Fig 5
Light-absorbing metabolites of chlorophyll are present in adipose tissue. (A) HPLC chromatogram of an adipose extract. 2.5 grams of abdominal adipose tissue from a rat fed a chlorophyllrich diet was extracted with acetone and the acetone concentrate subjected to HPLC. In the chromatogram, only compounds that displayed 675-nm fluorescence, characteristic of chlorophyll and its metabolites possessing a chlorin ring, are shown. Five major peaks are observed along with several minor peaks. For peaks with letters, the corresponding absorption spectra are shown below. (B-D) Absorption spectra of labeled peaks in A (b-d, respectively). Numbers above peaks are peak maxima in nm. Numbers in the center are the ratios of the Soret band, around 400 nm, to the Q y band at around 655 nm. All spectra are consistent with those of metabolites of chlorophyll. Spectrum C has been assigned to a metalated porphyrin.
Source publication
Sunlight is the most abundant energy source on this planet. However, the ability to convert sunlight into biological energy as adenosine-5'-triphosphate (ATP) is thought to be limited to chloroplasts in photosynthetic organisms. Here we show that mammalian mitochondria can also capture light and synthesize ATP when mixed with a light-capturing meta...
Contexts in source publication
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... and plasma extracts from rats fed chlorophyll-rich diets were further analyzed by HPLC to elucidate the source of the red 675-nm fluorescence. Fig. 5A shows a representative chromatogram with compounds in the eluting solvent that displayed 675-nm fluorescence when excited with 410-nm light. Rat fat extracts and plasma extracts both contained similar chlorophyll-derived metabolites (similar chromatograms not illustrated). Two groups of compounds eluting at 23- 30 minutes and 40-46 ...
Context 2
... had similar retention times to those of the chlorophyll metabolites without the phytyl tail, with at least one carboxylate group, such as P-a. The absorption spectra (the locations of the absorbance maxima and the Soret-to- Q y -band ratios) of this group of compounds were consistent with demetalated chlorophylls (Rabinowitch, 1944), as shown in Fig. 5B. In addition, the spectra of this group of peaks were indicative of coordination to a metal ion. A representative spectrum of such a presumably metalated metabolite is shown in Fig. 5C, showing a red shifted Soret band, a blue shifted Q y -band and a Soret-to-Q y -band ratio of ,1. The compounds eluting between 40 and 46 minutes had ...
Context 3
... the absorbance maxima and the Soret-to- Q y -band ratios) of this group of compounds were consistent with demetalated chlorophylls (Rabinowitch, 1944), as shown in Fig. 5B. In addition, the spectra of this group of peaks were indicative of coordination to a metal ion. A representative spectrum of such a presumably metalated metabolite is shown in Fig. 5C, showing a red shifted Soret band, a blue shifted Q y -band and a Soret-to-Q y -band ratio of ,1. The compounds eluting between 40 and 46 minutes had similar retention times to that of the demetalated chlorophyll-a standard (pheophytin-a). In addition, these compounds partitioned with hexanes (polarity index50.1) when mixed with ...
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... 2000;Fernandes et al., 2007;Scheie and Flaoyen, 2003). The acidic environment of the stomach is thought to bring about loss of magnesium from the chlorophyll (Ferruzzi and Blakeslee, 2007;Ma and Dolphin, 1999). Our absorbance data from extracted pigments from rat fat is consistent with the presence of chlorophyll metabolites bonded to a metal (Fig. 5). If true, the presence of a metal derivative in fat tissue suggests that the pigment was actively re-metalated to take part in coordination chemistry. The identification of several metabolites in the fat and plasma of rats and swine fed a chlorophyll-rich diet that are similar to ones found in plants is significant. However, the ...
Citations
... The coloration of leaves is primarily governed by the composition and distribution of pigments such as chlorophyll (Chl), carotenoids, and anthocyanins. Among these, chlorophyll is particularly critical as it captures light energy for photosynthesis, giving leaves their characteristic green hue [8][9][10]. In variegated leaves, the white or albino sectors are often marked by a significant reduction or complete absence of chlorophyll, accompanied by disrupted chloroplast development, leading to altered photosynthetic efficiency [2,11]. ...
Background
The ‘Gonggan’ mandarin, an elite local cultivar from Zhaoqing City, Guangdong Province, combines the qualities of mandarin and sweet orange. A leaf-variegated mutant enhances its ornamental and economic value, providing an excellent model for studying chloroplast development and photosynthetic pigment metabolism in citrus.
Results
We found that, in this variegated mutant, chloroplasts are severely deficient or absent in mesophyll cells. Physiological assessments revealed lower levels of chlorophyll, carotenoids, net photosynthetic rate (Pn), and stomatal conductance (Gs), alongside significantly higher non-photochemical quenching (NPQ) and the non-photochemical quenching coefficient (qN), reflecting increased photoprotective energy dissipation. To uncover the molecular basis of leaf variegation, high-quality genome assemblies and transcriptomes were generated for both the normal and variegated ‘Gonggan’ mandarin, enabling comparative multi-omics analysis. Key genes involved in chloroplast development, such as TOC159, PDV2, THA8, and SIG5, were downregulated in the variegated leaves. Similarly, structural genes linked to chlorophyll degradation, including CLH2, SGR, NOL, and NYC1, exhibited altered expression. Downregulation of transcription factors GLK, GNC, and GNC-LIKE (GNL), known regulators of chloroplast development and chlorophyll biosynthesis, was also observed.
Conclusions
These findings suggest that disrupted expression of critical genes impacts chloroplast development and pigment metabolism, causing the leaf variegation phenotype. Overall, this study lays a foundation for functional genomics research and potential germplasm improvement of ‘Gonggan’ mandarin, and provides new insights into the mechanisms driving color variation in citrus.
... In support of this, when pyropheophorbide A (ppA), a chlorophyll metabolite, was combined with intact mouse mitochondria and the mixture was exposed to red light, ATP yield increased [3]. When similar experiments were performed in C. elegans, both ATP synthesis and life span increased [7]. ...
... Our results employing pheoA are relevant because it is the likely metabolite formed in vivo after eating green plants and therefore has health implications ( Figure 5 and Table 3) [29,30]. Multiple studies in vivo support a role for the combination of red light and chlorophyll in biochemical pathways like the mitochondrial ETC [3,6,7]. While tertiary amines are not physiological electron donors, understanding the photochemical reactions of chlorophyll metabolites is valuable. ...
The photoreduction of plastoquinone, a para-benzoquinone, by chlorophyll initiates photosynthesis in chloroplasts. The direct photoreduction of biologically relevant quinones by dietary chlorophyll metabolites has been reported and may influence health outcomes. We examined red light-mediated photoreduction of ortho- and para-naphthoquinones including vitamin K3 using the photosensitizers methylene blue and pheophorbide A, a chlorophyll metabolite. Naphthoquinone reduction was monitored by UV/Visible spectroscopy and required a photosensitizer, red light and a tertiary amine electron donor. Combinations of methylene blue and ethylenediaminetetraacetic acid or pheophorbide A and triethanolamine in 20% dimethylformamide were employed for all photoreduction experiments. Hydrogen peroxide was generated during the photochemical reactions by singlet oxygen-dependent oxidation of the reduced naphthoquinones. Hydrogen peroxide was quantified with horseradish peroxidase following irradiation; the reduced naphthoquinones acted as peroxidase co-substrates. Histidine, a singlet oxygen scavenger, enhanced the rate of photoreduction by limiting the re-oxidation process. Catalase slowed the rate of photoreduction by regenerating molecular oxygen from hydrogen peroxide so that it could be photoexcited to singlet oxygen. The rates and extent of naphthoquinone photoreduction were dependent on molecular oxygen exposure in different reaction formats including in a cuvette and a plate well. Reduction of the tetrazolium salt MTT to the formazan via electron transfer from the photoreduced quinones was also used to quantitate the extent of photoreduction.
... Other approaches involve engineering the endosymbiosis of bacterial and eukaryotic cells, as well as turning eukaryotic mitochondria into photosynthesizing organelles 73 . A notable approach involved engineering the endosymbiosis of mammalian cells and photosynthesizing Synechococcus elongatus PC7942 cyanobacteria 74 . ...
In mammalian cells, signalling pathways orchestrate cellular growth, differentiation and survival, as well as many other processes that are essential for the proper functioning of cells. Here we describe cutting-edge genetic-engineering technologies for the rewiring of signalling networks in mammalian cells. Specifically, we describe the recombination of native pathway components, cross-kingdom pathway transplantation, and the development of de novo signalling within cells and organelles. We also discuss how, by designing signalling pathways, mammalian cells can acquire new properties, such as the capacity for photosynthesis, the ability to detect cancer and senescent cell markers or to synthesize hormones or metabolites in response to chemical or physical stimuli. We also review the applications of mammalian cells in biocomputing. Technologies for engineering signalling pathways in mammalian cells are advancing basic cellular biology, biomedical research and drug discovery.
... Recent research suggests that by consuming green plants, the sun's energy may be used to perform chemical reactions that ultimately influence health, longevity, and even our susceptibility to diseases of aging [2][3][4]. Qu et al. showed that the combination of chlorophyll derivatives and red light reduced ubiquinone (also called Coenzyme Q) to ubiquinol in vitro [2]. Ubiquinone, a membrane-bound para-quinone nearly identical to plastoquinone, is an essential component of the electron transport chain (ETC) in mitochondria used to produce ATP, and it also functions as a lipid-soluble antioxidant [5,6]. ...
... In the absence of ppA or red light, no increase in ATP yield was observed. Furthermore, when C. elegans samples were fed ppA and exposed to red light, both ATP synthesis and life span increased [3]. ...
... While tertiary amines are not relevant electron donors in vivo, the range of photochemical reactions by chlorophyll metabolites beyond the confines of intact chloroplasts has not been explored in any detail. Even if electron donors are limited in vivo, a single photoreduction event by a chlorophyll metabolite may be sufficient to increase catechol antioxidant capacity or favor CoQ 0 hydroquinone, thereby increasing ATP yield [3]. ...
Photosynthesis is initiated when the sun’s light induces electron transfer from chlorophyll to plastoquinone, a para-quinone. While photosynthesis occurs in the intact chloroplasts of living plants, similar photochemical reactions between dietary chlorophyll metabolites and quinones are likely and may affect health outcomes. Herein, we continue our studies of the direct photoreduction of para-quinones and ortho-quinones that were generated by the photo-oxidation of catechols. Chlorophyll metabolites, including pheophorbide A, chlorin e6, and pyropheophorbide A, as well as methylene blue were employed as photosensitizers. We detected hydrogen peroxide using horseradish peroxidase following the photo-oxidation of the catechol dopamine, even in the presence of EDTA, a tertiary amine electron donor. Under ambient oxygen, hydrogen peroxide was also detected after the photoreduction of several para-quinones, including 2,3-dimethoxy-5-methyl-p-benzoquinone (CoQ0), methoxy-benzoquinone, and methyl-benzoquinone. The combinations of methylene blue and EDTA or pheophorbide A and triethanolamine as the electron donor in 20% dimethylformamide were optimized for photoreduction of the para-quinones. Chlorin e6 and pyropheophorbide A were less effective for the photoreduction of CoQ0 but were equivalent to pheophorbide A for generating hydrogen peroxide in photo-oxidation reactions with photosensitizers, oxygen, and triethanolamine. We employed dinitrophenylhydrazine to generate intensely colored adducts of methoxy-benzoquinone, methyl-benzoquinone, and 1,4-benzoquinone.
... This effect became widely known as Low-Level Laser Therapy (LLLT) or Photobiomodulation (PBM). Recently developed LLLT and PBM, which are performed using red NIR wavelengths, are known to have effects such as wound healing [9,13,14], pain relief [15], inflammation reduction [16,17], animal life extension [18], vision improvement [19], cognitive ability improvement [20], and hair loss improvement [21]. Light-emitting diodes (LEDs) are suitable for laser therapy because they emit low levels of power that do not irritate or burn the skin. ...
The study aimed to explore the impact of a novel near-infrared LED (nNIR) with an extended spectrum on skin enhancement and hair growth. Various LED sources, including White and nNIRs, were compared across multiple parameters: cytotoxicity, adenosine triphosphate (ATP) synthesis, reactive oxygen species (ROS) reduction, skin thickness, collagen synthesis, collagenase expression, and hair follicle growth. Experiments were conducted on human skin cells and animal models. Cytotoxicity, ATP synthesis, and ROS reduction were evaluated in human skin cells exposed to nNIRs and Whites. LED irradiation effects were also studied on a UV-induced photoaging mouse model, analyzing skin thickness, collagen synthesis, and collagenase expression. Hair growth promotion was examined as well. Results revealed both White and nNIR were non-cytotoxic to human skin cells. nNIR enhanced ATP and collagen synthesis while reducing ROS levels, outperforming the commonly used 2chip LEDs. In the UV-induced photoaging mouse model, nNIR irradiation led to reduced skin thickness, increased collagen synthesis, and lowered collagenase expression. Additionally, nNIR irradiation stimulated hair growth, augmented skin thickness, and increased hair follicle count. In conclusion, the study highlighted positive effects of White and nNIR irradiation on skin and hair growth. However, nNIR exhibited superior outcomes compared to White. Its advancements in ATP content, collagen synthesis, collagenase inhibition, and hair growth promotion imply increased ATP synthesis activity. These findings underscore nNIR therapy’s potential as an innovative and effective approach for enhancing skin and promoting hair growth.
... Chlorophylls and their derivatives have been extensively studied for their beneficial biological properties [11]. Chlorophylls have beneficial effects on inflammation, oxidation mechanisms, wound healing, and the production of calcium oxalate crystals, among other things [12]. In in vitro and in vivo studies, chlorophyll and its natural and industrial derivatives have shown antioxidant functions, antimutagenic activity, the regulation of xenobiotic metabolizing enzymes, and the activation of apoptotic events in cancer cell lines [13]. ...
... B, which resulted from the water contents [5,11]. It has been shown that heavy metal accumulation is responsible for a decreased water content in plants and displays a negative effect on the total chlorophyll concentration [12]. However, this was not observed in our study. ...
Modern urban societies generate tremendous amounts of hazardous wastes, including toxic organics and metals. Toxic metals harm plants and pose a risk to human health; examples of them are copper (Cu), zinc (Zn), palladium (Pb), and cadmium (Cd). Wetland plants are excellent for the ecological restoration of toxic metal-affected environments. Phragmites australis (common reed) belongs to the family Poaceae and is a broadly distributed wetland grass that is native to Bahrain, Europe, and America. P. australis shows a high content of chlorophyll. This study aimed to assess percentages of water, chlorophyll, and toxic metal content using acetone extraction; the calculation of the concentrations was performed according to the equations proposed by Lichtenthaler and the percentage of water content was calculated. After the metal exposure, the reed plants were digested, and their total mineral analysis was accomplished by atomic absorption spectroscopy; statistical analysis was conducted by Statistical Package for the Social Sciences (SPSS) version 21. The results revealed that the immature stage showed the highest chlorophyll a (mean 1641.5 (µg/g)) carotenoids (mean 359.75 (µg/g)) and total chlorophyll (mean 2183.93 (µg/g)), and the mature flowering stem had the highest chlorophyll b (mean 676.45 (µg/g)). The mature flowering stem stage showed the highest Pb (mg/L) and Cd (mg/L) values; on the other hand, Cu was the highest in the fully elongated non-flowering stage (0.108 mg/L), and the highest Zn content was found in the immature stage (mean 2.083). Owing to its growth in contaminated environments, P. australis can be considered a potential source of phytonutrients; higher concentrations were mostly available in the immature and mature flowering stages, with a favorable immature stage. The use of such marginal wetland plants may be very useful in reducing the pollution burden of urban built environments. These plants offer a green and sustainable solution for the disposal of waste from urban areas. Hence, further planning and execution of such a green solution are pivotal for creating environmental sustainability.
... Photobiomodulation reduces the viscosity of the water and ultimately enhances ATP synthase, and decreases ROS levels [272,273]. Further evidence showed that chlorophyll metabolites within the mitochondria may be other photoacceptors, because when treated with photobiomodulation, they catalysed the coenzyme Q reduction, activated cytochrome c oxidase, and enhanced mitochondrial activity and ATP production [274]. Photobiomodulation can improve the activity of mitochondria in distressed neurons, and in this way stimulate the expression of some protective genes, such as neurotrophic factor genes [275]. ...
Parkinson's disease (PD) is a common age-related neurodegenerative disorder whose pathogenesis is not completely understood. Mitochondrial dysfunction and increased oxidative stress have been considered as major cause and central event responsible for the progressive degeneration of dopaminergic (DA) neurons in PD. Therefore, investigating mitochondrial disorders plays a role in understanding the pathogenesis of PD and can be an important therapeutic target for this disease. This study discusses the effect of environmental, genetic and biological factors on mitochondrial dysfunction and also focuseson the mitochondrial molecular mechanisms underlying neurodegeneration, and its possible therapeutic targets in PD, including reactive oxygen species generation, calcium overload, inflammasome activation, apoptosis, mitophagy, mitochondrial biogenesis, and mitochondrial dynamics. Other potential therapeutic strategies such as mitochondrial transfer/transplantation, targeting microRNAs, using stem cells, photobiomodulation, diet, and exercise were also discussed in this review, which may provide valuable insights into clinical aspects. A better understanding of the roles of mitochondria in the pathophysiology of PD may provide a rationale design of novel therapeutic interventions in our fight against PD.
... There is some evidence that supporting redox processes, through co-enzymes for instance, may help with metabolic illnesses 136,137 . There is even some evidence that the ingestion of chlorophyll, the chromophore central to photosynthesis, might alter mitochondrial ATP production 138 . It is thus perhaps not too much of a stretch to suggest that elements of the SARS-CoV-2 virus might be incorporated into the redox function of mitochondria. ...
The SARS-CoV-2 pandemic has added new urgency to the study of viral mechanisms of infection. But while vaccines offer a measure of protection against this specific outbreak, a new era of pandemics has been predicted. In addition to this, COVID-19 has drawn attention to post-viral syndromes and the healthcare burden they entail. It seems integral that knowledge of viral mechanisms is increased through as wide a research field as possible. To this end we propose that quantum biology might offer essential new insights into the problem, especially with regards to the important first step of virus-host invasion. Research in quantum biology often centres around energy or charge transfer. While this is predominantly in the context of photosynthesis there has also been some suggestion that cellular receptors such as olfactory or neural receptors might employ vibration assisted electron tunnelling to augment the lock-and-key mechanism. Quantum tunnelling has also been observed in enzyme function. Enzymes are implicated in the invasion of host cells by the SARS-CoV-2 virus. Receptors such as olfactory receptors also appear to be disrupted by COVID-19. Building on these observations we investigate the evidence that quantum tunnelling might be important in the context of infection with SARS-CoV-2. We illustrate this with a simple model relating the vibronic mode of, for example, a viral spike protein to the likelihood of charge transfer in an idealised receptor. Our results show a distinct parameter regime in which the vibronic mode of the spike protein enhances electron transfer. With this in mind, novel therapeutics to prevent SARS-CoV-2 transmission could potentially be identified by their vibrational spectra.
... ATP production in isolated mouse mitochondria increased when they were treated with pyropheophorbide A, a chlorophyll metabolite, and exposed to red light (670 nm). 10 In the absence of either, no increase in ATP production was observed. Pyropheophorbide A accumulated in brain, in fat, and in the gut and intestines of mice. ...
... ATP synthesis and life span increased when C. elegans were fed pyropheophorbide A and exposed to red light. 5,10 Further, ingested chlorophyll metabolites including pheophorbide A and pyropheophorbide A were still capable of photoexcitation by visible light, as evidenced by fluorescence imaging in vivo. ...
... 38,43 Though EDTA is not physiologically relevant as an electron donor, its effect supports the hypothesis that pheoA (less so for chlorin e6 and CuChl) can be photoexcited showed accumulation of pyropheophorbide A, a metabolite nearly identical to pheoA, in fat, brain and mitochondria; therefore, it is not surprising that pheoA solubility would affect its reactivity in addition to its cellular localization. 10 Decreased pheoA solubility is consistent with our hypothesis that HCA did not compete effectively with LDH-A because pheoA bound to LDH-A and produced 1 O 2 and likely other ROS in closer proximity to oxidizable amino acids ( Figure 6A & C). ...
While plant-derived oxidants can protect cells from oxidative damage, limited research has examined the role of dietary chlorophyll. Photoreduction of ubiquinone by chlorophyll metabolites and red light has been reported in vitro and in animal models. Herein we examined photo-oxidation and photoreduction reactions of catechols, dopamine and hydrocaffeic acid. Photo-oxidation of dopamine by methylene blue and the chlorophyll metabolites pheophorbide A, chlorin e6 and sodium copper chlorophyllin was studied by monitoring aminochrome, the cyclized product of the dopamine o-quinone with its amine. Singlet oxygen scavengers including sodium azide, ascorbate and glutathione decreased aminochrome formation by methylene blue and pheophorbide A. Addition of EDTA, a tertiary amine electron donor, to the reaction of dopamine, photosensitizer and red light decreased aminochrome formation. Photoreduction of the dopamine o-quinone produced by mushroom tyrosinase was achieved by both methylene blue and pheophorbide A only when an electron donor was included. Due to limited solubility, photo-oxidation and photoreduction reactions by pheophorbide A required 5-7.5% dimethylformamide for optimal reactivity. Catalytic photoreduction of 2,3-dimethoxy-5-methyl-p-benzoquinone by methylene blue or pheophorbide A and tertiary amine electron donors was observed. Among the chlorophyll metabolites, pheophorbide A was more effective than chlorin e6 or sodium copper chlorophyllin in photo-oxidation of dopamine and photoreduction reactions. Singlet oxygen inhibited lactate dehydrogenase A activity, and higher molecular weight protein cross-links were observed on SDS-PAGE. Hydrocaffeic acid competed with lactate dehydrogenase A for reaction with singlet oxygen produced by methylene blue; however, no protection by hydrocaffeic acid (HCA) was observed when pheophorbide A was used. Cysteine modification of lactate dehydrogenase A by the o-quinone of hydrocaffeic acid was detected using a redox cycling stain. Inclusion of an electron donor decreased protein labeling.
... Since IFs are ubiquitous in cells, physical energy transfer may operate over a network of IFs, provided other IFs have properties similar to those of MC IFs. At this time we are unaware of other research groups exploring energy transfer over protein structures, although an alternative albeit entirely speculative mechanism based on Davydov's vibration solitons (DVS) propagating along polypeptides has been discussed quite extensively [44][45][46]. These DVS were invoked as the means of ATP hydrolysis energy transfer within enzymes, in the form of vibrational energy of C--O groups. ...
ATP production by mitochondria isolated from yeast cells (S. cerevisiae) was accelerated by exciton energy transfer from intermediate filaments (IFs). The effect was dependent on mitochondrial concentration and the intensity of light used to generate excitons. Presumably, mitochondrial cytochrome c (CC) was activated by IF exciton energy transfer to CC in the inner mitochondrial membrane (IMM), generating electronically excited CC, and the respective excitation energy was then used in the ATP production chain. A qualitative model was proposed describing observations, although more experiments are required before the detailed mechanisms could be deduced. The present results support the earlier proposed hypothesis of ATP production in vertebrate retina by excess photons in daytime, when retina needs extra energy for recovering the used opsins. Additionally, it shows that at early stages of evolution mitochondria could have been using solar radiation to produce ATP.
