Researchers at the University of California, Berkeley, say that the hormone oxytocin, which is also thought to be the love hormone, may help renew old muscle and improve bone health.

The researchers injected oxytocin under the skin of older mice. They claim that the injection helped the mice restore the reformative capability of their muscle, which helped them heal better when compared to older mice that were not given oxytocin.

Study authors also suggest that the action on old mice was also very fast. The researchers claim that muscle repair in old mice was at around 80 percent when compared to young mice.

Irina Conboy, associate professor of bioengineering and lead investigator of the study, suggests that unfortunately a majority of the molecules that were used to enhance tissues are also related with cancer, which limits experiments on humans.

"Our quest is to find a molecule that not only rejuvenates old muscle and other tissue, but that can do so sustainably long-term without increasing the risk of cancer," says Conboy. "This is the hormone that makes your heart melt when you see kittens, puppies and human babies. There is an ongoing joke among my research team that we're all happy, friendly and trusting because oxytocin permeates the lab."

Conboy and her team highlight that although oxytocin is found both in young boys as well as in girls. It is still unclear when the level of oxytocin begins to drop in humans. The researchers also said that it is not known what levels of oxytocin are required in the human body to maintain healthy tissues.

The oxytocin hormone has other benefits and previous research suggests that it reduces the development of osteoporosis. The research was done on mice, which had their ovaries removed to imitate menopause.

The researchers reveal that they also gave an oxytocin injection to younger mice, but it did not cause a notable alteration to muscle regeneration. The scientists say that it is a good sign as it shows that oxytocin changes old tissues only "without making muscle stem cells divide uncontrollably."

The experiment on young mice also found that when oxytocin was blocked it affected their capability to heal muscle, which resembles to old tissue after an injury.

The findings can lead to therapies that can reverse the effect of age on muscles. However, more research is needed before clinical trials can start on humans.