Cytotoxic Evaluation of Eurycoma longifolia Jack Root Extract on Chromosome Aberrations in Human Lymphocytes In vitro

This study aimed to investigate chromosomal aberrations of Eurycoma longifolia Jack (EL) root extract in human lymphocytes in vitro. Human whole blood was cultured in medium solution that treated with distilled water, 20% DMSO, extract of EL roots at the concentration of 2.5, 5, 10, 20, 40, 80 µg/mL (extracted with distilled water and ethanol), and nontreated (blank: only culture medium and whole blood). All experiments were cultured for 72 hours in the 37°C incubator. The effects of EL roots extract on cytotoxicity were compared with the control groups including the blank, distilled water, and 20% DMSO. This study found that EL root extract significantly decreased metaphase cell number and increased chromosome aberrations dose dependent manner (p<0.01). The 7 types of chromosome aberration that were observed consisted of dicentric chromosome, single chromatid breaks, isochromatid break, isochromatid gap, single chromatid gap, fragmentation, and deletion. The dicentric chromosome was the most common chromosomal aberrations type that was treated with EL root extract both distilled water and ethanol. Moreover, the ethanolic extract of EL root was more effective to stimulate chromosome aberrations compared to the water extract of EL root (the deletion and fragmentation were not found in the water extract of EL root). This study demonstrated that the phytochemicals of EL root extract had cytotoxicity effect (decreased metaphase cells and increase cells death) and genotoxic effect (increased chromosomal aberrations. The use of EL root crude extract with distilled water is therefore safer for cells. However, when EL is used at high levels, it may lead to the inhibition of cell division process and cause side effects (toxicity). EL extracts consist of various phytochemicals with different properties and dosages, thus more studies should be conducted on the effect of those substances on cytotoxicity, especially their effects on genotoxicity humans.

A new species of the Cyrtodactylus brevipalmatus group (Squamata, Gekkonidae) from the uplands of western Thailand

An integrative systematic analysis recovered a new species of the Cyrtodactylus brevipalmatus group from the uplands of Thong Pha Phum National Park, Kanchanaburi Province in western Thailand. Cyrtodactylus thongphaphumensis sp. nov. is deeply embedded within the brevipalmatus group, bearing an uncorrected pairwise sequence divergence of 7.6–22.3% from all other species based on a 1,386 base pair segment of the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs. It is diagnosable from all other species in the brevipalmatus group by statistically significant mean differences in meristic and normalized morphometric characters as well as differences in categorical morphology. A multiple factor analysis recovered its unique and non-overlapping placement in morphospace as statistically significantly different from that of all other species in the brevipalmatus group. The description of this new species contributes to a growing body of literature underscoring the high degree of herpetological diversity and endemism across the sky-island archipelagos of upland montane tropical forest habitats in Thailand, which like all other upland tropical landscapes, are becoming some of the most imperiled ecosystems on the planet

A comparative cytogenetic study of Hypsibarbus malcolmi and H. wetmorei (Cyprinidae, Poropuntiini)

Cyprininae are a highly diversified but demonstrably monophyletic lineage of cypriniform fishes. Here, the karyotype and chromosomal characteristics of Hypsibarbus malcolmi (Smith, 1945) and H. wetmorei (Smith, 1931) were examined using conventional, nucleolus organizing regions (NORs) and molecular cytogenetic protocols. The diploid chromosome number (2n) of H. malcolmi was 50, the fundamental number (FN) was equal to 62, and the karyotype displayed 8m + 4sm + 38a with NORs located at the centromeric and telomeric positions of the short arms of chromosome pairs 1 and 2, respectively. 2n of H. wetmorei was 50, FN 78, karyotype 14m + 14sm + 22a with the NORs at the telomeric position of the short arm of chromosome pair 2. 2n and FN in males and females were identical. Fluorescence in situ hybridization using different microsatellite motifs as probes also showed substantial genomic divergence between both studied species. In H. wetmorei, (CAG)n and (CAC)n microsatellites accumulated in the telomeric regions of all chromosomes, while in H. malcolmi, they had scattered signals on all chromosomes. Besides, the (GAA)n microsatellites were distributed along all chromosomes of H. malcolmi, but there was a strong hybridization pattern in the centromeric region of a single pair in H. wetmorei. These cytogenomic difference across the genomes of these Hypsibarbus Rainboth, 1996 species are markers for specific evolutionary differentiation within these two species

An eDNA‐based assessment of Garra cambodgiensis (stonelapping minnow) distribution on a megadiverse river, the Mekong

Abstract Garra cambodgiensis (stonelapping minnow) has experienced significant population declines, prompting intensive research and management, although its distribution in river systems such as the Mekong remains obscure. Effective conservation and management necessitate accurate monitoring and survey data on the distribution of freshwater species. Traditional surveying techniques for fish may be challenging and generate insufficient data on species distribution. This study developed an eDNA‐based method for detecting G. cambodgiensis to address this void. Twenty‐one locations were surveyed. Water samples were collected in triplicate from the river's surface at each site and processed within 48 h in a dedicated laboratory. Primers and probes for G. cambodgiensis were meticulously designed and species‐specificity tested to ensure accurate detection without interference from co‐occurring species in the same geographic range. Each water sample was analysed by qPCR using six technical replicates. The results of qPCR were reported as positive with quantifiable eDNA concentration (copies/mL), below the limit of quantification, or non‐detectable. G. cambodgiensis eDNA was detected in water samples collected from 10 out of 21 sampling sites, with concentrations ranging from 8.5 to 2990.0 copies/mL. Importantly, G. cambodgiensis eDNA was consistently detected in all three replicate water samples at each site where the qPCR experiment yielded positive results. The findings of this study demonstrate the feasibility and effectiveness of incorporating eDNA‐based monitoring or surveys for G. cambodgiensis in the ecologically diverse Mekong River. Monitoring based on eDNA can aid in targeting and informing conservation and management of G. cambodgiensis in its natural habitat. Comprehensive and robust information on species distribution can be obtained via an eDNA‐based survey, which could contribute to more efficient and informed decision‐making processes in fisheries management and conservation efforts

Distinguishing fanged frogs (Limnonectes) species (Amphibia: Anura: Dicroglossidae), from Thailand using high resolution melting analysis

Abstract Morphologically, species of fanged frogs (Limnonectes) are exceedingly similar, making it difficult to distinguish them within the complex. In Thailand, it has been difficult to distinguish between the sympatric species L. bannaensis and L. taylori, particularly among tadpoles, adolescents, and adult females. A precise identification contributes to a greater understanding of biodiversity, particularly for assessing distributions and population dynamics. Therefore, a novel approach is required. The objective of this study was to develop a high resolution melting analysis (HRM) for the rapid and accurate identification of six species of Limnonectes of the L. kuhlii complex found in Thailand, particularly the two sympatric fanged frogs. Here, HRM assays using 16S rRNA mitochondrial primers were designed and developed. There was as much as a 25.3% variation in the nucleotide sequence of the fragment amplified by HRM16S primers among the six species of Limnonectes. Prior to conducting an in vitro HRM, the DNA sequences were used in a simulation HRM, uMELT Quartz, to predict the melting curve for each species of Limnonectes. There were discrepancies between the predicted melting curves of each species generated by the programme. Consequently, in vitro HRM tests were conducted. The obtained melting curve and Tm values were consistent with those predicted, albeit with a slightly different Tm value and a more distinct melting curve. All evaluated species of Limnonectes could be easily distinguished from one another by comparing the melting curve shapes. The HRM assay was then used to confirm the species of 18 Limnonectes samples in comparison to the reference samples (confidence interval > 90%). In addition, the results of HRM were consistent with those of experts who used morphological analysis to identify species. The HRM was found to be useful, and therefore the method would also contribute to future ecological and systematic studies on the target species

Phylogenetic relationships and genetic diversity of the Polypedates leucomystax complex in Thailand

Taxonomic uncertainty of the Asian tree frog Polypedates leucomystax complex presents the challenging task of inferring its biogeographical history. Here, we describe its dispersion and the genetic relationships among different populations in Thailand, where we connect the population of the P. leucomystax complex of the Sunda Islands to the Indochina (mainland) population based on analyses of 266 sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Our maternal genealogy implies that there are four well-supported lineages in Thailand, consisting of Northern A (clade A: Polypedates sp.), Nan (clade B: P. cf. impresus), Southern (clade C: P. cf. leucomystax) and Northern D (clade D: P. cf. megacephalus), with Bayesian posterior probability >0.9. Phylogeny and haplotype networks indicate that clades A, B and D are sympatric. In contrast, clade C (P. cf. leucomystax) and clade D (P. cf. megacephalus) are genetically divergent due to the geographical barrier of the Isthmus of Kra, resulting in an allopatric distribution. Climatic conditions, in particular differences in rainfall on each side of the Isthmus of Kra, may play an important role in limiting the immigration of both clades. For the within-populations of either clades C or D, there was no significant correlation between geographic and genetic distance by the isolation-by-distance test, indicating intraspecific-dispersal of each clade. Population expansion occurred in clade C, whereas clade D showed a constant population. Taken together, the P. leucomystax complex in South East Asia may have diversified under climatic pressure, leading to allopatric and/or sympatric speciation

Contribution to the knowledge of Rhaphidophorinae (Orthoptera: Ensifera: Rhaphidophoridae) from Thailand: three genera Neorhaphidophora, Eurhaphidophora and Minirhaphidophora

Dawwrueng, Pattarawich, Gorochov, Andrei V., Tanomtong, Alongklod, Suwannapoom, Chatmongkon (2020): Contribution to the knowledge of Rhaphidophorinae (Orthoptera: Ensifera: Rhaphidophoridae) from Thailand: three genera Neorhaphidophora, Eurhaphidophora and Minirhaphidophora. Zootaxa 4853 (2): 235-253, DOI: https://doi.org/10.11646/zootaxa.4853.2.

Positive effects of Andrographis paniculata extract on growth performance, haematology, serum biochemistry, organosomatic indices and resistance against Aeromonas hydrophila in hybrid catfish (Clarias macrocephalus × Clarias gariepinus)

ABSTRACTThis research was conducted to determine the effects of Andrographis paniculate extract on hybrid catfish. The fish were fed 0, 0.2, 0.4 and 0.6 g/kg extract to supplement their diets for 90 days. The highest weigh gain, average daily growth, specific growth rate, feed efficiency and protein efficiency ratio, as well as the lowest feed conversion rate, were found in the group fed 0.6 g/kg. RBC were at their highest in all treatment groups, while the highest levels of total WBC and haematocrit percentage were observed in the group fed 0.6 g/kg. ALT and triglyceride were at their lowest levels in all treatment groups, while the highest amounts of glucose were found in all treatment groups. The highest levels of high-density lipoprotein and the lowest cholesterol were observed in fish fed 0.6 g/kg. Lysozyme activity was initially observed at a significant difference on days 60–90, the highest activity was found in the group fed 0.6 g/kg. After bacterial challenge test, lysozyme activity and WBC were significantly increased in all treatment groups, the lowest cumulative mortality was found in the group fed 0.6 g/kg. These results suggest that 0.6 g/kg of the extract has positive effects on hybrid catfish

A new species of the Cyrtodactylus brevipalmatus group (Squamata, Gekkonidae) from Tak Province, northwestern Thailand

An integrative taxonomic analysis was used to delimit and diagnose a new species of the Cyrtodactylus brevipalmatus group from Tak Province in western Thailand. Although Bayesian phylogenetic analyses place C. denticulatus sp. nov. within the brevipalmatus group, the new species is neither nested within nor is it the sister species of any other species in the brevipalmatus group. Furthermore, based on the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs, it bears an uncorrected pairwise sequence divergence of 7.87–21.94% from all other species in the brevipalmatus group. Cyrtodactylus denticulatus sp. nov. is differetiated from all other species in the brevipalmatus group by having a number of unique charateristics such as denticulate ventrolateral body folds and ventrolateral subcaudal ridges, characters not seen in any other species of the group (n = 51 individuals). Additionally, based on a multiple factor anlaysis, C. denticulatus sp. nov. does not overlap with any other species in multivariate space. The discovery of C. denticulatus sp. nov. underscores the unrealized diversity of upland ecosystems across Thailand and the urgent need for increased exploration and conservation of these unique imperiled montane refugia, especially in this era of climate change

A new species of stream toad of the genus Ansonia Stoliczka, 1870 (Anura: Bufonidae) from Nakhon Si Thammarat Range in southern Thailand

Suwannapoom, Chatmongkon, Grismer, L. Lee, Pawangkhanant, Parinya, Poyarkov, Nikolay A. (2022): A new species of stream toad of the genus Ansonia Stoliczka, 1870 (Anura: Bufonidae) from Nakhon Si Thammarat Range in southern Thailand. Zootaxa 5168 (2): 119-136, DOI: https://doi.org/10.11646/zootaxa.5168.2.