Phytochemical Profile and Evaluation of the Allelopathic Effect of the Aqueous Extract of Fimbristylis miliacea (L.) Vahl (Cyperaceae)

Abstract

The allelopathic potential of some plant species has been scientifically proven over the years. The use of such natural compounds with phytotoxic activity is an alternative to synthetic herbicides. Thus, this research aims to analyze the phytochemical profile and the allelopathic effect of aqueous extracts of Fimbristylis miliacea (L.) Vahl. The allelopathic potential was evaluated by germination bioassays using seeds from two receptor species (Lactuca sativa L. and Emilia fosbergii Nicolson) and seven concentrations of aqueous extracts of F. miliacea aerial and underground parts in triplicate. The variables evaluated were germination (G) andJournal of Agricultural Studies 311 germination speed index (GSI). The data obtained were submitted to F test and the averages to regression analysis. In addition, phytochemical analyses were performed to analyze possible allelochemicals present in aqueous extracts of F. miliacea through phytochemical screening and by high performance liquid chromatography (HPLC). The aqueous extracts of aerial and underground parts of F. miliacea inhibit the germination of E. fosbergii seeds at all concentrations analyzed (0.94, 1.87, 3.75, 7.5, 15 and 30%). However, the same extracts do not show any effects when evaluated in L. sativa seeds. The aqueous extract of F. miliacea shows important chemical constituents (gallic acid, chlorogenic acid, rutin, luteolin, apigenin, acacetin, and alkaloids) that can be directly related to the allelopathic effects observed in E. fosbergii seeds.

Phytochemical Screening, Antioxidant and Antifungal Activity of Methanolic Extract of Fimbristylis dichotoma and Fimbristylis miliacea

“…A study by [1] revealed the presence of flavonoids, tannins and phenolic in an aerial of F. miliacea. Findings by [14] also found that flavonoid and tannins were presence in F. miliacea extract but absence of saponins. It's contrary to the findings of [5] where it was found that only saponins was presence in F. dichotoma aerial parts.…”

“…The methanolic extracts of Fimbristylis genus showed the promising effect of antimicrobial against several microorganisms tested [2]. The presence of various metabolites such as saponins and terpenoids have been implicated in various biological activities [14]. The antimicrobial activity of phenolic compounds in F. miliacea has been linked to the suppression of cellular enzymes, which is generally dependent on the rate at which the compounds enter the cell, but it can also be caused by changes in membrane permeability.…”

“…There are about 300 species in the genus Fimbristylis and only a few species used in herbal medicine. Numerous species of Fimbristylis have been reported to have various chemical constituents such as phenolic, flavonoid, flavanol, tannin [1], saponin, cardiac glycosides [5], flavanones, flavones, triterpenoid, alkaloid [14], phenols, quinones, steroids [15], protein and chalcones [16]. Methanol extract of Fimbristylis ovata showed a significant result in the zone of inhibition against Escherichia coli [2].…”

Phytotoxic Effects of Allelochemical Acacetin on Seed Germination and Seedling Growth of Selected Vegetables and Its Potential Physiological Mechanism

“…The aqueous extracts of aerial and underground parts of Fimbristylis miliacea (L.) Vahl. inhibited the germination of Emilia fosbergii Nicolson seeds, and showed important chemical constituents including acacetin that can be directly related to the allelopathic effects observed in E. fosbergii seeds [9].…”

“…Acacetin was found in many plant species and showed strong phytotoxic activities [1][2][3][4][5][7][8][9], indicating that acacetin had potential to be used as a herbicide in weed management. Moreover, the potential allelopathic effects of acacetin released by some invasive weeds such as C. odoratum could be a serious threat to crops [5].…”