UNIMAS Journal (Universiti Malaysia Sarawak)
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Phytochemical Profiling of Garcinia rostrata, Garcinia dryobalanosides and Garcinia cuneifolia and Their Antibacterial Activity: Phytochemical profiling of Garcinia
No full textGarcinia spp. have been used in traditional medicine to treat various ailments, and recent studies have confirmed their pharmacological activities. In this context, the present study focused on three Garcinia spp., namely Garcinia rostrata, Garcinia dryobalanoides and Garcinia cuneifolia, which gain less attention in terms of their phytoconstituent and biological activity data. Methodologically, in this study, the phytochemical constituents of the three Garcinia sp. was determined through gas chromatography mass spectrometry (GC-MS) whereby the antimicrobial activity was evaluated using the Disc diffusion and Dilution method. The results showed that the extract from Garcinia dryobalanoides exhibited the most potent antibacterial activity against Bacillus amyloliquefaciens compared to the other species. The phytochemical analysis found that Garcinia dryobalanoides extract contained significant amounts of (Z)-18-Octadec-9-enolide and n-hexadecanoic acid, which are known to possess antibacterial properties. These major constituents were found to interact synergistically to produce the observed antibacterial activity. The findings suggested that Garcinia dryobalanoides could be a promising source for developing new antibiotics to combat bacterial infections. Overall, this study highlights the potential of Garcinia spp. for discovering new bioactivities, particularly their antibacterial properties. Further research is needed to explore the full range of phytochemical constituents and biological activities of these plants, which could lead to the development of new drugs to combat antibiotic resistance
Effects of Extraction Method on Yield, Phenolic and Flavonoid Content of Leaf, Stem and Root of Cassia alata Linn.: Extraction method on yield, phenolic and flavonoid
No full textThe study of medicinal plants has gained significant interest among researchers because of their potential for therapeutic purposes and the production of natural drugs. In Sarawak, Cassia alata is one of the native plants used for medicinal purposes, such as treatment for constipation, ringworm, and other skin diseases. This study determined the yield of extraction, total phenolic content (TPC), and total flavonoid content (TFC) of the leaf, stem, and root of C. alata using various extraction methods and solvent extractions. The extractions were performed using soxhlet extraction (SE) and ultrasonic-assisted extraction (UAE) with ethanol and chloroform. Among all, the extract obtained from SE with ethanol solvent (SE-EtOH) showed the highest yield in all plant parts (leaf: 28.62 %, stem: 10.06 %, and root: 9.79 %). Meanwhile, the TPC and TFC estimated using the Folin-Ciocalteu phenol reagent and aluminium chloride colorimetric assay methods showed that the highest TPC and TFC were from the leaf extract obtained using UAE and chloroform (UAE-Chlo-L) with a TPC value of 117.436 mg GAE/g DW and a TFC value of 568.778 mg QE/g DW, respectively. Overall, the findings demonstrated that chloroform was an effective solvent system for all plant parts on the TPC and TFC, with the leaf part containing the greatest value, and that ultrasonic-assisted extraction was the best approach. This exploration is beneficial for the determination of methods that produce optimum yield, phenolic, and flavonoid content in C. alata’s species
Early Assessment of Forest Growth in a Logged over Coastal Lowland Mixed Dipterocarp Forest in Bintulu, Sarawak, Malaysia: Growth of lowland dipterocarp forest in Sarawak
No full textManaging regrowth forests sustainably is a necessary tactic to address climate change as these forests' ability to capture and sequester carbon is much higher due to their potential high growth rate. These forests also retained high tree diversity if subjected to selective logging previously. The objectives of this study were to investigate growth rate of tree species in a logged over coastal lowland mixed dipterocarp forest. This study was carried out in 10 established plots (50 m × 20 m) at a logged-over forest in Universiti Putra Malaysia Bintulu Sarawak Campus, Sarawak, Malaysia and trees with 10 cm diameter breast height (dbh) and above were measured. There were 611 individual trees of 159 species and 43 families were found in a one-hectare. The majority of trees (86%) were found in smaller diameter classes (<30 cm) with only 2% in diameter classes of more than 50 cm. The study area still retains a mixed dipterocarp forest feature. The stand has a good growth rate. Overall dbh increment was 0.34 cm yr-1 with dipterocarps documented 0.39 cm yr-1. A reverse growth dominance was observed in this study where smaller trees recorded higher growth. Thus contributing up to 72% of carbon sequestrated by this group of trees
Computational Analysis of Epstein-Barr Virus BamHI A Rightward Transcript (BART) MicroRNAs (miRNAs) Regulation on Messenger RNAs and Long Non-Coding RNAs in Nasopharyngeal Cancer: Epstein-Barr Virus Regulation on ceRNA Network
No full textTo date, the regulatory framework mediated by Epstein-Barr virus (EBV) BamHI A rightward transcript (BART) microRNAs (miRNAs) via their interaction with long non-coding RNAs (lncRNAs) in the context of nasopharyngeal cancer (NPC) pathogenesis remains partially understood. To derive a more complete insight into this phenomenon, we embarked on a computational study to identify BART miRNAs, mRNAs, lncRNAs, and all associated factors relevant to NPC tumourigenesis and to characterise their interactions. In silico integration of multi-level RNA expression and construction of regulatory networks were performed. We found six EBV BART miRNAs (ebv-miR-BART21-3p, ebv-miR-BART19-3p, ebv-miR-BART15, ebv-miR-BART2-5p, ebv-miR-BART20-3p and ebv-miR-BART11-5p) that could interact with four mRNAs (EYA4, EYA1, EBF1 and MACROD2) associated with NPC pathogenesis. These mRNAs can interact with six non-EBV miRNAs (hsa-miR-1246, hsa-miR-93-5p, hsa-miR-16-5p, hsa-miR-135b-5p, hsa-miR-211-5p and hsa-miR-1305), which in turn, could interact with three lncRNAs (CASC2, TPTE2P1 and ARHGEF26-AS1). These findings could shed light on the roles of dysregulated competing endogenous RNA (ceRNA) network in NPC oncogenesis. In addition, we have also predicted the oncogenic and tumour suppressive functions of BART miRNAs and lncRNAs, and more precisely, the involvement of BART miRNAs in DNA repair regulation and apoptosis
Physicochemical Investigation and Analysis of Nypa Sap (Nypa fruticans Wurmb) using a Novel Collecting Device: Nypa sap novel device from Sarawak, Malaysia
No full textA sweetener from Nypa fruticans Wurmb offers significant health benefits. The traditional process of sap tapping requires careful attention to enhance cleanliness. In this research, a nypa sap harvesting device has been developed, and a time study for its installation has been conducted. The physicochemical properties of the sap gathered from the device were evaluated and compared with the traditional method in terms of total soluble solids(TSS) reading, pH level, total dissolved solid (TDS) and electrical conductivity (EC) value, and glucose content. Both methods showed no significant difference, with an average TSS reading of 14 to 15 brix, pH of 3.57-3.97, glucose content of 25.9 to 32.4, TDS of 2340-2726 ppm, and EC reading of 4679-5472 s/cm. Slight differences in physicochemical properties were observed due to the random selection of trees for the experiment. The use of the device was found to improve the physical cleanliness of the sap by 97% and chemical purity by 7% to 11%. The colour of the sap collected with the device was milky white compared to the traditional bamboo method, resulting in a yellowish-white sap. The time study showed a 40% improvement compared to the first trial, indicating the practicality of the device, which can be easily installed by the operator. The physicochemical properties of the sap collected using the device can be further improved with the addition of preservatives. The findings are expected to enhance sap harvesting hygiene and the quality of sap, directly affecting the quality and benefits of the derived products
Simulation of Hybrid Microbial Fuel Cell-Adsorption System Performance: Effect of Anode Size on Bio-Energy Generation and COD Consumption Rate: Simulation of hybrid microbial fuel cell-adsorption system performance
No full textLandfill leachate discharged into watercourse without proper treatment can pollute the water source due to its high chemical oxygen demand (COD). The high pollutant load in landfill leachate has become one of the potential substrates in bio-energy generation by using microbial fuel cell (MFC). MFC integrated with adsorption system has been introduced as an approach to overcome the limitation of stand-alone MFC, which is able to treat the landfill leachate more effectively while simultaneously generating bio-energy. Anode size has been reported to have a significant influence on the power generation of MFC via lab-scale experiments, however the simulation studies on MFC are still limited. This study aimed to develop a simulation model to predict the effect of graphite fiber brush anode size on the performance of a single chamber air-cathode hybrid MFC-Adsorption system, in terms of COD removal and bio-energy generation. The highest power density of 1.33 mW/m2 was achieved with 20% anode brush removed. The highest current generation of 2.37 mA and voltage of 7.11 mV was obtained with the largest anode surface area of 0.1288 m2 and resistance of 2.76 Ω. The highest COD consumption by electrogenic microorganisms was 4.96 x 10-9 Lmol/mg, and predicted to decrease with decreasing anode size. The efficiency of the simulation model could be further improved by incorporating parameters such as charge transfer kinetic at anode and cathode, adsorption effect by activated carbon as well as the substrate and microbial population behaviour. The simulation model developed was significant towards enhancing the bio-energy generation and reducing the cost of MFC for industrial application.
Financial Ratios and Portfolio Construction
Get PDFThis paper aims to provide empirical evidence of portfolio construction using the current, return on equity, and debt-to-equity ratio across the top three industries in Malaysia. This study analysed 30 companies listed on Bursa Malaysia from three different industries: the energy industry, the plantation industry, and the consumer products and services industry. We find that all 17 portfolios generate positive returns except Portfolio 12. There is no statistically significant difference between the mean of the portfolio with the highest ratios and the mean of the portfolio with the lowest ratios for the three financial ratios. The results of the study provide valuable insight for portfolio managers and investors
From Taxes to Prosperity: The Role of Tax Revenue in Malaysia’s Economic Growth
Get PDFThis study examines the relationship between Malaysia economic growth and tax revenue. The data were taken from year 2011 to 2020 from the World Bank and OECD. The data were analyzed using the descriptive analysis, correlation, Variance Inflation Factor (VIF), and Ordinary Least Squares (OLS). This study reveals a high and positive link between OT and GDP and between SCC and GDP, a very strong and positive relationship between PCG and GDP, a very weak and negative relationship between TGS and GDP, and a moderate and negative relationship between TP and GDP. In conclusion, the study on the relationship between tax revenues and economic growth in Malaysia has significant policy consequences and provides insightful information. The awareness of this association may help lawmakers create fiscal policies that encourage sustained economic growth, including the right tax rates, incentives, and structures. Furthermore, it could assist with resource allocation, budget planning, and predicting future tax revenues
A Study of Malaysian Pharmaceutical Companies on Financial Leverage and Firm Performance
Get PDFThis study investigates the relationship between financial leverage and firm performance among pharmaceutical companies in Malaysia, with specific objectives of assessing the impact of debt-to-equity ratio (DR) and interest rates on return on assets (ROA). Using a sample of seven publicly traded pharmaceutical firms listed on Bursa Malaysia and secondary data derived from their financial statements for the period of 2011-2020, the study evaluates firm size, liquidity, and profitability as key variables. The results reveal a significant positive relationship between financial leverage and ROA, contrary to prior studies that report a negative correlation. Firm size emerges as a critical factor, with larger firms exhibiting higher profitability but also a greater likelihood of financial distress. The findings suggest that Malaysian pharmaceutical companies should strategically manage their debt-to-equity ratios, optimize resource allocation, and explore research and development opportunities to enhance performance. Future research should expand the dataset to include firms outside the main market and investigate additional factors, such as short-term and long-term debt, influencing firm performance
Credit Risk Management and Its Effect on Financial Performance between Conventional and Islamic Banks in Malaysia
Get PDFBanks are essential to a nation's economic development. In order to guarantee banks can remain in the financial sector, risks must effectively be managed in this sector. The main goal of this research is to gaze into the link between credit risk management (CRM) and the financial performance (FP) of conventional and Islamic banks in Malaysia. The sample collected for this empirical study covered twelve years of data from 2011 until 2022. The sample for this study is consist of 15 conventional and 15 Islamic banks in Malaysia. Regression analyses are used to determine the impact of CRM and its components namely non-performing loans ratio (NPLR), capital adequacy ratio (CAR), and loan-to-deposit ratio (LDR) on the banks’ performance which is measured by return on assets (ROA) and return on equity (ROE). The results revealed that NPLR and CAR in conventional banks had a significant negative relationship with the profitability in terms of ROA. However, only CAR had a significant relationship with Islamic banks’ performance. Furthermore, the findings showed a significant negative association between CAR and LDR on conventional banks’ profitability as measured by ROE. Whereas NPLR and CAR significantly negative associated with Islamic banks' ROE. This study could provide empirical evidence for bank manager and regulators in Malaysia to help them better understand the risks of banks so that they can formulate better policies to promote prudent management and decision-making