Phenolic Antioxidant Capacity: A Review of the State of the Art | InTechOpen, Published on: 2017-03-08. Authors: Rubén San Miguel-Chávez

A profile of endogenous hormones and sugars in leaves and pseudobulbs of Laelia anceps subsp. anceps (Orchidaceae) plants induced and non-induced to flowering by the effect of different doses of exogenous gibberellic acid (GA₃), considering the current and back growth structures (CGS and BGS), were investigated. A factorial experiment with five doses of GA₃ and two growth structures was designed. Adult plants with undifferentiated vegetative buds were selected and sprayed with doses of 0, 400, 600, 800, and 1000 mg GA₃ L⁻¹. The main results showed a strong interaction between GA₃ dose and growth structures, which promoted the highest kinetin (KIN) concentration in CGS. Exogenous GA₃ increased endogenous GA₃ in leaves and pseudobulbs induced (I-Leaf and I-PSB) and non-induced (NI-Leaf and NI-PSB) to flowering. For sugar concentration, the 400 mg L⁻¹ GA₃ dose promotes significant interaction with the CGS in NI-PSB. In general, the hormone profile revealed opposite balances of endogenous hormone concentrations for KIN, zeatin (ZEA), trans-zeatin (T-ZEA), indoleacetic acid (IAA), indole-3-butyric acid (IBA) and GA₃, not only for growth structures but also for vegetative organs analyzed, depending on whether the plants were induced or not induced to flowering, with the highest concentration of endogenous hormones in pseudobulbs. Likewise, different sugar concentration balances were observed. These balances of both endogenous hormones and sugars are likely to be involved in the flowering of L. anceps.

Salvia semiatrata Zucc. (Lamiaceae) is endemic to Oaxaca, Mexico, and is known for its analgesic properties. Terpenoids and phenolic compounds with antinociceptive potential have been characterised from this species. The aim of this research was to determine the variation in terpenoids and flavonoids in ethyl acetate extracts of S. semiatrata collected from ten different localities, as well as to evaluate the antinociceptive effect between plants with higher and lower contents of these secondary metabolites. Quantification of S. semiatrata compounds was performed via HPLC-DAD, whereas in vivo evaluation of the antinociceptive effect was performed via formalin test. The results showed that the most abundant groups of metabolites are oleanolic acid (89.60–59.20 µg/mg), quercetin (34.81–16.28 µg/mg), catechin (11.30–9.30 µg/mg), and 7-keto-neoclerodan-3,13-dien-18,19:15,16-diolide (7-keto) (8.01–4.76 µg/mg). Principal component and canonical correspondence analysis showed that the most contrasting localities in terms of compound content and climatic variables are Miahuatlán and Santiago Huauclilla. The differences in metabolite content between the two locations did not affect the antinociceptive effects evaluated at a dose of 300 mg/kg, p.o. In conclusion, the results indicate that S. semiatrata is effective in relieving pain, regardless of the site of collection, reinforcing its traditional use as analgesic.

Antecedentes: Salvia purpurea Cav., comúnmente conocida como “salvia moradita”, es una planta medicinal usada en Oaxaca, Veracruz y Chiapas por sus propiedades analgésica, antiinflamatoria y antidiarreica. Sin embargo, no existen evidencias científicas que soporten su potencial para el alivio del dolor. Hipótesis: Terpenos y compuestos fenólicos son responsables de la actividad antinociceptiva de extractos de S. purpurea . Especie estudiada: Salvia purpurea Cav. (Lamiaceae). Lugar de estudio y año: Salvia purpurea se colectó en Santiago Huauclilla, Oaxaca, en octubre de 2017. Métodos: La toxicidad aguda (Dosis letal media, DL50) de los extractos de acetona, metanol y acuoso de S. purpurea se determinó mediante el protocolo de la OCDE (2001). Los extractos se administraron vía oral (p.o.) en un rango de dosis de 3 a 300 mg/kg para evaluar el efecto antinociceptivo utilizando las pruebas de estiramiento abdominal y formalina en ratones. El análisis por HPLC se realizó para identificar la naturaleza de los metabolitos presentes en los extractos activos en comparación con sus respectivos estándares. Resultados: La toxicidad aguda de todos los extractos fue calculada como DL50 > 2000 mg/kg, p.o. El efecto antinociceptivo fue significativo en todas las dosis probadas y en forma no dependiente de la dosis para todos los extractos y en ambas pruebas. El análisis fitoquímico permitió identificar a compuestos de naturaleza terpénica y fenólica. Conclusiones: Los resultados del presente estudio refuerzan el uso como analgésico y antiinflamatorio de S. purpurea en la Medicina Tradicional Mexicana, donde terpenos y compuestos fenólicos participan en dichas actividades.

Background: Chiranthodendron pentadactylon, known in Mexico as the “tree of the little hands”, flower’s infusion is used to treat kidney failure associated with diseases such as diabetes. The aim of this work is to evaluate the antioxidant effect of the methanolic extract of its flowers on oxidative damage in kidneys caused by streptozotocin in rats. Methods: The extract phytochemical profile was performed with HPLC. Antioxidant potential in vitro was determined with DPPH and total phenolic tests; antioxidant evaluation in vivo was performed in diabetic rats administered daily via the intragastric route (100 and 200 mg/kg) for 6 weeks; serum glucose/creatinine, food/water consumption, and urinary volume were measured. Relative weight, protein/DNA ratios and oxidative stress were measured in renal tissue. Results: The extract showed 20.53% of total phenolic content and IC₅₀ of 18.05 µg/mL in DPPH, and this was associated with ferulic acid, phloretin and α-amyrin. Both doses showed a moderate decrease in the protein/DNA ratio in renal tissue, and the same behavior was observed for total urinary protein loss and serum creatinine, while the best antioxidant effect was exerted by a lower dose, which increased catalase activity and decreased lipid peroxidation in the kidneys. Conclusions: Results demonstrated that C. pentadactylon methanolic flower’s extract improves renal function through antioxidant mechanisms during experimental diabetes.