Effects of chelating calcium in cryopreservation extender on frozen-thawed dog semen / [Efeitos da quelação de cálcio no meio de criopreservação no sêmen descongelado de cão]

We evaluated the effect of reducing free calcium in the cryopreservation medium, using the calcium chelator ethylene diamine tetracetic acid (EDTA) at 0.3% and 0.5% concentrations. Three male mixed breed dogs were subjected to semen collection by digital manipulation (n=16). Each ejaculate was divided in three aliquots, and each one was diluted in TRIS-glucose-egg yolk extender with 6% glycerol and 0.5% Equex STM Paste® (TGE, control); and added with 0.3% EDTA (EDTA 0.3) or 0.5% EDTA (EDTA 0.5). Calcium concentration reduced in EDTA 0.3 and all the calcium ions were chelated in EDTA 0.5. The EDTA addition did not affect sperm morphology or plasma membrane integrity; however, by removing all free calcium (EDTA 0.5), the sperm motility reduced (64.7% in TGE and 45% in EDTA 0.5; p<0.05). Acrosome integrity and sperm binding ability were not improved by calcium chelation. The failure to prevent the premature AR may explain why sperm longevity was not affected by calcium removal. Thus, the partial or complete calcium removal, through EDTA addition, is not able to prevent acrosomal damage or premature acrosomal reaction, and therefore does not improve the dog sperm binding ability.(AU)

Avaliou-se o efeito da redução do cálcio livre no meio de congelamento, usando-se o quelante de cálcio etilenodiaminotetracético (EDTA) a 0,3% e 0,5%. Três cães machos sem raça definida foram submetidos à coleta de sêmen por manipulação digital (n=16). Cada ejaculado foi diluído em diluidor controle com TRIS-glicose - gema de ovo (TGE, controle), ou em diluidor TGE enriquecido com 0,3% (EDTA 0,3) ou 0,5% de EDTA (EDTA 0,5). A concentração de cálcio reduziu no meio EDTA 0,3, e todos os íons de cálcio foram quelados no meio EDTA 0,5. A adição do EDTA e a consequente quelação do cálcio não afetaram a morfologia espermática ou a integridade da membrana plasmática, no entanto, ao remover todo o cálcio do meio (EDTA 0,5), a motilidade espermática se reduziu (64,7% no TGE e 45% no EDTA 0,5; P<0,05). A integridade do acrossoma e a capacidade de ligação do espermatozoide não melhoraram com a quelação do cálcio. Apesar da influência da concentração de cálcio sobre a motilidade espermática após o descongelamento, a falha em prever a reação acrossomal prematura pode explicar por que a longevidade espermática não foi afetada pela remoção do cálcio no meio. Dessa forma, a remoção parcial ou total do cálcio, por meio da adição de EDTA, não é capaz de prevenir o dano no acrossoma ou a reação acrossomal prematura e, portanto, não aumenta a capacidade do espermatozoide de se ligar ao oócito.(AU)

Cocos nucifera (L.) (Arecaceae): A phytochemical and pharmacological review

Cocos nucifera (L.) (Arecaceae) is commonly called the “coconut tree” and is the most naturally widespread fruit plant on Earth. Throughout history, humans have used medicinal plants therapeutically, and minerals, plants, and animals have traditionally been the main sources of drugs. The constituents of C. nucifera have some biological effects, such as antihelminthic, anti-inflammatory, antinociceptive, antioxidant, antifungal, antimicrobial, and antitumor activities. Our objective in the present study was to review the phytochemical profile, pharmacological activities, and toxicology of C. nucifera to guide future preclinical and clinical studies using this plant. This systematic review consisted of searches performed using scientific databases such as Scopus, Science Direct, PubMed, SciVerse, and Scientific Electronic Library Online. Some uses of the plant were partially confirmed by previous studies demonstrating analgesic, antiarthritic, antibacterial, antipyretic, antihelminthic, antidiarrheal, and hypoglycemic activities. In addition, other properties such as antihypertensive, anti-inflammatory, antimicrobial, antioxidant, cardioprotective, antiseizure, cytotoxicity, hepatoprotective, vasodilation, nephroprotective, and anti-osteoporosis effects were also reported. Because each part of C. nucifera has different constituents, the pharmacological effects of the plant vary according to the part of the plant evaluated.