Histochemical Characterization of Salacia korthalsiana Miq. (Polipog) Root

Abstract

Salacia korthalsiana Miq., locally known in the Philippines as Polipog, is a wild climbing shrub traditionally valued for its anti-inflammatory, antiseptic, and antimicrobial properties. While indigenous communities utilize its leaves, stems, and roots to treat ailments ranging from respiratory issues to hypertension, scientific mapping of its bioactive compounds within specific tissues remains limited. This study performed a histochemical characterization of Polipog root to localize secondary metabolites in situ, providing a visual and chemical basis for its medicinal use. Methodology involved free-hand sectioning of plant parts followed by specific staining reagents, including Dragendorff’s reagent for alkaloids, antimony trichloride for steroids, and Toluidine Blue for tannins. Results from the root analysis revealed a significant accumulation of bioactive compounds. Alkaloids (golden yellow) were localized in the pith and endodermis, while steroids (yellow) were detected in the pith, phloem, and endodermis. Tannins (green/greenish-blue) showed the widest distribution, appearing in the cortex, endodermis, phloem, pith, and pericycle. Notably, tests for terpenoids yielded negative results in the root samples. These findings correlate the presence of alkaloids and tannins with the plant’s reported analgesic and antimicrobial efficacy. By identifying the specific tissues where these pharmacological precursors reside, this research validates the ethnobotanical importance of S. korthalsiana and provides essential data for the standardization of herbal preparations and future drug extraction.