Antinociceptive effect of Nephelium lappaceum L. fruit peel and the participation of nitric oxide, opioid receptors, and ATP-sensitive potassium channels.

Introduction: Nephelium lappaceum L. (Sapindaceae) is a plant known as rambutan. It is used for various purposes in traditional medicine. Objective: We aimed to evaluate the antinociceptive effects of the ethanol extract of the fruit peel of N. lappaceum (EENL), the mechanisms involved in these effects, and the acute toxicity in zebrafish. Methods: We performed chromatography coupled to mass spectrometry, acute toxicity assay in zebrafish, and evaluation in mice submitted to models of nociception and locomotor activity. Results: We identified (epi)-catechin, procyanidin B, and ellagic acid and its derivatives in EENL. We did not find any toxicity in zebrafish embryos incubated with EENL. The locomotor activity of mice submitted to oral pretreatment with EENL was not changed, but it reduced the abdominal constrictions induced by acetic acid, the licking/biting time in both the first and second phase of formalin testing and capsaicin testing, and carrageenan-induced paw mechanical allodynia. Oral pretreatment with EENL increased latency time in the hot plate test. This antinociceptive effect was significantly reversed by naloxone, L-arginine, and glibenclamide respectively showing the participation of opioid receptors, nitric oxide, and KATP channels as mediators of EENL-induced antinociception. Conclusion: EENL causes antinociception with the participation of opioid receptors, nitric oxide, and KATP channels, and is not toxic to zebrafish.

Sunscreen protection factor enhancement through supplementation with Rambutan (Nephelium lappaceum L) ethanolic extract.

The use of plant bioactives in cosmetic formulations are increasing due to the search for new sustainable sources of raw materials, greater concern for safety and possible social impacts caused by the incorrect use of natural resources. Plant extracts have been the subject of several studies in several industrial areas. However, the potential use of tropical fruits extracts in cosmetic formulations remains largely unexplored. Considering the impact on public health and the possibility of using wastes from fruit processing, the aim of this work is to identify, evaluate and develop a sunscreen based on rambutan peel extracts (Nephelium lappaceum L) as a natural additive for enhancing the final product sun protection factor (SPF). The phytochemical screening revealed the presence of tannins and flavonoids and the absence of coumarins. Even presenting a low sunscreen factor when used alone (SPF value 0.4), rambutan extract at 1.00% FTP concentration improved the photoprotective result (11.2) of the formulation containing 7.5% of ethylhexyl metoxycinnamate (EHMC) by 134%. The addition of rambutan extract in the formulation shows the potential to reduce the use of synthetic photoprotectors by about 64% of the total synthetic organic filters used to achieve the SPF value of 26.3. In addition, the sunscreen formulation supplemented with rambutan extract containing 1.00% RTP shows the potential to minimize the risk of synthetic agent toxicity and a 45% reduction in the cost of sunscreen production.