Oxidative Stress and Cancer: Harnessing the Therapeutic Potential of Curcumin and Analogues Against Cancer.

Reactive oxygen species (ROS) are a class of bioactive molecules that are the by-products of many cellular functions. These molecules are present in normal cells at homeostatic levels but have been studied extensively in cancer due to their dysregulation resulting in pro- and anti-tumorigenic environments. Completely understanding the paradoxical nature of ROS in cancer is imperative to fully realize its modulation as cancer therapy. Studies into ROS have shown far-reaching effects in cancer, including how ROS levels regulate signaling, response to treatment, drug resistance, etc. Many drugs were studied with the hopes of regulating the ROS levels in cancer; however, patient response varied. Plant-derived medications offered new avenues of drug treatment over the last few decades, and the phytochemical Curcumin gained ground as an interesting cancer therapeutic. Curcumin is an active phenolic compound used in traditional medicine around the world. Although it suffers from a poor pharmacokinetic profile, Curcumin exerts anti-tumorigenic, as well as ROS-modulating activities. Analogs and derivatives of Curcumin are under development to improve upon its anti-cancer properties and enhance its bioavailability, currently a major limitation of its usage. This review highlights ROS function in cancer treatment focused on ROS, including Curcumin and its analogs.

Motor Variability during Sustained Contractions Increases with Cognitive Demand in Older Adults.

To expose cortical involvement in age-related changes in motor performance, we compared steadiness (force fluctuations) and fatigability of submaximal isometric contractions with the ankle dorsiflexor muscles in older and young adults and with varying levels of cognitive demand imposed. Sixteen young (20.4 ± 2.1 year: 8 men, 9 women) and 17 older adults (68.8 ± 4.4 years: 9 men, 8 women) attended three sessions and performed a 40 s isometric contraction at 5% maximal voluntary contraction (MVC) force followed by an isometric contraction at 30% MVC until task failure. The cognitive demand required during the submaximal contractions in each session differed as follows: (1) high-cognitive demand session where difficult mental math was imposed (counting backward by 13 from a 4-digit number); (2) low-cognitive demand session which involved simple mental math (counting backward by 1); and (3) control session with no mental math. Anxiety was elevated during the high-cognitive demand session compared with other sessions for both age groups but more so for the older adults than young adults (p < 0.05). Older adults had larger force fluctuations than young adults during: (1) the 5% MVC task as cognitive demand increased (p = 0.007), and (2) the fatiguing contraction for all sessions (p = 0.002). Time to task failure did not differ between sessions or age groups (p > 0.05), but the variability between sessions (standard deviation of three sessions) was greater for older adults than young (2.02 ± 1.05 vs. 1.25 ± 0.51 min, p < 0.05). Thus, variability in lower limb motor performance for low- and moderate-force isometric tasks increased with age and was exacerbated when cognitive demand was imposed, and may be related to modulation of synergist and antagonist muscles and an altered neural strategy with age originating from central sources. These data have significant implications for cognitively demanding low-force motor tasks that are relevant to functional and ergonomic in an aging workforce.

Sex differences in marathon running with advanced age: physiology or participation?

UNLABELLED: The sex difference in marathon performance increases with age and place of the finisher, even at the elite level. Sociological factors may explain the increased sex gap, but there is limited empirical evidence for specific factors. PURPOSE: The purposes of this study were to determine the sex difference in velocity for the marathon across the place of finisher (1st-10th place) with advanced age and (2) to determine the association between the sex difference in participation (ratio of men-to-women finishers) and the sex difference in running velocity. METHODS: Running times of the first 10 placed men and women in the 5-yr age brackets between 20 and 79 yr and the number of men and women who finished the New York City marathon were analyzed for a 31-yr period (1980-2010). RESULTS: The sex difference in running velocity increased between the 1st and the 10th place because of a greater relative drop in velocity of women than men (P < 0.001). The sex difference increased with advanced age and decreased across the 31 yr, but more for the older age groups (P < 0.001). The number of women finishers also increased relative to men for the 31 yr, but more in the older age groups (P < 0.001). Importantly, approximately 34% of the sex difference in velocity among the first-place finishers was associated with the ratio of men-to-women finishers (r = 0.58, r² = 0.34, P < 0.001). CONCLUSIONS: The greater sex difference in velocity that occurs with age and with increased place was primarily explained by the lower number of women finishers than men. These data provide evidence that lower participation rates and less depth among women competitors can amplify the sex difference in running velocity above that due to physiological sex differences alone.

Is there a sex difference in the age of elite marathon runners?

PURPOSE: The purposes of this study were to determine i) if there is a sex difference in the age of the elite marathon runners and ii) if the sex difference in performance altered across the years that women have participated in the marathon. METHODS: Age at time of competition and running times of the first five placed male and female runners who competed in the seven marathons of the World Marathon Majors Series were analyzed. Data from as many years as was available online were retrieved so that 410 men and 410 women were included in the analysis. The marathons and years included the Berlin (1999-2009), Boston (2000-2009), Chicago (1997-2009), London (2001-2009), New York City (1990-2009), International Athletic Association Federation World Championship (1983, 1987, and every 2 yr from 1991), and Olympic (every 4 yr since 1984) marathons. RESULTS: Women were older than men (mean ± SD = 29.8 ± 4.2 vs 28.9 ± 3.8 yr), but for only two of the seven marathons, the Chicago and the London marathons (P < 0.05): the sex difference in age was not consistent across the years. There was no sex difference in age for the Berlin, Boston, New York City, World Championship, and Olympic marathons. Men were faster than women (11.6% ± 1.8%). The sex difference in running velocity varied across marathons (least for the World Championships, 10.2%) and also across years, but not systematically. This sex difference in running velocity increased from first to fifth place across all marathons. CONCLUSIONS: These data indicate that men and women physiologically peak at a similar age in marathon running performance. The sex difference in performance of elite marathon runners varied across years but has not systemically decreased or varied since the 1980s.