Tropical life sciences research最新文献

Reproductive health and male fertility are closely related to dietary practices. In recent years, Malaysia has shown a lot of interest in using herbal plants as dietary supplements or in the treatment of numerous diseases. Aquilaria malaccensis, commonly known as karas or gaharu, has recently gained attention for its potential to cure many diseases due to its pharmacological properties. However, studies on its effect on male fertility and reproductive organs are very scarce. This study was conducted to determine the effect of A. malaccensis on male reproductive organs' weight (testis, epididymis, prostate gland and seminal vesicle) and sperm quality (sperm count, sperm morphology and sperm motility) in adult Sprague Dawley rats. Twenty-four male Sprague Dawley rats were allocated into four treatment groups; Control (C: 1 mL of distilled water, n = 6), Treatment 1 (T1: 1 g A. malaccensis/kg body weight, n = 6), Treatment 2 (T2: 2 g A. malaccensis/kg body weight, n = 6) and Treatment 3 (T3: 3 g A. malaccensis/kg body weight, n = 6), respectively. Distilled water and A. malaccensis were administered by oral gavage once daily for 28 days. The rats were euthanised on Day 29 for assessment of reproductive organs' weight and sperm quality. Result shows that weight of testis, epididymis, prostate gland, seminal vesicle and sperm motility did not differ (p > 0.05) among control and treated groups. A significant increase (p < 0.05) of sperm number (1.36 × 10^-6) and a decrease (p < 0.05) in percentage of the abnormal sperm (8.17%) were observed in T1 group when compared to Control group. Incremental dosage of A. malaccensis seemed to decrease number of sperm (T3: 0.78 × 10^-6 < T1: 1.36 × 10^-6 with p < 0.05) and increase percentage of abnormal sperm (T3: 18.83% > T2: 12.17% > T1: 8.17% with p < 0.05). In conclusion, the administration of either 1, 2 or 3 grams of A. malaccensis did not alter the reproductive organs' weight and sperm motility. However, the higher concentration of A. malaccensis consumed by the rats seemed to have detrimental effects on the number and morphology of sperm.

Deforestation in Cameron Highlands, Malaysia has increased significantly in the past few years to accommodate the growing population of Cameron Highlands. This led to a rapid urbanisation in Cameron Highlands which increased anthropogenic activities, causing degradation of the natural environment. Such environmental changes highlight the necessity of wildlife and resource inventories of available forested areas to improve existing conservation and management plans, especially for threatened taxa such as the non-volant small mammals. However, very few studies are known to focus on the effect of deforestation on non-volant small mammals, especially in the adjacent forest. This survey aimed to document non-volant small mammals from four habitat types (restoration areas, boundary, disturbed and undisturbed areas) of Terla A and Bertam, and undisturbed forest of Bukit Bujang Forest Reserve, Cameron Highlands, Malaysia. Samplings were conducted in two phases between August 2020 to January 2021. A total of 80 live traps were deployed along the transect lines in all three study sites, and 10 camera traps were set randomly in each forested area. Results demonstrated that species diversity (H') is higher at Terla A Forest Reserve compared to Bertam and Bukit Bujang Forest Reserve. In contrast, species diversity in the boundary area (S = 8, H' = 2.025) and disturbed forest area (S = 8, H' = 1.992) had similar number of species (S) compared to others study habitat; restoration area had the lowest species diversity (S = 3, H' = 0.950). Berylmys bowersi was the most captured species from trappings and Lariscus insignis was the most frequently recorded species from camera trappings for all study sites. The results of the survey provided new information on non-volant small mammals in Cameron Highlands for future research, conservation, and management.

Oxidative stress and inflammation have been proven to be implicated in the pathogenesis of type 2 diabetes. Recent studies showed that Ethulia conyzoides had in-vitro antioxidant activity. This study investigated the in-vivo antidiabetic, antioxidant, and anti-inflammatory potential of the residual aqueous fraction of Ethulia conyzoides in type 2 diabetic-induced male Wistar rats. Sub-acute antidiabetic studies were done with varying doses (100, 200, and 400 mg/kg body weight) of residual aqueous fraction for 21 days. Blood glucose levels, serum insulin, and in vivo antioxidant and pro-inflammatory cytokines-tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) -were measured at the end of the treatment. When rats were given different concentrations of residual aqueous fraction, there was a significant (p < 0.05) reduction in blood glucose, malondialdehyde (MDA), IL-1β, and TNF-α levels, as well as a significant (p < 0.05) increase in SOD (superoxide dismutase), catalase and insulin levels when compared to the diabetic control group. Furthermore, the 400 mg/kg body weight dosage concentration was found to be the most effective. This result suggests that the residual aqueous fraction of Ethulia conyzoides possesses significant antidiabetic, antioxidant and anti-inflammatory activities.

Microbial infection is a frequent complication of diabetic foot ulcers, with up to 82% of ulcers being infected at the initial stage of diabetes. Furthermore, the emergence of beta lactam resistant pathogens managed to eliminate the use of beta lactam antibiotics as a chemotherapeutic alternative. This further increases the amputation and mortality rate. Hence, the aim of this study is to evaluate antimicrobial efficacy of a ketone derivative 2-octylcyclopentanone against diabetic wound pathogens. The inhibitory activity of the compound was determined using disc diffusion and broth microdilution assay. Generally, 2-octylcyclopentanone showed broad-spectrum antimicrobial activity, particularly against beta lactam resistant pathogens. The compound showed comparably better antimicrobial activity than all reference antibiotics, including chloramphenicol, streptomycin, ampicillin and penicillin. In addition, the same compound also inhibits a clinically isolated Pseudonomas aeruginosa that was resistant to all reference antibiotics. The activity was microbicidal based on the low minimal lethality concentration recorded, particularly on MRSA, P. aeruginosa and Candida utilis. The killing efficiency of the compound was concentration dependent. During kill curve analysis, the inhibitory activity of 2-octylcyclopentanone was concentration and time-dependent. 99.9% of reduction of bacterial growth was observed. MRSA and P. aeruginosa, two significant diabetic wound infections, are totally inhibited by the molecule at a concentration of minimum lethality concentration. In short, 2-octylcyclopentanone exhibited significant inhibitory towards wide range of diabetic wound pathogens. Which is considered crucial since it will provide a safe and effective alternative treatment for diabetic ulcer infection.

Species of the genus Chattonella (Raphidophyceae) are a group of marine protists that are commonly found in coastal waters. Some are known as harmful microalgae that form noxious blooms and cause massive fish mortality in finfish aquaculture. In Malaysia, blooms of Chattonella have been recorded since the 1980s in the Johor Strait. In this study, two strains of Chattonella were established from the strait, and morphological examination revealed characteristics resembling Chattonella subsalsa. The molecular characterization further confirmed the species' identity as C. subsalsa. To precisely detect the cells of C. subsalsa in the environment, a whole-cell fluorescence in-situ hybridisation (FISH) assay was developed. The species-specific oligonucleotide probes were designed in silico based on the nucleotide sequences of the large subunit (LSU) and internal transcribed spacer 2 (ITS2) of the ribosomal DNA (rDNA). The best candidate signature regions in the LSU-rRNA and ITS2-rDNA were selected based on hybridisation efficiency and probe parameters. The probes were synthesised as biotinylated probes and tested by tyramide signal amplification with FISH (FISH-TSA). The results showed the specificity of the probes toward the target cells. FISH-TSA has been proven to be a potential tool in the detection of harmful algae in the environment and could be applied to the harmful algal monitoring program.

The objective of this study was to describe the structure and histochemistry of the systemic organs in the female marine water-strider Asclepios annandalei from Pranburi river estuary, Thailand. Results from this study revealed for the first time that the integumentary system of this species consisted of three layers including epicuticle, exocuticle and endocuticle. The muscular system apparently contained only skeletal muscle along the body. In the urinary system, we observed well-developed Malpighian tubules, each of which was covered with the simple cuboidal epitheliums. These epitheliums also contained the secretory granules that were reacted positively with periodic acid Schiff (PAS). The digestive system of this species was composed of three distinct parts including foregut, midgut and hindgut. The respiratory system was composed of the respiratory organ, which was rarely found near the integument system. This organ was lined with a simple squamous epithelium. Two regions of nervous system, i.e., frontal ganglion connected to the eye structure and ventral nerve cord, were found. Each ganglion basically consisted of two layers, outer cortex and inner medullae. The outer cortex contained three types of cells, including neurosecretory cells, neuroglial cells and neurons. The cytoplasmic inclusion of neurosecretory cells contained secretory granules, which reacted positively with PAS, indicating the presence the glycoprotein. The neuroglia and neuron were also observed in the inner medullae layer. The female reproductive system (the ovarian structure, the reproductive tract and the accessory organ) of this gerrid species was seen under histological sections. The well-developed integument system and Malpighian tubule as well as the abundant respiratory organ is a characteristic of this species, which might be useful for the adaption to the estuarine condition.

This study investigated the influence of spent mushroom compost (SMC) of Pleurotus eous strain P-31 on the growth, development and soil rhizobial population associated with nodulation of cowpea (Vigna unguiculata Walp.) black-eye variety, under greenhouse conditions at 28 ± 2ºC for 12 weeks. Sandy loam soil was combined with different percentages of SMC to obtain the following combinations (0%, 5%, 10%, 15%, 20%, 25%, 30%, 100%). Lower concentrations, SMC (5%-25%) promoted plant height, number of leaves, total leaf area, total chlorophyll, chlorophyll a and b as well as dry matter accumulation of shoot and roots after 12 weeks at 28°C-32°C. Soil: SMC concentrations beyond 30% SMC variably depressed the various developmental criteria used in assessing growth. The trend obtained in the assessed parameter were statistically significant (p ≤ 0.05) in decreasing order: 5% SMC < 10% SMC < 15% SMC, < 20% SMC, < 25% SMC, < 30% SMC, < 100% SMC. The cowpea plant efficiently assimilated nitrogen (N₂) from the soil: compost. Nodule formation by cowpea was commensurate with increasing percentage of spent compost was highest in 5% SMC (89/plant) and declined with increasing proportion of SMC: soil mixture up to 25% but nodulation of cowpea plant was completely depressed in the absence of soil (100% SMC) pots. The Nodule Index data showed that the best nodule size and weight were formed by cowpea growing in medium containing 5% SMC (18) and 10% SMC (12) and thereafter declined. The nodules were red to pinkish in colour epitomising leghaemoglobin which could initiate nodulation and N₂ fixation in soil. This study has shown that 5% SMC-20% SMC could provide favourable conditions in soil as a biofertiliser to improve the growth, development and nodulation of cowpea.

Flying foxes are threatened throughout their geographic range, and there are large gaps in the understanding of their landscape-scale habitat use. This study identified potential habitats in Limbang, Sarawak and informed potential distribution based on dispersal and interview surveys. Here, biological surveys were combined with interviews of local communities in Limbang Mangrove National Park (LMNP), Sarawak to illustrate distribution and the communities' perception on the protected flying fox (Pteropus vampyrus). Mangrove forest areas were surveyed for for the presence of flying foxes and villagers were interviewed regarding the use by flying foxes of agricultural areas and instances of conflict. Boat and questionnaire surveys were conducted for nine days from 18 to 27 February 2021. The surveys did not record any flying fox roosting sites within the national park and was instead observed to fly from Menunggul Island, Brunei into the national park in the evenings and back to Brunei in the mornings. A total of 27 flying foxes were recorded during the boat survey. Flying foxes were detected from 8/154 survey points and their spatial distribution appeared to be concentrated along Sungai Limpaku Pinang. Most respondents were aware of the species while some have directly observed them in fruit orchards, mangroves, rivers and mixed dipterocarp forests. Eleven perception-based questions were presented, and results showed that locality and income were the most influential parameters exhibiting conservation awareness through Boosted Regression Trees (BRT) analysis. Most respondents believe that flying foxes can uplift the local economy through ecotourism opportunities. However, these findings need to be carefully interpreted as the species has a large home range. Hence, long-term monitoring should be established to generate a larger dataset for stronger analysis to better represent the distribution and occurrence of this species in LMNP.

Ten nests were collected from Kerachut and Teluk Kampi, Penang Island between 2 August 2009 and 9 December 2009, and each one nest was split into three small clutch sizes for incubation at three nesting depths (45 cm, 55 cm and 65 cm), with a total of 30 modified nests for this experiment. Three important objectives were formulated; to observe on the survival hatchings among the three nesting depths, to study on the effects of sand temperature on incubation period among the three nesting depths, and to investigate the influence of sand temperature on hatchling's morphology. Main result shows that the mean survival of the hatchlings was 25.40% at 45 cm nesting depth, followed by mean 17.60% at 55 cm nesting depth, and lastly, the mean was 21.50% at 65 cm nesting depth. Overall, there are 56.63% survival hatchlings, 10.97% dead hatchlings and 32.40% unhatched eggs were produced. The incubation period was also found to be significantly correlated with sand temperature, p > 0.001, and nesting depth, p < 0.001. The hatchling's length and weight varies is sizes across the nesting depths, p < 0.001. However, the small difference in hatchling sizes per nesting depths are not strong enough to prove the significant correlation with sand temperature, p > 0.05. This article provides a basic knowledge from the splitting clutch design method. A sum of 50%-60% survivals hatchlings produced were incubating under small range of clutch sizes, 29 to 49 eggs. This article provides basic result on the survival hatchlings, eggs survivorship, incubation period, temperature, hatchling's morphology and discussion on implication of this method on conservation in Malaysia.

This study utilised a bio-sorbent from exhausted coffee husk (ECHBS) for the removal of ion Pb²⁺ from an aqueous solution. Four different activation methods were conducted by chemical activation with KOH, H₃PO₄, ZnCl₂, and without chemical activation. In addition, the influence of process parameters such as heating temperature, heating time and heating gradient were investigated. Based on the experimental results, ECHBS without chemical activation (biochar) had the highest Pb²⁺ ion removal efficiency. The results showed that the heating temperature of 500°C, the heating time of 60 min and the heating rate of 15°C/min were optimum for preparation of the biochar. Under the optimum conditions, the removal efficiency and adsorption capacity reached 99% and 3.3 mg/g, respectively. The experimental data indicated that the adsorption isotherms are well fitted with the Langmuir Equilibrium isotherm model. Furthermore, the adsorption of the biochar follows the pseudo-second-order model. The result obtained from the present study confirmed that exhausted coffee husk is a suitable low-cost bio-sorbent for removing ion Pb²⁺.