Antioxidant and anti-inflammatory effects of fractions from ripe fruits of Solanum lycocarpum St. Hil. (Solanaceae) and putative identification of bioactive compounds by GC-MS and LC-DAD-MS

Brazilian biodiversity includes species of the genus Solanum that have several biological activities, in addition to their relevance to agriculture, economics and popular medicine. The ripe fruits of Solanum lycocapum are an important nutritional food source, since they have levels of vitamin C, total soluble sugars, sucrose, phosphorus, and iron comparable or exceed the levels present in fruits such as pineapples, bananas, oranges, and mangoes. The pulp of the fruit is consumed by the population, and it is also used to produce jellies; to make marmalade, replacing the quince, and it can also be mixed with peaches in the preparation of peach. The objective of this study was to evaluate the anti-inflammatory and antioxidant activities of fractions obtained from the ripe fruits and to identify the constituents with these biological properties. The ripe fruits were collected, dried, crushed, and subjected to extraction by exhaustive percolation, obtaining an ethanol extract that was partitioned with solvents of increasing polarities, obtaining hexane (HEX), ethyl acetate (AC), and hydroethanol (HE) fractions. The AC fraction showed higher antioxidant potential compared to BHT (2,6-di-tert-butyl-4-methylphenol) and similar activity to AA (ascorbic acid) by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical assay, while HEX and HE fractions exhibited of IC50 values similar to BHT. The AC fraction also presented similar activity to BHT by FRAP (Ferric Reducing Antioxidant Power) test. Intraperitoneal treatment with HEX (100 and 300 mg/kg) and HE (100 mg/kg) fractions caused significant inhibition of paw edema induced by carrageenan, 4 and 6 h after the inflammatory stimuli. When analyzed by GC-MS, fatty acids, phytosterols, and triterpenoid were identified in the HEX fraction, whilst 31 compounds were annotated in the AC and HE fractions analyzed by LC-DAD-MS, being phenylpropanoid derivatives, chlorogenic acids, and steroidal glycoalkaloids. The ripe fruits of S. lycocarpum have antioxidant and anti-inflammatory activities, and the detected chemical compounds, especially caffeoylquinic acid derivatives, spermidine, stigmasterol, and beta-sitosterol, may be correlated with these activities. The ripe fruits of this species can be a food alternative rich in bioactive compounds and with benefits for human health.