Natural active provides multiple benefits

 Northern plants have developed natural defences to protect themselves against the lethal effects of cold and drastic temperature changes. One of the adaptations these plants have developed is to enter into dormancy by slowing down their metabolism during the winter season. Since the photosynthesis pathway is independent of global plant metabolism, dormancy creates an energy imbalance in evergreen plants. More energy is created (through light exposure and photosynthesis that is not slowed down during dormancy) than consumed, resulting in the formation of damaging reactive oxygen species.1 Northern plants have evolved in order to be able to fight this oxidative stress: they have increased their capacity of scavenging reactive oxygen species (ROS). For instance, cold-adapted leaves produce increased levels of ascorbate, glutathione and ?-tocopherol, while the activities of catalase, SOD, and glutathione reductase are augmented.2 Some conifers also increase their production of zeaxanthin, a carotenoid pigment, to better dissipate the excess energy.3 These examples are some of the means developed by northern plants to eliminate damaging molecules like ROS and to maintain cell homeostasis even in stressful conditions. Therefore, cold-adapted evergreen plants offer a very interesting source of various antioxidants and other defense molecules that can be formulated into cosmetic care products for enhanced skin protection and balance.

Tsuga canadensis

Tsuga canadensis (Canadian hemlock) is a northern tree periodically exposed to strong cold conditions followed by a period of moderate to high temperatures. Canadian hemlock is a beautiful evergreen, the kind you see on a Christmas card, with soft green needles attached to gently arching branches, often reaching to the ground. Cones are small and drooping with rounded scales. The tree grows, quite impressively, between 50 ft to 70 ft (15 m to 20 m) tall and 30 ft (10 m) wide. Light is never a problem for the hemlock as it grows regardless in full shade (deep woodland), semi-shade (light woodland), or no shade at all. It is abundant in North America (US and Canada). Canadian hemlock has traditionally been used as a source of medicines by several native North American Indian tribes. It was considered to have soothing, purifying, and wound healing properties. A decoction of the inner bark was traditionally used externally for the treatment of eczema and other skin conditions. Hemlock contains tannins and flavonols (organic compounds), which are believed to be responsible for some of its medicinal properties. The leaves (needles) are also rich in vitamin C. Canadian hemlock is highly suspected of being the famous “Tree of Life” or “Annedda”, as it was called by the Iroquois, that saved the life of Jacques Cartier and his crew on his second voyage to Canada in 1536.4 On that particular trip, Cartier and his ships were imprisoned by the ice that formed early that year on the Saint- Lawrence River, and forced to spend a long and savagely cold winter on the new continent. Soon, as fresh food became rare, most of the French sailors became ill with a disease unknown to them: scurvy. The disease results from a lack of vitamin C which is an essential cofactor in the body for hydroxylation reactions, as needed for the correct synthesis of collagen.5 People affected with scurvy would show spots on the thighs and legs, suppurating wounds, and would lose their teeth. Scurvy was a deadly disease by then, but Cartier’s men were saved by the “magical” potion from the “Tree of Life” that the Native American Indians prepared for them.