Alpha-Pinene (α-pinene) is said to be the most widely encountered monoterpene in nature , and as its name indicates, pinene is an integral constituent of the fragrance of the forest. It’s also the main component of turpentine. The alpha and beta isomers of pinene are also found in frankincense, juniper, common herbs like parsley and rosemary, spices like nutmeg, and citrus fruit like lemons and limes.
Breathing deeply in a crisp pine forest can be invigorating and refreshing, and it’s really not surprising given that α-pinene is an expectorant and bronchodilator , just like tetrahydrocannabinol (THC).  This highlights an explanation for why cannabis has been described for many years as having useful applications for asthmatics.
In addition to its effectiveness in aiding respiration, α-pinene has anti-inflammatory properties.  Researchers have found that the α-pinene isomer inhibits inflammation in a specific cell type found in our cartilage, called chondrocytes, thus providing a natural agent for treating osteoarthritis. 
α-Pinene has demonstrated anti-cancer activity against human liver cancer cell lines by obstructing tumor cell growth. [5, 6] Also, the essential oil extracted from frankincense, containing about 62% α-pinene, showed a strong effectiveness against breast cancer cells.  Another interesting study found that when a group of twelve people who worked at large companies in Tokyo went “forest-bathing”, their natural killer (NK) cell activity increased.  NK cells are integral to our immune systems, and provide quick responses to cells infected with viruses and parasites. α-Pinene was one chemical constituent measured in the forest atmosphere that was not detected in urban Tokyo. The authors found that α-pinene, in addition to other terpenes like D-limonene, significantly increased NK activity, as well as the expression of other cytolytic (cell-destroying) molecules like perforin, a protein produced by NK cells that creates lesions in cellular membranes.
Cannabis is often linked to short-term memory loss, however, chemovars high in α-pinene may not submit to that stereotype, as the terpene has been recognized as a memory aid. [9-11] Thus, α-pinene presents an exciting plant-derived molecule offering neuroprotective potential for enhanced management of memory disorders like dementia.  Reversible inhibition of the enzyme called acetylcholinesterase provides a useful mechanism for treating neurodegenerative disorders like dementia. The neurotransmitter acetylcholine plays a crucial role in our central nervous systems, especially in regards to our cognitive abilities.
α-Pinene inhibits acetylcholinesterase , an enzyme that stops the signals between nerve and muscle cells. Acetylcholine carries electrical signals from nerve cells to muscle cells inside synapses. Once it executes its mission, however, it must be removed or destroyed to prevent confusion with other spent or active neurotransmitters. This is where acetylcholinesterase is a necessary biochemical agent, as it breaks down acetylcholine into acetic acid and choline. When this enzyme is inhibited, though, muscular paralysis can ensue. Doctors are now intentionally obstructing this enzyme in attempts to reverse the common symptoms of Alzheimer’s disease. By inhibiting acetylcholinesterase, intra-synaptic acetylcholine increases in concentration, as does the amount of time it’s an intact, functional neurotransmitter.  Substances, like α-pinene, that permit acetylcholine to function longer exemplify the main strategy of commercial drugs used in treating Alzheimer’s disease, since the disease is associated with a decrease in acetylcholine concentration and the neurons that use it.
Cannabis varieties reported to contain higher pinene levels include the legendary Jack Herer, Blue Dream, the Kush Group, and AK-47.
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