Antinociceptive, anti-inflammatory and hypoglycemic activities of the ethanolic Turnera subulata Sm. flower extract in adult zebrafish (Danio rerio).

Turnera subulata Sm. belongs to the family Turneraceae and is found in Brazil. The present study evaluated the antinociceptive, anti-inflammatory, and hypoglycemic potential of T. subulata flower extract (EtFloTsu) in zebrafish (Danio rerio). The total phenol and flavonoid contents of EtFloTsu were determined and identified using the Folin Ciocalteu reagent and aluminum chloride (AlCl3), respectively. The constituents of the extract were identified by HPLC-DAD, and the in vitro antioxidant activity (DPPH) was determined, toxicity in brine shrimp, and acute toxicity of 96 h in adult zebrafish. In addition, adult zebrafish (n = 6/fish) were treated orally with EtFloTsu (4, 20, or 40 mg/kg; vo) and subjected to formalin-induced nociception tests (with its possible mechanism of action with camphor), carrageenan-induced inflammation, and D-glucose-induced hyperglycemia (111 mM). Oxidative stress in the liver and brain tissues was assessed. EtFloTsu showed high levels of phenolic and flavonoid compounds with antioxidant activity. The phytochemicals chlorogenic acid, luteolin-7-o-glucoside, vitexin, and apigenin-7-o-glucoside were also identified in EtFloTsu. The synergism between these constituents was possibly responsible for the antinociceptive (via TRPA1), anti-inflammatory, and hypoglycemic effects of EtFloTsu in adult zebrafish, without causing toxicity in animals. Therefore, T. subulata flowers have therapeutic agents that could treat pain, inflammation, diabetes, and related complications.Communicated by Ramaswamy H. Sarma.

Graviola Fruit Bar Added Acerola By-Product Extract Protects Against Inflammation and Nociception in Adult Zebrafish (Danio rerio).

Studies involving foods associated with pain reversal and anti-inflammatory effects using zebrafish are rarely reported in the literature. This study aimed to evaluate the effect of graviola (Annona muricata L.) fruit bar (GFB) and GFB added with acerola (Malpighia glabra L) seed extract (ASE) on acute nociception and abdominal inflammation in adult zebrafish (Danio rerio). Acute nociception was induced by formalin, capsaicin, cinnamaldehyde, acidic saline, glutamate (cutaneous models), and hypertonic saline (corneal model), and inflammation was induced by carrageenan. Both GFB and ASE exhibited antinociceptive effect modulated by the nitrergic system, guanylate cyclase, and transient receptor potential ankyrin 1 and acid-sensing ion channels. The antinociceptive effect of GFB also appears to be modulated by the opioid system and glutamatergic receptors (N-methyl-D-aspartate receptor). Only ASE presented corneal antinociceptive effect. Both samples showed anti-inflammatory effect, being more significant the effect of GFB. The addition of acerola by-product extract in GFB results in a product with greater biological potential.