Biochemical Content Research Articles

Role of Postharvest Oxalic Acid Treatment on Quality Properties, Phenolic Compounds, and Organic Acid Contents of Nectarine Fruits during Cold Storage

Due to the soft texture of the nectarine fruit, there are difficulties in long-term storage of this fruit. Therefore, it is of great importance to extend the postharvest storage period of this fruit species. In this study, the effect of postharvest OA (Oxalic acid) applications (0, 0.5, 1 and 1.5 mM) on the quality and biochemical contents of nectarine fruits was investigated. On the 40th day of storage, 1.5 mM OA doses reduced weight loss (1.96%) and fruit flesh firmness (36 N) by approximately 44% and 20%, respectively, compared to the control group. The most effective dose in reducing the respiratory rate was again 1.5 mM OA. The 1 mM OA dose was determined to prevent the decay rate approximately by 16% compared to the control group. Organic acid contents showed a continuous decreasing trend during storage and malic acid was determined to be the dominant acid in nectarine fruits. At the end of storage, it was determined that a 1.5 mM OA dose prevented the decrease in malic acid content approximately 35% more than the control group. Chlorogenic acid and rutin were detected at a higher rate than other phenolics. It was observed that 1.5 mM OA dose prevented the breakdown of chlorogenic acid and rutin compounds more so than other doses during storage. In this study, it was determined that a 1.5 mM OA dose especially protected the quality properties and biochemical contents of nectarine fruits in the cold storage more than the control group.

Assessment of the Environmental Impact of Discharges from Fishmeal Factories Located in Levrier Bay, Nouadhibou-Mauritania

Levrier Bay, located in the western part of Mauritanian Cost, has a strategic position in Mauritania’s fish economy and reproduction environment. Recently, fishmeal factories have multiplied in the bay. This study was carried out in Levrier Bay. It is the first one in this area which is interested in assessing the environmental impact of fishmeal factory discharges by measuring several parameters such as suspended matter, chemical oxygen demand (COD), biological oxygen demand (BOD), conductivity, turbidity, and salinity. A total of 27 samples were collected at 9 sites distributed on the link between effluents from factories and the Atlantic Ocean (discharge site). Results show that some parameters are over permissible values, like suspended matter content (SS), which reached 2020 mg. L.-1 level. The turbidity measure shows excessively high values (50 to 961 mg.L.-1); impacted by effluents at the reject point, the seawater conductivity and salinity are particularly low (4.53 to 188.2 and 13 to 56.4, respectively). The total organic carbon (TOC) values ranged from 200 to 780 mg/L, whereas the highest measured level of chemical oxygen demand was 4010 mg.L.-1 Biochemical oxygen demand content ranged from 685 to 961 mg/L. The biodegradability index (COD/BOD) shows that these effluents are not easily biodegradable because the index > 3.

Bioactive Contents and Fruit Traits of Some Apple Cultivars Grown in Kayseri

This study was carried out to determine the physical properties, biochemical and bioactive compounds of different apple cultivars grown in Yahyalı district of Kayseri province. The plant material of the research consisted of apple cvs. ‘Scarlet Spur’, ‘Starking Delicious’, ‘Starkrimson Delicious’, ‘Golden Delicious’, and ‘Super Chief’. In the study fruit weight, length, width, firmness, soluble solid contents (SSC), titratable acidity (TA), vitamin C, total phenolics, total flavonoids, and antioxidant activities (DPPH and FRAP assays) were investigated. In the findings, significant differences were determined between the fruit characteristics of the cultivars. The highest fruit weight (289.96 g) and length (32.61 mm) were measured from ‘Scarlet Spur’, while the highest fruit width (34.86 mm) was measured from ‘Scarlet Spur’ and ‘Starkrimson Delicious’. The SSC was determined between 11.65 (‘Super Chief’)-14.30% (‘Starkrimson Delicious’), and TA between 0.47% (‘Super Chief’)-1.13% (‘Golden Delicious’). The highest vitamin C content was measured in ‘Starking Delicious’ cultivar (66 mg100 g-1) compared to the others. In terms of total phenolic content, ‘Scarlet Spur’ (38.2 g GAE L-1) and ‘Super Chief’ (36.5 g GAE L-1) cultivars had the highest values, while ‘Super Chief’ had the highest values in terms of total flavonoids (23.5 g QE L-1), and antioxidant activity (FRAP, 490.7 mmol TE L-1; DPPH, 1145.9 mmol TE L-1). As a result, it was revealed the differences between the physical, biochemical, and bioactive contents of apple cultivars grown in Yahyalı district of Kayseri province.

In vivo polyamine applications to globe artichoke: Effects on plant growth-development and some bioactive components

The globe artichoke, Cynara cardunculus var. scolymus (L.), is an important member of the Asteraceae family, being used as a food and due to it has certain health-improving qualities in the treatment of various disorders since ancient times. Low molecular weight organic compounds with a role in several crucial cellular and physiological processes of plants are known as polyamines. They participate in processes such as cell division, differentiation, and growth, the sprouting of seeds, root formation, and flower and fruit development. They have been identified as particularly efficient against biotic and abiotic stress factors. The present research aimed that the evaluation of effects of various polyamine (PA) types and concentrations on three different artichoke cultivars by biometric measurements and biochemical analyses. For this purpose, seedlings of three artichoke cultivars (‘Sakız OP’, ‘Bayrampaşa OP’, and ‘Olympus F1’) were sprayed with various concentrations (0, 50, 100 and 250 mg L-1) of three distinct types of significant polyamines, including putrescine, spermidine, and spermine. Several growth parameters were examined in the current research. The effects on the total phenol and antioxidant capacities, as well as changes in the amounts of cynarin and 1,5-O-dicafeoylquinic acid, were also evaluated. The results revealed that there were statistically differences based on cultivars and treatment concentrations. Among the three forms of PA spermine was potent at increasing total phenolic content, while putrescine was effective at increasing total antioxidant content. On the other hand, putrescine, spermine and, spermidine had no positive effects on cynarin and 1,5-O-dicaffeoyquinic acid levels. Results clearly revealed that each biometric data and biochemical content could not be determined by a single polyamine type and concentration. It can be concluded that to improve the biometric values and biochemical content are depending on cultivar and dosage of various PAs.

Pineapple (Ananas comosus [L.] Merr.) Cv. queen peel herbal tea with a variety of drying temperatures: bioactive compounds, antioxidant activity and antimicrobial activity

Pineapple peel is a by-product that is potentially developed to be herbal teas. The research objectives were to find out the proper drying temperature on total biochemical content, antioxidant and antimicrobial activity, and sensory properties of pineapple peel herbal tea. The pineapples peel herbal tea was prepared by drying peels in a cabinet dryer for 12 hours at 50, 60 and 70oC. Qualitatively, phytochemical screening was analyzed for the presence of flavonoids, alkaloids, tannins, phenols, and terpenoids. Quantitatively, total phenols, flavonoid, and alkaloid were determined by the colourimetric method. The DPPH methods applied to measure free radical scavenging activity, and the diffusion method was determined antimicrobial activity. The phytochemical screening showed the absence of terpenoid in pineapple peel teas dried at three different temperatures. The drying temperature at 60oC and 70oC produced total bioactive compounds (phenolic, flavonoid, and alkaloid) better than 50oC. Furthermore, the most significant antioxidant activity against DPPH was obtained from the product dried at 60oC with an IC50 of 448.31 ppm. All those herbal teas were suitable for the growth suppressing of Bacillus subtilis and Candida albicans. This study found that pineapple peel tea herbal with 60oC drying temperature was the most significant value based on bioactive components, antioxidant and antimicrobial activity, which are considered potential herbal tea products.

Effects of plasma treatment on germination and biochemical content of chicory (sonchus oleraceus l.)

An experiment was conducted to explore the changes of germination rate, protein and vitamin C content in the seeds and the chlorophyll content of the seedlings under different irradiation time and intensity. Experiments showed that plasma treatment of chicory seeds promoted the germination and biological content of bitter seeds in 100-300W, 5-15s, and the germination rate was relatively higher under 200W conditions, the content of vitamin C and protein in seeds was relatively higher under 300W conditions. Bangladesh J. Bot. 52(2): 445-450, 2023 (June) Special

Effects of plasma treatment on germination and biochemical content of chicory (sonchus oleraceus l.)

An experiment was conducted to explore the changes of germination rate, protein and vitamin C content in the seeds and the chlorophyll content of the seedlings under different irradiation time and intensity. Experiments showed that plasma treatment of chicory seeds promoted the germination and biological content of bitter seeds in 100-300W, 5-15s, and the germination rate was relatively higher under 200W conditions, the content of vitamin C and protein in seeds was relatively higher under 300W conditions. Bangladesh J. Bot. 52(2): 445-450, 2023 (June) Special

Proximate and Micronutrient Analysis of the leaf extracts of some Indian Medicinal plants from Western Maharashtra

The current study was undertaken to estimate the proximate and micronutrient analysisof the leaf powders of Cynodon dactylon (L.) Pers., Annona squamosa Linn., Moringa oleifera Lam., Ocimum tenuiflorum Linn.and Terminalia catappa Linn. Determination of biochemical contents was performed by different biochemical methods. Cynodon dactylon (L.) Pers., Annona squamosa Linn., Moringa oleifera Lam., Ocimum tenuiflorum Linn. And Terminalia catappa Linn.leaf powdersexhibited the presence of all the essential nutrients, minerals and vitamins in good amounts and holda good proximate and mineral value. The plant leaf powders can thus be looked forward as the probable sources for food supplementation and medicinal foods, after further investigation of the anti-nutritive factors present in them and their enzymatic and molecular effect on human health.The high minerals, vitamins and proteins content could be explored in the development of nutraceuticals and can also be used as food ingredients for human or animal diet.

Trophic status determination of the Egyptian Eastern Mediterranean Sea based on phytoplankton diversity and their biochemical contents

The present study attempted to test the applicability of using phytoplankton as a bioindicator for assessing water quality along the Eastern Alexandria coast, Egypt. Eight stations were selected to cover the different characteristics of seawater during the summer 2022. Six algal groups were detected in different ratios: Bacillariophyceae, Cyanophyceae, Dinophyceae, Chlorophyceae, Silicoflagellata, and Euglenophyceae. Phytoplankton abundance was found highest at the Port Said (PS) beach, and the lowest abundance was detected at Ras El Bar (RB) beach. According to the evaluation of phytoplankton abundance, all the studied stations are oligotrophic state except PS was eutrophic. Based on Chl a concentration, the selected stations could be described as good-bad from west to east. The Shannon diversity and Pielou evenness indexes classified the studied stations as being moderate pollution except for PS and RB stations. The existence of organic pollution indicators species like Navicula, Synedra, and Euglena is a warning indication of the declining water quality especially in B and M stations. The biochemical compositions of the collected phytoplankton were spatial fluctuated. Protein and carbohydrates were the dominant macromolecules in the phytoplankton community compared with lipids. These macromolecules are used to assess trophic states whereas the ratio between protein and carbohydrate > 1 represents a healthy coast as observed in some stations. Thus, phytoplankton should be considered a bioindicator within Water Framework Directive monitoring programs for the Mediterranean Sea. For the long-term monitoring of the Mediterranean Sea’s ecosystem, it is recommended that the macromolecules of phytoplankton should be determined.

Exploring the Nutritional Potential of Microtermes obesi Consumed by the Ethnic Communities of Baksa District, Assam, India

The practice of eating insects is widespread throughout the world. The use of edible insects in animal feed and human diet is being advocated on a universal scale as an alternative source of protein, lipids and micro - nutrients which is correlated with global food security. Termites are nutritionally endowed eusocial insects belonging to the order Isoptera. Microtermes obesi, a termite species has been a part of traditional cuisine among different communities of Assam. Therefore, the present study was assigned to investigate the presence of nutrient composition and antioxidant properties of M. obesi, an edible termite species collected from Baksa district of Assam. In the current investigation, the nutritional values recorded from M. obesi adult comprised of 7.68±0.02% moisture content, 45.15±1.97g/100gm crude protein, 8.40±2.05 g/100gm crude fat, 28.76±1.31 mg/100gm Na, 22.86±2.19 mg/100gm K, 108.36±2.18 mg/100gm Fe, 58.09±1.38 mg/100gm Ca, 20.47±3.15 mg/100gm S, and 132.88±2.15 mg/100gm P. The biochemical contents such as total phenolic, total flavonoid and DPPH radical scavenging activity are recorded as 108.17±2.43 mg gallic acid equivalent (GAE)/100g, 58.06±3.26 mg quercetin equivalent (QE)/100g and 84.90±2.15% respectively. Findings of this study demonstrated the presence of rich nutritional and high antioxidant qualities in M. obesi termite species and also provided scientific validation on the entomophagy practice of M. obesi which can be consumed as alternative source of nutrient in animal feed with potential health benefits.

Detrimental influence of industrial effluents, especially heavy metals, on limnological parameters of water and nutritional profile in addition to enzymatic activities of fish, Sperata seenghala (Sykes, 1839) from diverse Ramsar sites, India (Punjab).

The present research was designed to determine the nutritive value of the liver and intestine of fish, Sperata seenghala, the impact of effluence load on limnological parameters of water and proximate composition of fish organs, especially on fatty acids, liver enzymatic activities, seasonal variations in the nutritional profile of fish, and to check and compare the pollution status of Ramsar sites in Punjab by calculating the water quality index, heavy metal pollution index, and metal index from June 2018 to August 2020. WQI of Harike wetland was found to be 53.95, which depicts that water quality in this region is "poor". At Nangal wetland, water quality index was reported to be "excellent" quality water and fit for the whole ecological unit. Overall heavy metal pollution index for Harike wetland was reported 174.569, whereas for Nangal wetland it was 5.994, depicting massive contaminant loads in a polluted region. MI value was also recorded as being higher (6.9336) in polluted habitat than in control habitat (0.8175). In fish liver, significant (p < 0.05) higher mean total lipids (6.73%), total proteins (3.98%), moisture (77.69%), ash (3.56%), and carbohydrates (3.79%) were observed in the samples from Nangal wetland than Harike wetland. A similar trend was reported in all biochemical contents of the fish intestine. Enzyme activities such as aspartate-aminotransferase and alanine-aminotransferase were significantly elevated (p < 0.05) in the specimens collected from the polluted region. The mean total n-3 (except in spring), n-6 polyunsaturated fatty acids (except in winter), and average monounsaturated and saturated fatty acids diminished significantly (p < 0.05) in the liver of fish from contaminated habitat than control site. In the intestine of fish collected from the polluted region, significant reductions in the mean total n-3 (except in autumn as well as summer), total n-6 PUFAs (in autumn and winter), and total SFAs were reported than control site.

Ameliorative Effects of Luteolin and Activated Charcoal on Growth Performance, Immunity Function, and Antioxidant Capacity in Broiler Chickens Exposed to Deoxynivalenol.

Deoxynivalenol (DON, Vomitoxin) is a threatening mycotoxin that mainly produces oxidative stress and leads to hepatotoxicity in poultry. Antioxidant dietary supplements dramatically boost immunity, safeguarding animals from DON poisoning. Luteolin (LUT) is an active plant-derived compound that poses influential antioxidants. This study explored the effectiveness of LUT in combination with activated charcoal (AC) in detoxifying DON in broilers. The 180 one-day broiler chickens were allocated into five different groups having six replicates in each group, provided with ad libitum feed during the trial period (28 days) as follows: in the control group, basal diet (feed with no supplementation of LUT, AC or DON); in group 2, a basal diet added with 10 mg/kg DON from contaminated culture (DON); in group 3, a basal diet augmented by 350 mg/kg LUT and DON 10 mg/kg (DON + LUT); in group 4, a basal diet supplemented by DON 10 mg/kg + AC 200 mg/kg (DON + AC); and in group 5, a basal diet supplemented by 10 mg/kg DON + 350 mg/kg LUT + 200 mg/kg AC (DON + LUT + AC). Concerning the control group, the DON-treated broilers demonstrated a significant decrease in growth performance (p < 0.05) and serum immunoglobulin (p < 0.05) contents, negatively changing the serum biochemical contents and enzymatic activities and an increase in histopathological liver lesions. Furthermore, DON substantially increased (p < 0.05) malondialdehyde (MDA) concentration and decreased total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) levels in the serum and liver. The intake of AC and LUT to the DON-contaminated diet decreased DON residue in the liver and potentially reduced the adverse effects of DON. Considering the results, supplementation of LUT with mycotoxin adsorbent has protective effects against mycotoxicosis caused by DON. It could be helpful for the development of novel treatments to combat liver diseases in poultry birds. Our findings may provide important information for applying LUT and AC in poultry production.

Sequential extraction of value-added bioproducts from three Chlorella strains using a drying-based combined disruption technique

In this study, the sequential extraction of the three types of biochemicals from microalgae is employed, which is a more realistic and practical solution for large-scale extraction of bioproducts. The drying, grinding, organic solvent treatment, and ultra-sonication were combined to disrupt cells and sequentially extract bioproducts from three microalgae strains, Chlorella sorokiniana IG-W-96, Chlorella sp. PG-96, and Chlorella vulgaris IG-R-96. As the drying is the most energy-intensive step in cell disruption and sequential extraction, the effect of this step on sequential extraction deeply explored. The results show that total ash-plus contents of biochemicals in freeze-dried samples (95.4 ± 2.8%, 89.3 ± 3.9%, and 77.5 ± 4.2 respectively) are higher than those in oven-dried samples (91.0 ± 2.8%, 89.5 ± 3.0%, 71.4 ± 4.8%, respectively) showing the superiority of freeze drying over oven drying merely for Chlorella vulgaris IG-R-96 (p-value = 0.003) and non-significant variation for Chlorella sorokiniana IG-W-96 (p-value = 0.085) and Chlorella sp. PG-96 (p-value = 0.466). Variation among biochemical contents of strains is due to the difference in cell wall strength confirmed by TEM imaging. The freeze-dried samples achieved higher lipid yields than oven-dried samples. The total carbohydrate yields followed the same pattern. The extraction yields of total protein were higher in freeze-dried samples than in oven-dried. Total mass balance revealed that drying-based sequential extraction of value-added bioproducts could better demonstrate the economic potential of sustainable and renewable algal feedstock than independent assays for each biochemical.Graphical

Effects of Various Nitrogen Sources on the Growth and Biochemical Composition of &lt;I&gt;Chlorella&lt;/I&gt; sp.

Highlight Research Each species of microalga has a preferable nitrogen source for their optimal growth. The nitrogen sources in the grown media affected the growth rate and biochemical composition of Chlorella FNUB01. (NH2)2CO (urea) was found to be the best alternative nitrogen source for Chlorella FNUB01. For producing 1 g of Chlorella FNUB01, the use of urea reduced the cost of medium by 72.6%. Abstract Chlorella sp. is a potential microalgae species to be produced commercially for feed, growth accelerator, and immuno-modulator in fish and shrimp culture. This study aimed to evaluate the various nitrogen sources on the growth, biomass production, and biochemical composition of Chlorella sp. FNUB01. The nitrogen sources used in this study were urea (NH2)2CO, potassium nitrate (KNO3), and ammonium nitrate (NH4NO3). Sodium nitrate (NaNO3) was used as a control as it is a part of the commercial medium BG-11. Generally, the sources of nitrogen in the media affected the growth and chemical composition of Chlorella sp. FNUB01. This green microalga grew better in the urea-containing medium which accounted for 1.5 times the concentration of that cultured in BG-11 (40 x106 cells. mL-1). Meanwhile, this microalgae species experienced the lowest growth when cultured in NH4NO3-containing medium. The biomass productivity of Chlorella sp. FNUB01 cultured in urea (0.93 g.L-1) was comparable to those grown with NaNO3 as the N source. A similar pattern was recorded for protein, chlorophyll, and carotenoid content as these biochemical contents were affected by N availability in the medium. Urea was an alternative low-cost N source for the culture of Chlorella sp. FNUB01. Replacement of NaNO3 with urea could reduce the cost of the medium by 72.6%.

PIOSL: An improved version of PROSPECT model for simulating leaf optical properties by considering leaf internal structural variations

Leaf radiative transfer simulation is an important tool for studying the quantitative relationships between plant biochemical parameters and leaf spectra, at the leaf scale. This type of simulation can be used to investigate leaf structures and their biochemical parameters with regard to reflectance and transmittance, and can produce mathematical representations of the radiative transfers of leaves. Most current radiative transfer models represented by PROSPECT are based on the assumption that all leaf interiors are turbid and homogeneous, ignoring the impacts of leaf layer structures on their spectra. A leaf is composed of two heterogeneous layers, we assume that the optical properties of each layer are different. A PIOSL (PROSPECT considering the internal optical structure of leaves) model was proposed, with the assumption that a leaf is composed of two stacked plates with different biochemical parameters and structures. The PIOSL model was used to simulate the directional-hemispherical reflectance of plant leaves for four publicly available datasets. The structural parameters and biochemical contents of the two layers used in the simulation were determined using the bald eagle search optimization algorithm. The results showed that the structural parameters of the first layer were generally higher than those of the second layer in leaves of different plant species; chlorophyll was mainly distributed in the upper layer, while water and dry matter were concentrated in the lower layer—although some plant species showed different trends. PIOSL outperformed PROSPECT-4 to simulate leaf optical properties of various plant species.We therefore concluded that the PIOSL model better explains the responses of leaf biochemical parameters to leaf spectra, and provides a new strategy for modeling the leaf radiative transfer process.

Variability in the energy reserves of swordfish (Xiphias gladius) of the southeastern Pacific Ocean: A temporal and intra-individual perspective

The temporal dynamics of energy reserves are associated with the physiological processes (i.e., reproduction) in marine fishes, in which storage organs play a key role for efficient energy investment. We evaluated the temporal (i.e., seasons) and intra-individual (i.e., organs) dynamics of adult female swordfish (Xiphias gladius) during its feeding period off the Chilean coast in the southeastern Pacific Ocean (SEPO). The biochemical composition (i.e., lipids, proteins, and glucose), energy content and fatty acid profile of the muscle, liver and gonad were evaluated during the austral autumn, winter, and spring. Our results showed principally an intra-individual effect in both the muscle and liver in the autumn and spring. Herein, a trend of higher amounts of lipids and total energy were found in the muscle, while the liver showed greater protein and glucose contents. Consequently, the muscle showed a higher saturated, monounsaturated, and polyunsaturated fatty acid contents than the liver. Although the gonad showed no significant temporal effect in the lipids and proteins contents, an increasing trend of each biochemical constituent, fatty acid group and gonadosomatic index were found from autumn to winter. Consistently, the glucose and total energy content as well Fulton's condition factor were significantly higher in winter. These findings reflect the spatial-temporal physiological dynamic of swordfish based on the storage of energy reserves in different organs during its feeding period. In this way, the products obtained from swordfish could have an added value depending on the season and capture zone, which could benefit the exploitation and regulation measures of this resource under an ecological approach of conservation and sustainability in the SEPO.

Pengaruh Perbedaan Jenis dan Konsentrasi Sumber Nitrogen (NaNO3 dan urea) terhadap Produksi Biomasa Spirulina Platensis

The goal of this study was to investigate the effect of the concentration and the type of nitrogen sources in the cultivation medium on the production of biomass and biochemical content (carbohydrates, proteins, fats) in the Spirulina platensis biomass. Types of nitrogen sources included NaNO3 and urea, where the concentrations were varied from 0.5 to 3.5 g/L. The results showed that the use of urea tended to produce more S. platensis biomass than the use of NaNO3. The best concentrations that produced the highest biomass were NaNO3 2.5 g/L (biomass 0.6745 g/L) and urea 0.5 g/L (biomass 0.7158 g/L). The use of urea also tended to produce a higher specific growth rate and a shorter doubling time than the use of NaNO3. The high concentration of nitrogen sources caused the pH of the medium to increase more rapidly due to the accumulation of ammonium in the medium. Using NaNO3 can produce biomass with a higher protein content (28.34-36.98%) than using urea (25.86-33.52%).

Poster 152: Detrimental Effects of Chlorhexidine on Articular Cartilage Viability, Matrix, and Mechanics

Objectives: Chlorhexidine gluconate (CHG) is commonly used in antiseptic irrigation solutions for bacterial decontamination during orthopaedic surgery. Although the chondrotoxicity of CHG to articular cartilage has been reported, CHG irrigation is utilized by some surgeons to limit surgical site infection and to salvage grafts after accidental contamination during joint surgery. The full extent of CHG irrigation-related chondrotoxicity, as well as its effects on articular cartilage extracellular matrix and mechanical properties, are unknown. The purpose of this study was to determine the in vitro effects of a single one-minute CHG exposure on the viability, biochemical content, and mechanics of native articular cartilage explants. Methods: Articular cartilage explants (n=6 per group) were harvested from the femoral condyles of the porcine stifle and sectioned at the tidemark. Explants were bathed in Irrisept® chlorhexidine solution (0.05% CHG in sterile water) at varying concentrations (0% control, 0.01% CHG, and 0.05% CHG) to stimulate surgical irrigation for 1 minute, followed by complete phosphate-buffered saline wash and culture. After seven days of culture in chondrogenic medium, the explants were analyzed for viability (live/dead assay); collagen content (hydroxyproline assay); glycosaminoglycan (GAG) content (dimethyl methylene blue assay); and compressive mechanical testing (creep indentation testing). Statistical analyses were performed using a one-way ANOVA with post hoc Tukey test. Results: Seven days after CHG exposure, a dose-dependent decrease in mean chondrocyte viability was observed in the CHG groups (p&lt;0.001), with &lt;3% viability observed in the 0.05% CHG group (Figure 1). There was no significant difference in mean collagen content per wet weight among groups. Conversely, 0.05% CHG exposure led to a decrease in mean GAG per wet weight compared to negative control (p=0.029) and 0.01% CHG (p=0.046) (Figure 2). These changes in GAG content corresponded to observed changes in the compressive mechanical properties of the explants. A dose-dependent decrease in mean aggregate modulus and shear modulus was observed after CHG exposure (p&lt;0.029), indicating weakening of the cartilage matrix and increased deformation in response to compressive loads (Figure 3). Conclusions: One-minute CHG exposure to articular cartilage explants led to dose-dependent decreases in chondrocyte viability, GAG content, and compressive mechanical properties. These detrimental effects were observed for both 0.05% and 0.01% CHG concentrations. There is a paucity of literature examining the effects of CHG on articular cartilage matrix and mechanics, and the findings of this study suggest a lack of matrix maintenance following cell death, raising concern for risk of mechanical failure of the cartilage tissue. Clinicians should be judicious regarding the use of CHG irrigation at these concentrations in the presence of native articular cartilage.

Paper 08: In Vitro Effects of Triamcinolone and Methylprednisolone on the Viability and Mechanics of Native Articular Cartilage

Objectives: The chondrotoxic effects of methylprednisolone acetate (MP) and triamcinolone acetonide (TA) have been well described. Prior studies have demonstrated a dose-dependent chondrotoxic effect of intra articular (IA) steroids starting at 7 mg for MP and 18 mg for TA. However, the effects of these steroids on the mechanical properties of articular cartilage are largely unknown. The purpose of this study was to investigate the in vitro effects of a single one-hour MP or TA exposure on the viability, mechanics, and biochemical content of native articular cartilage explants. Methods: Articular cartilage explants (n=6 per group) were harvested from the femoral condyle of the bovine stifle. Explants were exposed to chondrogenic medium containing a clinical dose of MP or TA for one hour, followed by fresh medium wash and exchange. Explants in the negative control group underwent the same treatment with chondrogenic medium alone. At t=24 hours post-treatment, samples were assessed for viability (live/dead), mechanical properties (creep indentation and Instron tensile testing), biochemical (collagen and glycosaminoglycan) content, and pyridinoline cross linking via mass spectrometry. Results: Mean cell viability was significantly decreased in native explants exposed to MP (35.5%) compared to control (49.8%, p &lt; 0.001) and TA (45.7%, p = 0.003) (Figure 1). There was significant weakening of mechanical properties of steroid-treated native explants when compared to control (Figure 2), with decreases in aggregate modulus (646.3 kPa vs 312.8 kPa [MP] and 257.0 kPa [TA), p &lt; 0.001), shear modulus (370.1 kPa vs 191.2 kPa [MP] and 157.4 kPa [TA], p &lt; 0.001), and ultimate tensile strength (UTS) (9.650 MPa vs 5.648 MPa [MP], p = 0.021 and 6.065 MPa [TA], p = 0.040). The Young’s modulus in TA-exposed native cartilage (7.924 MPa) was significantly lower than MP (12.35 MPa, p = 0.026) exposed explants but not significantly different compared to control (11.97 MPa, p =0.072). No significant differences in collagen and glycosaminoglycan content were found in the steroid-treated groups (Figure 3). Pyridinoline cross linking was significantly decreased in explants exposed to TA compared to control (p = 0.027). Conclusions: The results of this in vitro study suggest that a single clinical dose of MP is chondrotoxic and that a single clinical dose of MP or TA can lead to substantial early decreases in both the tensile and compressive properties of native articular cartilage. The shear modulus of steroid-exposed explants in this study dropped 48-57% compared to healthy control. In human knee cartilage, drops in shear modulus of this magnitude have been correlated with the progression from healthy knee cartilage to ICRS grade 1-2 osteoarthritis. Furthermore, decreases in Young’s modulus by 25-50% have been correlated with the same degree of osteoarthritis, and the Young’s modulus of steroid exposed cartilage dropped an average of 34% in this study. Although there were no detectable changes to the extracellular matrix composition or structure, a single one-hour steroid exposure was enough to cause chondrotoxicity and altered mechanics to native explants 24 hours after exposure, which raises the concern for risk of mechanical failure of the cartilage tissue. Clinicians should be judicious regarding use of intra-articular steroids, particularly in patients with intact healthy articular cartilage.

Use of titanium dioxide doped multi-wall carbon nanotubes as promoter for the growth, biochemical indices of Sesamum indicum L. under heat stress conditions

The behavior of multi-walled carbon nanotubes (MWCNTs) and titanium dioxide nanoparticles (TiO2 NPs) as plant growth enhancers was still unclear; however, in this study, the effects of MWCNTs, TiO2NPs, 5%TiO2@MWCNTs, 10%TiO2@MWCNTs and 15%TiO2@MWCNTs on physical and biochemical contents in Sesamum indicum L. under heat stress conditions were studied. The content of malondialdehyde (MDA) and hydrogen peroxide (H2O2) concentrations were reduced by the spraying MWCNTs and TiO2 NPs on plants. The hydrogen peroxide (H2O2) content was reduced by 49.02% in plants treated with 15%TiO2@MWCNTs while 42.14% reduction was found in plants treated with 10%TiO2@MWCNTs. The proportion of oil and the peroxidase enzyme activity in plants treated with 15%TiO2@MWCNTs were increased by 48.99%, for the oil content, and 2.39 times for POD activity respected to the stressed plants. The proportion of unsaturated fatty acids increased in plants treated with 15%TiO2@MWCNTs, 10%TiO2@MWCNTs and TiO2 NPs by 2.7, 2.52, and 2.09 times, respectively, greater than the control of the Shandweel-3 variety. Finally, plants treated with 15%TiO2@MWCNTs showed increases in seed yield and weight 1000-seeds by 4.42 and 1.67 times, respectively. These findings suggest that TiO2@MWCNTs more effective than separated MWCNTs and TiO2 NPs in improve plant growth. In addition, the cultivar Shandweel-3 showed an improvement in growth indicators more than the Giza-32 cultivar.