Agha-Hosseini F, Borhan-Mojabi K, Monsef-Esfahani HR, et al. Efficacy of purslane in the treatment of oral lichen planus. Phytother Res. July 7, 2009. [Epub ahead of print].

Oral lichen planus (OLP) is a T-cell-mediated autoimmune disease characterized by oxidative stress and inflammation of the squamous epithelial tissue lining the oral cavity. OLP lesions can cause pain and difficulty eating and speaking. OLP is possibly linked to the development of squamous cell carcinoma. Current conventional therapies are non-curative symptomatic treatments that only act temporarily and most are associated with significant adverse effects. In this randomized, double-blind, placebo-controlled clinical trial, researchers have examined the effect of treatment with an alcoholic extract of purslane (Portulaca oleracea) on OLP. Purslane has omega-3 fatty acids, beta-carotene, vitamins A, C, and E, and melatonin, and it possesses anti-inflammatory, antiulcerogenic, antifungal, and antioxidant effects.

Aerial parts of purslane were collected during the spring in Karajin the Tehran Province, Iran, and a voucher specimen was deposited at the Instituteof Plantsin Karaj, Iran. The plant material was extracted 3 times with 80% ethanol, filtered, dried, and encapsulated into 235 mg capsules with lactose. The researchers recruited 37 patients (females: n=21, males: n=16) from the Department of Oral Medicine at the Tehran and Qazin Universities of Medical Sciences (Tehran, Iran) between April 1, 2006, and May 1, 2008. The patients had OLP diagnosed according to a modified definition of the World Health Organization (WHO) criteria. The patients were given lesion scores (LS) from 5 (white striae and erosive area>1 cm²) to 0 (no lesions). The subjects' pain and discomfort was rated on a visual analogue scale (VAS) from 0 (no pain) to 10 (extreme pain). The symptomatic response (SR) was calculated by subtracting the final VAS score from the initial VAS score. The clinical response (CR) was calculated as the change in LS from baseline to 6 months, each number reduction constituting a degree of improvement. The subjects were randomized to receive 235 mg/day purslane extract (n=20, 60 lesions) or the placebo (n=17, 46 lesions) for 6 months. 

The patients had oral lesions at the following sites in decreasing order: buccal mucosa, gingiva, tongue, labial mucosa, and the palate. In the purslane group, 83% of patients had partial to complete clinical improvements (54% with 2 to 4 degrees of improvement), while 17% had no response to treatment. In the control group, 17% of patients had a partial improvement (all only 1 degree of improvement), 73% showed no improvement, and 10% experienced a worsening of symptoms. The CR was significantly better in the purslane group compared to the control group (P<0.001). All of the patients in the purslane group had a partial to complete SR (57% with 2 to 3 degrees of improvement). In the control group, 71% of the subjects showed a partial response (all only 1 degree of improvement), 15% had no response, and 14% experienced a worsening of symptoms. The SR was significantly better in the purslane group compared to the control group (P<0.001). No adverse side effects were observed in either group.

The authors conclude that purslane is beneficial in the treatment of OLP without the adverse side effects of conventional treatments. Omega-3 fatty acids, melatonin, and other purslane constituents have antioxidant and anti-inflammatory effects that may be involved synergistically in the mechanisms of action. Purslane's antioxidant components may help prevent the formation of cancerous lesions associated with OLP, but more research is required. Further clinical studies with larger samples of patients and longer follow-up periods are needed to confirm the results of this study.