No abstract

The demand for dry juniper (Juniperus communis) needles as a raw material for the food, pharmaceutical, and cosmetic industries has increased rapidly in recent years. Juniper needles are known to be rich in terpenoids and phenolics, but their chemical composition and antibacterial properties have not been well-characterized. In this study, we describe the soluble phenolic and terpenoid composition of juniper needles collected in Finland (n = 125) and demonstrate that the concentration of these compounds clearly increased with latitude and altitude with, however, a stronger latitudinal effect (a higher content of monoterpenoids, proanthocyanidins, and flavonols in northern latitudes). Analysis of methanolic extracts showed quite good activity against both antibiotic-sensitive and -resistant Staphylococcus aureus strains and suggested an important role of the soluble phenolic fraction. Finally, we demonstrate the relative lack of toxicity of juniper extracts on keratinocytes and fibroblastic cells, raising the possibility of their use in preventing bacterial skin infection.

Resin salve prepared from Norway spruce (Picea abies) has been used for centuries in traditional medicine to treat skin diseases. The authors studied with transmission and scanning electron microscopy, and with electron physiology, changes in cell wall and cell membrane of Staphylococcus aureus after exposure of the bacterial cultures to resin. After exposure, cell wall thickening, cell aggregation, changed branching of fatty acids, and dissipation of membrane potential of the bacterial cells were observed. The authors conclude that spruce resin affects the cell viability via changes in the cell wall and membrane, and impairs, thereby, the synthesis of energy in the bacteria.

Resin salve made from Norway spruce (Picea abies) is traditionally used in folk medicine to heal skin ulcers and infected wounds. Its antimicrobial properties were studied against certain human bacteria important in infected skin wounds. The sensitivity of the resin against Gram-positive and Gram-negative bacteria was studied in vitro by methods that are routinely used in microbiology laboratories. The resin salve exhibited a bacteriostatic effect against all tested Gram-positive bacteria but only against Proteus vulgaris of the Gram-negative bacteria. Interestingly, the resin inhibited the growth of bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE), both on agar plates and in culture media. The study demonstrated antimicrobial activity of the resin salve and provided objective evidence of its antimicrobial properties. It gives some explanations why the traditional use of home-made resin salve from Norway spruce is experienced as being effective in the treatment of infected skin ulcers.