Scholarly Publications

Unraveling the Mystery in Search of Nephroprotective Therapeutics from Sri Lankan Flora.

2023-06-07T00:00:00Z

Unraveling the Mystery in Search of Nephroprotective Therapeutics from Sri Lankan Flora. Amarasiri, A.M.S.S. Drug-induced nephrotoxic1ty has become a serious ! iealth problem worldwide due to the wide use of pharmaceutical agents with potential toxicities. Doxorubicin i1: one such anthracycline drug in which the use in cancer chemc,therapy has been largely limited due to its dose-dependent organ toxicities including n phrotoxicity (Heravi et al., 2018). Doxorubicin-induced nephrotoxicity is well explair,ed via the mechanisms of oxidative stress, inflammation, and apoptosis in previous repo,ts (Ibrahim et al., 2020). Despite the fact that doxorubicin chemotherapy has been in practice for almost six decades and associated toxicities are well recognized, no specific antidote has been developed to eliminate its toxic effect>. Although the antidote; d1 xrazoxane has been commonly used to reduce doxorubicin-induced cardiotoxicity, the m.e of the same drug in alleviating free radical pathologies related to nephrotoxicity is quite challenging due to marked heterogeneity in cell populations (Lahoti et al., W 12). These limitations of current therapeutic approaches kd scientists to pay attentio 1 to alternative therapeutic strategies, particularly the conventional system of medicine, to prevent disease progression and improving kidney functi,m in doxorubicin-induced 1 tephrotoxicity. The multifactorial nature of the effects of drug-induced nephrotoxicity often demands therapeutic approaches with multiple protective ,:ffects to alleviate associated risks (Sharma et al., 2020). In this context, polyherbal fon nulations offer an invaluable resource for the development ofr.ew pharmaceuticals due to their potential bio-interactions within and between the constitJcnts (Caesar and Cech, 2()19). On some occasions, the desired pharmacological effect!, of the medicinal herbs are generated only when they are potentiated by other plants, rather than using them aione (Sharma et al., 2020). Due to this comparable efficacy and the fewer side effects reported, a revival of interest is being observed worldwide for polyherbal formulations at Jresent. Hence, the present study is based on a polyherbal :ombination of Sri Lankan medicinal plants that will be safe and therapeutically benefici, las potential therapeutic agents in the management of kidney-related diseases, pa ticularly for doxorubidn-induccd nephrotoxicity. The polyhcrbal combination was de ived based on initial investigations on Abelmoschus moschatuc; Medikus. (leaves), Asp<. ragus falcatus L. (leaves), Barleria prionitis L. (whole plant), Gme/ina arborea Roxb. stem bark), and Vetiveria zizanioides (L,) Nash (root). These medicinal plants were initially selected with refer, nee to pharmacopeias and other monographs related to traditional medicine (A urveda Pharmacopoeia, 1985; Amarasiri, et al., 2020a).

Use of Livestock Resources for Food Security in the Context of Climate Change

2018-03-07T00:00:00Z

Use of Livestock Resources for Food Security in the Context of Climate Change Seresinhe, Thakshala Human population having physical social and economic access to sufficient, safe and nutritious food that meet their dietary needs and food preferences for an active and healthy life, at any given time is considered as food secul"ity. Household food security is the application of this concept to the family level, with individuals within households and families as the focus of attention. Livestock contributes greatly to food security because: (1) they are suppliers of global calories, proteins, and essential micronutrients, (:!) they are produced in areas that have difficulty in growing crops, (3) most of the feed for livestock is not appropriate for human consumption, and (4) they provide manure for crop production. The livestock sector contributes to the livelihoods of one billion of the poorest populations in the world and employs mo~e than one billion people especially in developing countries. Livestock products are an important agricultural commidity for global food security because they provide 17% of global kilocalorie consumption and 33% of global protein consumption. There is growing demand for livestock products, and its rapid growth in developing countries has been clearly identified. Worldwide milk production is expected to increase from 664 million tonnes (in 2006) to 1077 million tonnes (by 2050), and meat production will double from 258 to 455 million tonnes. Global climate change is primarily caused by greenhouse gas (GHG) emissions that result in warming of the atmosphere. The livestock sectc, r contributes approximate!y 15% of global GHG emissions and thus may increase land degradation, air and water pollution, and declines in biodiversity at the same timt'. Climate change will affect livestock production through competition for natural re:;ources, quantity and quality of feeds, livestock diseases. heat stress and biodiversity loss while the demand for livestock products is expected to increase by 100% in 2050.

Water repellent Soils: Origin, Characteristics, and Significance in Sri Lankan context.

2015-03-04T00:00:00Z

Water repellent Soils: Origin, Characteristics, and Significance in Sri Lankan context. Leelamanie, D.A.L. In general, dry soils readily absorb water. Usually a strong attraction exists between mineral soil particles and water. However, all sorls do not exhibit these wettable characteristics, as some soils may repel water. A wat,,r repellent soil can be defined as a soil that does not wet spontaneously when water is applied on the surface. When placed on a water repellent soil, water just , emain on the surface or runs off instead of soaking into the soil. Reduced waier entry, or the infiltration, into water repellent soils will consequently lead to increased surface runoff and topsoil erosion, contributing to the land degradation. In additio11, water repellency induces the development of fingered ,,r preferential flow paths, md creation of unstable, irregular wetting fronts. As a result of reduced infiltration, gett, ng the required water into the root zone becomes a major problem. Less availability of ,,ater in the root zone retards plant growth, reducing the quantity and the quality of crop production. In contrast to its negative impacts, water repellency (hydrophobicity) of soil aggregates reduces their affinity for water. Reduction of the rate of water entrv into the aggregates may help in hampering the pressure buildup within aggregates, improving their stability against slaking.

Pesticide Effects on Earthworms: An Integrated Approach to Tropical Risk Assessment.

2014-03-19T00:00:00Z

Pesticide Effects on Earthworms: An Integrated Approach to Tropical Risk Assessment. Mangala, P.; De Silva, C.S. Intensification and Expansion of agriculture in tropical regions is heavily relying on the use of pesticides. Pesticides however, are generally toxic to non-target soil organisms and as a consequence may hamper proper functioning of the soil. Therefore, to comprehend about the sustainability of tropical agriculture, information on the effects of pesticides on beneficial soil organisms like earthworms, termites, springtails which play an important role in the soil ecosystem are required. Nevertheless, pesticide toxicity under tropical conditions is only rarely assessed and understanding the effects in such conditions remains a priority to date. Tropical risk assessment l)ften is relying on data generated under temperate conditions (De Silva, 2009., Owojori et al, 2013). Such an approach is rather questionable, mainly due to deviating climatic conditions. Consequently, it is essential to understand pesticide toxicity and the ccnsequent ecological effects under tropical conditions. Temperature and soil type may act as critical factors that modify pesticide toxicity. The effects of three commonly used pesticides, chlorpyrifos, carbofuran and carbendazim, on the survival, growth and reproduction of the standard test species Eisenia andrei were investigated in different soil types at representative temperate and tropical conditions. In case of survival, toxicity of chlorpyrifos and carbofuran in artificial soil was higher at 26 ·c than at 20 ·c. But in natural soils, carbofuran was most toxic at 20 ·c while chlorpyrifos re mained more toxic at 26 ·c.The higher activity of earthworms at higher temperatures may trigger a higher uptake of pesticides causing larger effects on survival under representa tive tropical conditions. However, sub-lethal endpoints, such as growth and reproduction, did not show clear differences between the tested temperatures and varied with different soil types indicating that the nature of the pesticide and soil type were more important than temperature. Effects of carbendazim on survival, growth and reproduction of Eisenia andrei were lower at 26 ·c than at 20 ·c suggesting temperature may also influence the stability of the pesticide and its degradation kinetics, resulting in a lower toxicity at higher temperatures. It is suggested that pesticide toxicity may differ with temperature and soil type; therefore temperate data should only be used v.ith caution in tropical risk assess ment (De Silva et al, 2009., De Silva, 2011., De Silva, 2013). Tropical risk assessment currently uses data generated with the temperate com- post worms Eisena Jetida and Eisena andrei. These species are less ecologically I elevant as they are rarely found in natural soils. One good alternative is to use indigenous species specific to tropical regions. Therefore the toxicity of chlorpyrifos, carbofuran and manco• zeb to the tropical earthworm species Perionyx excavatus was investigated. In addition effects of both pure compounds and formulated products were compared to estimate the possible added toxicity of formulated products that is often neglected in toxicity studies. Carbofuran was most toxic to Perionyx excavatus under tropical conditions followed by chlorpyrifos and mancozeb. In case of survival, comparison with toxicity data generated for chlorpyrifos and carbofuran revealed that Perionyx excavatus was more sensitive than the standard species Eisenia andrei. However, for sub-lethal effects differences ,n sen• sitivity were relatively small. Generally, the toxicity of formulated products was higher than that of the pure compounds (De Silva et al, 201ob., De Silva & Amarasinghe, 2008). Nevertheless, results suggest that the toxicity of formulated products may be masked by interactions with the soil resulting in more or less similar toxicities of formulations and the pure compounds. In addition studies show that Perionyx excavatus may be used as a good alternative test species under tropical conditions in future studies, applying the available standard test guidelines for Eisenia sp. Lack of cost-effective tests with short duration often hampers the risk assessment of pesticides under tropical conditions. Recently the earthworm avoidance test has been considered a good alternative in toxicity studies. Earthworm avoidance tests were per• formed with the standard temperate test species Eisenia andrei and the tropical ,,arth• worm species Perionyx excavatus, using a in two-chamber test system with artificial soil and a sele ted natural soil at a representative tropical temperature (26°C). The EC50 values for the effects on avoidance behaviour for both chlorpyrifos and carbofuran indicated that Eisenia andrei was a factor of 2-3 more sensitive than Perionyx excavatus under tropi· cal conditions. An important finding was the attraction of Perionyx excavatus at lower concentrations of both pesticides tested and in both soils; hence it was suggested to use avoidance tests with local species with extra caution as it might lead to wrong estimations of the effects. Comparison.with literature data showed that endpoints generated through earthworm avoidance tests are generally less sensitive than reproduction but more sensi• tive than survival and therefore could be used in the initial risk assessment to facilitate pesticide regulation in tropical regions (De Silva & van Gestel, 2009a., De Silva & Senivi• ratne, 2008., De Silva, 2009) The standard test guidelines for earthworm toxicity testing often use the OECD artificial soil, which is composed of sand, kaolin clay and sphagnum peat. Development of a tropical artificial soil is timely needed due to increasing costs, non-availability and environment concerns associated with sphagnum peat. The suitability of!ocally available, environmentally friendly substrates such as coco peat (composted and non-composted), saw dust and paddy husk was investigated. Modified artificial soils were prepared by sub• stituting sphagnum peat in the standard artificial soil. ,Survival, growth and reproduction of Eisenia andrei in the m