Latest Research News on Carotenoid: Jan 2021
Carotenoid Action on the Immune Response
Early studies demonstrating the ability of dietary carotenes to prevent infections have left open the possibility that the action of these carotenoids may be through their prior conversion to vitamin A. Subsequent studies to demonstrate the specific action of dietary carotenoids have used carotenoids without provitamin A activity such as lutein, canthaxanthin, lycopene and astaxanthin. In fact, these nonprovitamin A carotenoids were as active, and at times more active, than β-carotene in enhancing cell-mediated and humoral immune response in animals and humans. Another approach to study the possible specific role of dietary carotenoids has used animals that are inefficient converters of carotenoids to vitamin A, for example the domestic cat. Results have similarly shown immuno-enhancement by nonprovitamin A carotenoids, based either on the relative activity or on the type of immune response affected compared to β-carotene. Certain carotenoids, acting as antioxidants, can potentially reduce the toxic effects of reactive oxygen species (ROS). These ROS, and therefore carotenoids, have been implicated in the etiology of diseases such as cancer, cardiovascular and neurodegenerative diseases and aging. Recent studies on the role of carotenoids in gene regulation, apoptosis and angiogenesis have advanced our knowledge on the possible mechanism by which carotenoids regulate immune function and cancer. 
Carotenoid actions and their relation to health and disease
Based on extensive epidemiological observation, fruits and vegetables that are a rich source of carotenoids are thought to provide health benefits by decreasing the risk of various diseases, particularly certain cancers and eye diseases. The carotenoids that have been most studied in this regard are β-carotene, lycopene, lutein and zeaxanthin. In part, the beneficial effects of carotenoids are thought to be due to their role as antioxidants. β-Carotene may have added benefits due its ability to be converted to vitamin A. Additionally, lutein and zeaxanthin may be protective in eye disease because they absorb damaging blue light that enters the eye. Food sources of these compounds include a variety of fruits and vegetables, although the primary sources of lycopene are tomato and tomato products. Additionally, egg yolk is a highly bioavailable source of lutein and zeaxanthin. These carotenoids are available in supplement form. However, intervention trials with large doses of β-carotene found an adverse effect on the incidence of lung cancer in smokers and workers exposed to asbestos. Until the efficacy and safety of taking supplements containing these nutrients can be determined, current dietary recommendations of diets high in fruits and vegetables are advised. 
Carotenoids have been reported to react with virtually any radical species likely to be encountered in a biological system. The products of such reactions are frequently short-lived radical species that can decay to more stable products. In some cases, stable adducts can be observed, but in the majority of interactions with radicals, carotenoids break down to degradation products very similar to what is seen with oxidative degradation. It is only recently that the biological activity of these breakdown products has begun to be investigated. 
A Prospective Study of Neuro-Cognitive Enhancement with Carotenoids in Elderly Adult Males with Early Age Related Macular Degeneration
Background: Diets rich in carotenoids may reduce cognitive impairment. Little is known about dietary zeaxanthin.
Objective: Evaluate zeaxanthin carotenoid supplementation against change in cognitive status.
Methods: American Psychological Association (APA) certified cognitive evaluation from the Zeaxanthin and Vision Function Study (USFDA Investigative New DrugIND#78,973), a 1 year prospective randomized controlled trial (RCT) of elderly males with mild age related macular degeneration. Neurocognitive testing Repeatable Battery for the Assessment of Neuropsychological Status Update RBANS and Trail Making A & B. Subjects evaluated at baseline and 1 year after dietary isomer RR zeaxanthin (8 mg/d) alone or combined with lutein (9 mg/d) using one way ANOVA, (P<0.05) and T testing.
Results: n=50 subjects completed both study visits. Delayed memory in the zeaxanthin group improved from RBANS score of 91.8 (SD 16) to 99.4 (SD 12), P = 0.04.
Conclusions: Zeaxanthin, typically minimally present in the US diet, may nonetheless be important in the context of emerging relationships in primates between dietary xanthophyll carotenoids and cognitive function. Additional larger scale RCTs is indicated to investigate the clinical utility of this carotenoid in nutritional neuroscience. 
Shelf Life Studies of Carotenoid Pigments Produced from Rhodotorula minuta
Aim: Storage stability of carotenoid pigment (extracellular and intracellular) extracted from Rhodotorula minuta grown in Malt Yeast Extract Broth (MYEB), coconut water and rice was studied for a period of 15 days at ambient temperature (29°C) and refrigeration temperature i.e. 4°C with respect to absorbance at 520 nm at 5 days interval.
Methods and Results: Rhodotorula minuta RAI3 obtained from air of dairy environment was used in shelf life study of the carotenoid pigment. The yeast culture was maintained on Malt Yeast Extract Agar (MYEA) slant and working culture in Malt Yeast Extract Broth (MYEB) with incubation at 30°C for 3-5 days. Color of pigment was stable both at ambient temperature (29°C) and refrigeration temperature (4°C) for 15 days of the study with A520 of 0.420, 0.140, 0.10 and 0.090 and 0.412, 0.320, 0.270 and 0.189 extracellular in MYEB, coconut water, and rice.
Conclusion: Storage stability for 15 days both at the ambient temperature (29°C) and the refrigeration temperature (4°C) was noticed during storage of the extra and intracellular pigment of Rhodotorula minutaRAI3.
Signiﬁcance and Impact of the Study: The present study aided in understanding storage stability of extra and intracellular pigments extracted from Rhodotorula minuta both at the ambient temperature (29°C) and the refrigeration temperature (4°C) for 15 days. 
 Chew, B.P. and Park, J.S., 2004. Carotenoid action on the immune response. The Journal of nutrition, 134(1), pp.257S-261S.
 Krinsky, N.I. and Johnson, E.J., 2005. Carotenoid actions and their relation to health and disease. Molecular aspects of medicine, 26(6), pp.459-516.
 Krinsky, N.I. and Yeum, K.J., 2003. Carotenoid–radical interactions. Biochemical and biophysical research communications, 305(3), pp.754-760.
 G. Hoffmann, K., P. Richer, S., S. Wrobel, J., Chen, E. and J Podella, C. (2015) “A Prospective Study of Neuro-Cognitive Enhancement with Carotenoids in Elderly Adult Males with Early Age Related Macular Degeneration”, Ophthalmology Research: An International Journal, 4(1), pp. 1-8. doi: 10.9734/OR/2015/17131.
 Yadav, K. and Prabha, R. (2017) “Shelf Life Studies of Carotenoid Pigments Produced from Rhodotorula minuta”, Microbiology Research Journal International, 18(6), pp. 1-8. doi: 10.9734/MRJI/2017/30967.