Synergistic and antagonistic effects of zinc bioaccumulation with lead and antioxidant activities in Centella asiatica

This study was carried out by using Centella asiatica grown using a hydroponic system under laboratory conditions to study synergistic and antagonistic effects of Zn bioaccumulation with added Pb and the changes in antioxidant activities in leaves and roots of C. asiatica. The antioxidant activities included superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX). The treatments Zn (2 ppm) + Pb (0.4 ppm) and Zn (4 ppm) + Pb (0.6 ppm) increased the accumulation of Zn in leaves by 14.06 and 16.84%, respectively, but decreased by 7.36% uptake in roots (Zn 4 ppm + Pb 0.6 ppm). This showed that Pb and Zn acted synergistically to Zn accumulation in leaves but antagonistically in roots. CAT and SOD activities in leaves were increased when Zn was added together with Pb. In roots, CAT, APX and SOD activities were increased but GPX was decreased. Owing to their sensitivities to Zn with Pb, SOD and CAT could be used as biomarkers to monitor the toxicity of Pb and Zn exposure in the leaves and roots of C. asiatica

Magnesium in local edible ulam (Centella asiatica) and its relation to their habitat soils in Peninsular Malaysia

The aim of this study was to determine the Mg levels in Centella asiatica and their relationship to the habitat soils. Based on the levels of Mg in soils from the 12 sampling sites, its concentration was found to range from 13080 to 45350 µg/g dw. Although higher than the continental crust and European topsoils baselines, the soils of Peninsular Malaysia were considered 'unpolluted to moderately polluted' based on EF and 'deficiency to minimal enrichment' based on Igeo. As for plants, the highest Mg level was found in roots (3250 ± 815 µg/g dw), followed by leaves (2900 ± 565 µg/g dw) and stems (1660 ± 393 µg/g dw). This is in agreement with the transfer factor (TF). Based on correlation analysis and multiple linear regression analysis, Mg-Soil was found as a significant and the most important factor controlling the Mg uptake from the soils to the three plant parts. The direct relationships between Mg(plant)-Mg(Soil) also indicates that C. asiatica roots, leaves and stems are able to reflect the Mg levels of the sampling sites. Thus, the experimental transplantation studies under field and laboratory conditions confirmed the results from the field collected samples and indicated the roots, leaves and stems can be used as good biomonitors of Mg levels in the habitat soils

Assessment of Heavy Metal Content and Consumption Risks At Selected Paddy Field in Malaysia: A Review

As the Malaysian population grows, there is a high demand for rice, the main staple food in this region. This has caused the overuse of agrochemicals that contain heavy metals and the utilization of contaminated groundwater to increase paddy yield, posing a risk to humans. This study reviewed the accumulated heavy metals in paddy fields of Malaysia's Selangor, Kedah and Sabah states and further calculated the consumption risks of rice grains from the selected areas. The study revealed that paddy soil in Ranau Valley (Sabah), Kota Marudu (Sabah) and Tanjung Karang (Selangor) showed presences of Cu and Cd in high concentration, respectively, creating higher potential to be uptake by paddy roots. These findings also revealed that Ranau Valley (Sabah) paddy grains contained high Cu and Cd concentrations, while Sabak Bernam (Selangor) contained high Pb concentrations. Further, a higher Cd concentration was reported from the Ranau Valley (Sabah), while the higher Pb concentrations were reported from the samples collected from Sabak Bernam (Selangor), Tanjung Karang (Selangor) and Kubang Pasu (Kedah). Based on the health risk indices calculation in this study, carcinogenic and non-carcinogenic health risks in all study areas except in Kubang Pasu (Kedah) and Langkawi (Kedah) are likely to occur due to Cu mining activities, ultrabasic soil contamination, utilization of contaminated groundwater and rock phosphate fertilizer and vehicular emission. Regular assessment of heavy metal content and consumption risks of paddy is essential to ensure the paddy field is free from contamination and will help protect the ecosystem and human health

Fungal and bacterial species in degrading carbamazepine: a metabolite perspective: Mini-review

Carbamazepine (CBZ) is a ubiquitous pharmaceutical pollutant found in various water environments. This is due to the ineffective CBZ removal, despite employing advanced physiochemical treatment technologies in the current conventional wastewater treatment plants. Thus, bioremediation that utilizes enzymes in microorganisms' systems to bio-mineralize CBZ is suggested as an alternative or complementary technique to remove CBZ more effectively. However, information from published research on the biodegradation of CBZ, the toxicity of metabolites, or toxicity testing was rarely evaluated or assessed cohesively. This aspect is important because if bioremediation of CBZ produces toxic metabolites, it will defeat the main purpose of bioremediation. Thus, the focus of this review is to assess the effectiveness of fungi and bacteria in the biodegradation of CBZ, particularly by looking at the type of enzymes expressed, and the metabolites produced. In this review, information related to the fungal and bacterial species that were reported to degrade CBZ was collated from the published literature and analyzed. Results of the analysis showed that cytochrome P450, laccase, and manganese peroxidase were the common enzymes responsible to degrade CBZ. However, such enzymatic activities can sometimes produce epoxy-CBZ, which is a more toxic compound than the parent compound. Only the fungus Pleurotus ostreatus was able to oxidize epoxy-CBZ via the acridine pathway into acridone, the latter a metabolite that is susceptible to further biodegradation into nontoxic metabolites. However, the identity of the end metabolites is not reported nor characterized. Further, Pseudomonas spp. is the most promising bioremediating agent since it can metabolize CBZ into catechol, the latter can enter the carbon central pathways to generate energy for the bacterial cells

In Vitro and In Silico study on the interaction between apigenin, kaempferoland 4-hydroxybenzoic acid in xanthine oxidase inhibition

Xanthine oxidase (XO) is a biological enzyme that takes part in purine catabolism. It catalyses the conversion of hypoxanthine to xanthine and eventually xanthine to uric acid. The catabolism reaction increases the level of uric acid and subsequently leads to hyperuricemia. Allopurinol is a XO inhibitor that is used clinically to prevent purine catabolism. Although it is an effective XO inhibitor, it causes some side effects. Therefore, a more effective inhibitor with fewer side effects is in an urgent need. Phenolic compounds have been identified as effective XO inhibitors in many studies. In vitro and in silico study were conducted to investigate the interaction between apigenin, kaempferol and 4-hydroxybenzoic acid in XO inhibition. Apigenin was found to be the most effective XO inhibitor among the compounds tested with the best docking score of -8.2 kcal/mol as demonstrated in the molecular docking simulation which indicated its favourable interaction with XO enzyme. Additive interactions between compounds namely apigenin-kaempferol, apigenin-4-hydroxybenzoic acid and 4-hydroxybenzoic acid-kaempferol were demonstrated in both in vitro and in silico studies. The results showed that 4-hydroxybenzoic acid- apigenin (-7.4 kcal/mol) was the most stable ligands combination docked to XO. The multiple ligands docking simulation showed independent ligands bound to the XO active site at non-interfering regional location. In conclusion, the combination of these three compounds can be explored further for their additive interaction in XO inhibition, which could be beneficial in terms of the enhanced effectiveness and lower side effects when each is used at lower dose to give the same effect

Comparative Assessment of Three Fungal Genus in Mycoremediation of Spent Engine Oil: A Brief Review

Spent engine oil is composed of various aliphatic hydrocarbons, aromatic hydrocarbons, lubricative additives, and traces of heavy metal. Improper disposal of spent engine oil can lead to deleterious effects on humans due to spent engine oil properties, which can exert toxicity, mutagenicity, and carcinogenicity on cells and organs. The conventional method to remove hydrocarbon in the spent engine oil is not only expensive but unable to degrade the hydrocarbon completely. In comparison, the mycoremediation approach has been reported to be environmentally friendly, efficient, and cost-effective. The main objective of this review article is to identify the fungal isolate which is most efficient to degrade spent engine oil by assessing the biomass production and the percentage of spent engine oil degraded. Based on the comparative information obtained, Mucor sp. showed the highest biomass production in the presence of spent engine oil. Trichoderma sp. and Aspergillus niger were found to have average biomass production and it depending on the strain and incubation period. Both A. flavus and A. nidulans were found to have the lowest biomass production. In terms of spent engine oil degradation, Mucor sp, Trichoderma sp. and A. niger showed >55% degradation as compared to A. flavus and A. nidulans which have less than 50% degradation. Therefore, from the results of the study, it can be concluded that Mucor sp. has the best potential to degrade spent engine oil within a short period based on the high biomass production and percentage of degradation. The comparative data also suggest that by selecting the right strain and right incubation period, the percentage of spent engine oil degradation by using Trichoderma sp. and A. niger could also increase

An investigation of arsenic contamination in Peninsular Malaysia based on Centella asiatica and soil samples

The first objective of this study was to provide data of arsenic (As) levels in Peninsular Malaysia based on soil samples and accumulation of As in Centella asiatica collected from 12 sampling sites in Peninsular Malaysia. The second objective was to assess the accumulation of As in transplanted C. asiatica between control and semi-polluted or polluted sites. Four sites were selected which were UPM (clean site), Balakong (semi-polluted site), Seri Kembangan (semi-polluted site) and Juru (polluted site). The As concentrations of plant and soil samples were determined by Instrumental Neutron Activation Analysis. The As levels ranged from 9.38 to 57.05 μg/g dw in soils, 0.21 to 4.33 μg/g dw in leaves, 0.18 to 1.83 μg/g dw in stems and 1.32–20.76 μg/g dw in roots. All sampling sites had As levels exceeding the CCME guideline (12 μg/g dw) except for Kelantan, P. Pauh, and Senawang with P. Klang having the highest As in soil (57.05 μg/g dw). In C. asiatica, As accumulation was highest in roots followed by leaves and stems. When the As level in soils were higher, the uptake of As in plants would also be increased. After the transplantation of plants to semi-polluted and polluted sites for 3 weeks, all concentration factors were greater than 50 % of the initial As level. The elimination factor was around 39 % when the plants were transplanted back to the clean sites for 3 weeks. The findings of the present study indicated that the leaves, stems and roots of C. asiatica are ideal biomonitors of As contamination. The present data results the most comprehensive data obtained on As levels in Malaysia

Barium levels in soils and Centella asiatica

In this study, Centella asiatica and surface soils were collected from 12 sampling sites in Peninsular Malaysia, and the barium (Ba) concentrations were determined. The Ba concentration [µg/g dry weight (dw)] was 63.72 to 382.01 µg/g in soils while in C. asiatica, Ba concentrations ranged from 5.05 to 21.88 µg/g for roots, 3.31 to 11.22 µg/g for leaves and 2.37 to 6.14 µg/g for stems. In C. asiatica, Ba accumulation was found to be the highest in roots followed by leaves and stems. The correlation coefficients (r) of Ba between plants and soils were found to be significantly positively correlated, with the highest correlation being between roots-soils (r=0.922, p<005), followed by leavessoils (r=0.890, p<005) and stems-soils (r=0.848, p<005). This indicates that these three parts of C. asiatica are good biomonitors of Ba pollution. For the transplantation study, four sites were selected as unpolluted [(Universiti Putra Malaysia (UPM)], semi-polluted (Seri Kembangan and Balakong) and polluted sites (Juru). Based on the transplantation study under experimental field and laboratory conditions, Ba concentrations in C. asiatica were significantly (p<0.05) higher after three weeks of exposure at Seri Kembangan, Balakong and Juru. Thus, these experimental findings confirm that the leaves, stems and roots of C. asiatica can reflect the Ba levels in the soils where this plant is found. Three weeks after back transplantation to clean soils, the Ba levels in C. asiatica were still higher than the initial Ba level even though Ba elimination occurred. In conclusion, the leaves, stems and roots of C. asiatica are good biomonitors of Ba pollution

Preliminary assessment of Polytrichum commune extract as an antimicrobial soap ingredient

Mosses have long been used in traditional Chinese medicine due to the presence of secondary metabolites which have shown high biological activities. In particular, these secondary metabolites have demonstrated effective antibacterial activity against pathogenic microorganisms. In this study, the influence of different extraction solvents on the antibacterial activities of the Polytrichum commune was carried out using the disc diffusion method. Results showed that both 12.5 mg/mL of methanol moss extract and 6.25 mg/mL of ethanol moss extract were the most effective concentrations against Bacillus cereus and Pseudomonas aeruginosa. Additionally, the P. commune extracts were included as an added ingredient in soap bases to produce antibacterial soap prototypes where the effectiveness of the soaps containing the extracts in removing microorganisms from actual test individuals was carried out. Results of the thumb impression test of test individuals showed that the growth of microbial reduced after washing hands with the usage of both liquid and solid soap with the addition of P. commune extracts. Moreover, the antibacterial soaps performed better in eliminating microorganisms in comparison to control soaps without P. commune extracts. Taken together, P. commune extract could be a good candidate as a value-added ingredient utilized to produce antibacterial soaps due to its antibacterial properties