Cells on the surface of the skin are constantly being replaced by regeneration from below. The repair of a wound is a scaling up of this normal process, with additional complex interactions among cells, formation of new blood vessels, collagen, more extensive cell division and cell migration, as well as strict control of inflammatory cells and the cytokines they release to resolve the inflammation.

Cells were pretreated with indicated concentrations of Tβ4 peptide for 2 hours and then incubated with 200 μM H2O2 for 48 hours (A-C). Protein expressions were assessed by Western blot analysis (A). The production of NO (B) and PGE2 (C) were measured by Griess reaction and ELISA, respectively. Data replicated the quantifications of NO and PGE2 with the standard deviation of at least three experiments (n = 4). The bar graph shows the fold increase in protein expression compared with control cells. * Statistically significant differences compared with the control, p<0.05. # Statistically significant difference compared with the H2O2—treated group.


Many early studies of oxytocin for autism were limited because they assessed only a single dose and had relatively few participants, and later experiments with more doses failed to show the same promise. In 2010, clinical psychologist Adam Guastella at the University of Sydney in Australia studied 16 male adolescents with autism spectrum disorder, and found that one dose of oxytocin could improve their ability to gauge the emotions of others by looking at their eyes13. But when he tried giving twice-daily doses of the hormone for two months, he found no significant improvements in social interaction or social cognition14. “Studies to this point have really shown limited benefit of oxytocin in improving psychiatric illnesses over time,” he says. Guastella says that getting to the bottom of oxytocin's complex neurological effects will take time. “If we want a simple answer, we're not going to get it.”
About ten years ago, psychology studies started to show that single doses of oxytocin, delivered through an intranasal spray, could promote various aspects of social behaviour in healthy adults. People who inhaled oxytocin before playing an investment game were more willing to entrust their money to a stranger than were placebo-treated players10. A dose of the hormone also increased the amount of time that people spent gazing at the eye region of faces11, and improved their ability to infer the emotional state of others from subtle expressions12.
Oxytocin secreted from the pituitary gland cannot re-enter the brain because of the blood-brain barrier. Instead, the behavioral effects of oxytocin are thought to reflect release from centrally projecting oxytocin neurons, different from those that project to the pituitary gland. Oxytocin receptors are expressed by neurons in many parts of the brain and spinal cord, including the amygdala, ventromedial hypothalamus, septum and brainstem.
Thymosin β4 has been tested in multicenter trials sponsored jointly by RegeneRx Biopharmaceuticals Inc (Rockville, MD, USA) and Sigma Tau (Pomezia, Italy) in the United States and Europe in patients with bed sores, ulcers caused by venostasis, and Epidermolysis bullosa simplex and was found to accelerate bed sore and stasis ulcer repair by one month. It has also been tested in patients with chronic neurotrophic corneal epithelial defects and found to promote repair.
“People got quite excited,” recalls clinical neuroscientist Evdokia Anagnostou, who co-directs the Autism Research Centre at Holland Bloorview Kids Rehabilitation Hospital in Toronto, Canada. But Anagnostou says that some preliminary steps were skipped over as researchers rushed to test oxytocin as a psychiatric drug. “To be honest, if we had done it properly, we wouldn't have done it the way we did. It went a little bit too fast,” she says. Because oxytocin had cleared the early, standard steps of drug development decades earlier, some researchers did not systematically test a range of doses to see whether they had differing psychological effects.

Romantic attachment: In some studies, high levels of plasma oxytocin have been correlated with romantic attachment. For example, if a couple is separated for a long period of time, anxiety can increase due to the lack of physical affection. Oxytocin may aid romantically attached couples by decreasing their feelings of anxiety when they are separated.[101]
When stressed, individuals become mentally and emotionally overwhelmed quite easily. Although individuals can quickly experience the effects of stress on their mental well-being, physical health is also at risk. Some stress is normal. However, chronic stress levels can increase the risk of heart disease and other serious health complications. Regardless of your personal stressor, it is critical to try managing rising stress levels to protect your current and future health. The following highly effective methods will help everyone unwind and promote a more positive state of mind.
Romantic attachment: In some studies, high levels of plasma oxytocin have been correlated with romantic attachment. For example, if a couple is separated for a long period of time, anxiety can increase due to the lack of physical affection. Oxytocin may aid romantically attached couples by decreasing their feelings of anxiety when they are separated.[101]
Thymosin β4 has been tested in multicenter trials sponsored jointly by RegeneRx Biopharmaceuticals Inc (Rockville, MD, USA) and Sigma Tau (Pomezia, Italy) in the United States and Europe in patients with bed sores, ulcers caused by venostasis, and Epidermolysis bullosa simplex and was found to accelerate bed sore and stasis ulcer repair by one month. It has also been tested in patients with chronic neurotrophic corneal epithelial defects and found to promote repair.
In humans, 5-HTP is the nutrient precursor to the neurotransmitter serotonin – widely known as the 'happy neurotransmitter' – meaning 5-HTP converts directly into serotonin in the brain. As well as being in our bodies, it's found naturally in the seeds of a woody shrub native to West Africa. By taking it as a supplement, in theory, you will end up with more serotonin in your brain. Serotonin deficiency is linked to depression, anxiety and a whole host of physical and mental ailments. Raising its levels seems to help brain cells send and receive chemical messages, which in turn boosts mood.
Three groups of mice were individually placed in cages with aggressive mice and experienced social defeat, a stressful experience for them. One group was missing its oxytocin receptors, essentially the plug by which the hormone accesses brain cells. The lack of receptors means oxytocin couldn't enter the mice's brain cells. The second group had an increased number of receptors so their brain cells were flooded with the hormone. The third control group had a normal number of receptors.
“The study is kind of a high-water mark for the field, putting different levels all together: a robust behaviour, a brain region, and a cellular basis for it,” says Richard Tsien, a neuroscientist also at Langone. Tsien has been studying the action of oxytocin on neuronal circuits in detail, by examining slices of the hippocampus, a region involved in learning and memory. In a 2013 study6 of rats, Tsien's team found that oxytocin selectively acts on a type of cell called an inhibitory interneuron in a way that quiets background chatter within the neuronal circuit. “Oxytocin improved signal transmission, almost doubling the ability of information to flow through the system,” Tsien says. In effect, it is producing more signal and less noise.
As reactive oxygen species (ROS) have been implicated in the pathogenesis of periodontitis [24], we examined whether H2O2 could down-regulate or up-regulate Tβ4 expression in PDLCs. As shown in Fig 1A and 1B, Tβ4 mRNA and protein expressions were down-regulated by H2O2 in a time- and concentration-dependent manner. Because maximal Tβ4 mRNA and protein expressions were achieved with 200 μM H2O2 within 48 hours in PDLCs, this concentration was used in subsequent experiments.

Six hours later, the mice were returned to cages with the aggressive mice. The mice that were missing their oxytocin receptors didn't appear to remember the aggressive mice and show any fear. Conversely, when mice with increased numbers of oxytocin receptors were reintroduced to the aggressive mice, they showed an intense fear reaction and avoided the aggressive mice.

Thymosin β4 was initially perceived as a thymic hormone. However this changed when it was discovered that it forms a 1:1 complex with G (globular) actin, and is present at high concentration in a wide range of mammalian cell types.[11] When appropriate, G-actin monomers polymerize to form F (filamentous) actin, which, together with other proteins that bind to actin, comprise cellular microfilaments. Formation by G-actin of the complex with β-thymosin (= "sequestration") opposes this.
In addition, in the Phase 1 clinical trial in healthy volunteers using a randomised, double-blind, placebo-controlled single- and multiple-dose Phase 1 clinical trial, the safety and pharmacokinetics of the intravenous administration of TB-4 was evaluated. From this, intravenous administration of TB-4 appears to be safe and well-tolerated by all subjects with no dose limiting toxicity or serious adverse events reported.
In regards to interventions, one study in treatment resistant depressed persons that combination therapy of 5-HTP with Carbidopa noted that 43 out of 99 (43.4%) patients improved with an average 200mg (variable 50-600mg) dosage of 5-HTP.[24] It has been noted[25] that since Cardidopa is a peripheral decarboxylase inhibitor that can prevent metabolism of monoamines including serotonin[26] that these results are unlikely to reflect monotherapy with 5-HTP, despite being within the 30-45% range sometimes seen with the placebo effect.[25][27]
For decades, 5-HTP has been recognized as important to appetite regulation. Higher levels of serotonin are linked to diminished appetite. Keeping serotonin levels from dipping can help keep appetite in check, and may help reduce cravings for carbohydrates. As a serotonin booster, 5-HTP may help to suppress appetite. Research indicates that 5-HTP may be effective in helping people who are overweight or obese lose weight.

Who is 5-HTP best for? Emotional eaters stand to benefit greatly, of course. So do carb addicts. Carbs help the body make 5-HTP — so when 5-HTP or serotonin are low, carb cravings kick in. Boosting 5-HTP with a supplement has been shown to slash carb cravings by more than 50 percent. And if a “fat gene” runs in your family, early evidence hints that this genetic tendency toward obesity is linked to “decreased activity of an enzyme that helps turn tryptophan into 5-HTP,” explains Michael T. Murray, ND, author of 5-HTP: The Natural Way to Overcome Depression, Obesity and Insomnia ($14.77, Amazon). Though more human research is needed, Dr. Murray believes 5-HTP supplements are a quick fix for the genetic glitch.


Obviously nobody is suggesting coming off your medication, and for many cases of depression and anxiety, a course of SSRIs and/or CBT can be life-saving. For me, during a period of bad anxiety, when I was torn between the idea of going back on antidepressants or not, I began searching for some sort of alternative aid online and soon came across a video of Jim Carrey. Carrey has struggled with depression for the majority of his adult life; he's a classic case of the sad clown. "I take... supplements," he tells Larry King in the clip I found. "Vitamins?" asks King. Not quite, but not far off either. A natural substance called 5-HTP. "It's a wonderful thing," Carrey smiles. "It's amazing." His description of how 5-HTP worked made it sound like a super-drug, a cure-all. All it would take for me would be an anonymous trip to Holland and Barrett and 15 quid. Like every other young person, I knew it as a quick fix for MDMA comedowns, but never considered buying it as a medication replacement. Obviously for severe depression and anxiety, a serious course of SSRIs or cognitive behavioural therapy would be more appropriate. But at this point, I was ready for something to ease the transition.

Provide a record of any correspondence between ASADA staff and the World Anti-Doping Authority containing the keywords:  "Thymosin", "Thymosin Beta 4", "TB-500", "TB500", "TB4" or "Thymomodulin" between June 2011 and September 2013. Provide audit logs showing the date upon which Thymosin Beta 4 was published as a banned substance on the check your substances website. Provide a log of all receipts (provided online or by telephone) given to athletes in response to requests containing the keywords "Thymosin", "Thymosin Beta 4", "TB-500", "TB500", "TB4" or "Thymomodulin" between June 2011 and September 2013.
Jump up ^ Carlier MF, Hertzog M, Didry D, Renault L, Cantrelle FX, van Heijenoort C, Knossow M, Guittet E (September 2007). "Structure, function, and evolution of the beta-thymosin/WH2 (WASP-Homology2) actin-binding module". Annals of the New York Academy of Sciences. 1112: 67–75. Bibcode:2007NYASA1112...67C. doi:10.1196/annals.1415.037. PMID 17947587.
To untangle the ways different hormones together influence behavior in more naturalistic contexts, we worked with the Tsimane people in Bolivia. Traditional societies like the Tsimane are not living relics of the past, but their lifeways – small, tight-knit communities that produce their own food – can reveal the kinds of situations our hormone systems are well adapted to.
Recent preclinical studies by us and others have revealed that endogenous neurorestoration is present after TBI, including neurogenesis, axonal sprouting, synaptogenesis, and angiogenesis, which may contribute to the spontaneous functional recovery.13-18 In addition, treatments that promote these neurorestorative processes have been demonstrated to improve functional recovery after brain injury.19,20 However, clinical trials in TBI have primarily targeted neuroprotection, and trials directed specifically at neurorestoration have not been conducted. The essential difference between neuroprotective and neurorestorative treatments is that the former target the lesion that is still not irreversibly injured and the latter treat the intact tissue.19 Thus, neurorestorative treatments can be made available for a larger number of TBI patients.

In the prairie vole, oxytocin released into the brain of the female during sexual activity is important for forming a pair bond with her sexual partner. Vasopressin appears to have a similar effect in males.[57] Oxytocin has a role in social behaviors in many species, so it likely also does in humans. In a 2003 study, both humans and dog oxytocin levels in the blood rose after five to 24 minutes of a petting session. This possibly plays a role in the emotional bonding between humans and dogs.[58]


Bartz found that when she averaged out the volunteers’ results, the sniffs of oxytocin hadn’t seemed to colour their memories of their mothers. But things changed when she looked at them individually. Those who felt more anxious about their relationships took a dimmer view of their mother’s parenting styles when they sniffed oxytocin, compared to the placebo. Those who were more secure in their relationships reacted in the opposite way – they remembered mum as being closer and more caring when they took the oxytocin.
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The studies that have been conducted have determined that this peptide is potent and that it occurs totally naturally. It does help to repair wounds using its anti-inflammatory characteristics. Unlike with growth factors and other repair factors, this peptide increases the migration of endothelial and keratinocyte. It also does not conjoin to extracellular matrixes and is noted as having a molecular weight that is very low, which enables it to travel far distances within tissues.
It turns out oxytocin is responsible for a lot more than just love. New science has found that this amazing molecule also influences how sociable each of us is, allowing us to 'tune in' to the social information around us, perceiving it in much higher resolution. Scientists are now applying this new knowledge in the lab, and as reporter Dr Graham Phillips finds out, they're discovering oxytocin's great potential to treat social disorders, like drug addiction and alcoholism.
Thymosin beta 4 accelerated skin wound healing in a rat model of a full thickness wound where the epithelial layer was destroyed. When Tb4 was applied topically to the wound or injected into the animal, epithelial layer restoration in the wound was increased 42% by day four and 61% by day seven, after treatment, compared to untreated. Furthermore, Tb4 stimulated collagen deposition in the wound and angiogenesis. Tb4 accelerated keratinocyte migration, resulting in the wound contracting by more than 11%, compared to untreated wounds, to close the skin gap in the wound. An analysis of skin sections (histological observations) showed that the Tb4 treated wounds healed faster than the untreated. Proof of accelerated cell migration was also seen in vitro, where Tb4 increased keratinocyte migration two to three fold, within four to five hours after treatment, compared to untreated keratinocytes.
In this study, Tβ4 mRNA down-regulation was detected in in vitro in PDLCs stimulated with the ROS. This down-regulation of Tβ4 was also observed in GCF of periodontitis patient [19] and endotoxin-induced septic shock of rats [39]. ROS were generated predominantly by polymorphonuclear leukocytes (PMN) during an inflammatory response and involved in tissue destruction associated with periodontal diseases [40]. Thus, we chose to use ROS-stimulated PDLCs in this study since ROS, such as superoxide and H2O2, have been proposed as key players in bone resorption [41] and implicated in the pathogenesis of rheumatoid arthritis and periodontitis [29].
How would that work? Feldman thinks that these types of behaviors are intimately linked with oxytocin in a positive feedback loop. “Oxytocin can elicit loving behaviors, but giving and receiving these behaviors also promotes the release of oxytocin and leads to more of these behaviors,” she says. She thinks that talk therapy alone can boost the oxytocin system, but admits that in some cases it might help to jump-start the feedback loop by administering oxytocin. If Guastella’s results support his hypothesis, talk and hormone therapy together might be the best recipe for breaking down dysfunctional communication between partners, especially in cases where the behaviors have been learned in childhood.
These studies demonstrate that in the animal model of TBI, early (6 hours post injury) treatment with Tβ4 i.p. at doses of 6 and 30 mg/kg reduces cortical lesion volume and hippocampal cell loss and improves functional recovery, suggesting its potential as a neuroprotective therapy for TBI. More importantly, delayed (24 hours post injury) treatment with Tβ4 administered i.p. at a dose of 6 mg/kg does not reduce lesion volume but significantly improves functional outcome in rats.34 Tβ4-induced angiogenesis, neurogenesis and oligodendrogenesis may contribute to functional recovery.34 Therefore, our data suggest that promoting endogenous neurorestorative processes using Tβ4 provides a novel therapeutic option for TBI. It should be noted that systemic administration of Tβ4 is safe and well-tolerated by animals and humans.26 Further investigation of the molecular mechanisms underlying Tβ4-mediated neuroprotection and neurorestoration is warranted.

It was also shown recently that delivery of Fgfs by release from peptide nanofibers, a gradual local delivery system, can increase neovascularization and reduce in-farct size in the ischemic rodent heart (Engel et al., 2006). Related to this, zebrafish have a natural ability to synthesize Fgfs after myocardial injury, a signal that appears to recruit Fgf receptor-expressing epicardial-derived cells toward regenerating muscle (Lepilina et al., 2006). Thus, what has been and what will be discovered about zebrafish heart regeneration is quite likely to illuminate possible strategies for enhancing regeneration in the mammalian heart (see Chapter 14.4).


The first study to show that Tβ4-promoted tissue repair was a dermal study performed in rats (Malinda et al., 1999). It had previously been found to promote angiogenesis and was reported to be high in platelets (Grant et al., 1995; Hannappel & van Kampen, 1987; Malinda, Goldstein, & Kleinman, 1997; Philp, Huff, Gho, Hannappel, & Kleinman, 2003). Since platelets are the first cells to enter a wound, it was clear that Tβ4 should be tested in dermal wounds in an animal model (Malinda et al., 1997, 1999; Philp, Badamchian, et al., 2003). In the first dermal study using 8 mm full-thickness punch wounds in rats, Tβ4 at 5 μg/50 μL of phosphate-buffered saline was found to accelerate wound closure, increase angiogenesis, and accelerate collagen deposition (Malinda et al., 1999). Tβ4 was only applied at the time of injury and at 48 h since after that the crust had formed. Visible macroscopic improvement was seen in the treated group by day 4. The study also found that Tβ4 promoted keratinocyte migration in vitro with activity in the picogram range. The findings were confirmed in various additional animal models (Table 1) and led to the clinical trials for hard to heal wound in patients as detailed in Table 2.
Tβ4 is a multifunctional regenerative small peptide containing 43-amino acids, and it is the major G-actin-sequestering molecule in eukaryotic cells.21 Tβ4 has pro-survival and pro-angiogenic properties, protects tissue against damage, and promotes tissue regeneration.22,23 It also plays a key role in corneal, epidermal and cardiac wound healing.21 Tβ4 participates in axonal path-finding, neurite formation, cell proliferation, and neuronal survival.24-26 Our previous studies show that Tβ4 reduces inflammation and stimulates remyelination and improves functional recovery in animal models of experimental autoimmune encephalomyelitis (EAE) and stroke.25,27 In summary, these pleiotropic properties make Tβ4 an ideal candidate for treatment of TBI.
The relationship between oxytocin and human sexual response is unclear. At least two non-controlled studies have found increases in plasma oxytocin at orgasm – in both men and women.1718 The authors of one of these studies speculated that oxytocin’s effects on muscle contractibility may facilitate sperm and egg transport.19 Murphy et al. (1987), studying men, found that oxytocin levels were raised throughout sexual arousal and there was no acute increase at orgasm.20 A more recent study of men found an increase in plasma oxytocin immediately after orgasm, but only in a portion of their sample that did not reach statistical significance. The authors noted that these changes “may simply reflect contractile properties on reproductive tissue.”21

Three groups of mice were individually placed in cages with aggressive mice and experienced social defeat, a stressful experience for them. One group was missing its oxytocin receptors, essentially the plug by which the hormone accesses brain cells. The lack of receptors means oxytocin couldn't enter the mice's brain cells. The second group had an increased number of receptors so their brain cells were flooded with the hormone. The third control group had a normal number of receptors.


Horvath, G. A., Stockler-Ipsiroglu, S. G., Salvarinova-Zivkovic, R., Lillquist, Y. P., Connolly, M., Hyland, K., Blau, N., Rupar, T., and Waters, P. J. Autosomal recessive GTP cyclohydrolase I deficiency without hyperphenylalaninemia: evidence of a phenotypic continuum between dominant and recessive forms. Mol.Genet.Metab 2008;94:127-131. View abstract.
The first bit of evidence that points to oxytocin as nature’s love glue comes from researchers who measured the hormone in couples. Psychology professor Ruth Feldman at Bar-Ilan University in Israel, spent years studying oxytocin’s role in the mother–child bond and recently decided to dive into the uncharted waters of romantic bonds by comparing oxytocin levels in new lovers and singles. “The increase in oxytocin during the period of falling in love was the highest that we ever found,” she says of a study she and her colleagues published in Psychoneuroendocrinology. New lovers had double the amount Feldman usually sees in pregnant women.
In another study, published in PNAS in 2010, men were given a dose of oxytocin and asked to write about their mothers. Those with secure relationships described their moms as more caring after the hormone dose. Those with troubled relationships actually saw their mothers as less caring. The hormone may help with the formation of social memories, according to the study researchers, so a whiff strengthens previous associations, whether good or bad.
Oxytocin was also correlated with the longevity of a relationship. Couples with the highest levels were the ones still together six months later. They were also more attuned to each other than the low-oxytocin couples when Feldman asked them to talk about a shared positive experience. The high-oxytocin couples finished each other’s sentences, laughed together and touched each other more often. Feldman says it’s still not clear whether oxytocin was responsible for the stability of the couple’s bond six months later or if couples who weren’t as connected failed to trigger the oxytocin system.
Research in the early 1960s showed that in rats, administration of α-MSH caused sexual arousal, and work on this continued in many labs up through the 1980s, when scientists at University of Arizona began attempting to develop α-MSH and analogs as potential sunless tanning agents, and synthesized and tested several analogs, including melanotan-I and melanotan II.[6][9]
5-HTP (5-Hydroxytryptophan) is a chemical by-product of the protein building block L-tryptophan. It is also produced commercially from the seeds of an African plant known as Griffonia simplicifolia 5-HTP is used for sleep disorders such as insomnia, depression, anxiety, migraine and tension-type headaches, fibromyalgia, obesity, premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), attention deficit-hyperactivity disorder (ADHD), seizure disorder, and Parkinson's disease..
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