Anesthesia or seizure-like behavior? The effects of two Amazonian plants, Acmella oleracea and Piper alatabaccum in zebrafish (Danio rerio).

Currently, available fish anesthetics can produce important side effects, including respiratory arrest and distress. Easy-to-implement alternatives with low toxicity are needed to ensure fish health as well as to help artisanal fisheries and fish sellers in handling and transporting fishes, and native plants seems to be the best alternative. We aimed to implement an anesthetic protocol using crude ethanolic extracts from flowers and leaves of two Amazonian plants, the Acmella oleracea and Piper alatabaccum. We first tested the extracts for anesthesia, using the zebrafish as model. Even though in some treatments the animals apparently entered deep anesthesia, many of them presented aberrant behaviors and even died. Thus, we performed new experiments testing the extracts effects on seizure-like behaviors of the fish. Only the leaf extract of A. oleracea has potential effects for fish anesthesia. Both the flower extract from this plant and the leaf extract from P. alatabaccum induced seizure-like behavior in the animals. In conclusion, besides bringing a possible new anesthetic protocol for fish, our work draws attention for the neurotoxic effects the anesthetic solutions may cause, since several studies defend other Piper species as anesthetic for fish and A. oleracea flowers' extract was already pointed as fish anesthetic.

A Simple and Efficient Protocol for the Cryopreservation of Zygotic Embryos of Macaw Palm [Acrocomia aculeata (Jacq.) Lodd. Ex Mart.], A Tropical Species with A Capacity for Biofuel Production.

BACKGROUND: The development of cryopreservation protocols for zygotic embryos has the advantage of direct embryo regeneration into plantlets, an important factor when one´s purpose is to preserve genetic plant resources. OBJECTIVE: Current study developed an efficient and simplified cryopreservation protocol for zygotic embryos of the macaw palm, a type of palm tree with great capacity for biodiesel production. MATERIALS AND METHODS: Embryos were obtained from seeds and rehydrated for 15 h in a 3% sucrose medium. Zygotic embryos were subsequently desiccated in a laminar flow cabinet for 0, 2, 4, 6 and 8 h. After each period, some embryos were cultured on a germination medium and others were placed in sterile cryotubes and immersed directly in liquid nitrogen for up to 360 d. Cryotubes were rewarmed by immersion at 40 degree C during 90 s (quick thawing). RESULTS: Germinability reduction occurred in proportion to desiccation time, with averages of 97 and 75% for 0 h and 8 h, respectively. In the case of cryopreserved zygotic embryos, the highest germination (81%) was obtained after 6-h desiccation, when the embryos had approximately 10% water content (FW basis). CONCLUSION: The zygotic embryos cryopreservation protocol covered in this study represents another option for preserving Acrocomia aculeata genetic resources.