Anti-Inflammatory Effects of Agrimoniin-Enriched Fractions of Potentilla erecta.

Potentilla erecta (PE) is a small herbaceous plant with four yellow petals belonging to the Rosaceae family. The rhizome of PE has traditionally been used as an antidiarrheal, hemostatic and antihemorrhoidal remedy. PE contains up to 20% tannins and 5% ellagitannins, mainly agrimoniin. Agrimoniin is a hydrolyzable tannin that is a potent radical scavenger. In this study we tested the anti-inflammatory effect of four PE fractions with increasing amounts of agrimoniin obtained by Sephadex column separation. First, we analyzed in HaCaT keratinocytes the expression of cyclooxygenase-2 (COX-2) induced by ultraviolet-B (UVB) irradiation. As COX-2 catalyzes the metabolism of arachidonic acid to prostanoids such as PGE2, we also measured the PGE2 concentration in cell culture supernatants. PE inhibited UVB-induced COX-2 expression in HaCaT cells and dose-dependently reduced PGE2. The PE fraction with the highest agrimoniin amount (PE4) was the most effective in this experiment, whereas fraction PE1 containing mainly sugars had no effect. PE4 also dose dependently inhibited the phosphorylation of the epidermal growth factor receptor (EGFR) which plays a crucial role in UVB-mediated COX-2 upregulation. A placebo-controlled UV-erythema study with increasing concentrations of PE4 demonstrated a dose dependent inhibition of UVB-induced inflammation in vivo. Similarly, PE4 significantly reduced UVB-induced PGE2 production in suction blister fluid in vivo. In summary, PE fractions with a high agrimoniin content display anti-inflammatory effects in vitro and in vivo in models of UVB-induced inflammation.

In vivo photoprotective and anti-inflammatory effect of hyperforin is associated with high antioxidant activity in vitro and ex vivo.

Hyperforin, a major constituent of St. John's Wort (Hypericum perforatum, HP), provides anti-inflammatory, anti-tumor, and anti-bacterial properties. Previous studies have shown anti-oxidative properties of St. John's Wort extracts; however, its free radical scavenging activity in skin cells or skin has not been assessed in detail so far. Therefore, the free radical scavenging activity of hyperforin was tested in the H(2)DCFDA-assay in vitro in HaCaT keratinocytes irradiated with solar simulated radiation. Hyperforin (EC(50) 0.7 µM corresponding to 0.42 µg/ml) was much more effective compared to Trolox (EC(50) 12 µg/ml) and N-acetylcysteine (EC(50) 847 µg/ml) without showing phototoxicity. The radical protection factor of a cream containing 1.5%w/w of a hyperforin-rich HP extract was determined to be 200 × 10(14) radicals/mg, indicating a high radical scavenging activity. The cream was further applied ex vivo on porcine ear skin and significantly reduced radical formation after infrared irradiation. Finally, the UV-protective effect of the HP cream was tested on 20 volunteers in a randomized, double-blind, vehicle-controlled study. HP cream significantly reduced UVB-induced erythema as opposed to the vehicle. Occlusive application of HP cream on non-irradiated test sites did not cause any skin irritation. Taken together, these results demonstrate that hyperforin is a powerful free radical scavenger.

Anti-inflammatory potential of a lipolotion containing coriander oil in the ultraviolet erythema test.

SUMMARY BACKGROUND: Coriander oil is used as an antimicrobial agent and as a natural fragrance. The present study investigated the anti-inflammatory potency of coriander oil in the ultraviolet (UV) erythema test in vivo. METHODS: 40 volunteers were enrolled in this monocentric,randomized,placebo-controlled double-blind study.Test areas on the back were irradiated with the 1.5 fold minimal erythema dose UV-B. Subsequently, the test areas were treated under occlusion for 47 hours with a lipolotion containing 0.5% or 1.0% essential coriander oil. Hydrocortisone (1.0%) and betamethasone valerate (0.1%) in the vehicle served as positive controls.The vehicle was used as place-bo.The effect of the test substances on the UV-induced erythema was measured photometrically after 48 hours.Additionally,the skin tolerance of the test preparations was assessed on non-irradiated skin. RESULTS: Compared to placebo, the lipolotion with 0.5% coriander oil significantly reduced the UV-induced erythema, but it was not as effective as hydrocortisone. The skin tolerance of both coriander oil concentrations was excellent. CONCLUSIONS: The lipolotion containing coriander oil displayed a mild antiinflammatory effect in this study. It could be useful in the concomitant treatment of inflammatory skin diseases.