or ordinal logistic regression. Mediation analysis was used to explore the effect of carotenoids on the relationship between sunburn and cancers.

Results

A total of 25,440 US adults from 1999 to 2018 were enrolled in this study. There were significant differences in sex, race and natural hair color between the sunburn and non-sunburn people. The severity of sunburn was significantly associated with serum trans-β-carotene, cis-β-carotene, combined lutein, and vitamin A. The odds ratios of severe reactions were 5.065 (95% CI: 2.266-11.318) in melanoma patients, 5.776 (95% CI: 3.362-9.922) in non-melanoma patients, and 1.880 (95% CI: 1.484-2.380) in non-skin cancers patients. Additionally, serum carotenoids were partially attributable to the effect of sunburn on skin and non-skin cancers.

Conclusion

Sunburn severity was associated with cancers, and severer sunburn was related with higher risk of cancers. Serum carotenoids were also associated with sunburn severity. Moreover, the relationship between sunburn and cancers was mediated by some serum carotenoids.

Efficacy of topical non-steroidal immunomodulators in the treatment of oral lichen planus: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to assess the efficacy and safety of topical non-steroidal immunomodulators (TNSIs) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

A search strategy designed for this purpose retrieved 1156 references. After analysis of titles and abstracts, 75 studies were selected for full-text analysis. Only randomized controlled clinical trials were selected, resulting in 28 studies included for qualitative and quantitative analysis.

RESULTS

The meta-analysis showed similar benefits in clinical response and symptom resolution between tacrolimus 0.1% and pimecrolimus 1% in comparison to topical steroids (TS). Pimecrolimus showed superior efficacy of clinical response but not for symptom resolution compared to placebo. Tacrolimus and pimecrolimus showed better performance preventing symptom relapse, while pimecrolimus also prevented clinical relapse better than TS. Cyclosporine was superior to placebo; however, TS showed better efficacy of clinical response. Thalidomide and retinoid were assessed in only one trial each, and both showed similar efficacy to TS. Rapamycin also presented similar clinical response to TS; however, the later showed greater reduction of symptoms. Mycophenolate mofetil 2% mucoadhesive was no better than placebo. No serious adverse effects have been reported. Cyclosporine showed a higher frequency and variety of adverse effects.

CONCLUSIONS

Topical tacrolimus and pimecrolimus are safe and effective alternatives for OLP treatment.

CLINICAL RELEVANCE

TS are usually the first choice for OLP treatment. Because some oral lesions may have a low response to treatment with TS, more topical therapeutic options, such as TNSIs, should be considered before systemic steroids are used.

Efficacy of topical non-steroidal immunomodulators in the treatment of oral lichen planus: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to assess the efficacy and safety of topical non-steroidal immunomodulators (TNSIs) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

A search strategy designed for this purpose retrieved 1156 references. After analysis of titles and abstracts, 75 studies were selected for full-text analysis. Only randomized controlled clinical trials were selected, resulting in 28 studies included for qualitative and quantitative analysis.

RESULTS

The meta-analysis showed similar benefits in clinical response and symptom resolution between tacrolimus 0.1% and pimecrolimus 1% in comparison to topical steroids (TS). Pimecrolimus showed superior efficacy of clinical response but not for symptom resolution compared to placebo. Tacrolimus and pimecrolimus showed better performance preventing symptom relapse, while pimecrolimus also prevented clinical relapse better than TS. Cyclosporine was superior to placebo; however, TS showed better efficacy of clinical response. Thalidomide and retinoid were assessed in only one trial each, and both showed similar efficacy to TS. Rapamycin also presented similar clinical response to TS; however, the later showed greater reduction of symptoms. Mycophenolate mofetil 2% mucoadhesive was no better than placebo. No serious adverse effects have been reported. Cyclosporine showed a higher frequency and variety of adverse effects.

CONCLUSIONS

Topical tacrolimus and pimecrolimus are safe and effective alternatives for OLP treatment.

CLINICAL RELEVANCE

TS are usually the first choice for OLP treatment. Because some oral lesions may have a low response to treatment with TS, more topical therapeutic options, such as TNSIs, should be considered before systemic steroids are used.

Medicinal Prospects of Antioxidants From Algal Sources in Cancer Therapy

Though cancer therapeutics can successfully eradicate cancerous cells, the effectiveness of these medications is mostly restricted to several deleterious side effects. Therefore, to alleviate these side effects, antioxidant supplementation is often warranted, reducing reactive species levels and mitigating persistent oxidative damage. Thus, it can impede the growth of cancer cells while protecting the normal cells simultaneously. Moreover, antioxidant supplementation alone or in combination with chemotherapeutics hinders further tumor development, prevents chemoresistance by improving the response to chemotherapy drugs, and enhances cancer patients' quality of life by alleviating side effects. Preclinical and clinical studies have been revealed the efficacy of using phytochemical and dietary antioxidants from different sources in treating chemo and radiation therapy-induced toxicities and enhancing treatment effectiveness. In this context, algae, both micro and macro, can be considered as alternative natural sources of antioxidants. Algae possess antioxidants from diverse groups, which can be exploited in the pharmaceutical industry. Despite having nutritional benefits, investigation and utilization of algal antioxidants are still in their infancy. This review article summarizes the prospective anticancer effect of twenty-three antioxidants from microalgae and their potential mechanism of action in cancer cells, as well as usage in cancer therapy. In addition, antioxidants from seaweeds, especially from edible species, are outlined, as well.