The strong reaction of simple phenolic acids during oxidative stress caused by nickel, cadmium and copper in the microalga Scenedesmus quadricauda

Synergistic regulation of hydrogen sulfide and nitric oxide on biochemical components, exopolysaccharides, and nitrogen metabolism in nickel stressed rice field cyanobacteria

The present study examined the regulatory mechanism of hydrogen sulfide (H2S) and nitric oxide (NO) in nickel (Ni) stressed cyanobacteria viz., Nostoc muscorum and Anabaena sp. by analyzing growth, photosynthetic pigments, biochemical components (protein and carbohydrate), exopolysaccharides (EPS), inorganic nitrogen content, and activity of enzymes comprised in nitrogen metabolism and Ni accumulation. The 1 µM Ni substantially diminished growth by 18% and 22% in N. muscorum and Anabaena sp. respectively, along with declining the pigment contents (Chl a/Car ratio and phycobiliproteins), and biochemical components. It also exerted negative impacts on inorganic uptake of nitrate and nitrite contents; nitrate reductase and nitrite reductase; and ammonium assimilating enzymes (glutamine synthetase, glutamate synthase, and glutamate dehydrogenase exhibited a reverse trend) activities. Nonetheless, the adverse impact of Ni can be mitigated through the exogenous supplementation of NaHS [sodium hydrosulfide (8 µM); H2S donor] and SNP [sodium nitroprusside (10 µM); NO donor] which showed substantial improvement on growth, pigments, nitrogen metabolism, and EPS layer and noticeably occurred as a consequence of a substantial reduction in Ni accumulation content which minimized the toxicity effects. The accumulation of Ni on both the cyanobacterial cell surface (EPS layer) are confirmed by the SEM-EDX analysis. Further, the addition of NO scavenger (PTIO; 20 µM) and inhibitor of NO (L-NAME; 100 µM); and H2S scavenger (HT; 20 µM) and H2S inhibitor (PAG; 50 µM) reversed the positive responses of H2S and NO and damages were more prominent under Ni stress thereby, suggesting the downstream signaling of H2S on NO-mediated alleviation. Thus, this study concludes the crosstalk mechanism of H2S and NO in the mitigation of Ni-induced toxicity in rice field cyanobacteria.

Physiological and transcriptome profiling of Chlorella sorokiniana: A study on azo dye wastewater decolorization

Over decades, synthetic dyes have become increasingly dominated by azo dyes posing a significant environmental risk due to their toxicity. Microalgae-based systems may offer an alternative for treatment of azo dye effluents to conventional physical-chemical methods. Here, microalgae were tested to decolorize industrial azo dye wastewater (ADW). Chlorella sorokiniana showed the highest decolorization efficiency in a preliminary screening test. Subsequently, the optimization of the experimental design resulted in 70% decolorization in a photobioreactor. Tolerance of this strain was evidenced using multiple approaches (growth and chlorophyll content assays, scanning electron microscopy (SEM), and antioxidant level measurements). Raman microspectroscopy was employed for the quantification of ADW-specific compounds accumulated by the microalgal biomass. Finally, RNA-seq revealed the transcriptome profile of C. sorokiniana exposed to ADW for 72 h. Activated DNA repair and primary metabolism provided sufficient energy for microalgal growth to overcome the adverse toxic conditions. Furthermore, several transporter genes, oxidoreductases-, and glycosyltransferases-encoding genes were upregulated to effectively sequestrate and detoxify the ADW. This work demonstrates the potential utilization of C. sorokiniana as a tolerant strain for industrial wastewater treatment, emphasizing the regulation of its molecular mechanisms to cope with unfavorable growth conditions.

Algal nutraceuticals: A perspective on metabolic diversity, current food applications, and prospects in the field of metabolomics

The current consumers' demand for food naturalness is urging the search for new functional foods of natural origin with enhanced health-promoting properties. In this sense, algae constitute an underexplored biological source of nutraceuticals that can be used to fortify food products. Both marine macroalgae (or seaweeds) and microalgae exhibit a myriad of chemical constituents with associated features as a result of their primary and secondary metabolism. Thus, primary metabolites, especially polysaccharides and phycobiliproteins, present interesting properties to improve the rheological and nutritional properties of food matrices, whereas secondary metabolites, such as polyphenols and xanthophylls, may provide interesting bioactivities, including antioxidant or cytotoxic effects. Due to the interest in algae as a source of nutraceuticals by the food and related industries, novel strategies should be undertaken to add value to their derived functional components. As a result, metabolomics is considered a high throughput technology to get insight into the full metabolic profile of biological samples, and it opens a wide perspective in the study of algae metabolism, whose knowledge is still little explored. This review focuses on algae metabolism and its applications in the food industry, paying attention to the promising metabolomic approaches to be developed aiming at the functional characterization of these organisms.

Effects of cadmium on the synthesis of active ingredients in Salvia miltiorrhiza

Cadmium (Cd) could pose threats to human health by affecting Salvia miltiorrhiza (SM) safety. Cd enrichment trait and its effects on the active ingredient synthesis in SM remain unknown. Here we investigated the Cd concentration using ICP-MS-based method, physiologies (contents of malondialdehyde and proline, and activities of superoxide dismutase, peroxidase [POD], and catalase [CAT]), and LC-MS/MS-based metabolites of SM under 25, 50, and 100 mg kg^-1 Cd stress. The results revealed that Cd concentrations, as it rose in soil, increased in roots and leaves of SM with transfer factors and bioconcentration factors below 1 in Cd-treated groups; POD and CAT activities and proline content increased and then declined. Amino acids and organic acids (especially d-glutamine [d-Gln], l-aspartic acid [l-Asp], l-phenylalanine [l-Phe], l-tyrosine [l-Tyr], geranylgeranyl-PP [GGPP], and rosmarinic acid [RA]) contributed more in discriminating SM roots of different groups. GGPP was negatively related to l-Tyr and l-Phe, and RA was positively related to d-Gln and l-Asp in SM. These results revealed that SM belonged to a non-Cd-hyperaccumulator with most Cd accumulated in roots, Cd could enhance phenolic acid synthesis via regulating amino acid metabolism and might inhibit tanshinone synthesis by declining the GGPP content, and proline, POD, and CAT played vital roles in resisting Cd stress. These provided new ideas and theoretical basis for further study on medical plants' response to heavy metals.

Role of secondary metabolites in distressed microalgae

Proficient photosynthetic microalgae/cyanobacteria produce a remarkable amount of various biomolecules. Secondary metabolites (SM) represent high value products for global biotrend application. Production improvement can be achieved by nutritional, environmental, and physiological stress as a first line tools for their stimulation. In recent decade, an increasing interest in algal stress biology and omics techniques have deepened knowledge in this area. However, deep understanding and connection of specific stress elucidator are missing. Hence, the present review summarizes recent evidence with an emphasis on the carotenoids, phenolic, and less-discussed compounds (glycerol, proline, mycosporins-like amino acids). Even when they are synthesized at very low concentrations, it highlights the need to expand knowledge in this area using genome-editing tools and omics approaches.

The interplay between microalgae and toxic metal(loid)s: mechanisms and implications in AMD phycoremediation coupled with Fe/Mn mineralization

Acid mine drainage (AMD) is low-pH with high concentration of sulfates and toxic metal(loid)s (e.g. As, Cd, Pb, Cu, Zn), thereby posing a global environmental problem. For decades, microalgae have been used to remediate metal(loid)s in AMD, as they have various adaptive mechanisms for tolerating extreme environmental stress. Their main phycoremediation mechanisms are biosorption, bioaccumulation, coupling with sulfate-reducing bacteria, alkalization, biotransformation, and Fe/Mn mineral formation. This review summarizes how microalgae cope with metal(loid) stress and their specific mechanisms of phycoremediation in AMD. Based on the universal physiological characteristics of microalgae and the properties of their secretions, several Fe/Mn mineralization mechanisms induced by photosynthesis, free radicals, microalgal-bacterial reciprocity, and algal organic matter are proposed. Notably, microalgae can also reduce Fe(III) and inhibit mineralization, which is environmentally unfavorable. Therefore, the comprehensive environmental effects of microalgal co-occurring and cyclical opposing processes must be carefully considered. Using chemical and biological perspectives, this review innovatively proposes several specific processes and mechanisms of Fe/Mn mineralization that are mediated by microalgae, providing a theoretical basis for the geochemistry of metal(loid)s and natural attenuation of pollutants in AMD.

Transcriptomic hallmarks of in vitro TiO2 nanotubes toxicity in Chlamydomonas reinhardtii

Recently, more accessible transcriptomic approaches have provided a new and deeper understanding of environmental toxicity. The present study focuses on the transcriptomic profiles of green microalgae Chlamydomonas reinhardtii exposed to new industrially promising material, TiO₂ nanotubes (NTs), as an example of a widely used one-dimensional nanomaterial. The first algal in vitro assay included 2.5 and 7.5 mg/L TiO₂ NTs, resulting in a dose-dependent negative effect on biological endpoints. At a working concentration of 7.5 mg/L, RNA-sequencing showed a mainly negative effect on the cells. In summary, the results indicated metabolic disruption, ^{such as ATP loss, damage to mitochondria and chloroplasts, loss of solutes due to permeated membranes,} and cell wall damage. Moreover, apoptosis-induced transcripts were detected. Interestingly, reactivation of transposons was observed. In signalling and transcription pathways, including chromatin remodelling and locking, the annotated genes were downregulated.

Nickel toxicity alters growth patterns and induces oxidative stress response in sweetpotato

Nickel (Ni) contaminated soil is a persistent risk to plant growth and production worldwide. Therefore, to explore the Ni toxicity levels in sweetpotato production areas, we investigated the influence of different Ni treatments (0, 7.5, 15, 30, and 60 mg L^-1) for 15 days on phenotype, Ni uptake, relative water content, gas exchange, photosynthetic pigments, oxidative stress, osmolytes, antioxidants, and enzymes of sweetpotato plants. The results presented that Ni at higher levels (30 and 60 mg L^-1) substantially reduced growth, biomass, and root morphological traits. The Pearson correlation analysis suggested that Ni toxicity causes oxidative injuries as persistent augmentation of hydrogen peroxide (H₂O₂) and malonaldehyde (MDA) and reduced RWC, gas exchange, and photosynthetic pigment. Furthermore, this study revealed that sweetpotato could tolerate moderate Ni treatment (up to 15 mg L^-1) by reducing oxidative stress. The results also indicated that the increase in the activities of mentioned osmolytes, antioxidants, and enzymes is not sufficient to overcome the higher Ni toxicity. Based on these results, we suggest using low Ni-contaminated soil for better growth of sweetpotato and also could be used as a phytoremediator in moderate Ni-contaminated soil.

Potential Psychoactive Effects of Microalgal Bioactive Compounds for the Case of Sleep and Mood Regulation: Opportunities and Challenges

Sleep deficiency is now considered an emerging global epidemic associated with many serious health problems, and a major cause of financial and social burdens. Sleep and mental health are closely connected, further exacerbating the negative impact of sleep deficiency on overall health and well-being. A major drawback of conventional treatments is the wide range of undesirable side-effects typically associated with benzodiazepines and antidepressants, which can be more debilitating than the initial disorder. It is therefore valuable to explore the efficiency of other remedies for complementarity and synergism with existing conventional treatments, leading to possible reduction in undesirable side-effects. This review explores the relevance of microalgae bioactives as a sustainable source of valuable phytochemicals that can contribute positively to mood and sleep disorders. Microalgae species producing these compounds are also catalogued, thus creating a useful reference of the state of the art for further exploration of this proposed approach. While we highlight possibilities awaiting investigation, we also identify the associated issues, including minimum dose for therapeutic effect, bioavailability, possible interactions with conventional treatments and the ability to cross the blood brain barrier. We conclude that physical and biological functionalization of microalgae bioactives can have potential in overcoming some of these challenges.

Total Phenolic Content, Biomass Composition, and Antioxidant Activity of Selected Marine Microalgal Species with Potential as Aquaculture Feed

There has been growing interest in microalgal biomolecules for health and cosmetics, as well as in the use of microalgae as aquaculture feed due to the need to replace fishmeal and fish oil with sustainable yet equally nutritious alternatives. Aim of this study is to evaluate the potential of five marine microalgal species, namely Chlorella minutissima, Dunaliella salina, Isochrysis galbana, Nannochloropsis oculata and Tisochrysis lutea, for the co-production of antioxidants and aquaculture feed. Batch cultivation was performed under saturating light intensity and continuous aeration. Freeze-dried biomass was extracted sequentially with water and methanol and evaluated for phenolic content and antioxidant activity, as well as proximate composition and fatty acid profile. Methanolic extracts of C. minutissima presented the highest phenolic content, measured with the Folin–Ciocalteu assay, and antioxidant activity. However, HPLC and LC-MS showed the presence of non-pigment compounds only in T. lutea. Total phenolic content and antioxidant activity were correlated to chlorophyll content. N. oculata and T. lutea were rich in eicosapentaenoic acid and docosahexaenoic acid, respectively, as well as in protein. In conclusion, N. oculata and T. lutea are suitable candidates for further optimization, while the data presented suggest that pigment effects on the Folin–Ciocalteu method require reconsideration.

Extraction and characterization of microalgae-derived phenolics for pharmaceutical applications: A systematic review

Microalgae are regarded as a rich trove of diverse secondary metabolites that exert remarkable biological activities. In particular, microalgae-derived bioactive phenolic compounds (MBPCs) are a boon to biopharmaceutical and nutraceutical industries due to their diverse bioactivities, including antimicrobial, anticancer, antiviral, and immunomodulatory activities. The state-of-the-art green technologies for extraction and purification of MBPCs, along with the modern progress in the identification and characterization of MBPCs, have accelerated the discovery of novel active pharmaceutical compounds. However, several factors regulate the production of these bioactive phenolic compounds in microalgae. Furthermore, some microalgae species produce toxic phenolic compounds that negatively impact the aquatic ecosystem, animal, and human life. Therefore, the focus of this review paper is to bring into light the current innovations in bioprospection, extraction, purification, and characterization of MBPCs. This review is also aimed at a better understanding of the physicochemical factors regulating the production of MBPCs at an industrial scale. Finally, the present review covers the recent advances in toxicological evaluation, diverse applications, and future prospects of MBPCs in biopharmaceutical industries.

Bioactive Metabolites Produced by Cyanobacteria for Growth Adaptation and Their Pharmacological Properties

Cyanobacteria are the most abundant oxygenic photosynthetic organisms inhabiting various ecosystems on earth. As with all other photosynthetic organisms, cyanobacteria release oxygen as a byproduct during photosynthesis. In fact, some cyanobacterial species are involved in the global nitrogen cycles by fixing atmospheric nitrogen. Environmental factors influence the dynamic, physiological characteristics, and metabolic profiles of cyanobacteria, which results in their great adaptation ability to survive in diverse ecosystems. The evolution of these primitive bacteria resulted from the unique settings of photosynthetic machineries and the production of bioactive compounds. Specifically, bioactive compounds play roles as regulators to provide protection against extrinsic factors and act as intracellular signaling molecules to promote colonization. In addition to the roles of bioactive metabolites as indole alkaloids, terpenoids, mycosporine-like amino acids, non-ribosomal peptides, polyketides, ribosomal peptides, phenolic acid, flavonoids, vitamins, and antimetabolites for cyanobacterial survival in numerous habitats, which is the focus of this review, the bioactivities of these compounds for the treatment of various diseases are also discussed.

Zinc biosorption by Dunaliella sp. AL-1: Mechanism and effects on cell metabolism

Phycoremediation is being considered as an eco-friendly and safe technology for toxics eradication from contaminated aquatic systems. The zinc biosorption capacity of Dunaliella sp. AL-1 was demonstrated. Zinc impacted cell growth and photosynthetic pigments accumulation showing exposure time and concentration-dependent effects. The investigation of the antioxidant protective response to zinc exposition proved a stimulation of guaiacol peroxidase (GPX) activity and an increased rate of total phenolics, flavonoids, condensed tannins and glutathione (GSH). The Box-Behnken design was used to optimize zinc removal conditions by Dunaliella sp. AL-1 strain. The maximum experimental zinc uptake was obtained when zinc concentration, algae dose, initial pH, and contact time were set at 25 mg/L, 0.5 g/L, 7.59 and 13 h 43 min, respectively. Under completely optimized conditions, the fraction of zinc removed intracellularly was much lower than the adsorbed on the cell surface. FTIR analysis Dunaliella sp. AL-1 biomass demonstrated that several functional groups as OH, CH₂, CO, PO, COO and CO may participate in the biosorption process. A comparative proteomic analysis through nano-HPLC coupled to LC-MS/MS, was performed from pre- and post-zinc treatments cells. Among 199 identified proteins, 60 were differentially expressed of which 41 proteins were down-regulated against 19 up-regulated ones. Target proteins have been demonstrated to be implicated in different metabolic processes mainly photosynthesis and antioxidant defenses.

Influence of polystyrene microplastic and nanoplastic on copper toxicity in two freshwater microalgae

There has been increasing concern over the toxic effects of microplastics (MP), nanoplastics (NP), and copper (Cu) on microalgae. However, the combined toxicity of the metal in the presence of polystyrene (PS) MP/NP on microalgae has not been well studied, particularly after long-term exposure (i.e., longer than 4 days). The primary aim of the present study was to investigate the effect of PS MP and NP on Cu toxicity on two freshwater microalgae, namely Chlorella sp. TJ6-5 and Pseudokirchneriella subcapitata NIES-35 after acute exposure for 4 days and up to 16 days. The results showed that both microalgae were sensitive to Cu, but tolerant to MP/NP. However, MP/NP increased the toxicity of Cu at EC50 in both microalgae, which was only noticeable in chronic exposure. Single and combined treatment of MP/NP and Cu induced higher oxidative stress and caused morphological and ultrastructural changes in both microalgae. The adsorption of Cu to MP and NP was low (0.23-14.9%), with most of the Cu present in free ionic form (81.6-105.8%). The findings on different sensitivity of microalgae to Cu in the presence of MP/NP may have significant implication as microalgae are likely to be exposed to a mixture of both MP/NP and Cu in the environment. For example, in air-blasting technology, MP and NP are used as abrasive medium to remove Cu-containing antifouling paints on hulls of ship and submerged surfaces. Wastewater treatment plants receive household wastes containing MP and NP, as well as stormwater runoffs and industrial wastes contaminated with heavy metals.

Insights into phenolic compounds from microalgae: structural variety and complex beneficial activities from health to nutraceutics

Phenolic compounds (PCs) are a family of secondary metabolites with recognized biological activities making them attractive for the biomedical "red" biotechnology. The development of the eco-sustainable production of natural bioactive metabolites requires using easy cultivable organisms, such as microalgae, which represents one of the most promising sources for biotechnological applications. Microalgae are photosynthetic organisms inhabiting aquatic systems, displaying high levels of biological and functional diversities, and are well-known producers of fatty acids and carotenoids. They are also rich in other families of bioactive molecules e.g. phenolic compounds. Microalgal PCs however are less investigated than other molecular components. This study aims to provide a state-of-art picture of the actual knowledge on microalgal phenolic compounds, reviewing information on the PC content variety and chemodiversity in microalgae, their environmental modulation, and we aim to report discuss data on PC biosynthetic pathways. We report the challenges of promoting microalgae as a relevant source of natural PCs, further enhancing the interests of microalgal "biofactories" for biotechnological applications (i.e. nutraceutical, pharmacological, or cosmeceutical products).

Challenging microalgal vitamins for human health

BACKGROUND

Vitamins' deficiency in humans is an important threat worldwide and requires solutions. In the concept of natural biofactory for bioactive compounds production, microalgae represent one of the most promising targets filling many biotechnological applications, and allowing the development of an eco-sustainable production of natural bioactive metabolites. Vitamins are probably one of the cutting edges of microalgal diversity compounds.

MAIN TEXT

Microalgae can usefully provide many of the required vitamins in humans, more than terrestrial plants, for instance. Indeed, vitamins D and K, little present in many plants or fruits, are instead available from microalgae. The same occurs for some vitamins B (B12, B9, B6), while the other vitamins (A, C, D, E) are also provided by microalgae. This large panel of vitamins diversity in microalgal cells represents an exploitable platform in order to use them as natural vitamins' producers for human consumption. This study aims to provide an integrative overview on vitamins content in the microalgal realm, and discuss on the great potential of microalgae as sources of different forms of vitamins to be included as functional ingredients in food or nutraceuticals for the human health. We report on the biological roles of vitamins in microalgae, the current knowledge on their modulation by environmental or biological forcing and on the biological activity of the different vitamins in human metabolism and health protection.

CONCLUSION

Finally, we critically discuss the challenges for promoting microalgae as a relevant source of vitamins, further enhancing the interests of microalgal "biofactory" for biotechnological applications, such as in nutraceuticals or cosmeceuticals.

Lycorine and UV-C stimulate phenolic secondary metabolites production and miRNA expression in Chlamydomonas reinhardtii

Studying stress pathways on the level of secondary metabolites that are found in very small concentration in the cells is complicated. In the algae, the role of individual metabolites (such as carotenoids, phenolic compounds, organic acids, and vitamins) and miRNAs that participate in plant's defence are very poorly understood during stressful conditions. Therefore, in the present experiment, the model organism Chlamydomonas reinhardtii was exposed to stress conditions (Lyc and UV-C irradiation) to detect these substances, even at very low concentrations. The purpose was to monitored changes at each response level with a future view to identifying their specific roles under different stress factors. In stress-treated cultures, numerous transcriptomic and metabolomic pathways were triggered in C. reinhardtii. Although Lyc significantly decreased the concentration of AA, suggesting that Lyc has a similar function in C. reinhardtii as in plants. The negative effect of UV-C radiation was based on the production of ROS and enhancement of antioxidant responses, resulting in increased levels of polyphenols and simple phenolic compounds. Both treatments did lead to extensive changes in transcript levels and miRNA expression patterns.

Physiological and metabolic responses of Scenedesmus quadricauda (Chlorophyceae) to nickel toxicity and warming

An ecologically important tropical freshwater microalga, Scenedesmus quadricauda, was exposed to Ni toxicity under two temperature regimes, 25 and 35 °C to investigate the interactive effects of warming and different Ni concentrations (0.1, 1.0 and 10.0 ppm). The stress responses were assessed from the growth, photosynthesis, reactive oxygen species (ROS) generation and metabolomics aspects to understand the effects at both the physiological and biochemical levels. The results showed that the cell densities of the cultures were higher at 35 °C compared to 25 °C, but decreased with increasing Ni concentrations at 35 °C. In terms of photosynthetic efficiency, the maximum quantum yield of photosystem II (F _v/F _m) of S. quadricauda remained consistent across different conditions. Nickel concentration at 10.0 ppm affected the maximum rate of relative electron transport (rETR_m) and saturation irradiance for electron transport (E _k) in photosynthesis. At 25 °C, the increase of non-photochemical quenching (NPQ) values in cells exposed to 10.0 ppm Ni might indicate the onset of thermal dissipation process as a self-protection mechanism against Ni toxicity. The combination of warming and Ni toxicity induced a strong oxidative stress response in the cells. The ROS level increased significantly by 40% after exposure to 10.0 ppm of Ni at 35 °C. The amount of Ni accumulated in the biomass was higher at 25 °C compared to 35 °C. Based on the metabolic profile, temperature contributed the most significant differentiation among the samples compared to Ni treatment and the interaction between the two factors. Amino acids, sugars and organic acids were significantly regulated by the combined factors to restore homeostasis. The most affected pathways include sulphur, amino acids, and nitrogen metabolisms. Overall, the results suggest that the inhibitory effect of Ni was lower at 35 °C compared to 25 °C probably due to lower metal uptake and primary metabolism restructuring. The ability of S. quadricauda to accumulate substantial amount of Ni and thrive at 35 °C suggests the potential use of this strain for phycoremediation and outdoor wastewater treatment.

Variations in the antioxidant and free radical scavenging under induced heavy metal stress expressed as proline content in chickpea

This study pertains to the effects of heavy metal salts viz., copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) on the chickpea accession ICC-4812. The salts were given as treatments to the chickpea seeds at various ascending levels of doses till proving toxic. The treatment of 24 h soaked and swollen seeds were then extended to 7 days duration from the date of treatment. Atomic absorption spectrophotometric analysis of bioassay tissue Cicer, showed maximum uptake of 9.41 mg/g and minimum of 1.65 mg/g tissue dry weight for Pb and Zn respectively. The study reveals that enhanced antioxidant responses are associated with substantial proline accumulation indicating induced stress. Ferric reducing antioxidant power assay measuring antioxidant activity was highest in the chickpea seedling treated with Zn, whereas, free radical scavenging activity was highest in the treatments with Mn. The total phenolic and flavonoid contents ranged between 0.24-0.97 and 0.27-1.00 mg/g of dry matter content respectively. Higher Pb and Zn doses seem to elicit higher proline levels therefore, suggesting an extreme condition of induced abiotic stress. Dose dependent protein oxidation coupled with DNA degradation was observed in all treatments, depicting genotoxicity. Unweighted pair-group method arithmetic average analysis presented similarity coefficients between the treatments.