Cecropia pachystachya Trécul: a promising ingredient for skin-whitening cosmetics

Abstract Because it promotes the lightening of pigment spots, tyrosinase inhibition is one of the mechanisms of depigmenting cosmetic products. Considering the adverse effects produced by synthetic depigmenting actives, the search for new therapeutic options is desirable, and plant extracts are possible candidates for hyperpigmentation treatment. Glycolic extracts of Cecropia pachystachya Trécul are, therefore, the focus of this study. Its chemical characterization, antioxidant activity, tyrosinase inhibition, and cell viability were evaluated. Glycolic extracts were obtained by macerating the leaves of C. pachystachya in grain alcohol and glycerin or propylene glycol. Both had a similar chemical constitution, the glycerin being more efficient in concentrating phenolic compounds and flavonoids. Analyses by UHPLC-MS detected quinic acid, chlorogenic acid isomers, proanthocyanidin dimers type B and C, catechin/epicatechin, orientin/isoorientin, isoorientin 2"-O-xyloside, vitexin/isovitexin, and rutin. 5-O-caffeoylquinic acid was then quantified was then quantified, with predominance in the extract produced with propylene glycol. These extracts showed a high antioxidant capacity by the method of DPPH, ß-carotene, and nitric oxide. As for depigmenting activity, both extracts were able to inhibit tyrosinase. Cell viability assay also revealed that the extracts could safely be used in concentrations of ≤ 125 µg/mL. Thus, this study demonstrated for the first time that the glycolic extracts of C. pachystachya have promising chemical and biological characteristics for the development of a multifunctional cosmetic with antioxidant and tyrosinase-inhibition activities

Adjusting RT-qPCR conditions to avoid unspecific amplification in SARS-CoV-2 diagnosis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 2019 and quickly spread around the world, forcing global health authorities to develop protocols for its diagnosis. Here we report dimer formation in the N2 primers-probe set (CDC 2019-nCoV Real-Time RT-PCR) used in the diagnostic routine, and propose alternatives to reduce dimerization events. Late unspecific amplifications were visualized in 56.4% of negative samples and 57.1% of no-template control, but not in positive samples or positive control. In silico analysis and gel electrophoresis confirmed the dimer formation. The RT-qPCR parameters were optimized and the late unspecific amplifications decreased to 11.5% in negative samples and no-template control. The adjustment of PCR parameters was essential to reduce the risk of false-positives results and to avoid inclusive results requiring repeat testing, which increases the costs and generates delays in results or even unnecessary requests for new samples.

Preclinical studies indicate that INFLATIV, an herbal medicine cream containing Pereskia aculeata, presents potential to be marketed as a topical anti-inflammatory agent and as adjuvant in psoriasis therapy.

OBJECTIVES: A previous study reported that the hexane fraction (HF) obtained from Pereskia aculeata leaves showed promising topical anti-inflammatory activity. Intending its future use in clinical practice, a herbal medicine cream named INFLATIV was developed. Its anti-inflammatory and antipsoriatic potential were investigated. INFLATIV was subjected to preliminary accelerated stability tests and to a degradation profile assessment. METHODS: INFLATIV was prepared at 6% and 12%. The anti-inflammatory activity was assessed by croton oil single and multiple application challenge in mice. Mouse tail test was used for antipsoriatic potential investigation. Cutaneous atrophy test was performed. Preliminary accelerated stability tests were performed together with a degradation profile by GC-MS analysis. KEY FINDINGS: The anti-inflammatory activity shown by INFLATIV was comparable to dexamethasone. However, the skin atrophy caused by that drug was not observed. INFLATIV modified skin parakeratotic differentiation into orthokeratosis, which revealed its antipsoriatic potential. The ingredients used were suitable to carry the bioactives as they were well permeated by the skin. The preliminary accelerated stability tests indicated that INFLATIV 6% is more stable than 12%. CONCLUSIONS: The results demonstrated the relevant therapeutic and marketing potentials of INFLATIV, which is likely to be further evaluated in clinical trials for drug registration process with regulatory agencies.

Effects of dimethylsulfoxide and pentoxifylline in the vitality of cutaneous flaps in rats.

OBJECTIVES: to verify the influence of dimethylsulfoxide and pentoxifylline on the vitality of cutaneous flaps in rats and the tissue repair process. METHODS: were studied 30 Wistar rats, submitting them to a 2cm wide by 8cm long dorsal cutaneous flap, of caudal base. We distributed the animals in three groups: Control Group (n=10) with application gauze moistened with 0.9% Saline in the flap bed for 30 seconds; Dimethylsulfoxide group (n=10), with administration of 1ml of 5% dimethylsulfoxide divided into five injections of 0.2ml in the transition of the flap segments; Pentoxifylline group (n=10), with administration of pentoxifylline 20mg/kg, diluted to 1ml and divided into five injections of 0.2ml in the transition of the flap segments. Drugs were administered intraoperatively, in a single dose and subcutaneously. We observed the skin flaps for changes in color and texture. On the 10th postoperative day, we checked the dimensions of viable and necrotic tissues, followed by excision of the specimen for histological analysis. RESULTS: the measurements of length of the viable and necrotic tissues between groups showed no differences. Histological analysis showed that the Dimethylsulfoxide group presented neovascularization, inflammatory infiltrate with leukocytes and more structured conjunctival stroma. The Pentoxifylline group showed neovascularization and inflammatory infiltrate, with moderate to intense granulation. The control group evolved with a higher rate of necrosis in the distal segment. CONCLUSION: dimethylsulfoxide and pentoxifylline influenced the vitality of the flap and the tissue repair process. However, they did not prevent necrosis macroscopically.

Effects of dimethylsulfoxide and pentoxifylline in the vitality of cutaneous flaps in rats / Efeitos do dimetilsulfóxido e da pentoxifilina na vitalidade de retalhos cutâneos em ratos

ABSTRACT Objectives: to verify the influence of dimethylsulfoxide and pentoxifylline on the vitality of cutaneous flaps in rats and the tissue repair process. Methods: were studied 30 Wistar rats, submitting them to a 2cm wide by 8cm long dorsal cutaneous flap, of caudal base. We distributed the animals in three groups: Control Group (n=10) with application gauze moistened with 0.9% Saline in the flap bed for 30 seconds; Dimethylsulfoxide group (n=10), with administration of 1ml of 5% dimethylsulfoxide divided into five injections of 0.2ml in the transition of the flap segments; Pentoxifylline group (n=10), with administration of pentoxifylline 20mg/kg, diluted to 1ml and divided into five injections of 0.2ml in the transition of the flap segments. Drugs were administered intraoperatively, in a single dose and subcutaneously. We observed the skin flaps for changes in color and texture. On the 10th postoperative day, we checked the dimensions of viable and necrotic tissues, followed by excision of the specimen for histological analysis. Results: the measurements of length of the viable and necrotic tissues between groups showed no differences. Histological analysis showed that the Dimethylsulfoxide group presented neovascularization, inflammatory infiltrate with leukocytes and more structured conjunctival stroma. The Pentoxifylline group showed neovascularization and inflammatory infiltrate, with moderate to intense granulation. The control group evolved with a higher rate of necrosis in the distal segment. Conclusion: dimethylsulfoxide and pentoxifylline influenced the vitality of the flap and the tissue repair process. However, they did not prevent necrosis macroscopically.

RESUMO Objetivos: verificar a influência do dimetilsulfóxido e da pentoxifilina na vitalidade e no processo de reparo tecidual de retalhos cutâneos em ratos. Método: foram estudados 30 ratos Wistar, nos quais foi confeccionado retalho cutâneo dorsal de 2cm de largura por 8cm de comprimento, de base caudal, e distribuídos em três grupos: Grupo Controle (n=10) com aplicação de gaze umedecida com solução salina a 0,9%, no leito do retalho, por 30 segundos; Grupo dimetilsulfóxido (n=10) com injeção de 1ml de dimetilsulfóxido a 5% divididos em cinco injeções de 0,2ml na transição dos segmentos do retalho; Grupo pentoxifilina (n=10) com injeção de 1ml pentoxifilina 20mg/kg, divididos em cinco injeções de 0,2ml na transição dos segmentos do retalho. Os fármacos foram administrados no transoperatório, em dose única e por via subcutânea. Os retalhos cutâneos foram observados quanto às alterações de cor e textura. No décimo dia de pós-operatório aferiu-se a dimensão do tecido viável e de necrose, seguido da exérese da peça para análise histológica. Resultados: a medida da dimensão de tecido viável e de necrose dos grupos não apresentou diferenças. A análise histológica mostrou que o grupo dimetilsulfóxido apresentou neovascularização, infiltrado inflamatório com leucócitos e estroma conjuntivo mais estruturado. O grupo pentoxifilina, mostrou neovascularização e infiltrado inflamatório com granulação moderada e intensa. O grupo controle evoluiu com maior índice de necrose no segmento distal. Conclusão: dimetilsulfóxido e pentoxifilina influenciaram na vitalidade do retalho e no processo de reparo tecidual. Entretanto, não evitaram a necrose macroscopicamente.

In vivo wound healing activity of gels containing Cecropia pachystachya leaves.

OBJECTIVES: To evaluate the in-vivo wound healing and in-vitro antioxidant activity of gels containing the ethyl acetate extract of Cecropia pachystachya (ECP) 2% and 5%, and to perform the chemical fingerprint of ECP by HPLC-DAD. METHODS: The wound healing activity of the gels was evaluated for 21 days, using the excision model in rats followed by histopathological and histomorphometric analysis. The in-vitro antioxidant effect of ECP was investigated using 1-diphenyl-2-picrylhydrazyl, reducing power, ß-carotene bleaching and thiobarbituric acid reactive substances assays. Also, a HPLC analysis was performed to identify the chemical markers orientin, iso-orientin and chlorogenic acid. KEY FINDINGS: The group of animals treated with ECP 5% presented oedema and inflammatory infiltrate with less intensity than the other groups. Both ECP 2% and 5% gels showed less neovascularization and cellularity, and better tissue repair when compared to the control, which showed a younger and homogeneous tissue. CONCLUSIONS: This study had demonstrated that the ECP gels promoted the acceleration of the healing process when compared to the control group. Wound contraction, angiogenesis, epithelialization and the collagen deposition support further evaluation of C. pachystachya leaves in the topical treatment and management of skin wounds.

Pereskia aculeata: A plant food with antinociceptive activity.

CONTEXT: Pereskia aculeata Miller (Cactaceae) is a cactus distributed from south to northeast of Brazil, where its leaves are commonly used as a vegetable, in skin wound healing, and to treat inflammation. OBJECTIVES: The objective of this study was to perform the chemical characterization and to evaluate the antinociceptive activity of the hydromethanolic fraction obtained from the methanol extract of P. aculeata leaves. MATERIALS AND METHODS: Chemical characterization was performed by UPLC-MS analysis. The antinociceptive activity was evaluated by the acetic acid-induced writhing, formalin, and tail-flick tests in mice, administering the single oral doses of 100, 200, and 300 mg/kg 1 h before each test. RESULTS: Tryptamine, abrine, mescaline, hordenine, petunidin, di-tert-butylphenol isomers, and quercetin were identified. The antinociceptive activity was inversely proportional to the administered doses in the acetic acid test, as the dose of 100 mg/kg reduced by 78% the number of writhings, while the doses of 200 and 300 mg/kg reduced by 64% and 41%, respectively. In the formalin test, the dose of 300 mg/kg inhibited by 50% and 86% the licking paw time in the first and second phases, respectively, while the doses of 200 mg/kg (45% and 62%, respectively) and 100 mg/kg (15% and 48%, respectively) were less effective. The sample did not respond to the tail-flick test. Those results suggested a peripheral and central antinociception devoid of an opioid effect. CONCLUSION: Pereskia aculeata not only is a plant food with high nutritional value but also presents analgesic potential. It is the first time that this bioactivity is reported for this species.

Antimicrobial activity of recombinant Pg-AMP1, a glycine-rich peptide from guava seeds.

Antimicrobial peptides (AMPs) are compounds that act in a wide range of physiological defensive mechanisms developed to counteract bacteria, fungi, parasites and viruses. These molecules have become increasingly important as a consequence of remarkable microorganism resistance to common antibiotics. This report shows Escherichia coli expressing the recombinant antimicrobial peptide Pg-AMP1 previously isolated from Psidium guajava seeds. The deduced Pg-AMP1 open reading frame consists in a 168 bp long plus methionine also containing a His6 tag, encoding a predicted 62 amino acid residue peptide with related molecular mass calculated to be 6.98 kDa as a monomer and 13.96 kDa at the dimer form. The recombinant Pg-AMP1 peptide showed inhibitory activity against multiple Gram-negative (E. coli, Klebsiella pneumonia and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Staphylococcus epidermides) bacteria. Moreover, theoretical structure analyses were performed in order to understand the functional differences between natural and recombinant Pg-AMP1 forms. Data here reported suggest that Pg-AMP1 is a promising peptide to be used as a biotechnological tool for control of human infectious diseases.