Bryophyllum pinnatum (Lam.) Oken (BP) is a plant that is used worldwide to treat inflammation, infections, anxiety, restlessness, and sleep disorders. While it is known that BP leaves are rich in flavonoids, the extent of the beneficial and toxic effects of its crude extracts remains unclear. Although some neurobehavioral studies using leaf extracts have been conducted, none has examined the effects of water-extracted leaf samples. The zebrafish is a powerful animal model used to gain insights into the efficacy and toxicity profiles of this plant due to its high fecundity, external development, and ease of performing behavioral assays. In this study, we performed behavioral testing after acute exposure to different concentrations of aqueous extract from leaves of B. pinnatum (LABP) on larval zebrafish, investigating light/dark preference, thigmotaxis, and locomotor activity parameters under both normal and stressed conditions. LABP demonstrated dose-and time-dependent biphasic effects on larval behavior. Acute exposure (25 min) to 500 mg/L LABP resulted in decreased locomotor activity. Exposure to 300 mg/L LABP during the sleep cycle decreased dark avoidance and thigmotaxis while increasing swimming velocity. After sleep deprivation, the group treated with 100 mg/L LABP showed decreased dark avoidance and increased velocity. After a heating stressor, the 30 mg/L and 300 mg/L LABP-treated groups showed decreased dark avoidance. These results suggest both anxiolytic and psychoactive effects of LABP in a dose-dependent manner in a larval zebrafish model. These findings provide a better understanding of the mechanisms underlying relevant behavioral effects, consequently supporting the safe and effective use of LABP for the treatment of mood disorders.

Kalanchoe pinnata (Crassulaceae) is a medicinal plant distributed in several areas of the World. Their leaves have been used, in folk medicine, for anxiety and sleep disorders among other proposes. Chemically, this plant is composed by organic acids, flavonoids, bufadienolides, triterpenoids and some ubiquitous compounds. In this study, the fresh leaves of K. pinnata were extracted in an accelerated solvent extraction (ASE) system using H 2 O (cold and hot) as well as with EtOH:H 2 O 1:1. The obtained crude extracts were analyzed by HPLC-UV-MS. As a result, were identified organic acids and flavonoids, these beingand trans-p-coumaryl glutaric acid the main compounds in the studied extracts. Obtained results revealed the predominance of flavonoids in extracts prepared using hot H 2 O (70.26 ± 2.19%) or EtOH:H 2 O 1:1 (74.65 ± 5.39%) while a reduction in the amount of these compounds was observed in the extracts prepared using cold H 2 O (54.41 ± 2.93%). Additionally, crude extracts from leaves of K. pinnata extracted with hot H 2 O and EtOH:H 2 O 1:1 showed in vitro cytotoxicity on five tested cancer cell lines: murine melanoma (B16F10), human melanoma (A2058), human cervical carcinoma (HeLa), human leukemia (HL-60), and human glioblastoma (U87-MG), with IC 50 values in the range of 10.6 ± 2.5 -91.3 ± 7.2 g/mL. On the other hand, the extract prepared using cold H 2 O displayed reduced potential. These crude extracts were also tested against human foreskin fibroblasts (non-tumorigenic cells) showing IC 50 values ranging from 79.5 to 90.2 g/mL. In conclusion, our results showed the impact that different extraction methods have on the chemical composition and pharmacological activity, which are notable for the anticancer activity associated to flavonoids.