Phytochemical study of Muehlenbeckia platyclada (F. Muell) leaves

Medicinal plants have active substances with therapeutic potential that have been used in the treatment of various diseases in humans since the most primitive populations. The use of those plants establishes a direct relationship with the theme of planetary health as it allows to relate the health of the planet's natural systems and the health of human civilization. The plant species Muehlenbeckia platyclada, belonging to the Polygonaceae family, is important in traditional medicine, presenting antinociceptive and analgesic activities proven in several studies. The general objective of the current study is to understand the chemical and phytochemical characteristics of M. platyclada. From the leaves, the humidity and total ash contents were quantified as well as phytochemical prospecting was carried out. An aqueous extract and four ethanolic extracts of different concentrations were prepared from the leaves of the plant drug. Total phenol and flavonoid levels were quantified and the presence of antioxidant activity was verified. As a result: The sum of total ash and humidity content produced a value of 96.39%. It was possible to observe that the reactions for tannins, flavonoids, coumarins, terpenoids/steroids, and saponins were positive while anthraquinones and alkaloids were negative. The average phenol contents ranged from 1.83 to 8.53mg/100g (of organic plant material), concerning the extracting solvents (p < 0.05). The extracting liquid that provided the highest yield of phenols and flavonoids was 50% ethanol, using the hot and cold extraction method. Regarding antioxidant activity, the effective concentration (EC50) for rutin (positive control) was 5.50mg/mL and ranged from 14.30±0.10 to 65.66±7.79 mg/mL, being identified the aqueous extract as the one with the greatest activity. Phytochemical prospecting and investigation into antioxidant activity allow the classification of the studied plant as a potential anti-inflammatory and antitumor agent.