Introduction The aim of this study was to evaluate whether delphinidin is cytoprotective or cytotoxic in osteosarcoma cell lines, and to elucidate the underlying mechanisms. Materials and methods The present study investigated whether apoptosis or autophagy is induced by delphinidin in human osteosarcoma cell lines. Delphinidin was used as the antioxidant, along with two autophagy inhibitors: 3-methyladenine and bafilomycin A1. Cell viability and known autophagic markers, such as LC3-II expression, were evaluated. Reactive oxygen species (ROS) formation and cell cycle analysis were also investigated. Results Delphinidin showed concentration-dependent cytotoxicity to osteosarcoma cell. Delphinidin is closely associated with apoptotic cell death mechanisms and pathways related to ROS accumulation. In addition, we observed delphinidin-induced autophagosome formation and increasing levels of LC3-II conversion. However, in spite of delphinidin induced autophagy, the cytotoxic effects induced in the osteosarcoma cells may not be operating via autophagic cell death mechanisms. Conclusions Delphinidin compromises the cellular protective mechanisms by inhibiting autophagy, permitting ROS to accumulate and finally enhance apoptotic cell death. Our results indicate that delphinidin may play a critical role as a chemotherapeutic agent by preventing the development and progression of osteosarcoma cells. ER - Keywords Delphinidin Cytotoxicity Autophagy Apoptosis Osteosarcoma

Moon DK, et al. Yonsei Med J. 2018 Jul;59(5):669-676. https://doi.org/10.3349/ymj.2018.59.5.669

Although melanogenesis is a defense mechanism against ultraviolet (UV)-induced skin damage, abnormally excessive melanin production causes pigmentation disorders. Tyrosinase, as a key factor for melanin synthesis, plays an important role in inducing skin pigmentation. Therefore, the inhibition of tyrosinase is crucial in preventing skin pigmentation in the cosmetics and medicine fields. However, the majority of well-known tyrosinase inhibitors have been discontinued due to toxic effects on the skin or lack of selectivity and/or stability. In this study, we evaluated possible anti-melanogenic effects of catechin-7-O-α-L-rhamnopyranoside (C7R) isolated from the stem bark of Ulmus parvifolia, to discover a new tyrosinase inhibitor that has both safety and stability. When C7R was pretreated in B16F10 melanoma cells stimulated by α-melanocyte-stimulating hormone, this compound reduced melanin accumulation and murine tyrosinase activity. In line with these results, C7R inhibits tyrosinase purified from a mushroom in vitro like kojic acid and arbutin. Furthermore, C7R exhibited a competitive inhibition on a Lineweaver-Burk plot. Next, the underlying mechanisms of the C7R-mediated tyrosinase inhibitory effect were sought through docking simulation and pharmacophore analysis between tyrosinase residues and C7R. The results of these analyses showed that C7R had binding energy of -14.5kcal/mol, and indicated that C7R interacts with tyrosinase through an aromatic ring and various hydrophobic and hydrogen bonds. Together, our results suggest that C7R can be applied as a novel natural anti-melanogenic agent that inhibits tyrosinase.

Introduction: Strains of the genus Dermabacter is a recently established species, recognized as relatively rare opportunistic human pathogen, and is infrequently isolated from clinical specimens, including blood cultures, abscesses, wounds, bone, eye, and skin. Presentation of case: We present a 78-year old female with chronic symmetrical peripheral gangrene and hand infection. The patient underwent surgical debridement with amputation on gangrene with infection of both fingers. At 2 weeks postoperatively, pus discharge was newly observed and the patient underwent reoperation. In the subsequent reinfection, unknown organism has been repeatedly identified, may be the most likely causative agent. On the basis of phenotypic and genotypic distinctness and DNA-DNA hybridization results, new strain should be placed in the genus Dermabacter as representing a novel species, for which the name Dermabacter jinjuensis sp. nov. is proposed. Discussion: We judged the novel species as the causative bacteria. Because of, a novel species called D. jinjuensis was repeatedly identified more than common bacteria. It can be considered as a postoperative nosocomial infection or opportunistic infection. It is not clear how the infection of D. jinjensis occurred. Conclusion: This is the first reported case of a human D. jinjuensis infection. We were able to treat patients without any complications by operative treatment and administering appropriate antimicrobial agents according to antibiotics susceptibility test.

Distal radius physeal fractures are common in pediatric patients. Although most of these fractures heal without complication, some result in significant physeal arrest. If significant physeal arrest occurs, the various treatment methods can be applied depending on the severity of deformity and remaining growth of the patient. We present a 16-year old female with distal radial physeal arrest who presented four years after initial injury. Radiologically, forearm bone length discrepancy was 7 mm. But, she had a secondary ulnar impaction syndrome. She underwent open wedge corrective osteotomy of distal radius on volar side and ulnar shortening osteotomy, simultaneously. Early mobilization and rehabilitation were started soon after the surgery. At 18 months postoperatively, the ROM was assessed to be almost identical as the unaffected side and the patient presented with no significant symptoms. Distal radial fracture is one of the most common fractures in pediatric population. And distal radial physis is often involved in these fracture, which can lead to physeal arrest. However, even if forearm bone length discrepancy occurs, if the difference is within 1 cm, it is often asymptomatic. In this case, the forearm bone length discrepancy was mild, but due to symptom, we performed surgical treatment. Distal radial physeal arrest due to distal radial fracture is relatively common in children, and long-term follow-up is needed. Moreover, relatively mild deformity caused by physeal arrest may also cause symptoms, so careful observation is needed.