Biologically, methanogens in the colon can use carbon dioxide and hydrogen to produce methane as a by-product. It was previously considered that humans do not utilize methane. However, in a recent study on rodents, results demonstrated that methane could exert anti-inflammatory, anti-oxidant and anti-apoptotic effects. Furthermore, it has bee suggested, that methane-rich saline could be a promising therapeutic agent for clinical treatment of pancreatitis. Methane gas may also be a promising option for the clinical treatment of Acute Lung Injury and Spinal Cord Injury. The exact mechanism underlying the antioxidative, anti-inflammatory, and antiapoptotic activities of methane is not obvious. Different researchers have proposed different hypotheses. Some have hypothesized that methane might accumulate transiently at the interfaces of cell membranes, thereby changing the physicochemical properties or the in-situ functionality of proteins embedded within this environment. Other investigators have suggested that methane could exert effects on membrane channels affecting G-proteins, membrane or receptor-mediated signaling, or acetylcholine-activated ion channel kinetics. It is unknown if mammalian cells contain an oxygenase that is capable of using methane as a substrate, or if the biological effects of methane are caused by the formation of small amounts of the reactive alcohol, methanol, and/or changes in the redox milieu of the cell due to changes in NAD(P)+/NAD(P)H ratio, and whether or not there is a cellular “receptor” for methane. There are also questions remaining around the difference between intraperitoneal vs inhaled administration of methane.