Score another point for resveratrol, the red wine compound that has captured headlines for its potential life-extending benefits. The molecule, which extends lifespan in worms and flies and has other health benefits in rodents, may also help weight loss. New research shows it decreases food intake and boosts metabolism in lemurs, small primates endemic to Madagascar.

According to a press release from the open access journal BMC Physiology, where the work was published,

Fabienne Aujard, from the Centre National de la Recherche Scientifique, Paris, France, worked with a team of researchers to investigate the effect of dietary supplementation with resveratrol on the weight, metabolism and energy intake of six mouse lemurs. She said, "The physiological benefits of resveratrol are currently under intensive investigation, with recent work suggesting that it could be a good candidate for the development of obesity therapies. We've found that lemurs eating a diet supplemented with the compound decreased their energy intake by 13% and increased their resting metabolic rate by 29%".

The researchers demonstrated that a four-week resveratrol supplementation was associated with a decrease in food intake and a reduction in seasonal body-mass gain. The response to resveratrol supplementation also involved significant changes in the animals' body temperatures. According to Dr Aujard, "These results provide novel information on the potential effects of resveratrol on energy metabolism and control of body mass in a primate".

Previous research has shown that resveratrol can combat the ill-effects of obesity in rodents fed a high-fat diet. But the doses used in both rodent and the lemur studies are too high to be replicated in humans; the equivalent dose for an average person would be about 14 grams per day. Sirtris, a Massachusetts company owned by GlaxoSmithKline, is developing compounds thought to mimic the molecular effects of the resveratrol more potently. One compound is currently in clinical trials for type 2 diabetes. (For more on Sirtris, see The Argument over Aging in TR's July 2010 issue.)

Photosynthetic humans--endowed with the power to derive energy from the sun--are a popular construct of science fiction. But Pamela Silver, a biologist at Harvard Medical School, aims to push that concept into reality.

Silver's research focuses on cyanobacteria, a microbe responsible for almost 50 percent of the earth's photosynthetic ability. Her team aims to harness the organisms' photosynthetic powers by engineering them to generate fuel and other valuable chemicals.

But Silver is also experimenting with a more fantastical use for the microbes. In a recent experiment, researchers injected fluorescently labeled cyanobacteria into zebrafish embryos, a species commonly used in research. The fish are transparent, making them easy to observe during development. Much to Silver's surprise, the fish survived and grew, as did the fluorescent microbes living inside their cells. "When we put E. coli into fish, they blew up, but they are extremely tolerant of cynabacteria," Silver said at a synthetic biology conference in Boston last week, where she presented the research. Right now, the system doesn't make enough energy to maintain the fish, but the researchers are experimenting with different engineering approaches to enhance production.

The video below shows Zebrafish embryos (green) that have been injected with photosynthetic cyanobacteria (red).

The ability to run on sunlight would certainly be a handy superpower. But what if you still like to eat? James Liao, a biologist at UCLA, has developed a new strategy to enhance cells' ability to burn fat by adding a metabolic pathway from bacteria and plants. (For more details, see Making Fat Disappear.) "Female mice show a huge decrease in diet-induced obesity, and they accumulate much less fat," said Liao at the conference. Results for male mice are less dramatic, though it's not clear why.

Want to drop a few pounds on your next vacation? Head for the mountains, the taller the better.

Researchers from Germany studied 20 obese men both at low altitude in Munich and while spending a week at 8700 feet, in a field station near the peak of Germany's highest mountain, Zugspitze. Participants lost an average of two pounds that week and kept it off for the next month, without making any changes in diet or activity levels. During their high altitude stay, the men were given unrestricted access to food and restricted to short walks.

The researchers found that basal metabolism increased at high altitude, though it's not clear why. Levels of leptin, a hormone known to suppress hunger, also increased, perhaps in response to decreased oxygen. Participants ate less, even after symptoms of altitude sickness had disappeared. And they continued to eat less after returning to Munich, at least during the four week follow-up period of the study. The research was published this month in the journal Obesity.