Medicinal Plants Used as Alternative Medicines by Inhabitants of Mapanas, Northern Samar, Philippines

Abstract

Medicinal plants, whose organs contain substances that can be used for therapeutic purposes or which are precursors for the synthesis of useful drugs, have been used in healthcare since time immemorial. The study specifically aimed at collecting and identifying plant species least commonly utilised as medicine and screening these plants for the presence of secondary metabolites. This descriptive research utilised the purposive sampling technique. The data was gathered using a semi-structured interview guide to ascertain the residents’ knowledge of medicinal plants. The leaves of the medicinal plants were extracted manually using a plant juicer to get the crude extract, which was then subjected to phytochemical screening for the presence of secondary metabolites, using different standard procedures. Results show a total of 44 plant species with medicinal applications, and these belonged to 24 plant families.  Among these species, it was found that the five least commonly used medicinal plants were Coleus blumei Benth.; Citrus reticulata Blanco; Ocimum tenuiflorum L.; Piper betle Linn.; and Sansevieria trifasciata Prain.  Phytochemical analyses of these plants confirm the presence of anthraquinones, saponins, steroids, sterols, tannins, terpenoids, flavonoids, alkaloids, and phenolic compounds, although not all species characterised contain all these metabolites.   The presence of these metabolites could possibly be the reason why these plants are effective as alternative medicines. Coleus blumei (L) Benth. possessed the greatest number of secondary metabolites, with only alkaloids absent from the tested extract. Likewise, these results imply that residents of the municipality of Mapanas, Northern Samar, Philippines, have a wealth of indigenous knowledge about plant species that possess medicinal attributes, utilising them as alternatives to expensive commercial drugs.  It is therefore recommended that further chemical screening of these plants to characterise the active components or functional groups of these secondary metabolites through the Fourier Transform Infrared (FTIR) spectroscopy technique be done as a basis for drug discovery or development.