Fraxinol Stimulates Melanogenesis in B16F10 Mouse Melanoma Cells through CREB/MITF Signaling.

Melanin pigment produced in melanocytes plays a protective role against ultraviolet radiation. Selective destruction of melanocytes causes chronic depigmentation conditions such as vitiligo, for which there are very few specific medical treatments. Here, we found that fraxinol, a natural coumarin from Fraxinus plants, effectively stimulated melanogenesis. Treatment of B16-F10 cells with fraxinol increased the melanin content and tyrosinase activity in a concentration-dependent manner without causing cytotoxicity. Additionally, fraxinol enhanced the mRNA expression of melanogenic enzymes such as tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2. Fraxinol also increased the expression of microphthalmia-associated transcription factor at both mRNA and protein levels. Fraxinol upregulated the phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB). Furthermore, H89, a cAMP-dependent protein kinase A inhibitor, decreased fraxinol-induced CREB phosphorylation and microphthalmia-associated transcription factor expression and significantly attenuated the fraxinol-induced melanin content and intracellular tyrosinase activity. These results suggest that fraxinol enhances melanogenesis via a protein kinase A-mediated mechanism, which may be useful for developing potent melanogenesis stimulators.

ß-Cell protection and antidiabetic activities of Crassocephalum crepidioides (Asteraceae) Benth. S. Moore extract against alloxan-induced oxidative stress via regulation of apoptosis and reactive oxygen species (ROS).

BACKGROUND: Medicinal plants are becoming more popular in the treatment of various diseases because of the adverse effects of the current therapy, especially antioxidant plant components such as phenols and flavonoids have a protective role against oxidative stress-induced degenerative diseases like diabetes. Thus, the purpose of this study was to investigate ß-cell protection and antidiabetic activities of Crassocephalum crepidioides (Asteraceae) Benth. S. Moore. METHOD: The in-vitro study was conducted by the pancreatic ß-cell culture and α-amylase inhibition technique which includes two methods, namely starch-iodine method and 3,5-dinitrosalicylic acid (DNSA) method. On the other hand, the in-vivo study was performed by oral glucose tolerance test (OGTT) method and alloxan-induced diabetes method by using Wistar albino rat. At the end pancreatic specimens were removed and processed for histopathological study. RESULT: The plant extract showed significant (*p < 0.05, **p < 0.01) effect on hyperglycemia as compared to standard (Gliclazide) in OGTT. The plant extract showed efficient protection activity of pancreatic ß-cell from cell death in INS-1 cell line by significantly reduced (*p < 0.05, **p < 0.01) the levels alloxan-induced apoptosis and intracellular reactive oxygen species (ROS) accumulation. In addition, the plant extract showed a significant (*p < 0.05, **p < 0.01) effect on hyperglycemia by increases in percent of ß-cells present in each islet (45% - 60%) compared to the diabetic group. CONCLUSION: The result showed that C. crepidioides had ß-cell protection and antidiabetic activities in pancreatic ß-cell culture and Wistar albino rat.

Anti-Helicobacter pylori Activity of Six Major Compounds Isolated from Rumex acetosa.

Gastric problems are often caused by the well-known Helicobacter pylori (H. pylori) bacterium. One of the biggest obstacles to the treatment of H. pylori infections is increasing the antibiotic resistance. During our search for naturally derived anti-H. pylori compounds, six major compounds were isolated from the methylene chloride (CH2Cl2) and ethyl acetate (EtOAc) fractions of Rumex acetosa that showed anti-H. pylori activity. Three anthraquinones and three anthraquinone glucosides were identified as the major chemical constituents of the CH2Cl2 and EtOAc fractions, respectively. The chemical structures were identified to be emodin (1), chrysophanol (2), physcion (3), emodin-8-O-ß-d-glucoside (4), chrysophanol-8-O-ß-d-glucoside (5), and physcion-8-O-ß-d-glucoside (6) by UV, 1H NMR, 13C NMR, and mass spectrometry. Anti-H. pylori activity, including the minimum inhibitory concentration (MIC) value of each compound, was evaluated against two H. pylori strains. All isolates exhibited anti-H. pylori activity with different potencies, with an MIC value ranging between 3.13 and 25 µM. However, some variations were found between the two strains. While compound 5 displayed the most potent antibacterial activity with an MIC50 value of 8.60 µM and an MIC90 value of 15.7 µM against H. pylori strain 51, compound 1 exhibited the most potent inhibitory activity against H. pylori strain 43504. The two compounds also showed moderate urease inhibitory activity, with compound 1 demonstrating activity higher than that of compound 5. Furthermore, a molecular docking study revealed the high binding ability of compounds 1 and 5 to the active site of H. pylori urease. The present study suggests that the six anthraquinones isolated from R. acetosa with the whole parts of this plant may be natural candidates for the treatment of H. pylori infection. Further studies are required to determine the exact mechanism of action and to evaluate safety issues in the human body.

Targeting Autophagy for Developing New Therapeutic Strategy in Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IVDD) is a prevalent cause of low back pain. IVDD is characterized by abnormal expression of extracellular matrix components such as collagen and aggrecan. In addition, it results in dysfunctional growth, senescence, and death of intervertebral cells. The biological pathways involved in the development and progression of IVDD are not fully understood. Therefore, a better understanding of the molecular mechanisms underlying IVDD could aid in the development of strategies for prevention and treatment. Autophagy is a cellular process that removes damaged proteins and dysfunctional organelles, and its dysfunction is linked to a variety of diseases, including IVDD and osteoarthritis. In this review, we describe recent research findings on the role of autophagy in IVDD pathogenesis and highlight autophagy-targeting molecules which can be exploited to treat IVDD. Many studies exhibit that autophagy protects against and postpones disc degeneration. Further research is needed to determine whether autophagy is required for cell integrity in intervertebral discs and to establish autophagy as a viable therapeutic target for IVDD.

Anatomical and Chemical Characterization of Ulmus Species from South Korea.

Ulmus species (Ulmaceae) are large deciduous trees distributed throughout Korea. Although their root and stem bark have been used to treat gastrointestinal diseases and wounds in folk medicine, commercial products are consumed without any standardization. Therefore, we examined anatomical and chemical differences among five Ulmus species in South Korea. Transverse sections of leaf, stem, and root barks were examined under a microscope to elucidate anatomical differences. Stem and root bark exhibited characteristic medullary ray and secretary canal size. Leaf surface, petiole, and midrib exhibited characteristic inner morphologies including stomatal size, parenchyma, and epidermal cell diameter, as well as ratio of vascular bundle thickness to diameter among the samples. Orthogonal projections to latent structures discriminant analysis of anatomical data efficiently differentiated the five species. To evaluate chemical differences among the five species, we quantified (-)-catechin, (-)-catechin-7-O-ß-D-apiofuranoside, (-)-catechin-7-O-α-L-rhamnopyranoside, (-)-catechin-7-O-ß-D-xylopyranoside, (-)-catechin-7-O-ß-D-glucopyranoside, and (-)-catechin-5-O-ß-D-apiofuranoside using high-performance liquid chromatography with a diode-array detector. (-)-Catechin-7-O-ß-D-apiofuranoside content was the highest among all compounds in all species, and (-)-catechin-7-O-α-L-rhamnopyranoside content was characteristically the highest in Ulmus parvifolia among the five species. Overall, the Ulmus species tested was able to be clearly distinguished on the basis of anatomy and chemical composition, which may be used as scientific criteria for appropriate identification and standard establishment for commercialization of these species.

Comparative Studies of Fraxinus Species from Korea Using Microscopic Characterization, Phytochemical Analysis, and Anti-Lipase Enzyme Activity.

Fraxinus species belongs to the Oleaceae family, commonly known as Ash tree, and has been utilized as a folk medicine with various medicinal properties, including anti-obesity activity. The goal of the present study was to establish quality control parameters using microscopic characterization, phytochemical differentiation, and anti-lipase activity evaluation of five Fraxinus plants in Korea. Microscopic evaluation of the lower surface, petiole, and midrib of leaves, and stem bark showed discriminative anatomical characteristics, such as the stomatal index of the lower leaf surface; the number of sclerenchyma cells, and the diameter of parenchyma cells in the petiole and midrib; and the cork cell size and fiber frequency in the stem bark. Phytochemical analysis using high-performance liquid chromatography revealed the significant variation in the chemical profiles of the 12 major secondary metabolites among the samples. The orthogonal projections to latent structure-discrimination analysis efficiently differentiated each group belonging to each Fraxinus plant with the anatomical and quantification data. F. rhynchophylla and ligstroside showed the most potent anti-lipase activity among the plants and the 12 major metabolites, respectively. These findings could serve as the scientific criteria for the appropriate identification and establishment of standards for the use of Fraxinus species as medicinal plants.

Comparative Inner Morphological and Chemical Studies on Reynoutria Species in Korea.

Reynoutria species are medicinal plants that belong to the family Polygonaceae and are widely distributed in eastern Asia, North America and Europe. Although the phylogeny and morphological and anatomical studies of some species in Korea have been previously reported, there are no discriminative anatomical and chemical data available. Therefore, anatomical characterization of the leaf, stem and root, and high performance liquid chromatography-diode array detector (HPLC-DAD) analyses were carried out to assess the differences in anatomical and chemical profiles among the Reynoutria plants in Korea, i.e., R. japonica, R. sachalinensis, R. forbesii and R. japonica for. elata. The anatomical evaluation showed discriminative characteristics, such as the shape of the stomata and the stomatal index of the lower leaf surface; the ratio of the adaxial/abaxial height, the size of the vascular bundles and the frequency of druse in the midrib, petiole, and stem; and the pericycle number in the root. For the HPLC analysis, ten compounds corresponding to each major peak were isolated from R. japonica roots and their structures were identified by comprehensive spectroscopic studies. Samples collected before the flowering season showed higher contents of these ten major compounds than those collected after the flowering season. The orthogonal projections to latent structures-discrimination analysis (OPLS-DA) with the inner morphological and HPLC quantification results, clearly discriminated these plants. These results provide anatomical parameters and HPLC profiling that can be used to distinguish the four Reynoutria plants, which supports quality control for their precise identification.

A new anti-Helicobacter pylori juglone from Reynoutria japonica.

A 70% ethanol extract from the root portion of Reynoutria japonica afforded one new and three known juglone derivatives, namely, 2-methoxy-6-acetyl-7-methyljuglone (1), 2-ethoxy-6-acetyl-7-methyljuglone (2), 2-methoxy-7-acetonyljuglone (3), and 3-acetyl-7-methoxy-2-methyljuglone (4) together with two phenolics (5 and 6), an anthraquinone (7), a stilbene (8) and a phthalide (9). Their structures were elucidated on the basis of comprehensive spectroscopic studies including IR, MS, and 1H, 13C, 2D NMR spectra. Compound 3 is a new compound in nature, and compounds 4-6 have been isolated for the first time from R. japonica. The isolates were evaluated for their antibacterial activity against three strains (43504, 51, and 26695) of Helicobacter pylori. The four isolated juglone derivatives (1-4) showed potent growth inhibitory activity. Among them, compounds 1-3 exhibited stronger inhibitory activity than those of the positive controls, juglone and metronidazole, for the three strains and that of another reference, clarithromycin, for the 43504 and 51 strains. Specifically, the new juglone compound 3 displayed the most potent antibacterial activity against all three strains, 43504, 51, and 26695, with MIC values of 0.06, 0.06 and 0.13 µM, respectively, and MIC50 values of 0.14, 0.11 and 0.15 µM, respectively.

Inner morphological and chemical differentiation of Boehmeria species.

The present study was designed to establish quality control parameters for pharmacognostic evaluation and differentiation of eight locally derived Boehmeria species, B. gracilis, B. nivea, B. pannosa, B. platanifolia, B. quelpaertensis, B. spicata, B. splitgerbera, B. tricuspis, and two varieties named B. japonica var. longispica, B. nivea var. concolor, which have been utilized as the folk medicine, 'Mo-Si-Pool' in Korea. Although the outer morphological study of these species had been reported, there is no pharmacognostical description yet. Therefore, inner morphological evaluation on leaf midrib, petiole and stem of eight Boehmeria species and two varieties was accomplished along with preliminary phytochemical analysis by HPLC-DAD profiling. The microscopic data showed discriminative inner morphological characteristics such as collenchyma cell layer, thickness of cortex and xylem, frequency of druse and hairs, and number of vascular bundles. The HPLC profiles exhibited more than four characteristic peaks. The molecular ions of the four peaks (1-4) were tentatively identified by ESI-MS, and their structures were identified by NMR spectroscopy to be the flavonoids, rutin (1), isoquercetin (2) and kaempferol-3-O-rutinoside (3), and a phenanthroquinolizidine alkaloid, (-)-cryptopleurine (4). While compounds 1 and 2 were detected in all samples, compound 4 was determined only in B. japonica var. longispica, B. pannosa and B. quelpaertensis and B. splitgerbera. These findings provide the initial scientific criteria for proper identification and establishment of standards for use of Boehmeria species in traditional medicine.

Anatomical characterization and LC-MS profiling of Adenophora roots from Korea

ABSTRACT "Sasam (沙參)" is a crude drug that is defined in the in Korean Herbal Pharmacopoeia as the root of Adenophora triphylla var. japonica (Regel.) Hara or A. stricta Miq., Campanulaceae. The dried roots of the Adenophora spp. are available in markets, and the roots of various species are similar to each other in shape, making it difficult to distinguish one from another using only the outer morphological appearance. Therefore, the present study aimed to establish quality control parameters for pharmacognostic evaluation and differentiation of five Adenophora species and two varieties grown in Korea. Inner morphological evaluation of the root of these plants was accomplished and preliminary chemical analysis was performed by liquid chromatography-mass spectrometry profiling. As a result, significant differences among samples were found in anatomical characteristics such as number and thickness of cork layer, existence of stone cell in cork layer, frequency of vessels, and area of intercellular space. Significant differences were found among the samples in the content of three components including shashenoside I and a new alkyl glycoside, adenophoroside I. These findings could provide the scientific criteria for the proper identification and establishment of standards for the use of "Sasam".