Promising natural products for the treatment of cutaneous leishmaniasis: A review of in vitro and in vivo studies.

Although there are available treatments for cutaneous leishmaniasis (CL), the drugs used are far from ideal, toxic, and costly, in addition to the challenge faced by the development of resistance. Plants have been used as a source of natural compounds with antileishmanial action. However, few have reached the market and become phytomedicines with registration in regulatory agencies. Difficulties related to the extraction, purification, chemical identification, efficacy, safety, and production in sufficient quantity for clinical studies, hinder the emergence of new effective phytomedicines against leishmaniasis. Despite the difficulties reported, the major research centers in the world see that natural products are a trend concerning the treatment of leishmaniasis. The present work consists of a literature review of articles with in vivo studies, covering the period from January 2011 to December 2022, providing an overview of promising natural products for CL treatment. The papers show encouraging antileishmanial action of natural compounds with reduced parasite load and lesion size in animal models, suggesting new strategies for the treatment of the disease. The results reported in this review show advances in using natural products as safe and effective formulations, which can stimulate clinical studies to establish clinical therapy. In conclusion, the information in this review article serves as a preliminary basis for establishing a therapeutic protocol for future clinical trials that can validate the safety and efficacy of natural compounds, providing the development of affordable and safe phytomedicines for the treatment of CL.

Nanotechnology Promoting the Development of Products from the Biodiversity of the Asteraceae Family.

Biodiversity is a hallmark of the Asteraceae family. Several species are known for their pharmacological potential. The search for new substances has permeated the chemistry of natural products for years. However, the development of a final product is still a challenge. Plant extracts have physicochemical characteristics that sometimes hinder administration, requiring a formulation. In this context, nanotechnology emerges as a tool to improve the pharmacokinetic parameters of several pharmacologically active substances. Nanoemulsions, liposomes, and nanoparticles are used to carry the active ingredients and thus improve therapeutic action, especially for substances with solubility and absorption problems. This paper aimed at compiling all the studies that used nanotechnology to develop formulations from species of the Asteraceae family from 2010 to 2021 in a literature review. The search showed that nanoemulsions are the most developed formulation associated with essential oils. The use of nanotechnology promoted an improvement in the pharmacokinetic parameters of active substances.

Biological properties of functional flavoring produced by enzymatic esterification of citronellol and geraniol present in Cymbopogon winterianus essential oil.

The chemical composition and biological properties of citronella essential oil were modified by enzymatic esterification reaction of the major monoterpenic alcohols with cinnamic acid. The almost complete conversion of geraniol and citronellol present in the citronella (Cymbopogon winterianus) essential oil, into geranyl (99%) and citronellyl (98%) cinnamates was obtained after 48 hours of reaction using a molar ratio of 3:1 (cinnamic acid/alcohol), lipase concentration (Novozym 435) of 15% (w/w) and 70 °C. The esterified oil showed higher antimicrobial activity against Staphylococcus aureus bacteria resistant to oxacillin and penicillin and also greater larvicidal activity against Aedes aegypti larvae compared to unesterified oil. The results concerning the evaluation of toxicity against Artemia salina and cytotoxicity against monkey kidney epithelial cells also showed the superiority of the esterified oil.

Evaluation of the chemical composition and antioxidant activity of extracts and fractions of Ocotea notata (Ness) Mez (Lauraceae).

The specie Ocotea notata (Nees & Mart). Mez is a tree with 5 meters high, that can be found in restinga regions in the Brazilian coast. This study describes a phytochemical investigation, total phenolic content and the antioxidant activity of extracts and fractions by DPPH and ORAC. Phenolic content revealed equivalent concentration between evaluated samples, similar to found in the leave extract (66.4 mEq GA/g). By DPPH, extracts and fractions showed effective concentration (EC50) lower than the standards Ginkgo biloba 761® (23.60 ± 0.64 µg/ml) and quercetin (6.06 ± 0, 92 µg/mL); for the ORAC method, ethyl acetate partition showed a value of 2.06 mmol Trolox equivalent g-1 better than obtained in Ginkgo biloba (1.03 ± 0.25 mmol.Trolox equivalent g-1. The butanol partition (0.52 mmol.Trolox equivalent g-1) and the aqueous residue (0.74 mmol Trolox equivalent g-1) have a lesser ORAC potential than ethyl acetate partition. The butanolic partition, investigated by LC-DAD-MS/MS and QTOF-MS, revealed six major compounds: miquelianin (1), isoquercitrin (2), quercitrin (3), kaempferol-3-O-pentose (4), afzelin (5) and isorhamnetin-glucuronide (6).

Potential use of Piper nigrum ethanol extract against pyrethroid-resistant Aedes aegypti larvae.

Fractionation of Piper nigrum ethanol extract, biomonitored by assays on pyrethroid-resistant Aedes aegypti larvae yielded isolation of the larvicidal amides piperolein-A and piperine. Comparing LC50 values, the ethanol extract (0.98 ppm) was the most toxic, followed by piperolein-A (1.46 ppm) and piperine (1.53 ppm).

Potential use of Piper nigrum ethanol extract against pyrethroid-resistant Aedes aegypti larvae

Fractionation of Piper nigrum ethanol extract, biomonitored by assays on pyrethroid-resistant Aedes aegypti larvae yielded isolation of the larvicidal amides piperolein-A and piperine. Comparing LC50 values, the ethanol extract (0. 98 ppm) was the most toxic, followed by piperolein-A (1. 46ppm) and piperine (1. 53ppm).

O fracionamento do extrato etanólico de Piper nigrum biomonitorado por ensaios em larvas de Aedes aegypti resistentes a piretróides resultou no isolamento das amidas larvicidas piperoleína-A e piperina. Comparando-se os valores de CL50, o extrato etanólico (0. 98ppm) foi o mais tóxico, seguido pela piperoleína-A (1. 46ppm) e piperina (1. 53ppm).