Ethnopharmacology, phytochemistry and pharmacology of Benincasae Exocarpium: A review.

Benincasae Exocarpium (BE, Dongguapi in Chinese), as the dried outer pericarp of Benincasa hispida (wax gourd) in Cucurbitaceae family, is one of traditional Chinese medicines with the same origin as medicine and food. Up to now, 43 compounds were isolated from BE, including flavonoids, alkaloids, tannins, phenolic acids, soluble fiber and carbohydrates. Modern pharmacological studies and clinical practice showed that BE has diuretic, hypolipidemic effects, hypoglycemic, antioxidant, antibacterial, and other effects. The folk uses, functional factors, pharmacological activities, patents and clinical applications of BE were reviewed in this paper. In addition, the paper also discussed the current problems for the further studies. The information summarized in this paper provides valuable clues for the comprehensive utilization of medicine and food resources and gives a scientific basis for the development of medicinal plants of BE.

Chemical constituents and pharmacological activities of medicinal plants from Rosa genus.

The genus Rosa (Rosaceae family) includes about 200 species spread in the world, and this genus shows unique advantages in medicine and food. To date, several scholars concentrated on compounds belonging to flavonoids, triterpenes, tannins, polysaccharide, phenolic acids, fatty acids, organic acids, carotenoids, and vitamins. Pharmacological effects such as antineoplastic and anti-cancer properties, anti-inflammatory, antioxidant, liver protection, regulate blood sugar, antimicrobial activity, antiviral activity, as well as nervous system protection and cardiovascular protection were wildly reported. This article reviews the chemical constituents, pharmacological effects, applications and safety evaluations of Rosa plants, which provides a reference for the comprehensive utilization of medicine and food resources and gives a scientific basis for the development of medicinal plants of the genus Rosa.

Healing effect of carboxymethyl chitosan-plantamajoside hydrogel on burn wound skin.

BACKGROUND: It is known that hydrogels based on carboxymethyl chitosan (CMCS) have properties controling microbial growth, reducing inflammatory cell infiltration, and promoting collagen deposition. Plantamajoside (PMS), a natural Chinese herbal medicine with biological activity, has the properties of reducing inflammation, anti-oxidation, and promoting wound healing. However, the effects of carboxymethyl chitosan/plantamajoside hydrogel on partial thickness burn wounds remain unclear. METHODS: The healing effect of carboxymethyl chitosan/plantamajoside hydrogel was evaluated by in vitro cell viability assay, cell migration assay, and further evaluated in a rat model of partial-thickness burn wounds. RESULTS: The hydrogels were highly porous with a pore size of about 250 µm, and these pores were interconnected. After adding plantamajoside, a dense microstructure was further formed. The hydrogels containing 0.25% plantamajoside significantly increased the viability and migration of L929 cells (P < 0.05). Carboxymethyl chitosan/plantamajoside hydrogel significantly improved wound healing, granulation tissue proliferation and re-epithelialization, and promoted collagen deposition (P < 0.05). Carboxymethyl chitosan/plantamajoside hydrogel also significantly decreased IL (interleukin)-1ß, IL-6 and TNF-α expression, and increased IL-10 expression (P < 0.05). Furthermore, carboxymethyl chitosan/plantamajoside hydrogel significantly promoted the expression levels of VEGF, CD31, α-SMA (α-smooth muscle actin) and collagen III, and reduced the expression level of collagen Ⅰ (P < 0.05). Our data suggest that carboxymethyl chitosan/plantamajoside hydrogel promotes burn wound healing by accelerating angiogenesis and collagen deposition and reducing the inflammatory response.

Enhanced lincomycin production by co-overexpression of metK1 and metK2 in Streptomyces lincolnensis.

Streptomyces lincolnensis is generally utilized for the production of lincomycin A (Lin-A), a clinically useful antibiotic to treat Gram-positive bacterial infections. Three methylation steps, catalyzed by three different S-adenosylmethionine (SAM)-dependent methyltransferases, are required in the biosynthesis of Lin-A, and thus highlight the significance of methyl group supply in lincomycin production. In this study, we demonstrate that externally supplemented SAM cannot be taken in by cells and therefore does not enhance Lin-A production. Furthermore, bioinformatics and in vitro enzymatic assays revealed there exist two SAM synthetase homologs, MetK1 (SLCG_1651) and MetK2 (SLCG_3830) in S. lincolnensis that could convert L-methionine into SAM in the presence of ATP. Even though we attempted to inactivate metK1 and metK2, only metK2 was deleted in S. lincolnensis LCGL, named as ΔmetK2. Following a reduction of the intracellular SAM concentration, ΔmetK2 mutant exhibited a significant decrease of Lin-A in comparison to its parental strain. Individual overexpression of metK1 or metK2 in S. lincolnensis LCGL either elevated the amount of intracellular SAM, concomitant with 15% and 22% increase in Lin-A production, respectively. qRT-PCR assays showed that overexpression of either metK1 or metK2 increased the transcription of lincomycin biosynthetic genes lmbA and lmbR, and regulatory gene lmbU, indicating SAM may also function as a transcriptional activator. When metK1 and metK2 were co-expressed, Lin-A production was increased by 27% in LCGL, while by 17% in a high-yield strain LA219X.