Propolis is a resinous substance that bees collect from the buds and bark of plants. It’s a purely vegetable substance, the bees process it by adding wax, pollen, and various enzymes. The name comes from the greek  word "pro" (before) and "polis" (city): figuratively it means "defender of the city" because bees use it to protect the hive from external threats (such as diseases and predators ). Propolis produced by bees consists of several substances: plant resins, vitamins, amino acids, minerals, and bioflavonoids; it contains also galangin, which is a bioflavonoid, is especially useful when it comes to protecting the hive.