Burapha Science Journal

Toxicity of Glufosinate-Ammonium Herbicide in Giant Freshwater Prawn (Macrbrachium rosenbergii)

Butsayamat Wongchan — 2025-09-09

Background and Objectives : Nowadays, the Thailand export agricultural product was intensively expanded. Therefore, Thailand agricultural sector expels the promotion in chemical using trends in agricultural system. By these economic forces, farmers have encountered large-scale farming production sufficiently for increase consumer demands such agrochemicals using such as chemical fertilizers and herbicides is an important factor for farmers relying on. Herbicides are widely used not only to increase crop yields but also to control weed growth and dissipation that hinders nutrient needs for crop. So far, high volume of herbicide imports value is an evidence reflecting the remains agrochemicals farming system in contribution to the environmental pollution and crisis via inappropriate and excessive usage. Thereby the improper chemicals practice and usage arising from overuse or runoff into nearby ecosystems leads to the herbicide accumulation in environments such as soil, water, and even the air that causes the long-term contamination. Aquatic animals Inevitably affects to this risk by exposure to herbicide–contaminated environments. Aquatic animal health is damaged by herbicide effect in either immediate toxicity or long-term accumulation in animal tissue. Although the concentration of herbicides detected in aquatic animals remains in safety range for consuming, the long-period exposure of such chemicals bring into health risk, especially the human diet made from these aquatic animals. Glufosinate ammonium is herbicide disrupting cell structure and function of plants, but has no effect in aquatic invertebrates. This study aimed to investigate the short-term toxicological effects of glufosinate ammonium on the giant freshwater prawn (Macrobrachium rosenbergii), a commercially and ecologically important species in Thailand. However, limited data about the response to its glufosinate ammonium exposure in this species was little studied. Therefore, the objective of this research is to examine the physiological and biochemical effects of this herbicide on M. rosenbergii. The changes in tissues and blood cells were observed including characterizing the acetylcholinesterase (AChE) expression using the Western blot technique in the nervous system. This key enzyme acts as a valuable biomarker for neurotoxicity in aquatic organisms. Thereby determining the alteration in both cellular and molecular responses, this study provides better understanding pathophysiological effect on post-exposure herbicides of aquatic animals in contribution to threatening human health risk via the contaminated food consuming.

Methodology : Glufosinate ammonium toxicity was assessed in this study for determining its effect on cumulative mortality rate in relation to acetylcholinesterase (AChE) expression as well as the physiological response after glufosinate ammonium exposure was investigated by measuring the total hemocytes and histopathological alteration in muscular and intestinal tissue. After glufosinate ammonium exposure to healthy giant freshwater prawns at effective concentrations from 0 (control), 250, 300, 350, 400, and 450 µL/L, respectively. For simulating possible duration time and exposure levels in nature this experimented duration time were performed at 24, 48, 72, and 96 hours.Moreover, the responsive biochemical function in protein expression profile and AChE expression by using western blot analysis was determined for neurotoxic damage AChE acting as a biomarker.

Main Results : The study for glufosinate ammonium toxicity revealed an increased mortality of post-exposure of M. rosenbergii in time and concentration dependent manner that evidenced on the increased cumulative mortality.Western blot analysis demonstrated the significantly decrease in AChE expression while increased exposure time. AChE was detected at molecular weight of approximately 71 kilodaltons (kDa) in hemolymph. The awkwardly decreased in AChE expression in glufosinate ammonium-exposed prawns revealed its neuronal disruptive effect on neuromuscular function. For histopathological examination, the exposed prawns displayed the structural damage of hemocytes in multiple cell types, including large granular hemocytes (LGH), small granular hemocytes (SGH), and hyaline-type cells (H-type). Evidence on irregular cell boundaries, disrupted cell membranes and cytoplasmic disintegration suggested the herbicide effect on to the immunity compromises. For histological study, swelling and degeneration of muscular tissue was shown, thereby its direct effect on muscle structure and function. Similarly, after exposure pathological changes was shown in prawn intestinal tissues such as lumen dilation and fusion of microvilli, thereby reducing nutrient absorption and hindering digestion efficiency. Therefore, much longer exposure time with an effective concentration of glufosinate-ammonium, the growth and health was retarded by the persistent changes at vital structure of the exposed prawns.

Conclusions : The health burden of giant freshwater prawns (Macrobrachium rosenbergii) is caused by the toxic effect of glufosinate ammonium exposure, leading to a high morbidity rate in a concentration- and time exposure-dependent manner. At a high dose and with increased time of exposure, glufosinate ammonium exerted its effect by causing a decline in AChE activity in relation to decreased acetylcholinesterase (AChE) expression. At the biochemical and histological levels in glufosinate ammonium–exposed prawns, hemocyte morphological abnormalities and tissue structural damage caused by disturbed AChE activity were observed. From these results, AChE is determined as a sensitive biomarker for effectively patrolling herbicide contamination in aquatic ecosystems.

Necessary and Sufficient Conditions for the Concurrent Point of Cevians with Area-Bisecting and Perimeter-Bisecting Properties in a Given Triangle

Somkid Intep — 2025-10-08

Background and Objectives : The problem of fairly dividing a pizza between two individuals such that both receive equal quantities has been a long-standing topic of mathematical interest. This has led to a range of studies involving various geometric shapes and principles to ensure equal division not only in terms of area but also in terms of boundary length (or crust). In 1994, Carter and Wagon demonstrated that a circular pizza could be equally divided into eight slices using four straight lines intersecting at any point, such that each of the resulting eight angles measures 45 degrees. This slicing method ensured each person received equal portions when slices were alternately distributed. Later in 2015, Nicollier extended this idea to equilateral triangular pizzas, introducing a division using six lines—three connecting an arbitrary interior point to the triangle’s vertices, and three drawn perpendicularly from that point to each side. By distributing these sections alternately, both individuals received equal areas and crust lengths. Further developments by Embacher and Humenberger in 2019 explored the division of acute or non-equilateral triangles into six smaller triangles from a chosen internal point. Their findings revealed that the area is equally divided when alternating regions are shaded black and white, but only if the point lies on the Stammler hyperbola—an important geometric curve containing the incenter, circumcenter, and excenter of the triangle. In 2020, Humenberger focused on unequal-sided triangular pizzas and proposed that crust bisection is guaranteed when the dividing point lies on a line connecting the incenter and circumcenter. For achieving area bisection, however, he utilized Cevians—line segments from each vertex to the opposite side intersecting at a common internal point—finding that equality in area occurs only if the intersection point lies along the triangle’s medians. Building upon this rich context, the current research aims to identify the necessary and sufficient conditions for a point within a triangle such that the Cevians intersecting at that point divide both the area and the perimeter of the triangle equally. While prior studies examined these two properties individually, this study focuses on their concurrent realization using only Cevians, which introduces a unique constraint that deepens the geometric inquiry.

Methodology : The investigation began with a conjecture formed through dynamic geometry software (GSP), which allowed for visual experimentation and hypothesis testing. Once a conjecture was formed, the authors pursued a rigorous mathematical proof using classical geometric theorems—chiefly, Ceva’s Theorem, which provides conditions for concurrency of Cevians in a triangle.

Key definitions were employed for precision:

A Cevian is a line segment drawn from a vertex of a triangle to the opposite side.
A median is a Cevian that intersects the opposite side at its midpoint.
The main median refers to the median corresponding to the triangle’s axis of symmetry in an isosceles triangle.
A point of Cevian concurrency is called a concurrent point.
A centroid is the common point of intersection of all three medians of a triangle.

Main Results : This research focuses on investigating the geometric conditions associated with the concurrency point of Cevians in a given triangle that simultaneously induces two notable properties: first, that the concurrency point partitions the triangle into six smaller subregions of equal geometric relevance; and second, that this point serves as both an area-bisecting and a perimeter-bisecting point of the triangle. The findings of the study lead to the identification of a fundamental geometric characterization. The necessary and sufficient condition for the concurrency point of the Cevians to possess both the area-bisecting and the perimeter-bisecting properties can be precisely formulated as follows: in the case of an isosceles triangle, the concurrency point must lie on the main median, whereas in the case of a scalene triangle, the concurrency point must coincide with the centroid of the triangle. These conclusions establish a clear distinction between symmetric and asymmetric triangular configurations and highlight the unique and significant role of the centroid in a scalene triangle. The validity of these results has been rigorously established through proofs constructed by employing Ceva’s theorem, in conjunction with proportional reasoning concerning both triangular areas and the segment lengths determined by the Cevians. This methodological framework not only ensures the logical soundness of the arguments but also demonstrates the deep interrelationship between classical Ceva-type concurrency conditions and the division properties of both the area and the perimeter of triangles. The outcomes of this investigation contribute to the broader understanding of triangle geometry by providing a comprehensive condition that unifies two fundamental partitioning properties within a single concurrency framework.

Conclusions : The study offers a nuanced extension to prior works (Humenberger, 2020) by merging two types of fairness criteria (area and boundary) under a single geometric constraint—the concurrency of Cevians. In summary, the research contributes a precise characterization of geometric conditions under which a triangle can be equally divided—both in area and crust—via intersecting Cevians. The central conclusion is that:

For isosceles triangles, the point of concurrency must lie on the main median.
For scalene triangles, the point must be the centroid.

This result advances our understanding of fair division in geometric terms, with potential applications not only in recreational mathematics (e.g., pizza problems) but also in educational settings where concepts like medians, centroids, and Cevians are introduced.

Assessment of Lipase Inhibitory Efficiency, Total Phenolic Content and Antioxidant Activity of Spirogyra sp. Extract from Closed-Circulation Cultivation System

Rawinipa Srimoon — 2025-10-20

Background and Objectives : Obesity is a lipid homeostasis dysfunction and hyperlipidemia condition, leading to the occurrence of the other chronic diseases such as cardiovascular disease, diabetes and hypertension. The enzyme which is importance in lipid digestion is lipase. Inhibition of lipase enzyme decreases the digestion and the absorption of lipid to the cells, causing in lower level of the lipid in blood. The studies of many natural lipase inhibitors may help the reduction of synthetic drug which causes long-term adverse side effects. Thus, the objectives of this research were to assess the lipase inhibitory efficiency, total phenolic content and antioxidant activity in Spirogyra sp. extract. Spirogyra sp. was the green-fresh water macroalgae with high nutrition values and antioxidants content such as phenolic and flavonoids compounds. But the phytochemicals containing in algae were variation because of the different aquatic habitat of algae. It made the unstable quality and productivity of algae from natural sources. In this study, Spirogyra sp. sample was cultivated from closed-circulating system, which the culture conditions were controlled for both productivity and quality of algae. Moreover, algae were non-contaminated from any toxic substances because there was the water treatment process both before and after cultivation. There has been no previous study on the assessment of lipase inhibitory efficiency, total phenolic content and antioxidant activity in Spirogyra sp., which was cultivated in the closed-circulation cultivation system.

Methodology : Spirogyra sp. sample was cultured in 1,000 L closed-circulating raceway pond type in transparent acrylic roof greenhouse. Water treatment was done using precipitation method coupled with the aerator before and after each cultivation cycle. Algae sample was picked, washed, dried at 50^OC for 2 days and blended. Dried powder sample was macerated with 70% ethanol at a ratio of dried powder : solvent was 1:5 weight by volume for 48 h, and evaporated to produce the crude extract. Afterthat, crude extract was determined the lipase inhibitory efficiency by measuring the rate of oleic acid released from triolein breakdown by pancreatic lipase enzyme, compared with the drug named Xenical (standard Orlistat). Total phenolic content was performed using Folin–Ciocalteu phenol reagent method. The antioxidant activity was conducted using the DPPH radical scavenging activity method. The enzyme inhibition kinetic was evaluated using the Lineweaver-Burg plot derived from the Michaelis-Menten equation. The relationship between lipase inhibition efficiency and, total phenolic content and DPPH antioxidant activity was also investigated using Pearson correlation coefficient.

Main Results : The results showed that lipase inhibition efficiency increased with increasing the extract concentration (p0.05). The inhibitory efficiency of Spirogyra sp. extract and the anti-obesity drug named Xenical at the same concentration of 40 mg/mL were 23.81±0.97% and 85.71±2.33 %, respectively, and the IC₅₀ value (the 50% lipase inhibition concentration) were 90.91±1.83 and 16.67±1.87 mg/mL, respectively. In comparison, the percentage of lipase inhibition of Xenical was 3.59 times higher than that of Spirogyra sp. extract while the IC₅₀ value of Xenical was 5.45 times lower than that of the extract. The lower IC₅₀ value showed the higher enzyme inhibition. Although the enzyme inhibitory efficiency of Spirogyra sp. extract was lower than Xenical, it is still counted that Spirogyra sp. extract had the lipase inhibition power. The behavior of lipase inhibition of Spirogyra sp. extract was non-competitive manner, with consideration to V_max, K_m, K_i and K_i' values derived from the Lineweaver-Burg plot. The V_max values (maximum reaction rate) were significantly decreased (p0.05), the K_m values (Michaelis-Menten constant) were significantly unchanged (p>0.005) and the K_i value was more than the K_i' value (Inhibition constant). This inhibition behavior meant that the inhibitor bound to both enzyme or enzyme-substrate complex at the allosteric sites, resulting in the decrease of the enzyme activity. In addition, the total phenolic content of Spirogyra sp. extracts was 36.65±0.25 mg gallic acid/g extract and the DPPH antioxidant activity was 3.13±0.03 mg Trolox/g extract. The percentage of DPPH radical scavenging was 70.30±0.64. Pearson correlation coefficient showed that the percentage of lipase inhibition was strong correlation with total phenolic content (r=0.8224), and moderate correlation with DPPH radical scavenging activity (r=0.7145) of the extract. It indicated that phenolic compounds and antioxidant activity in the extract play an important role in the efficiency of lipase inhibition. Generally, natural extract that contained high content of phenolic and flavonoid compounds, and high antioxidant activity, also showed the high lipase inhibition efficiency.

Conclusions : The results of this research provided that the extract of Spirogyra sp. cultivated in closed-circulating system, which the culture conditions were controlled for both quantity and quality of algae, was potential used as a lipase inhibitor. The extract had high content of total phenolic and antioxidant activity, influenced on the lipase enzyme inhibition capacity. Therefore, Spirogyra sp. extract has the potential development to the heathy product. However, this study was the assessment of lipase inhibitory potential of Spirogyra sp. extract only in test tube (in vitro), the studies on lipase inhibitors from natural extract should be done in cultured cells (in vitro) or a laboratory animal (in vivo) in order to confirm the exactly efficiency, possible side effects and the use safe of the extract.