Safety assessment, biological effects, and mechanisms of Myrica rubra fruit extract for anti-melanogenesis, anti-oxidation, and free radical scavenging abilities on melanoma cells.

OBJECTIVE: Currently, the cosmetic and medical industries are paying considerable attention to solve or prevent skin damage or diseases, such as hyperpigmentation and oxidation and free radical damage. In this study, the effective compounds in Myrica rubra fruit were extracted and studied the biological effects of these M. rubra fruit extracts. METHODS: In this study, we extracted M. rubra fruit using solutions with various ratios of water to ethanol (100:0, 50:50, 5:95) and studied the anti-melanogenesis, anti-oxidation and radical scavenging effects of these M. rubra fruit extracts on two melanoma cell lines: mouse melanoma (B16-F0) and human melanoma (A2058). The cytotoxicity, melanin synthesis, mushroom and cellular tyrosinase activities, enzyme kinetics, melanogenesis-related gene expression, melanogenesis-related protein secretion, radical DPPH scavenging activity and ROS inhibition after treatment with M. rubra fruit extracts were determined. RESULTS: The results showed that the water extract of M. rubra fruit was less cytotoxic to the melanoma cell lines, effectively inhibited melanin synthesis and tyrosinase activity and down-regulated the gene expression and protein secretion of MITF and TRP-1. In addition, the M. rubra fruit extracts also showed the abilities to scavenge DPPH free radicals and suppress ROS production. Finally, the effective compounds in the water extract were Myricetin-O-deoxyhexoside, Quercetin-O-deoxyhexoside, and Kaempferol-O-hexoside determined by LC/MS/MS assay. CONCLUSION: Overall, the water extract of M. rubra fruit is a safe and effective melanin inhibitor and anti-oxidant and can be applied widely in the fields of cosmetics and medicine.

Antioxidant and Antityrosinase Activity of Flemingia macrophylla and Glycine tomentella Roots.

The antioxidant and antityrosinase activities of the water extract of Flemingia macrophylla root (WEFM) were investigated. The results showed that WEFM exhibited radical scavenging and reducing activities, as well as ferrous ion chelating property. In addition, WEFM also protected phospholipids against oxidation, indicating that WEFM could protect biomolecules from oxidative damage. Meanwhile, in the range of 50-100 µg/mL, the tyrosinase inhibitory activity of WEFM increased with an increase in sample concentration and was superior to that of the water extract of Glycine tomentella root (WEGT). A high performance liquid chromatography analysis was used to determine the phenolic components, revealing that daidzin, daidzein, genistin, and genistein were present in WEFM and WEGT. Acting as an antioxidant and a tyrosinase inhibitor, these bioactive constituents could contribute to the protective effects of WEFM. Overall, the results showed that WEFM might serve as a natural antioxidant and tyrosinase inhibitor.

Antioxidant and antityrosinase activity of mulberry (Morus alba L.) twigs and root bark.

The antioxidant and antityrosinase activities of the ethanolic extract of mulberry twigs (EEMT) were investigated. The results showed that EEMT exhibited radical scavenging and reducing activity, as well as ferrous ion-chelating activity. In addition, EEMT also protected phospholipids against free radicals, indicating that EEMT could protect biomolecules from oxidative damage. Meanwhile, in the range of 0-60 µg/ml, the tyrosinase inhibitory activity of EEMT increased with increase in sample concentration, and was superior to that of the ethanolic extract of mulberry root bark (EEMR). High-performance liquid chromatography (HPLC) analysis was employed to determine the phenolic components, revealing that maclurin, rutin, isoquercitrin, resveratrol, and morin were present in EEMT. Acting as an antioxidant and a tyrosinase inhibitor, these bioactive constituents could contribute to the protective effects of EEMT. Overall, the results showed that EEMT might serve as a natural antioxidant and tyrosinase inhibitor.

Chemical identification of the sources of commercial Fructus Chebulae.

Twenty-eight commercial samples of Fructus Chebulae were collected from local herbal markets in Taiwan and were determined to have been derived from Terminalia chebula Retz. and Terminalia chebula Retz. var. parviflora Thwaites, which differ markedly in external appearance. Ten tannin-related constituents [gallic acid (1), chebulic acid (2), punicalagin (4), chebulanin (7), corilagin (8), neochebulinic acid (9), ellagic acid (11), chebulagic acid (12), chebulinic acid (13) and 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (14)] were identified and quantified by HPLC. Samples derived from T. chebula. var. parviflora, which are typically round-shaped, generally contained higher concentrations of 13 and 14 but lower levels of 12 compared with those from T. chebula, which are largely oval-shaped. The ratio of the concentration of 14 to that of 4 may serve as a potential parameter for differentiating samples from the two origins (T. chebula, ratio 0.6 +/- 0.3; T. chebula. var. parviflora, ratio 3.4 +/- 2.2). Levels of the three major bioactive constituents 12-14 were found to provide good references for the quality assessment of Fructus Chebulae. The ratio of the concentration of 12 to that of 14 may offer a guideline for determining quality as well as origin of the drug (lower-grade T. chebula, ratio 12.4 +/- 6.0; medium-grade T. chebula, ratio 8.8 +/- 7.9; higher-grade T. chebula, ratio 3.2 +/- 0.8; T. chebula var. parviflora, ratio 1.6 +/- 0.7).

Determination of hydrolyzable tannins in the fruit of Terminalia chebula Retz. by high-performance liquid chromatography and capillary electrophoresis.

A RP-HPLC method for determining fourteen components (gallic acid, chebulic acid, 1,6-di-O-galloyl-D-glucose, punicalagin, 3,4,6-tri-O-galloyl-D-glucose, casuarinin, chebulanin, corilagin, neochebulinic acid, terchebulin, ellagic acid, chebulagic acid, chebulinic acid, and 1,2,3,4,6-penta-O-galloyl-D-glucose) in the fruit of Terminalia chebula Retz. is described. The separation was achieved within 80 min using a binary gradient with mobile phases consisting of a pH 2.7 phosphoric acid solution and an 80% CH3CN solution. Capillary electrophoretic analyses were also attempted, and it was found that CZE (25 mM Na2B4O7, 5 mM NaH2PO4, pH 7.0) was an efficient method for the separation of gallotannins, while an MEKC method (25 mM Na2B4O7, 5 mM NaH2PO4, 20 mM SDS, pH 7.0, and 10% acetonitrile) provided a better separation for most of the tannins examined. The HPLC and CE methods developed were both successfully applied to the assay of tannins in commercial samples of Chebulae Fructus.