Ethnopharmacological relevance: We studied the local knowledge and uses of medicinal plants among
the Ivatan people of Batan Island by documenting their traditional practices.
Aim of the study: To identify the types of medicinal plants used in self-care by the indigenous people of
Batan Island, the Philippines and to investigate the extent to which the plants are used. Conservation of
medicinal plants and natural resources is becoming increasingly important; thus, this research aims to
collect information from local people concerning the use of medicinal plants on Batan Island.
Materials and methods: A total of 116 informants were interviewed, allowing for calculated informant
consensus factors (ICF), use value (UV), and fidelity levels (FL) for each medicinal plant species used to
cure various ailments. This helped to establish a consensus on which species are effective for particular
ailments, as well as the species’ relative importance, and enabled us to understand the extent of the
potential utilization of each species.
Results: We describe the therapeutic effects of 112 plant species used medicinally against 13 categories
of ailments. The highest ICF value (1.00) was cited for diseases of the ear and respiratory system and for
use during pregnancy, childbirth and the postnatal period. The maximum FL of 100% was found for
Carica papaya, Stachytarpheta jamaicensis, Musa sapientum, and Pedilanthus tithymaloides, used for the
treatment of constipation, cuts and wounds, diarrhea, and dislocations and fractures, respectively. The
highest UV was for Hibiscus rosa-sinensis (0.67). All plants with high UV were used for exogenous
diseases, certain infectious and parasitic diseases, injuries, poisonings and other consequences of
external factors, and diseases of the skin and subcutaneous tissues. In addition to its use for endogenous
disease and lifestyle-related diseases and illnesses, Moringa oleifera is also used for diseases of the
circulatory system, with a UV of 0.57 and Cocos nucifera is used for diseases of the genitourinary system,
with a UV of 0.56.
Conclusions: This study demonstrates that many plant species play an important role in local healing
practices and that knowledge of traditional medicine is still utilized and plays a significant role on
Batan Island. The documentation of this rich traditional ethno-medicinal knowledge has furnished us
with novel information that not only will provide recognition of this undocumented knowledge but
also could provide new avenues for pharmacological investigations to improve healthcare for a range of
ailments.