According to a scientific article published in Nature, a male Sumatran orangutan was observed self-treating a facial wound with medicinal plants in Southeast Asia. Three days after the injury, he ripped off leaves from a liana vine, chewed on them and applied the resulting juice onto the wound. As a final step, the orangutan covered the wound with the chewed leaves. The liana is a tropical plant that has antibacterial, anti-inflammatory, anti-fungal and antioxidant properties. This is the first documented case of wound treatment by a wild animal, providing insight into the origins of human wound care.