Biomass energy consumption and sustainable development: empirical evidence from Asian economies.

Biomass energy is an important source of energy consumption. It is a renewable, abundant, and easily produced energy source. Its usage supports economies in reducing their dependence on fossil fuels and safeguards national energy security. The literature has extensively explored the association between biomass energy and environmental quality. However, the influence of biomass energy on sustainable development is overlooked. Against this background, the objective of this research study is to empirically scrutinize the utility of biomass consumption as a source of renewable energy for sustainable development in the Asian region. The panel data used in the study is taken from World Development Indicators and Global Material Flows Database for twenty-one Asian countries covering the time 1990-2017. Numerous econometric techniques are used in the study to ensure the robustness of the results. To know the nature of cointegration, the tests designed by Kao (1999) and Pedroni (1999) and second-generation tests, inter alia, have been employed. Furthermore, the cointegration test of Westerlund (2007), among others, is used in this research. Moreover, fully modified ordinary least square, dynamic ordinary least square, and Driscoll and Kraay methods are used to estimate the model. Finally, the conclusion of the study proves the argument that the consumption of biomass as a source of renewable energy has a significantly positive impact on sustainable development in the selected Asian economies. It is recommended that the region should efficiently utilize biomass to the maximum extent to travel on the path of sustainable development.

Industrialization, Freight Transport and Environmental Quality: Evidence from Belt and Road Initiative Economies.

Belt and Road initiative has been proposed by China to initiate the cooperation among relevant countries in sector of energy and Trade. The study investigate highlighting the relationship between industrial value added per capita, transport freight and CO2 emission among the partner countries of Belt and Road initiatives by using panel of 33 economies from 1986-2017. Study includes panel autoregressive distributed lag model (ARDL) to estimate the long-run relationship among variables. Estimated results of pool mean group (PMG) indicates that increase in industrial value added per capita and transport freight deteriorates the quality of environment in long-run. However, short-run results of granger causality reveals positive and unidirectional causality running from industrial value added per capita to emission of CO2 while transport freight and CO2 emission shows bidirectional causality. The study emphasized to formulate environment friendly policies in industrial and transport sector.

Agricultural practices and quality of environment: evidence for global perspective.

The study emphasizes to examine the causal relationship among CO2 emission, agricultural value added, industrial production, urbanization, nuclear energy consumption, and economic growth across the panel of 59 countries. The data is collected from World Bank database over the period of 1982-2015. For econometric estimations, we have divided the sample into different income groups: low income, lower middle income, upper middle income, and higher income. In case of higher income countries, empirical results have reported the unidirectional causality from agricultural value added to CO2 emission, whereas, bidirectional causality between nuclear energy consumption and CO2 emission. Upper-middle-income countries have confirmed the bidirectional causality between CO2 emissions and agricultural added; however, unidirectional causality runs from nuclear consumption to CO2 emission. According to Granger causality estimations, agricultural value added and nuclear energy consumption do not cause the CO2 emission in low income and lower-middle-income countries. Long-run estimations have mentioned that higher agricultural value added leads to increase the CO2 emission, in upper middle income and higher income countries. On contrary, in case of low-income and lower-middle-income countries, agricultural value added has inverse relationship with CO2 emission. Higher nuclear energy consumption tends to reduce the CO2 emission, except the upper-middle-income countries.

Antimicrobial garlic-derived diallyl polysulfanes: Interactions with biological thiols in Bacillus subtilis.

BACKGROUND: Diallylpolysulfanes are the key constituents of garlic oils, known to exhibit broad spectrum anticancer and antimicrobial activity. Studies in vitro, and in mammalian cells, have shown they react, via thiol-polysulfane exchange, with their major low molecular weight thiol, glutathione. However, there are no detailed reports of diallylpolysulfane effects on other common thiol metabolites (cysteine and coenzyme A) or major thiol cofactors (e.g. bacillithiol) that many Gram positive bacteria produce instead of glutathione. METHODS: Diallylpolysulfanes were individually purified then screened for antimicrobial activity against Bacillus subtilis. Their impact on thiol metabolites (bacillithiol, cysteine, coenzyme A, protein thiols allyl thiols//persulfides) in B. subtilis cultures were analysed, by HPLC. RESULTS: Diallylpolysulfane bioactivity increased with increasing chain length up to diallyltetrasulfane, but then plateaued. Within two minutes of treating B. subtilis with diallyltrisulfane or diallyltetrasulfane intracellular bacillithiol levels decreased by ~90%. Cysteine and CoA were also affected but to a lesser degree. This was accompanied by the accumulation of allyl thiol and allyl persulfide. A significant level of protein-S-allylation was also detected. CONCLUSIONS: In addition to the major low molecular weight thiol, diallylpolysulfanes can also have an impact on other thiol metabolites and protein thiols. GENERAL SIGNIFICANCE: This study shows the rapid parallel impact of polysulfanes on different biological thiols inside Bacillus subtilis alongside the concomitant generation of allyl thiols and persulfides.

Redox Modulation at Work: Natural Phytoprotective Polysulfanes From Alliums Based on Redox-Active Sulfur.

PURPOSE OF REVIEW: This article provides a brief overview of natural phytoprotective products of allium with a special focus on the therapeutic potential of diallyl polysulfanes from garlic, their molecular targets and their fate in the living organisms. A comprehensive overview of antimicrobial and anticancer properties of published literature is presented for the reader to understand the effective concentrations of polysulfanes and their sensitivity towards different human pathogenic microbes, fungi, and cancer cell lines. RECENT FINDINGS: The article finds polysulfanes potentials as new generation novel antibiotics and chemo preventive agent. The effective dose rates of polysulfanes for antimicrobial properties are in the range of 0.5-40 mg/L and for anticancer 20-100 µM. The molecular targets for these redox modulators are mainly cellular thiols as well as inhibition and/or activation of certain cellular proteins in cancer cell lines. SUMMARY: Antimicrobial and anticancer activities of polysulfanes published in the literature indicate that with further development, they could be promising candidates for cancer prevention due to their selectivity towards abnormal cells.

Think Yellow and Keep Green-Role of Sulfanes from Garlic in Agriculture.

Reactive sulfur species from garlic have long been renowned for their health benefits and antimicrobial properties. In agriculture the subject matter is now gathering momentum in the search for new bio-pesticides to addressing emerging environmental concerns and tighter restrictions on the use of many conventional chemical pesticides. Although the precise modes of action of these garlic-derived bioactives is complex, recent research has provided a number of new insights that deepen our understanding of garlic-derived products, such as garlic extracts and oils. Herein, their activity against various crop-damaging pests is reviewed. In many cases, there seems to be a broad range of activity associated with the sulfur-containing compounds derived from Allium species, which manifests itself in diverse insecticidal, antifungal, and nematicidal activities. These activities open a new understanding to develop this natural chemistry as a "green pesticide".

The natural organosulfur compound dipropyltetrasulfide prevents HOCl-induced systemic sclerosis in the mouse.

INTRODUCTION: The aim of this study was to test the naturally occurring organosulfur compound dipropyltetrasulfide (DPTTS), found in plants, which has antibiotic and anticancer properties, as a treatment for HOCl-induced systemic sclerosis in the mouse. METHODS: The prooxidative, antiproliferative, and cytotoxic effects of DPTTS were evaluated ex vivo on fibroblasts from normal and HOCl mice. In vivo, the antifibrotic and immunomodulating properties of DPTTS were evaluated in the skin and lungs of HOCl mice. RESULTS: H2O2 production was higher in fibroblasts derived from HOCl mice than in normal fibroblasts (P < 0.05). DPTTS did not increase H2O2 production in normal fibroblasts, but DPTTS dose-dependently increased H2O2 production in HOCl fibroblasts (P < 0.001 with 40 µM DPTTS). Because H2O2 reached a lethal threshold in cells from HOCl mice, the antiproliferative, cytotoxic, and proapoptotic effects of DPTTS were significantly higher in HOCl fibroblasts than for normal fibroblasts. In vivo, DPTTS decreased dermal thickness (P < 0.001), collagen content in skin (P < 0.01) and lungs (P < 0.05), αSMA (P < 0.01) and pSMAD2/3 (P < 0.01) expression in skin, formation of advanced oxidation protein products and anti-DNA topoisomerase-1 antibodies in serum (P < 0.05) versus untreated HOCl mice. Moreover, in HOCl mice, DPTTS reduced splenic B-cell counts (P < 0.01), the proliferative rates of B-splenocytes stimulated by lipopolysaccharide (P < 0.05), and T-splenocytes stimulated by anti-CD3/CD28 mAb (P < 0.001). Ex vivo, it also reduced the production of IL-4 and IL-13 by activated T cells (P < 0.05 in both cases). CONCLUSIONS: The natural organosulfur compound DPTTS prevents skin and lung fibrosis in the mouse through the selective killing of diseased fibroblasts and its immunomodulating properties. DPTTS may be a potential treatment for systemic sclerosis.

Antiproliferative effect of natural tetrasulfides in human breast cancer cells is mediated through the inhibition of the cell division cycle 25 phosphatases.

For many years, in vitro and in vivo studies have reported that organosulfur compounds (OSCs), naturally found in Allium vegetables, are able to suppress the proliferation of various tumor cells. In spite of recent advances, the specific molecular mechanisms involved in OSC activity are still unclear. Considering the antiproliferative effects observed in cancer cells, we postulated that OSCs might target the cell division cycle (Cdc) 25 phosphatases which are crucial enzymes of the cell cycle. Our findings suggest phosphatases Cdc25 as possible targets of naturally occuring polysulfides contributing to their anticancer properties. We report on the inhibitory activity of tetrasulfides occurring naturally in garlic and onion towards the human Cdc25 phosphatases. Diallyl- and dipropyltetrasulfides have emerged as interesting irreversible inhibitors of the Cdc25 isoforms A and C in vitro. Furthermore, growth of both sensitive (MCF-7) and resistant (Vcr-R) human breast carcinoma cells was significantly decreased by these tetrasulfides. The observed antiproliferative effect appeared to be associated with a G2-M cell cycle arrest.

Allicin disrupts the cell's electrochemical potential and induces apoptosis in yeast.

The volatile substance allicin gives crushed garlic (Allium sativum) its characteristic odor and is a pro-oxidant that undergoes thiol-disulfide exchange reactions with -SH groups in proteins and glutathione. The antimicrobial activity of allicin is suspected to be due to the oxidative inactivation of essential thiol-containing enzymes. We investigated the hypothesis that at threshold inhibitory levels allicin can shunt yeast cells into apoptosis by altering their overall redox status. Yeast cells were treated either with chemically synthesized, pure allicin or with allicin in garlic juice. Allicin-dependent cell oxidation was demonstrated with a redox-sensitive GFP construct and the shift in cellular electrochemical potential (E(hc)) from less than -215 to -181mV was calculated using the Nernst equation after the glutathione/glutathione disulfide couple (2GSH/GSSG) in the cell was quantified. Caspase activation occurred after allicin treatment, and yeast expressing a human antiapoptotic Bcl-XL construct was rendered more resistant to allicin. Also, a yeast apoptosis-inducing factor deletion mutant was more resistant to allicin than wild-type cells. We conclude that allicin in garlic juice can activate apoptosis in yeast cells through its oxidizing properties and that this presents an alternative cell-killing mechanism to the previously proposed specific oxidative inactivation of essential enzymes.

Diallylpolysulfides induce growth arrest and apoptosis.

Garlic-derived organo sulphur compounds such as diallylsulfides provide a significant protection against carcinogenesis. Chemically synthesized, and highly pure diallylsulfides with a chain of 1-4 sulphur atoms, as well as a range of control compounds, were employed to investigate the influence of these agents on cell viability, cell cycle arrest and induction of apoptosis in HCT116 human colon cancer cells. Diallyltrisulfide, and even more efficiently diallyltetrasulfide treatment of HCT116 cells led to a reduced cell viability, cell cycle arrest and apoptosis. A similar activity was found for the propyl-analogues, while mono- and disulfides were considerably less active. Initial calculations point toward the ability of tri- and tetrasulfides to form reactive oxygen species (ROS). Here, we found that the induction of apoptosis was indeed dependent on the redox-state of the cell, with anti-oxidants being able to prevent sulfide-induced apoptosis. Furthermore, using HCT116 cells which were either positive or negative for p53 revealed that p53 is clearly dispensable for induction of apoptosis. Growth arrest and induction of apoptosis is associated with a considerable reduction of the level of cdc25C. These results support the therapeutic potential of polysulfides and allow insight into the mechanisms based on the polysulfide biochemistry.

Cell cycle arrest in early mitosis and induction of caspase-dependent apoptosis in U937 cells by diallyltetrasulfide (Al2S4).

Naturally occurring organic sulfur compounds (OSCs), such as linear allylsulfides from Allium species, are attracting attention in cancer research, since several OSCs were shown to act beneficially both in chemoprevention and in chemotherapy, while hardly exerting any harmful side effects. Hence, we investigated the possible role of different OSCs in the treatment of leukemia. Thereby, we found that the compounds tested in this study induced apoptosis in U937 cells, with an efficiency depending on the number of sulfides, and selected the most promising candidate, diallyltetrasulfide (Al2S4), for detailed mechanistic studies. Here we show that Al2S4 induced an accumulation of cells in early mitosis (G2/M phase), followed by the activation of caspase-dependent apoptosis. The compound counteracted different anti-apoptotic Bcl-2 family members (Bcl-xL, phospho-Bad and Bcl-2), promoted activation of Bax and Bak and induced the release of cytochrome c into the cytoplasm. Treatment by Al2S4 let to the identification of early apoptotic events including Bcl-xL degradation, Bak activation and release of cytochrome c followed by late events including Bcl-2 proteolysis, Bax activation, Bad dephosphorylation, caspase activation, nuclear fragmentation and phosphatidylserine exposure.

Perspective on recent developments on sulfur-containing agents and hydrogen sulfide signaling.

The last couple of years have witnessed the coming together of several initially unconnected lines of investigation which now link natural sulfur products to hydrogen sulfide release and wide ranging cardiovascular protection. It has become apparent that sulfur compounds contained within garlic, onions, mushrooms and various edible beans and fruits may be transformed chemically or enzymatically in the human body with subsequent formation of hydrogen sulfide. The latter has emerged during the last decade from a shadowy existence as toxic gas to be recognized as the third gaseous transmitter besides nitric oxide ( (.)NO) and carbon monoxide (CO). Hydrogen sulfide is formed endogenously in the human body by enzymes such as cystathionine beta-synthase (CBS) in the brain and cystathionine gamma-lyase (CSE) in liver, vascular and non-vascular smooth muscle. Although its exact chemical and biochemical modes of action are still not fully understood, levels of hydrogen sulfide in the brain and vasculature have unambiguously been associated with human health and disease. Not surprisingly, agents releasing hydrogen sulfide, as well as inhibitors of hydrogen sulfide synthesis (CBS and CSE inhibitors) have been investigated. Apart from linking our daily diet to a healthy brain and cardiovasculature, these findings may also provide new leads for drug design. Future studies will therefore need to focus on how such compounds are formed and transformed in the relevant plants, how food processing affects their chemical constitution, and how they release hydrogen sulfide (or control its levels) in the human body. Such multidisciplinary research should ultimately answer the all-important question if a hearty diet is also good for the heart.

The chemistry behind redox regulation with a focus on sulphur redox systems.

Sulphur metabolism in plants provides a wealth of natural products, including several chemically unusual substances, such as thiosulphinates, polysulphides and isothiocyanates. Many of these reactive sulphur species (RSS) exhibit a distinct redox behaviour in vitro, which translates into a rather interesting biological activity in vivo, such as antibiotic, fungicidal, pesticidal or anticancer activity. While the molecular basis for such activity has long remained obscure, research into sulphur-based redox systems during the past 5-10 years has achieved a better knowledge of the in vitro properties of RSS and has led to an improved understanding of their impact on intracellular redox signalling and control pathways in living cells. It has become apparent that the redox chameleon sulphur occurs in biological systems in about 10 different oxidation states, which give rise to an extensive and complicated network of sulphur-based redox events. Together, natural sulphur products from plants and their intracellular targets provide the basis for innovative design of novel antibiotics, fungicides, pesticides and anticancer agents.

Polysulfides as biologically active ingredients of garlic.

Garlic has long been considered as a natural remedy against a range of human illnesses, including various bacterial, viral and fungal infections. This kind of antibiotic activity of garlic has mostly been associated with the thiosulfinate allicin. Even so, recent studies have pointed towards a significant biological activity of trisulfides and tetrasulfides found in various Allium species, including a wide range of antibiotic properties and the ability of polysulfides to cause the death of certain cancer cells. The chemistry underlying the biological activity of these polysulfides is currently emerging. It seems to include a combination of several distinct transformations, such as oxidation reactions, superoxide radical and peroxide generation, decomposition with release of highly electrophilic S(x) species, inhibition of metalloenzymes, disturbance of metal homeostasis and membrane integrity and interference with different cellular signalling pathways. Further research in this area is required to provide a better understanding of polysulfide reactions within a biochemical context. This knowledge may ultimately form the basis for the development of 'green' antibiotics, fungicides and possibly anticancer agents with dramatically reduced side effects in humans.

Synthesis and biological evaluation of isomeric derivatives of naturally occurring spatozoate.

An isomer of the natural phthalate ester spatozoate (1), n-butyl 2-benzoyloxymethylbenzoate (2a) and a series of its new derivatives 2b-2s were synthesized and exposed to selected biological screening, as phthalates were reported to possess different biological activities. Compound 2g was found to be the most potent cytotoxic agent with a LD50 = 8.98 microg/ml. In a bactericidal assay the compounds showed a broad spectrum of activities. Compound 2a has a very promising fungicidal activity against Microsporum canis.