Plant Polyphenols and Their Association with Proteins

McManus, John P.; Lilley, Terence H.; Haslam, Edwin

doi:10.1021/bk-1983-0208.ch007

Cited by 15 publications

(8 citation statements)

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“…The egg is a nonfeeding stage and so was not significantly affected by the pyrogallol treatment. Plant phenolics interact with protein through several physical or chemical mechanisms including hydrogen bonding, hydrophobic interaction and covalent bonding (McManus et al 1983;Pierpoint 1983). The covalent interactions between oxidized phenolics (i.e., quinones) and dietary proteins are deleterious to insects Felton et al 1989).…”

Section: Resultsmentioning

confidence: 99%

Bioactivity of pyrogallol against melon fruit fly, Bactrocera cucurbitae

Sohal

Sharma

2011

Phytoparasitica

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The insecticidal effects of pyrogallol were studied by treating eggs and larvae of the melon fruit fly, Bactrocera cucurbitae (Coquillett) (Tephritidae: Diptera), with various concentrations (1, 5, 25, 125, 625 and 3125 ppm) of the phenolic compound. Although egg hatching decreased following treatment of 0-8-h old eggs with pyrogallol, the decrease was not significantly different from the control. Larval period and total development period declined significantly in 64-72-h-old and 88-96-h-old B. cucurbitae larvae fed on pyrogallol-treated diet. However, in the 44-48-h-old larvae, the larval period and total development period were not affected by pyrogallol treatment at any of the tested concentrations. None of them survived up to the pupal stage at the highest concentration. Number of pupae formed and adult emergence decreased significantly in all larval instars following feeding on pyrogallol-treated diet. The analysis of enzymes in 64-72-h-old larvae treated with LC 40 concentration (16.21 ppm) of pyrogallol at three time intervals, i.e., 24 h, 48 h and 72 h, showed significant induction in the activities of ascorbate peroxidase (APOX) and glutathione S-transferases (GSTs) at 24 h but a decrease was observed following prolonged treatment. On the other hand, superoxide dismutase (SOD) and peroxidases (POX) activity remained suppressed during the initial treatment interval but increased with prolonged treatment in 136-144-h-old larvae. The catalase (CAT) activity was suppressed at all treatment durations whereas glutathione reductase (GR) activity was not affected by pyrogallol treatment. An increase in the activities of ascorbate peroxidase, superoxide dismutase, peroxidases and glutathione S-transferases indicates an induction of defensive response of the melon fruit fly to the toxic effects produced by ingestion of pyrogallol. Although the effects of the compound on enzyme activity were tested on second instar, it would be interesting to see the effects on other instars too.

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Section: Resultsmentioning

confidence: 99%

Bioactivity of pyrogallol against melon fruit fly, Bactrocera cucurbitae

Sohal

Sharma

2011

Phytoparasitica

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“…Tannins are known to be protein precipitants (Van Sumere et al, 1975;Hagerman and Butler, 1981;McManus et al, 1983), and it has been proposed that they might interfere with protein digestion in an herbivore's gut by binding proteolytic enzymes or ingested proteins (Feeny, 1976;Rhoades and Cates, 1976). Since the growth of many herbivores is nitrogen limited (Mattson, 1980), any interference with protein digestion could have a severe negative impact on fitness.…”

Section: Introductionmentioning

confidence: 99%

Failure of tannic acid to inhibit digestion or reduce digestibility of plant protein in gut fluids of insect herbivores

1987

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The rate of hydrolysis of the abundant foliar protein, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPC), in enzymatically active gut fluid ofManduca sexta larvae is very rapid and is unaffected by the presence of tannic acid, even when tannic acid is present in the incubation mixture in amounts in excess of the amount of RuBPC. When this protein is dissolved in the denatured gut fluids ofM. sexta larvae orSchistocerca gregaria nymphs, large amounts of tannic acid must be added to bring about the precipitation of significant quantities of protein. The ability of insect gut fluid to prevent the formation of insoluble tannin-protein complexes is due to the presence of surfactants. On the basis of our results and a review of the findings of other investigators, we argue that there is no evidence that tannins reduce the nutritional value of an insect's food by inhibiting digestive enzymes or by reducing the digestibility of ingested proteins and, further, that the failure of tannins to interfere with digestion is readily explained on the basis of well-documented characteristics of the digestive systems of herbivorous insects. In challenging the currently popular notion that tannins are digestibility-reducing substances, we do not challenge the general utility of either the apparency theory or resource availability theory of plant defense. In debating the merits of these two analyses of plant-herbivore interactions, however, the demise of tannins as all-purpose, dose-dependent, digestibility-reducing defensive substances must be taken into account.

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“…The ingestion of tannins has been shown to interfere with normal growth and development in many foliage-feeding insects, although tannin-tolerant species are also well known (Bernays, 1981). Since tannins are known to be protein precip-itants (van Sumere et al, 1975;Hagerman and Butler, 1981;McManus et al, 1983), it has been proposed that they might reduce the nutritive value of plant tissues by forming indigestible complexes with foliar proteins or by precipitating and inactivating digestive enzymes in the digestive tract of an herbivore (Feeny, 1976;Rhoades and Cates, 1976). While it is well-documented that tannins can act as feeding deterrents and toxins to some insect herbivores, the idea that they are digestibility-reducing substances is currently being challenged (Bernays, 1981;Martin and Martin, 1984).…”

Section: Introductionmentioning

confidence: 99%

Effects of surfactants, pH, and certain cations on precipitation of proteins by tannins

1985

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Tannic acid and pin oak tannins precipitate large amounts of the abundant leaf protein, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPC), over a wide pH range (6.15-9.30) in the presence of sodium, potassium, magnesium, and calcium ions at concentrations comparable to those reported in the gut fluids of lepidopteran herbivores. The presence of lysolecithin, a surfactant known to be present in the gut fluids of some insects, significantly reduces the amount of RuBPC precipitated under these conditions. We conclude that high detergency is far more effective than high alkalinity in countering the potential protein-precipitating properties of tannins. We further conclude that tannins do not deserve the status they were once accorded as general, all-purpose, dose-dependent, antidigestive defensive chemicals. We also describe the application of the Schaffner-Weissman protein assay for studying the protein-precipitating capacity of plant extracts. This method is far superior to the one we have used in our earlier studies.

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Plant Polyphenols and Their Association with Proteins

Cited by 15 publications

References 0 publications

Bioactivity of pyrogallol against melon fruit fly, Bactrocera cucurbitae

Bioactivity of pyrogallol against melon fruit fly, Bactrocera cucurbitae

Failure of tannic acid to inhibit digestion or reduce digestibility of plant protein in gut fluids of insect herbivores

Effects of surfactants, pH, and certain cations on precipitation of proteins by tannins

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