Patchouli is a plant being studied for its anti-viral, anti-inflammatory, antibacterial and immunomodulatory effects (1).
Patchouli is frequently used in the fragrance industry to scent perfumes, essential oils and is used in aromatherapy.
The main bioactive of patchouli is patchouli alcohol, which is also being studied for its potential to treat such conditions as the flu, cancer and depression.
Patchouli may help reduce symptoms of depression. While studies have been limited and mainly performed in mice, patchouli shows early signs of having an antidepressant effect.
Researchers administered oral doses of 10, 20 and 40mg/kg of patchouli oil in mice. After two weeks of supplementation, they used the forced swim test to help determine the antidepressant effects.
Results reveal that a single administration (40mg/kg) significantly inhibited the immobility period in mice (immobility is considered a behavior of depression in mice).
Chronic administration of extract (20 and 40mg/kg) also significantly reduced the immobility period (2).
In addition, there was a significant increase of norepinephrine and dopamine levels (neurotransmitters) in the forebrains of the mice.
Mood is indirectly related to norepinephrine and dopamine levels; research shows that low levels are contributing factors to depression.
In another study, the inhalation of patchouli oil caused a 40 percent decrease in relative sympathetic activity. The sympathetic nervous system releases hormones to accelerate the heart rate — which induces the fight-or-flight response (3).
Patchouli may have anti-inflammatory properties. According to the results of a study published in a 2013 issue of Food and Chemical Toxicology, patchouli alcohol shows anti-inflammatory activities through suppressing the ERK-mediated NF-κB pathway in mouse macrophage and human colorectal cancer cells (4).
Macrophages are an integral part of the inflammation response. They are a complex group of cells that play multiple, sometimes opposing, roles in inflammation and tissue repair.
Macrophage dysfunction is associated with chronic inflammation and poorly healing wounds (5).
In a 2012 experimental study, researchers noted that combination therapy of patchouli alcohol, chrysanthemum and Curcuma wenyujin possessed potent anti-inflammatory activity in a mouse model. Specifically, it reduced ear vasodilation (indicative of inflammation) and carrageenan-induced paw edema (6)
Patchouli may help treat certain strains of viral influenza. In an in vitro and in vivo study conducted in mice, patchouli alcohol possessed anti-influenza A (H2N2) virus properties (7).
Researchers noted that the inhibition by patchouli alcohol appears strongly after penetration of the virus into the cell. In the influenza mouse model, patchouli alcohol showed protection against the viral infection at a dose of 5 mg/kg/day.
According to International Immunopharmacology, oral administration (20 mg/kg to 80 mg/kg) of patchouli alcohol in a mouse model infected with lethal levels of influenza virus A (FM1), significantly increased the survival rate and survival time.
For influenza virus infection at non-lethal levels, the quantity of infection in the lungs was significantly reduced five days after patchouli administration (8).
Whether or not patchouli will be a potential anti-influenza agent remains to be seen.
Patchouli shows antibacterial activity. Using an in vitro antibacterial test, researchers found that among the 31 tested chemical compounds, patchouli alcohol exerted strong antibacterial properties against E. coli, P. aeruginosa, B. proteus, S. dysenteriae, T. bacillus and S. aureus.
In addition, it had a greater affect in fighting H. pylori (a common cause of peptic ulcers) than amoxicillin without altering the normal flora of the gastrointestinal tract (9).
Patchouli may treat lung injury. Acute lung injury/acute respiratory distress syndrome is a condition characterized by pulmonary edema and acute inflammation. Building on their findings of patchouli’s anti-inflammatory properties, researchers set out to investigate if supplementation can improve inflammation associated with this syndrome.
Using a mouse model, they administered patchouli alcohol one hour before and after administering lipopolysaccharide to induce lung injury.
The results showed that patchouli significantly decreased the wet-to-dry weight ratio of lungs (use of lung weight is a biomarker for lung fluid) and the number of total cells, neutrophils and macrophages seven hours after the lipopolysaccharide challenge.
In addition, it also suppressed the production of inflammatory cytokines (signaling molecules that promote inflammation), such as tumor necrosis factor-α, interleukin-1β, and interleukin-6 (10).
Patchouli may help treat irritable bowel syndrome (IBS) with diarrhea. IBS affects between 25 and 35 million people in the U.S. IBS is a disorder that affects the large intestine (11).
While scientists are not sure of the exact cause, they have found that the colon in those with IBS contracts more often than those without the disorder.
In a recent 2018 study, researchers studied the effects of patchouli alcohol on stress-induced diarrhea-predominant irritable bowel syndrome. They found that supplementation in rats exerted a concentration-dependent inhibitory effect on the spontaneous contractions of the smooth muscle layers of the colon.
While more research is needed, patchouli may play a future role as a therapeutic treatment for IBS with diarrhea (12).
Patchouli may treat ulcerative colitis. Ulcerative colitis is a chronic disease in which the lining of the large intestine becomes inflamed and develops ulcers. It is a result of an abnormal response by the body’s immune system. Symptoms include cramps and abdominal pain, looser bowel movements, persistent diarrhea with blood in the stool and low energy (13).
In a recent study, researchers found that patchouli alcohol improves colitis in mice. The mice were supplemented with 10, 20 and 40mg/kg patchouli or sulfasalazine (an anti-inflammatory that is prescribed to treat ulcerative colitis) for seven days.
In their final assessment, researchers noted that supplementation improved colitis by suppressing inflammation, maintaining the integrity of intestinal epithelial barrier and inhibiting cell death signaling (14).
There is not enough information available to know what and if there are any side effects or interactions with patchouli use.
The only doses tested so far have been limited to animal studies. There have not yet been studies on the recommended dosage for humans.
Patchouli is a plant being studied for its anti-viral, anti-inflammatory, antibacterial and immunomodulatory effects. Patchouli alcohol is the major chemical component extracted from the plant.
Several in vitro and animal studies show its potential to treat lung injuries, depression, certain strains of the influenza virus, irritable bowel syndrome and ulcerative colitis.
In-depth human studies and trials are needed to determine the efficacy, optimal dosage and safety of patchouli.