Cytotoxic activity of Thai medicinal plants against human cholangiocarcinoma, laryngeal and hepatocarcinoma cells in vitro

<p>Abstract</p> <p>Background</p> <p>Cholangiocarcinoma is a serious public health in Thailand with increasing incidence and mortality rates. The present study aimed to investigate cytotoxic activities of crude ethanol extracts of a total of 28 plants and 5 recipes used in Thai folklore medicine against human cholangiocarcinoma (CL-6), human laryngeal (Hep-2), and human hepatocarcinoma (HepG2) cell lines in vitro.</p> <p>Methods</p> <p>Cytotoxic activity of the plant extracts against the cancerous cell lines compared with normal cell line (renal epithelial cell: HRE) were assessed using MTT assay. 5-fluorouracil was used as a positive control. The IC₅₀(concentration that inhibits cell growth by 50%) and the selectivity index (SI) were calculated.</p> <p>Results</p> <p>The extracts from seven plant species (<it>Atractylodes lancea</it>, <it>Kaempferia galangal</it>, <it>Zingiber officinal</it>, <it>Piper chaba</it>, <it>Mesua ferrea</it>, <it>Ligusticum sinense</it>, <it>Mimusops elengi</it>) and one folklore recipe (Pra-Sa-Prao-Yhai) exhibited promising activity against the cholangiocarcinoma CL-6 cell line with survival of less than 50% at the concentration of 50 μg/ml. Among these, the extracts from the five plants and one recipe (<it>Atractylodes lancea</it>, <it>Kaempferia galangal</it>, <it>Zingiber officinal</it>, <it>Piper chaba</it>, <it>Mesua ferrea</it>, and Pra-Sa-Prao-Yhai recipe) showed potent cytotoxic activity with mean IC₅₀values of 24.09, 37.36, 34.26, 40.74, 48.23 and 44.12 μg/ml, respectively. All possessed high activity against Hep-2 cell with mean IC₅₀ranging from 18.93 to 32.40 μg/ml. In contrast, activity against the hepatoma cell HepG2 varied markedly; mean IC₅₀ranged from 9.67 to 115.47 μg/ml. The only promising extract was from <it>Zingiber officinal </it>(IC₅₀= 9.67 μg/ml). The sensitivity of all the four cells to 5-FU also varied according to cell types, particularly with CL-6 cell (IC₅₀= 757 micromolar). The extract from <it>Atractylodes lancea </it>appears to be both the most potent and most selective against cholangiocarcinoma (IC₅₀= 24.09 μg/ml, SI = 8.6).</p> <p>Conclusions</p> <p>The ethanolic extracts from five plants and one folklore recipe showed potent cytotoxic activity against CL-6 cell. Sensitivity to other cancerous cell lines varied according to cell types and the hepatocarcinoma cell line. HepG2 appears to be the most resistant to the tested extracts.</p

A re-examination of the life and work of A.F.G. Kerr and of his colleagues and friends

Arthur Francis George Kerr’s life is reviewed and related to a previously published account. Kerr’s collecting activity is analysed using an expanded version of the Thai Biogeography Group’s database of collections. 8,666 of the total 48,970 collections are Kerr’s and 3,178 are those of his colleagues and friends. Therefore, the total number of collections made by Kerr and his acquaintances is likely to be larger and more diverse than previously believed. Mapping of these data using GIS show that Kerr’s collecting activities focussed on particular regions of Thailand at particular times. Also large areas of the country remained unexplored by Kerr and his acquaintances: a pattern that, to some extent, persists to this day. The large, but dispersed, archive of Kerr’s photographs, maps, living collections and correspondence indicate that he was a skilled photographer (taking at least 3,000 images), cartographer (producing many hand-drawn maps) and exceptionally acute, accurate and detailed observer (filling numerous notebooks and leaving other records). It is clear that digitising these collections to form an on-line dedicated website is highly desirable to further progress on the flora of Thailand and surrounding countries and would form an unique record of the social history of early 20thC Thailand

Using in situ seed baiting technique to isolate and identify endophytic and mycorrhizal fungi from seeds of a threatened epiphytic orchid, Dendrobium friedericksianum Rchb.f. (Orchidaceae)

© 2016 Kasetsart University. All orchids require association with mycorrhizal fungi for seed germination and development under natural conditions but their identification and feasibility are not known. The in situ seed baiting germination was examined of Dendrobium friedericksianum Rchb.f., a native threatened epiphytic orchid species, to detect fungi that promote germination. It was found that seed germination percentages were lowered by 0.1%, with a total of seven protocorms formed. Six endophytic fungi were isolated from seven protocorms in seed packets. Three binucleate Rhizoctonia-like fungal isolates which formed a teleomorphic state were morphologically identified as Tulasnella violea, Epulorhiza repen (anamorph Tulasnella) and Trichosporiella multisporum. The species of Beauvaria and Fusarium which are endophyte fungi were also isolated and may play an important role for plant growth and survival of D. friedericksianum. The results in this study suggested that in situ seed baiting is beneficial for screening compatible mycorrhizal fungi to promote the growth and propagation of epiphytic orchids

Cayratia emarginata (Vitaceae), a new species from Thailand and Vietnam

The new species Cayratia emarginata is validly published. A latin diagnosis, a full description and an illustration are provided. Diagnostic characters for this species are 3-foliolate leaves, farinose hairless petals and a cuspidate leaf apex