ABSTRACT
Salinity is one of the factors that negatively impact plant growth and productivity; therefore, it is necessary to seek solutions that help mitigate the degenerative action of saline stress on crops. The objective of this study was to evaluate the effects of salicylic acid (SA) on the germination and vigor of Mesosphaerum suaveolens (L.) Kuntze seeds subjected to salinity. The experiment was carried out using a completely randomized design, in an incomplete 5 × 5 factorial scheme, with five levels of electrical conductivity of irrigation water (ECw - 0.0, 1.45, 5.00, 8.55, and 10.00 dS m-1) and five doses of SA (0.0, 0.29, 1.00, 1.71, and 2.00 mM), with four replications of 50 seeds, totaling nine combinations generated via a central composite design. The germination percentage, first germination count, germination speed index, average germination time, percentage of abnormal seedlings, shoot, root, and seedling lengths, and total seedling dry mass were evaluated. Salicylic acid attenuated the effect of saline stress on initial growth, mitigating damage to root and shoot lengths. Seed priming with salicylic acid improved germination and seed vigor.(AU)
A salinidade é um dos fatores que promove a inibição no crescimento e produtividade vegetal, sendo necessária a busca por alternativas que auxiliem na mitigação da ação degenerativa do estresse salino às culturas. Objetivou-se com este trabalho avaliar doses de ácido salicílico na germinação e vigor de sementes de Mesosphaerum suaveolens (L.) Kuntze submetidas à salinidade. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial incompleto 5 x 5, com cinco níveis de condutividade elétrica da água de irrigação (CEa de 0,0; 1,45; 5,00; 8,55 e 10,00 dS m-1) e cinco doses de AS de (0,0; 0,29; 1,00; 1,71 e 2,00 mM L-1), com quatro repetições de 50 sementes, totalizando nove combinações geradas via matriz Composto Central de Box. As variáveis avaliadas foram: porcentagem de germinação, primeira contagem de germinação, índice de velocidade de germinação, tempo médio de germinação, porcentagem de plântulas anormais, comprimento da parte aérea, radícula e plântula e massa seca total de plântulas. O ácido salicílico atenua o efeito do estresse salino sobre o crescimento inicial, mitigando os danos sobre o comprimento de radícula e da parte aérea. O tratamento das sementes com ácido salicílico melhora a germinação e o vigor das sementes.(AU)
Subject(s)
Saline Waters/adverse effects , Germination/physiology , Salicylic Acid/adverse effects , Hyptis/physiology , SalinityABSTRACT
Many products had been used as chemical peeling agents to renew thin skin. Retinoic, Glycolic and Salicylic acids were used in many dermatological diseases with hypdrkeratinization and/or hyperpigmentation. To evaluate and compare the effects of these acids on the thin skin of adult female guinea pig. Twenty animals were used and were divided into four equal groups. Group I served as the control group, whereas the other treated groups were topically applicated daily on shaved area of back skin with Retinoic [0.05%], Glycolic [12%] and Salicylic [10%] acids in Groups II, III and IV, respectively. Thin skin specimens were processed for light and transmission electron microscopic studies. Morphometric and statistical studies were done. Groups II, III and IV showed high significant increase in mean thickness of epidermal nucleated keratinocytes as compared to Control group. Group II showed proliferation hyperkeratosis and acanthosis and shrinkage of the sebaceous glands with decreased sebum production. Group III showed skin peeling by removing superficial layers of epidermis, cytoplasmic and nuclear degeneration with disruption of intercellular junctions and degeneration in melanocytes with marked decrease of melanin. Both Retinoic and Glycolic acids apparently increased the production of collagen and elastic fibers as compared to control. Group IV showed skin peeling mainly by direct action on intercellular cement substance and partially by inducing proliferation hyperkertosis. Both Retinoic and Glycolic acids showed complementary actions in treatment of hyperpigmentation and as chemical peeling agents. Salicylic acid also is a peeling agent, but its effects could be covered by either Retinoic or Glycolic acids. It is recommended to use combination of both Retinoic and Glycolic acids to give better effects on various skin disorders with hyperkeratinization and hyperpigmentation
Subject(s)
Female , Animals, Laboratory , Tretinoin/adverse effects , Glycolates/adverse effects , Salicylic Acid/adverse effects , Skin/ultrastructure , Microscopy, Electron , Guinea Pigs , FemaleABSTRACT
In the present study the effects of selective cox-2 inhibitor celecoxib alone and in combination with low dose aspirin on stress induced gastric ulceration in rats was investigated in comparison to that of indomethacin. In addition the effect of the drug on the spontaneous healing of stress induced ulcer was determined. Statistical analysis of the results revealed that administration of celecoxib [30 mg/kg] or low dose aspirin [7.5 mg/kg] 1 hour prior to induction of stress was not associated with any significant aggravating effect on the ulcerogenic response to sttess Co administration of both drugs aggravated stress induced ulcer as evidenced by an ulcer index of 25.2 compared to 19.4 in control non treated rats and 29.7 in indomethacin [7.5 mg/kg] treated rats. Celecoxib treatment for 7 days following induction of stress ulcer resulted in delayed healing of ulcer as evidenced by an ulcer index of 16.9 compared to 15 in control non treated rats and 29 in indomethacin treated rats. It could be concluded that both cox-1 and cox-2inhibition are required for gastric ulceration, hence the use of selective cox-2 inhibitors in patients receiving low dose aspirin carries the risk of induction of gastric ulcer. In addition, caution should be exercised when switching patients intolerant to non selective non steroidal anti- inflammatory drugs [NSAIDs] to the cox-2 inhibitors, such patients might already be suffering from NSAIDs induced gastric ulcer, the healing of which may be delayed by selective cox-2 inhibitors