Leaf extracts of Garcinia parvifolia provided relatively high yields of four novel, cytotoxic prenylated depsidones. The structures were determined mainly by detailed NMR spectral analysis and X-ray crystallography.
A novel method for the control of Mansonia larvae was developed and tested. In this method, foliar absorption and translocation of a chemical insecticide, monocrotophos, a known systemic insecticide was studied in the Eicchornia plant. Acetone solution of the insecticide was painted onto leaves of the plant. At daily intervals, stems were severed and divided into equal sections which were introduced into bowls. Larvae of Aedes aegypti were tested for the presence of monocrotophos. It was found that translocation of the insecticide occurred at different rates in the stems and in some plants the chemical was also released into the surrounding water. Based on these results, 2 insecticides namely, monocrotophos and temephos were painted onto leaves of the host plant and their translocation to the root and water environment was examined by testing with Mansonia and Aedes aegypti larvae. The results again confirmed the translocation process and it was found that the insecticides were secreted into the surrounding water, thereby killing the larvae. However, in leaves painted with permethrin (synthetic pyrethroid) or flufenoxuron (chitin synthesis inhibitor), such a process was not detected. The potential of this new concept in Mansonia larval control is examined.
The known lignan (-)-grandisin [1] has been isolated from Cryptocarya crassinervia by using the brine shrimp lethality test to direct the isolation; its structure and relative stereochemistry have been determined by ir, 1H nmr, ms, and X-ray crystallography as an all-trans alpha, alpha'-diaryl-beta, beta'-dimethyltetrahydrofuran. Compound 1 is not significantly cytotoxic in our panel of human tumor cells.
This paper evaluated the total carbon stock of mangrove ecosystems in two contrasting sites: a fishing village in Delta Kelantan (DK) and Ramsar sites in Johor Park (JP). In both sites, aboveground carbon was significantly higher than belowground carbon, and stems contained more carbon than leaf and root partitions. The average carbon concentration of individual mangrove species (44.9-48.1%) was not significantly different but the larger biomass of the DK samples resulted in vegetation carbon stock that was higher than that in JP. Season played an important role in soil carbon stock-a pronounced wet season in DK coincided with the dry season in JP. The total carbon pool was estimated to be 427.88 t ha-1 in JP and 512.51 t ha-1 in DK, where at least 80% was contributed by soil carbon. The carbon dioxide equivalent was 1570.32 t ha-1 CO2e (JP) and 1880.91 t ha-1 CO2e (DK).
There has been a spurt in the spread of microbial resistance to antibiotics due to indiscriminate use of antimicrobial agents in human medicine, agriculture, and animal husbandry. It has been realized that conventional antibiotic therapy would be less effective in the coming decades and more emphasis should be given for the development of novel antiinfective therapies. Cysteine rich peptides (CRPs) are broad-spectrum antimicrobial agents that modulate the innate immune system of different life forms such as bacteria, protozoans, fungi, plants, insects, and animals. These are also expressed in several plant tissues in response to invasion by pathogens, and play a crucial role in the regulation of plant growth and development. The present work explores the importance of CRPs as potent antimicrobial agents, which can supplement and/or replace the conventional antibiotics. Different plant parts of diverse plant species showed the presence of antimicrobial peptides (AMPs), which had significant structural and functional diversity. The plant-derived AMPs exhibited potent activity toward a range of plant and animal pathogens, protozoans, insects, and even against cancer cells. The cysteine-rich AMPs have opened new avenues for the use of plants as biofactories for the production of antimicrobials and can be considered as promising antimicrobial drugs in biotherapeutics.
Four new bisindoles of the vobasine-iboga type, conodiparines A-D were obtained from Tabernaemontana corymbosa which showed appreciable activity in reversing resistance in vincristine-resistant KB cells.
Hydrogels are an attractive system for a myriad of applications. While most hydrogels are usually formed from synthetic materials, lignocellulosic biomass appears as a sustainable alternative for hydrogel development. The valorization of biomass, especially the non-woody biomass to meet the growing demand of the substitution of synthetics and to leverage its benefits for cellulose hydrogel fabrication is attractive. This review aims to present an overview of advances in hydrogel development from non-woody biomass, especially using native cellulose. The review will cover the overall process from cellulose depolymerization, dissolution to crosslinking reaction and the related mechanisms where known. Hydrogel design is heavily affected by the cellulose solubility, crosslinking method and the related processing conditions apart from biomass type and cellulose purity. Hence, the important parameters for rational designs of hydrogels with desired properties, particularly porosity, transparency and swelling characteristics will be discussed. Current challenges and future perspectives will also be highlighted.
PHAs (polyhydroxyalkanoates) have emerged as biodegradable plastics more strongly in the 20th century. A wide range of bacterial species along with fungi, plants, oilseed crops and carbon sources have been used extensively to synthesize PHA on large scales. Alteration of PHA monomers in their structures and composition has led to the development of biodegradable and biocompatible polymers with highly specific mechanical properties. This leads to the incorporation of PHA in numerous biomedical applications within the previous decade. PHAs have been fabricated in various forms to perform tissue engineering to repair liver, bone, cartilage, heart tissues, cardiovascular tissues, bone marrow, and to act as drug delivery system and nerve conduits. A large number of animal trials have been carried out to assess the biomedical properties of PHA monomers, which also confirms the high compatibility of PHA family for this field. This review summarizes the synthesis of PHA from different sources, and biosynthetic pathways and biomedical applications of biosynthesized polyhydroxyalkanoates.
Henna and walnut tree bark are widely used by Libyan women as cosmetics. They may contain lead (Pb), cadmium (Cd) and arsenic (As), which, in turn, pose a high risk to their health. This study aims to determine the levels of Pb, Cd and As in henna and walnut tree bark products sold in Libyan markets. The products were analyzed for their Pb, Cd and As content by using inductively coupled plasma mass spectrometry (ICP-MS) after a microwave acid digestion. The results showed a significant difference between the henna and walnut tree bark samples in terms of their heavy metals content (p < 0.05). The highest heavy metal concentrations were observed in the walnut tree bark samples whereas the lowest was observed in the henna samples. In addition, 60% of the henna and 90% of the walnut tree bark samples contained Pb levels and approximately 80% of the henna and 90% the walnut tree bark samples contained Cd levels, which are much higher than the tolerance limit. However, As concentrations in all the samples were lower. The results indicated that such cosmetics expose consumers to high levels of Pb and Cd and hence, to potential health risks. Thus, studying the sources and effects of heavy metals in such cosmetics is strongly recommended.
Flavonoids are widely distributed as secondary metabolites produced by plants and play important roles in plant physiology, having a variety of potential biological benefits such as antioxidant, anti-inflammatory, anticancer, antibacterial, antifungal and antiviral activity. Different flavonoids have been investigated for their potential antiviral activities and several of them exhibited significant antiviral properties in in vitro and even in vivo studies. This review summarizes the evidence for antiviral activity of different flavonoids, highlighting, where investigated, the cellular and molecular mechanisms of action on viruses. We also present future perspectives on therapeutic applications of flavonoids against viral infections.
With growing population and urbanization, there is an increasing exploitation of natural resources, and this often results to environmental pollution. In this review, the levels of heavy metal in lentic compartments (water, sediment, fishes, and aquatic plants) over the past two decades (1997-2017) have been summarized to evaluate the current pollution status of this ecosystem. In all the compartments, the heavy metals dominated are zinc followed by iron. The major reason could be area mineralogy and lithogenic sources. Enormous quantity of metals like iron in estuarine sediment is a very natural incident due to the permanently reducing condition of organic substances. Contamination of cadmium, lead, and chromium was closely associated with anthropogenic origin. In addition, surrounding land use and atmospheric deposition could have been responsible for substantial pollution. The accumulation of heavy metals in fishes and aquatic plants is the result of time-dependent deposition in lentic ecosystems. Moreover, various potential risk assessment methods for heavy metals were discussed. This review concludes that natural phenomena dominate the accumulation of essential heavy metals in lentic ecosystems compared to anthropogenic sources. Amongst other recent reviews on heavy metals from other parts of the world, the present review is executed in such a way that it explains the presence of heavy metals not only in water environment, but also in the whole of the lentic system comprising sediment, fishes, and aquatic plants.
The antioxidant and microbial stabilities of galangal (Alpinia galanga) extract in raw minced beef were examined at 4 +/- 1 degree C. Raw minced beef containing galangal extracts (0 to 0.10%, wt/wt) were prepared. Lipid oxidation during refrigerated storage was assessed by monitoring malonaldehyde formation, using the thiobarbituric acid reactive substances method. In minced beef, added galangal extract improved oxidative stability. Galangal extract at higher concentrations of 0.05% and 0.10% (wt/wt) were also found to extend the shelf-life of minced beef. Addition of alpha-tocopherol (0.02%, wt/wt) to galangal extract (0.05%, wt/wt) were observed to increase the oxidative but not the microbial stability of minced beef during the storage of 7 days. Galangal extract may prove useful in inhibiting lipid oxidation and increasing microbial stability of minced meat.
Stingless bee honey produced by Heterotrigona itama from different botanical origins was characterised and discriminated. Three types of stingless bee honey collected from acacia, gelam, and starfruit nectars were analyzed and compared with Apis mellifera honey. The results showed that stingless bee honey samples from the three different botanical origins were significantly different in terms of their moisture content, pH, free acidity, total soluble solids, colour characteristics, sugar content, amino acid content and antioxidant properties. Stingless bee honey was significantly different from Apis mellifera honey in terms of physicochemical and antioxidant properties. The amino acid content was further used in the chemometrics analysis to evaluate the role of amino acid in discriminating honey according to botanical origin. Partial least squares-discriminant analysis (PLS-DA) revealed that the stingless bee honey was completely distinguishable from Apis mellifera honey. Notably, a clear distinction between the stingless bee honey types was also observed. The specific amino acids involved in the distinction of honey were cysteine for acacia and gelam, phenylalanine and 3-hydroxyproline for starfruit, and proline for Apis mellifera honey. The results showed that all honey samples were successfully classified based on amino acid content.
Plants that contain high amounts of polyphenolic compounds are potential candidates for natural antioxidant sources. Studies are on going in the search for new sources of antioxidants. Not much data are available on the antioxidant capacity of tropical herbs. With this in mind, 19 commonly consumed Malaysian herbs were analyzed for their polyphenolic content and antioxidant activities. A majority of these plants have never been studied before with regards to their polyphenolic content and antioxidant activities. The shoots of Anacardium occidentale, the shoots and fruits of Barringtonia racemosa, Pithecellobium jiringa and Parkia speciosa had high polyphenolic contents (> 150 microg gallic acid equivalents/mg dried plant) and antioxidant activities when measured using the ferric reducing antioxidant power (FRAP) (>1.2 mM) and Trolox equivalent antioxidant capacity (TEAC) assays (>2.4 mM). A strong correlation was observed between the two antioxidant assays (FRAP vs TEAC) implying that the plants could both scavenge free radicals and reduce oxidants. There was also a strong correlation between the antioxidant activities and polyphenolic content suggesting the observed antioxidant activities were contributed mainly by the polyphenolics in the plants.
In this paper, we investigated the antibacterial mechanism and potential therapeutic targets of three antibacterial medicinal plants. Upon treatment with the plant extracts, bacterial proteins were extracted and resolved using denaturing gel electrophoresis. Differentially-expressed bacterial proteins were excised from the gels and subjected to sequence analysis by MALDI TOF-TOF mass spectrometry. From our study, seven differentially expressed bacterial proteins (triacylglycerol lipase, N-acetylmuramoyl-L-alanine amidase, flagellin, outer membrane protein A, stringent starvation protein A, 30S ribosomal protein s1 and 60 kDa chaperonin) were identified. Additionally, scanning electron microscope study indicated morphological damages induced on bacterial cell surfaces. To the best of our knowledge, this represents the first time these bacterial proteins are being reported, following treatments with the antibacterial plant extracts. Further studies in this direction could lead to the detailed understanding of their inhibition mechanism and discovery of target-specific antibacterial agents.
Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed in the lowlands of Thailand and Malaysia. The nutrient concentrations in the leaves of plants grown in these type of soils were studied with the aim of developing a nutritional strategy for adapting to such problem soils. In sago and oil palms that were well-adapted to peat soil, the N, P, and K concentrations were the same in the mature leaves, while the Ca, Mg, Na, and Fe concentrations were higher in the mature leaves of the oil palm than of the sago palm. Melastoma malabathricum and Melaleuca cajuputi plants that were well-adapted to low pH soils, peat. and acid sulfate soils were also studied. It was observed that a high amount of Al accumulated in the M. marabathricum leaves, while Al did not accumulate in M. cajuputi leaves. M. cajuputi plants accumulated large amounts of Na in their leaves or stems regardless of the exchangeable Na concentration in the soil, while M. malabathricum that was growing in saline-affected soils excluded Na. Positive relationships between macronutrients were recognized between P and N, between K and N, and between P and K. Al showed antagonistic relationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showed antagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weak antagonistic relationships with Zn, Mn, Cu, and Al.
Bioassay-guided fractionation of the extracts of Zieridium pseudobtusifolium and Acronychia porteri led to the isolation of 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone [1], which showed activity against (KB) human nasopharyngeal carcinoma cells (IC50 0.04 micrograms/ml) and inhibited tubulin assembly into microtubules (IC50 12 microM). Two other known flavonols, digicitrin [2] and 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone [5], were also isolated together with three new ones, 3-O-demethyldigicitrin [3], 3,5,3'-trihydroxy-6,7,8,4'-tetramethoxyflavone [4], and 3,5-dihydroxy-6,7,8,3',4'-pentamethoxyflavone [6]. All of these flavonols showed cytotoxic activity against KB cells.
Tocotrienols are forms of vitamin E that are present in several important food crops. Compared to tocopherols, less research has been conducted on these compounds because of their low bioavailability and distribution in plant tissues. Both tocotrienols and tocopherols are known for their antioxidant and anticancer activities, which are beneficial for both humans and animals. Moreover, tocotrienols possess certain properties which are not found in tocopherols, such as neuroprotective and cholesterol-lowering activities. The contents of tocotrienols in plants vary. Tocotrienols constitute more than 70% and tocopherols less than 30% of the total vitamin E content in palm oil, which is the best source of vitamin E. Accumulation of tocotrienols also occurs in non-photosynthetic tissues, such as the seeds, fruits and latex of some monocotyledonous and dicotyledonous plant species. The use of biotechnological techniques to increase the tocotrienol content in plants, their biological functions, and benefits to human health are discussed in this review.
Gold nanoparticles (AuNPs) are extensively studied nanoparticles (NPs) and are known to have profound applications in medicine. There are various methods to synthesize AuNPs which are generally categorized into two main types: chemical and physical synthesis. Continuous efforts have been devoted to search for other more environmental-friendly and economical large-scale methods, such as environmentally friendly biological methods known as green synthesis. Green synthesis is especially important to minimize the harmful chemical and toxic by-products during the conventional synthesis of AuNPs. Green materials such as plants, fungi, microorganisms, enzymes and biopolymers are currently used to synthesize various NPs. Biosynthesized AuNPs are generally safer for use in biomedical applications since they come from natural materials themselves. Multiple surface functionalities of AuNPs allow them to be more robust and flexible when combined with different biological assemblies or modifications for enhanced applications. This review focuses on recent developments of green synthesized AuNPs and discusses their numerous biomedical applications. Sources of green materials with successful examples and other key parameters that determine the functionalities of AuNPs are also discussed in this review.