Toxic Effects of Lemon Peel Constituents on Ceratitis capitata

Abstract

A series of experiments were conducted to evaluate the toxicity of lemon peel extracts incorporated into mediterranean fruit fly Ceratitis capitata diet. Extracts were obtained with different solvents: diethyl ether, ethyl acetate, and methanol. All three extracts were toxic to some extent; the diethyl ether extract was selected for further studies. Ether extracts of lemon peel were prepared weekly over a 2-month period, from fruits collected on the 1st d of the bioassay. Weekly GC-MS and UV analyses of the extracts demonstrated that the concentration of citral and coumarins decreased in the peel after harvest. We conducted a series of bioassays to evaluate the toxicity of the ether extract, and mixtures of this extract with citral, 5,7-dimethoxycoumarin. and linalool incorporated to C. capitata larvae's natural diet (lemon slices endocarp) at a concentration of 250 microg/g of diet. Significant larvicidal activity can be obtained from a fresh lemon peel extract; however, when the extract was obtained from stored lemons, toxicity decreased. Addition of small amounts of citral or 5,7-dimethoxycoumarin, and linalool to the stored lemon peel extract would bring back the toxicity to the rates of fresh lemons extracts. Finally, female adults of C. capitata fed on diets containing additional amounts of ether extract, 5,7-dimethoxycoumarin, and linalool, were exposed to different photoperiods to test for phototoxicity. The treatment was toxic and affected the oviposition capacity of females depending on photoperiod.

Oviposition of fruit flies (Diptera: Tephritidae) and its relation with the pericarp of citrus fruits

“…The flavedo constitution is cited by several authors as the most critical resistance mechanism to fruit flies infestation in citrus (Back and Pemberton, 1915;Greany et al, 1983;Salvatore et al, 2004;Ioannou et al, 2012). Possibly, when oil glands in the flavedo are broken, they release toxic compounds that, in contact with eggs and first instar larvae, can cause death before the larvae reach the albedo region (non-oily region of the peel) (Greany, 1989).…”

“…Oil toxicity in the flavedo region for eggs and larvae of C. capitata can be attributed to the higher content of limonene in oranges . Salvatore et al (2004) evaluated egg viability of C. capitata laid in epicarp of four orange cultivars and found values between 19 and 49% of viability. The same authors found that citral compounds, coumarin and linalool, extracted from lime 'Sicilian' caused mortality of larvae of C. capitata of up to 98%.…”

“…In the citrus culture, while fruit flies are considered major pests and causing economic losses (Muthuthantri and Clarke, 2012), many authors believe that fruit files are not perfectly adapted to development in citrus fruits (Salvatore et al, 2004). For Back and Pemberton (1915), this lower performance could be related to resistance mechanisms of citrus fruits, such as chemical components of glands in the flavedo (epicarp) and albedo (mesocarp) elasticity that could generate mechanical resistance and consequently hinder embryonic and larval development.…”

5,7-Dimethoxycoumarin inhibits neuronal apoptosis by targeting caspase-3 expression in rats with acute cerebral infarction

“…Both natural as well as synthetic coumarins are in clinical trials for the treatment of various types of cancers because of their tendency to induce carcinoma cell apoptosis [14]. 5,7-Dimethoxycoumarin (Figure 1), a derivative of coumarin present in vegetables has shown potent anti-cancer activity through induction of DNA damage and inhibition of carcinoma cell proliferation [15,16]. The chemical structure of 5,7-dimethoxycoumarinindicates that it has potential to act as anti-oxidant agent.…”

Inhibition of Mek 1/2 kinase activity and stimulation of melanogenesis by 5,7-dimethoxycoumarin treatment of melanoma cells

“…Coumarins and their synthetic derivative compounds have been used in clinical trials, alone or in combination with traditional drugs such as etoposide, for the treatment of various malignant tumors, including renal, lung and kidney carcinoma as well malignant melanoma (6). A coumarin derivative, the 5,7-dimethoxycoumarin, has been identified in a small group of vegetable species, among which Citrus limon L. (7) and Carica papaya L. (8). This molecule showed both a differentiating effect on HL-60 cell line (9) and an inhibition activity in DNA adduct formation, induced by carcinogens, in mouse mammary gland (10).…”