Abstract:
Wan chak motluk has been used as a remedy for gynecological diseases.
Nowadays, the products derived from Wan chak motluk are popularly
commercialized. In this study, Wan chak motluk which is cultivated and sold in
Thailand was investigated for taxonomic status, chemical identification and biological
activities. Thirteen samples were surveyed and collected from various cultivated parts
of Thailand. The results showed that Wan chak motluk is classified into 2 groups of
the genus Curcuma. They are Curcuma comosa Roxb and Curcuma sp. The
inflorescences and florets are distinguishing characteristics. Generally, C. comosa
possesses smaller and shorter lateral rhizomes than Curcuma sp. However, variation
of rhizomes could be found and some rhizomes were not easily identified by
consumers or traders. The general microscopic characteristics of these groups were
quite similar and could not be used as a tool for differentiation. Thin-layer
chromatographic method was appropriate as an identifying method using 2 solvent
systems, DCM: MeOH (99:1) and DCM: EtOAc: MeOH (93:4:7), and 2 reference
standards, 1,7-diphenyl-5-hydroxy-(1E)-l-heptene and 5-hydroxy-7-(4-hydroxyphenyl)-l-phenyl-
(1E)-l-heptene.
For the screening of the biological activities of those alcoholic extracts, the
extracts of C. comosa possessed significant uterotrophic activity, while Curcuma sp.
showed effects not significantly different from the control (ovariectomized rat). C.
comosa and Curcuma sp. showed moderate free radical scavenging activity (ED50
8.93-25.86 and 151.43-273.03 μg/ml, respectively) and cytotoxicity by brine shrimp
lethality assay (LC50 0.84-39.03 and 151.43-273.03 μg/ml, respectively). Though the
physicochemical properties of C. comosa raw materials were varied, all these
alcoholic extracts possessed acceptable uterotrophic activity. This work provides the
specifications together with thin-layer chromatographic fingerprints to be the
fundamental standard for the research and development of Wan chak motluk raw
materials and products on a commercialized scale. Additionally, the possible toxicity
of Wan chak motluk should be cautioned.