Tropical life sciences research最新文献

Azolla filiculoides is a tiny, free-floating aquatic fern and has a potential alternative protein and fibre source for ruminants, was investigated for its cultivation optimisation and feedstuff suitability. Study 1 was conducted to investigate the influence of different fertiliser types (control, broiler manure, sheep manure, cow manure) and concentrations (0.25 g/L-1.25 g/L) on the growth performance (fresh weight, doubling time, relative growth rate) and nutrient composition (dry matter, ash, crude protein, crude fibre, crude fat) of A. filiculoides. The optimised type of fertiliser and concentration in Study 1 were further adopted in Study 2 to evaluate the effect of different fertiliser processing methods on the growth performance, nutritive value and in vitro rumen digestibility of A. filiculoides upon cultivation. The findings in Study 1 showed that cultivation of A. filiculoides using sheep manure at the concentration of 1.00 g/L is the best resulted in the shortest doubling time (3 to 5 days) and produced fresh weight (FW), relative growth rate (RGR), crude protein (CP) and crude fibre (CF) at 132.2 g/m², 0.32 g/g/day, 21.2% DM^-1 and 14.4% DM^-1, respectively. Furthermore, unprocessed sheep manure (T3) exhibited superior (p < 0.05) fresh weight, relative growth rate, nutrient composition and fibre components compared to the burned manure treatment (T2). In vitro digestibility analysis discovered that T3 achieved a 24-hour accumulated gas production of 86.9 mL DM^-1, with in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD) and metabolisable energy (ME) of 82.9%, 43.7% and 5.8 MJ/kg DM, respectively. These findings suggest that Azolla filiculoides cultivation can be economically optimised using 1.00 g/L unprocessed sheep manure (fresh manure), potentially serving as a self-produced, nutritious feedstuff for ruminants.

Macodes limii J.J. Wood & A.L. Lamb is a terrestrial jewel orchid native to Sabah, recognised for its sparkling golden-yellow venations, uniformly distributed on its leaves. Despite its high ornamental value, the exploration of the plant's medicinal potential remains ambiguous. The current study was conducted to gain a fundamental understanding of the metabolite composition and regulation in M. limii plants from two different growing environments: wild and in vitro cultivation, as well as to analyse their phytochemical contents and antioxidant activity. The metabolite profiling of the M . limii plant extracts through gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has tentatively identified compounds from various classes including sugars, carbohydrates, sugar alcohols, amino acids, organic acids, phenolic derivatives and lipid and lipid-like compounds. Subsequently, the multivariate statistical analysis confirmed the existence of significant metabolite variations across distinct growth environments. Notably, the leaf extract derived from wild-grown plants displayed the highest levels of total phenolic and flavonoid content, contributing significantly to its higher antioxidant activity as measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The discovery has offered a fundamental understanding of the metabolites in M. limii jewel orchids, indicating that in vitro regenerated plants may represent a viable alternative for further investigating their therapeutic potential, thus helping to alleviate the impact on wild populations.

Macrobrachium rosenbergii, or giant river prawn, is the most economically crucial cultured freshwater crustacean. A predominant challenge in developing crustacean aquaculture is reproduction management, particularly ovary maturation, where identifying regulative mechanisms at the molecular level is critical. Ovary is the primary tissue for studying gene and protein expressions involved in crustacean growth and reproduction. Despite significant interest in M. rosenbergii, its gene discovery has been at a relatively small scale compared to other genera. In this study, comprehensive transcriptomic sequencing data for different maturation stages of the ovary of M. rosenbergii were observed. The 20 female M. rosenbergii samples evaluated were categorised into four maturation stages, 1 to 4. A total of 817,793,14, 841,670,70, 914,248,78 and 878,085,88 raw reads were obtained from stages 1, 2, 3 and 4, respectively. The assembled unique sequences (unigenes) post-clustering (n = 98013) was 131,093,546 bp with an average size of 1,338 bp. The BLASTX unigene search against National Centre for Biotechnology Information (NCBI), non-redundant (NR), nucleotide sequence (NT), Kyoto Encyclopaedia of Genes and Genomes Orthology (KO), Swiss-Prot, Protein Family (PFAM), Gene Ontology (GO), and euKaryotic Orthologous Groups (KOG) databases yielded 27,680 (28.24%), 7,449 (7.59%), 13,026 (13.29%), 22,606 (23.06%), 29,907 (30.51%), 30,025 (30.63%) and 14,368 (14.65%) significant matches, respectively, totalling to 37,338 annotated unigenes (38.09%). The differentially expressed genes (DEG) analysis conducted in this study led to identifying cyclin B, insulin receptor (IR), oestrogen sulfotransferase (ESULT) and vitellogenin (Vg), which are critical in ovarian maturation. Nevertheless, some M. rosenbergii ovarian maturation-related genes, such as small ubiquitin-like modifier (SUMO)-activating enzyme subunit 1, E3 ubiquitin-protein ligase RNF25, and neuroparsin, were first identified in this study. The data obtained in the present study could considerably contribute to understanding the gene expression and genome structure in M. rosenbergii ovaries throughout its developmental stage.

In this study, we examined the effects of experimental intraperitoneal infection with haemotropic Mycoplasma ovis (0.5 mL of blood containing 80% parasitaemia) on selected serum biomarkers and cellular pathology in mice. After infection, M. ovis cells appeared in the blood films within one week. A dose-dependent peak of parasitemia was observed during the 3^rd-week post-infection (pi), with a significant decrease in mean PCV between treatment versus control group at week 3 (t ₁₄ = -3.693, P < 0.02), week 5 (t ₁₄ = -2.096, P = 0.055), and week 7 (t ₁₄ = -4.329, P = 0.001). There was a significantly (t ₈ = -2.330, P = 0.048) lower serum oestrogen in treatment (10.38 ± 5.07) than control (17.43 ± 4.48), while serum progesterone was significantly (t ₈ = 5.415, P = 0.001) increased in treatment (27.37 ± 2.17) than control (15.92 ± 4.20). Serum haptoglobin was significantly (t ₈ = 8.525, P < 0.01) lower in treatment (8.72 ± 1.49) than control (18.16 ± 1.98) while the SAA was significantly (t ₈ = 3.362, P = 0.01) higher in treatment (16.79 ± 2.71) than control (11.59 ± 2.15). Prominent lesions observed in the ovary include degeneration, necrosis, vacuolation, and hypertrophy of the lutein cells in corpora lutea. In the lymph nodes, diffused cellular hyperplasia of the lymphoid tissue in the cortex. In the liver, degeneration and necrosis accompanied by leucocytic cellular infiltration and Kupffer cell proliferation within the sinusoids. There were diffused leucocytic infiltrations and proliferative lesions in the glomerulus of the kidneys. The disturbance in progesterone and ovarian pathology highlights the potential role of haemotropic M. ovis in reproductive disorders. The observed changes in biomarkers and cellular reactions following M. ovis infection in the mouse may be further advanced in sheep and goats.

Alzheimer's disease (AD) is a neurodegenerative condition brought on by aging and characterised by progressive decline in cognitive function and abnormalities in the central cholnergic system. β-amyloid deposits, neurofibril tangle aggregation, oxidative stress or reduced level of acetylcholine are a few causes that have been linked to AD. In this study, the bioassay-guided isolation from ethyl acetate (EtOAc) extract of Horsfieldia polyspherula bark led to the isolation of nine compounds namely, 16-phenylhexadecanoic acid (1), undecylbenzene (2), 3,4-dihydroxybenzoic acid (3), dodecanoic acid (4), tetradecanoic acid (5), pentadecanoic acid (6), 1-tridecene (7), stigmasterol (8) and trimyristin (9). Phytochemical analysis revealed the presence of flavonoids, steroids, lignin, alkaloids, phytosterol and triterpenoids. The DPPH scavenging activity of EtOAc extract was related to the phenolic content (116.67 ± 16.98 GAE mg/g) and other non-phenolics such as lower fatty acids. Meanwhile, the DPPH scavenging activity was found to be concentration-dependent and correlated with both flavonoid and phenolic content. Furthermore, EtOAc and methanol (MeOH) extracts of H. polyspherula bark showed significant inhibitory activity at 100 μg/mL on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), with EtOAc extract showing 77.2% and 64.1% inhibition and MeOH extract showing 37.5% and 39.2% inhibition, respectively. Additionally, the IC₅₀ for BuChE and AChE of the EtOAc extract were found to be effective, with 15.41 ± 0.78 μg/mL and 7.67 ± 0.13 μg/mL, respectively. Compound 1 exhibited dual inhibition of 40.99 ± 1.99 μM (BuChE) and 46.83 ± 2.44 μM (AChE), while compounds 2 and 3 showed IC₅₀ values above 200 μM. This study revealed that this plant shows a significant potential as anti-cholinesterase focusing on acetylcholinesterase (AchE) and butyrylcholinesterase (BuChE). This is the first report on Horsfieldia polyspherula and their biological activity.

Population of the tropical bed bug Cimex hemipterus (F.) (Hemiptera: Cimicidae), a temporary ectoparasite on both humans and animals, have surged in many tropical countries. Tropical bed bugs preferences when selecting a suitable harbourage and oviposition site were investigated. Two-choice and three choice colour assays were conducted to determine whether bed bugs will choose black, red or white coloured harbourages. Then, 50 1st instar were reared in containers containing black, red and white (control) paper served as the harbourages and observed for 12 weeks. Both fed and starve male, female and nymph strongly preferred red and black coloured harbourage compared to white coloured harbourage. Oviposition assays showed that female bed bugs prefered to laid their eggs on red coloured harbourages compared to black coloured harbourages. Rearing experiment showed that there was no significant difference (p > 0.05) between final population size of tropical bed bug. However, tropical bed bugs reared in container with red paper (600 ± 89.238) have the highest number of individuals followed by black (473 ± 133.841) and white (485 ± 84.234) paper. Bed bug preference towards coloured harbourage provide useful information for those developing new bed bug control method or improving bed bug infestation monitoring devices.

We investigated the host range of Cassytha filiformis L. in the heath forests using six 50-metre transects. Sixteen shrubs and tree species were infected by C. filiformis vines, including two exotic Acacia species. This paper also examined the density and vigour of C. filiformis when infecting the two most preferred and common hosts, the heath native Dillenia suffruticosa (Griff. ex Hook. f. and Thomson) Martelli, and the invasive Acacia mangium Willd. The results suggested that C. filiformis has higher vigour when infecting native hosts than in exotic A. mangium albeit being not statistically significant. The long thread-like stems of parasite were present at relatively high density when infecting A. mangium, regardless of the host conditions. We also assessed the functionality of the haustoria on both D. suffruticosa and A. mangium using histological methods. It was found that C. filiformis can establish a true haustorial endophytic connection with studied hosts. Under controlled conditions, C. filiformis pose as a possible candidate for a biological control agent of A. mangium to curtail the fast spreading of this introduced species in tropical Borneo.

Lactiplantibacillus plantarum is a widely studied species known for its probiotic properties that can help alleviate serum cholesterol levels. Whole-genome sequencing provides genetic information on probiotic attributes, metabolic activities and safety assessment. This study investigates the probiotic properties of strain CRM56-2, isolated from Thai fermented tea leaves, using Whole-Genome Sequencing (WGS) to evaluate the safety, health-promoting genes and functional analysis. Strain CRM56-2 showed bile salt hydrolase (BSH) activity, assimilated cholesterol at a rate of 75.94%, tolerated acidic and bile environments and attached to Caco-2 cells. Based on ANIb (98.9%), ANIm (99.2%), and digital DNA-DNA hybridisation (98.3%), strain CRM56-2 was identified as L. plantarum. In silico analysis revealed that it was not pathogenic and contained no antibiotic-resistance genes or plasmids. L. plantarum CRM56-2 possessed genes linked to several probiotic properties and beneficial impacts. The genome of strain CRM56-2 suggested that L. plantarum CRM56-2 is non-hazardous, with potential probiotic characteristics and beneficial impacts, which could enhance its probiotic application. Consequently, L. plantarum CRM56-2 demonstrated excellent cholesterol-lowering activity and probiotic properties.

Some biological aspects of local bloodworms in Thailand were investigated. In this study, the larvae of one species of bloodworm, identified as Chironomus pallidinubeculosus Tokunaga 1936, were reared in plastic containers at 25°C and fed with fish feed solutions three days per week. The eggs sample were processed by histological and TEM techniques. Yield (g/m²), moisture, ash, crude protein, crude lipid, crude fibre and gross energy (KJ/g) were determined in reared larvae. The results showed that C. pallidinubeculosus larvae could survive and be bred in plastic containers, controlled laboratory conditions, and have four instars. The suitable physico-chemical parameters during rearing were low to moderate dissolved oxygen (1.18 mg/L-5.00 mg/L), electrical conductivity (462 μS-714 μS), and total dissolved solids (249 mg/L-378 mg/L). Moreover, adults had a high average number of eggs per one egg mass from 193.2 ± 49.99 to 331.86 ± 80.23 and an average hatchability of 90.69% to 94.49% during the 1st to 3rd generations, respectively. The life cycle of this study was approximately 19 to 23 days. Polylecithal and centrolecithal eggs were observed. After gelatinous mass removal, the egg was covered by non-regularly exochorionic jelly. The internal morphology of the egg is mainly composed of proteid yolk, lipids and dense granular. Larvae constituted 89.78% water; they had a high 15th day yield (g/m²), and the minimum area of larvae for mass culture was 1.2 cm². The proximate composition analysis in reared larvae showed that crude protein, crude lipid crude fibre and gross energy were higher than its feed. The biology aspect study of the bloodworms found they were easy to culture; they should be considered a model organism for further ecology, nutrition and toxicology studies.

This paper highlighted the annual distribution, seasonality and reproduction status of two species of sea turtles in Negeri Sembilan, Peninsular Malaysia between January 2016 and July 2020 (55 months). These data were officially provided by the Department of Fisheries Malaysia (Negeri Sembilan's state), as a part of a conservation effort made by them to protect the endangered species, as the turtle's population residing in Negeri Sembilan is one of the smallest in Malaysia. Current status shows that the hawksbill turtles, Eretmochelys Imbricata population in Negeri Sembilan is in stable decline with an average of <30 nests per year, and an average of <10 nests per year for the green turtle, Chelonia mydas. The overall sum was 122 nests collected for both species from 2016-2020. This paper updated the status of the hawksbill and green turtle after 30 years from the first study recorded by Mortimer et al. in 1993.