First report of Cephalerous virescens causing Algal leaf spot of Averrhoa carambola in India.

Averrhoa carambola (Star fruit) is a drought resistant edible fruit belongs to family Oxalidaceae. It is native of Malaysia and further cultivation is extended to China, Southeast Asia, India and Northern South America. Star fruit has juicy texture and used in salads, beverages and traditionally it has been used for ayurvedic medicines in India, Brazil and China (Abduh et al. 2023). In early January 2023, we observed the symptoms of raised, more or less circular, orange to dark brown, velvet textured, scattered algal leaf spots (1-4 mm) on the upper surface of A. carambola leaves at College farm, Agricultural College, Aswaraopet (17.252039 latitude, 81.109573 longitude) (Supplementary Fig 1). The disease was observed in 2 hectare model orchard with incidence of 45% causing leaf defoliation and thereby reducing the yield and quality of fruits. Transverse section cutting of algal spots revealed the algal thalli at subcuticular region and causing necrosis of epidermal cells. Sporangiophores (n=20) raised from algal leaf spot were cylindrical, 4 to 5 celled, 200-450 µm long x 8-20 µm wide, and forming a head cell with suffultory cells and sporangia on the top. Sporangia (n=20) were spherical to elliptical, rusty brown and 17.5-29 µm long × 18-23.6 µm wide and the total number of sporangia produced by each sporangiophores varies from 1 to 6. Setae (n=20) were filamentous with three to six celled, 17.5-50 µm long × 2.5-7.5 µm wide (Supplementary Figure 2). In our collection, mature gametangia were not observed. Morphological characters were studied on 20 diseased leaf samples collected from randomly selected five plants. To isolate pathogen, fresh algal thalli (n=5) were scraped from host tissue, surface sterilized (70% alcohol (30 s), 1% sodium hypochlorite (30 s) and sterile distilled water (3 × 60 s), inoculated to trebouxia liquid media and incubated at 25 ± 2 °C with a 12 hours photoperiod for 72 hours (Vasconcelos et al. 2018). The resultant five algal filaments were subjected to PCR amplification. The primer pair PNS1/NS41 was used in a PCR to amplify a fragment of 18S rRNA (Davis and Kaur 2019). The 18S rRNA gene sequences of the algae were compared using the Basic Local Alignment Search Tool (BLAST; http://www.ncbi.nlm.nih.gov/Blast/Blast.cgi) showed that our partial sequence had 99.5% similarity to C. virescens (KM020142.1). Hence, it was classified as C. virescens and sequences was deposited in NCBI-GenBank with accession numbers (OR053653, OR243777, OR429406, OR429407 and OR243779). For proving pathogenicity, algal filaments obtained from trebouxia liquid media were inoculated to 6 months old healthy A. carambola plant. Pathogenicity test was negative and typical symptoms could not be produced even up to 150 days of inoculation. In previous studies also, due to difficulty with production of zoospores in synthetic media, Koch's postulates of C. virescens as a plant pathogen has not been demonstrated experimentally (Sunpapao et al. 2017; Sanahuja et al. 2018; Kumar et al. 2019). In the second experiment, zoosporangia spore suspension were prepared from small pieces of algal leaf spot tissue processed in a sterile pestle and mortar and filtered through sterile cheesecloth (Sunpapao et al. 2017). A total of five isolates of zoosporangia spore suspension (1 x 102 to 1 x 104/ml of water) was sprayed on healthy, surface sterilized leaves of A. carambola plants (n=5) until runoff with a handheld airpump sprayer and incubated in green house (T: 25 oC, H: 80%). During the experiment leaves were remain attached to plant (5 days old) and plants were 6 months old grown in plastic pots under controlled conditions. Two plants were inoculated with each isolate and three non inoculated control plants were included. Non inoculated controls were sprayed with sterile distilled water. The pathogenicity experiment was repeated. The initial symptoms were produced 60 days after inoculation and complete algal thalli was observed on 90 days after inoculation, control plants were without any symptoms upto 150 days. Reisolated algal thalli from symptomatic plants were morphologically similar to original algal thalli and molecularly identified as C. virescens (accession number OR067193 and OR243810). Red rust caused by C. virescens is a major algal disease in the world and causing severe leaf defoliation in various horticultural crops viz., Mangifera indica (Vasconcelos et al. 2018), Manilkara zapota (Sunpapao et al. 2017), Psidium guajava (Rajbongshi et al. 2022), Ziziphus mauritiana (Shareefa et al. 2022) and Anacardium occidentale (Dooh et al. 2022). The available literature suggest that, this is the first report of algal leaf spot on A. carambola caused by C. virescens in India. This report extends the range of known pathogens associated with A. carambola plant and serves as a basis for development and implementing disease management strategies.

Averrhoa carambola L. fruit and stem metabolites profiling and immunostimulatory action mechanisms against cyclosporine induced toxic effects in rat model as analyzed using UHPLC/MS-MS-based chemometrics and bioassays.

The Averrhoa carambola L. tree encompasses a myriad of phytochemicals contributing to its nutritional and health benefits. The current study aims at investigating the A. carambola L. the metabolite profile grown in tropical and temperate regions represented by fruit and stem, for the first time using UPLC/MS-based molecular networking and chemometrics. Asides, assessment of the immunostimulatory effect of ripe fruit and stem, was compared in relation to metabolite fingerprints. Eighty metabolites were identified, 8 of which are first-time to be reported including 3 dihydrochalcone-C-glycosides, 4 flavonoids, and one phenolic. Multivariate data analysis revealed dihydrochalcones as origin-discriminating metabolites between temperate and tropical grown fruits. Further, an in vivo immunomodulatory assay in a cyclosporine A-induced rat model revealed a potential immune-enhancing effect as manifested by down-regulation of inflammatory markers (IL-6, INF-γ, IL-1, TLR4, and ESR) concurrent with the up-regulation of CD4 level and the CD4/CD8 ratio. Moreover, both extracts suppressed elevation of liver and kidney functions in serum as well as reduction in oxidative stress with concurrent increased levels of T-protein, albumin, globulin, and A/G ratio. This study pinpoints differences in secondary metabolite profiles amongst A. carambola L. accessions from different origins and organ type and its immunomodulatory action mechanisms.

Averrhoa carambola L. fruit polyphenols ameliorate hyperlipidemia, hepatic steatosis, and hyperglycemia by modulating lipid and glucose metabolism in mice with obesity.

BACKGROUND: Hyperlipidemia, hepatic steatosis, and hyperglycemia are common metabolic complications of obesity. The objective of the present study is to investigate the in vivo protective effect of Averrhoa carambola L. fruit polyphenols (ACFP) on hyperlipidemia, hepatic steatosis, and hyperglycemia in mice with high-fat diet (HFD)-induced obesity and elucidate the mechanisms of action underlying the beneficial effects of ACFP. Thirty-six specific pathogen-free male C57BL/6J mice (4 weeks old, weighing 17.1-19.9 g) were randomly divided into three groups and fed with a low-fat diet (LFD, 10% fat energy), HFD (45% fat energy), or HFD supplemented with ACFP by intragastric administration for 14 weeks. Obesity-related biochemical indexes and hepatic gene expression levels were determined. The statistical analyses were conducted using one-way analysis of variance (ANOVA) followed by Duncan's multiple range test. RESULTS: The results showed that the body weight gain, serum triglycerides, total cholesterol, glucose, insulin resistance index, and steatosis grade in the ACFP group decreased by 29.57%, 26.25%, 27.4%, 19.6%, 40.32%, and 40%, respectively, compared to the HFD group. Gene expression analysis indicated that ACFP treatment improved the gene expression profiles involved in lipid and glucose metabolism compared to the HFD group. CONCLUSION: ACFP protected from HFD-induced obesity and obesity-associated hyperlipidemia, hepatic steatosis, and hyperglycemia by improving lipid and glucose metabolism in mice. © 2023 Society of Chemical Industry.

Effect of Na and Al doping on ZnO nanoparticles for potential application in sunscreens.

This study investigated the environment-friendly production and characterization of zinc oxide nanoparticles (ZnO NPs) doped with sodium (Na) and aluminum (Al) metals to decrease the photocatalytic activity of ZnO for use in sunscreen. The metal-doped zinc oxide (ZnO) materials were prepared by the microwave method using extracts of Averrhoa carambola, also known as star fruit, as a reducing agent. The effects of metal-ion doping on the crystal structure, morphology, and optical characteristics of ZnO were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), transmission electron microscopy (TEM), and ultraviolet-visible (UV-Vis) spectroscopy. The sun protection factor (SPF) of the sunscreen formulations containing undoped ZnO, Na-doped ZnO (Na/ZnO), and Al-doped ZnO (Al/ZnO) NPs were found to be 10.10, 25.10, and 43.08, respectively. Therefore, Na/ZnO and Al/ZnO showed increased SPF. Additionally, the prepared nanomaterials and sunscreens were effective against Gram-positive and Gram-negative bacteria and showed antioxidant activities. The methylene blue (MB) degradation was used to evaluate the photocatalytic activities of the undoped ZnO, Na/ZnO, and Al/ZnO NPs, which were found to be 66%, 46%, and 38%, respectively. Therefore, due to the structural defects of ZnO NPs, their photocatalytic activity was decreased with Na- and Al- doping. Additionally, Al/ZnO is an ideal candidate as an ingredient in sunscreens.

Anti-Obesity Evaluation of Averrhoa carambola L. Leaves and Assessment of Its Polyphenols as Potential α-Glucosidase Inhibitors.

Averrhoa carambola L. is reported for its anti-obese and anti-diabetic activities. The present study aimed to investigate its aqueous methanol leaf extract (CLL) in vivo anti-obese activity along with the isolation and identification of bioactive compounds and their in vitro α-glucosidase inhibition assessment. CLL improved all obesity complications and exhibited significant activity in an obese rat model. Fourteen compounds, including four flavone glycosides (1-4) and ten dihydrochalcone glycosides (5-12), were isolated and identified using spectroscopic techniques. New compounds identified in planta included (1) apigenin 6-C-(2-deoxy-ß-D-galactopyranoside)-7-O-ß-D-quinovopyranoside, (8) phloretin 3'-C-(2-O-(E)-cinnamoyl-3-O-ß-D-fucopyranosyl-4-O-acetyl)-ß-D-fucopyranosyl-6'-O-ß-D fucopyranosyl-(1/2)-α-L arabinofuranoside, (11a) phloretin3'-C-(2-O-(E)-p-coumaroyl-3-O-ß-D-fucosyl-4-O-acetyl)-ß-D-fucosyl-6'-O-(2-O-ß-D-fucosyl)-α-L-arabinofuranoside, (11b) phloretin3'-C-(2-O-(Z)-p-coumaroyl-3-O-ß-D-fucosyl-4-O-acetyl)-ß-D-fucosyl-6'-O-(2-O-ß-D-fucosyl)-α-L-arabinofuranoside. Carambolaside M (5), carambolaside Ia (6), carambolaside J (7), carambolaside I (9), carambolaside P (10a), carambolaside O (10b), and carambolaside Q (12), which are reported for the first time from A. carambola L. leaves, whereas luteolin 6-C-α-L-rhamnopyranosyl-(1-2)-ß-D-fucopyranoside (2), apigenin 6-C-ß-D-galactopyranoside (3), and apigenin 6-C-α-L-rhamnopyranosyl-(1-2)-ß-L-fucopyranoside (4) are isolated for the first time from Family. Oxalidaceae. In vitro α-glucosidase inhibitory activity revealed the potential efficacy of flavone glycosides, viz., 1, 2, 3, and 4 as antidiabetic agents. In contrast, dihydrochalcone glycosides (5-11) showed weak activity, except for compound 12, which showed relatively strong activity.

Genome-wide identification and expression profile of YABBY genes in Averrhoa carambola.

BACKGROUND: Members of the plant-specific YABBY gene family are thought to play an important role in the development of leaf, flower, and fruit. The YABBY genes have been characterized and regarded as vital contributors to fruit development in Arabidopsis thaliana and tomato, in contrast to that in the important tropical economic fruit star fruit (Averrhoa carambola), even though its genome is available. METHODS: In the present study, a total of eight YABBY family genes (named from AcYABBY1 to AcYABBY8) were identified from the genome of star fruit, and their phylogenetic relationships, functional domains and motif compositions, physicochemical properties, chromosome locations, gene structures, protomer elements, collinear analysis, selective pressure, and expression profiles were further analyzed. RESULTS: Eight AcYABBY genes (AcYABBYs) were clustered into five clades and were distributed on five chromosomes, and all of them had undergone negative selection. Tandem and fragment duplications rather than WGD contributed to YABBY gene number in the star fruit. Expression profiles of AcYABBYs from different organs and developmental stages of fleshy fruit indicated that AcYABBY4 may play a specific role in regulating fruit size. These results emphasize the need for further studies on the functions of AcYABBYs in fruit development.

Traditional Uses, Phytochemical Constituents and Pharmacological Properties of Averrhoa carambola L.: A Review.

Averrhoa carambola L. (star fruit) is an edible fruit that is extensively cultivated in southern China, Southeast Asia, India, and northern South America. It has a sweet and juicy taste and is frequently used in fruit salads and fruit platters, as a garnish in cocktail drinks and beverages, or squeezed into juice and served as a beverage. Traditionally, it has been used for treating diabetes and diabetic nephropathy, arthralgia, vomiting, lithangiuria, coughing, hangovers, and chronic paroxysmal headache for thousands of years. Currently, approximately 132 compounds have been isolated from A. carambola. Among them, flavonoids, benzoquinone, and their glycosides have been considered as biologically active substances, which are responsible for various biological activities. Pharmacological studies have revealed that crude extracts or monomeric compounds from A. carambola exhibit multiple bioactivities, such as anti-oxidant, anti-hyperglycemic, anti-obesity, anti-hyperlipidemic, anti-tumor, anti-inflammatory, hepatoprotective, cardioprotective, anti-hypertensive, neuroprotective, and others. Thus, A. carambola is a valuable treatment in Chinese medicine with therapeutic potential for multiple diseases, especially diabetes and diabetes-related diseases. Even though it is a very promising candidate in the development of functional food and the pharmaceutical industry, reports on its bioactivities have only been conducted in vivo and in vitro and there is a gap in research regarding clinical settings and safety. This review therefore provides a comprehensive and systematic overview of current progress on botany, ethnopharmacology, phytochemistry, pharmacology, and toxicity of A. carambola, providing a valuable reference for further developments and applications of A. carambola in the pharmaceutical industry and functional food.

Identification and functional analysis of SWEET gene family in Averrhoa carambola L. fruits during ripening.

Sugar Will Eventually be Exported Transporters (SWEETs), a type of sugar efflux transporters, have been extensively researched upon due to their role in phloem loading for distant sugar transport, fruit development, and stress regulation, etc. Several plant species are known to possess the SWEET genes; however, little is known about their presence in Averrhoa Carambola L. (Oxalidaceae), an evergreen fruit crop (star fruit) in tropical and subtropical regions of Southeast Asia. In this study, we established an Averrhoa Carambola L. unigenes library from fruits of 'XianMiyangtao' (XM) by RNA sequencing (RNA-seq). A total of 99,319 unigenes, each longer than 200 bp with a total length was 72.00 Mb, were identified. A total of 51,642 unigenes (52.00%) were annotated. Additionally, 10 AcSWEET genes from the Averrhoa Carambola L. unigenes library were identified and classified, followed by a comprehensive analysis of their structures and conserved motif compositions, and evolutionary relationships. Moreover, the expression patterns of AcSWEETs in 'XM' cultivars during fruit ripening were confirmed using quantitative real-time PCR (qRT-PCR), combined with the soluble sugar and titratable acids content during ripening, showed that AcSWEET2a/2b and AcSWEET16b might participate in sugar transport during fruit ripening. This work presents a general profile of the AcSWEET gene family in Averrhoa Carambola L., which can be used to perform further studies on elucidating the functional roles of AcSWEET genes.

Nutritional and medicinal properties of Star fruit (Averrhoa carambola): A review.

Star fruit (Averrhoa carambola), a popular fruit in many parts of the world, is considered to have many beneficial nutritional and medicinal effects. However, harmful nephrotoxic and neurotoxic effects have also been described. In this review, we have discussed the reported beneficial effects of star fruit, explored the potential mechanisms for such beneficial effects, and outline factors that may affect the safe level of consumption. The beneficial effects include the following: antioxidant (mediated via L-ascorbic acid, epicatechin, and gallic acid), hypoglycemic (mediated via high fiber levels and 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione), hypotensive (mediated via apigenin), hypocholesterolemic (mediated via micronized fiber), anti-inflammatory, anti-infective, antitumor effects, and immune-boosting effects. The presence of chronic kidney disease, gastroenteropathies, chronic pancreatitis, dehydration, consumption on an empty stomach, and higher concentration of oxalate in fruit/juice consumed predisposes to toxicity. The level of ingestion at which the beneficial effects transition to nephrotoxicity and neurotoxicity is still to be accurately ascertained. Furthermore, the relationship between the amount of star fruit ingested and the severity of toxicity is not certain and warrants further study.

Nephrotoxicity and neurotoxicity following star fruit (Averrhoa carambola) ingestion: a narrative review.

In recent times, star fruit (Averrhoa carambola) nephrotoxicity and neurotoxicity have been increasingly reported, both in individuals with pre-existing renal disease and those with previously normal renal function. We summarise the clinical findings of star fruit toxicity in humans and outline the important pathogenetic insights provided by animal studies. Google Scholar, EMBASE, Scopus and PubMed were searched from 1995 through July 2020 for case reports/series on renal or neurological manifestations of star fruit toxicity in humans and mechanisms of star fruit toxicity in animal studies. Ten case series and 28 case reports in humans (total number of individuals=136) were included and 8 animal studies were analysed. Ninety-four (69.1%) patients had prior renal impairment. Renal histology showed acute oxalate nephropathy with tubulointerstitial nephritis or tubular necrosis. Neurotoxicity manifestations ranged from hiccups to status epilepticus. Oxalate and caramboxin are considered the main substances causing nephrotoxicity and neurotoxicity. Caramboxin inhibits GABA binding and activates the glutamatergic receptors. Haemodialysis improved outcomes in neurotoxicity. Nephrotoxicity and neurotoxicity need to be looked for with star fruit toxicity, both in individuals with abnormal or normal renal function. Once star fruit intoxication is identified, early renal replacement therapy should be considered. Further studies on the mechanisms of star fruit toxicity are needed.

Acute Kidney Injury Following Star Fruit Ingestion: A Case Series.

Star fruit (Averrhoa carambola) is a popular fruit in many tropical countries, including Sri Lanka. It is rich in oxalic acid, which is nephrotoxic in higher concentrations. The development of both acute (AKI) and chronic kidney injury after oxalate nephropathy is often underrecognized. Here we discuss the risk factors, clinical features, treatment, and outcomes of 4 patients who developed AKI after star fruit ingestion. Baseline clinical characteristics, the amount of star fruit ingested, clinical presentation, investigation, and outcome of the patients (ages 28, 50, 54, and 55 y; all male) were traced. More common symptoms of acute star fruit intoxication were nausea, vomiting, and abdominal and back pain, followed by low urine output and high serum creatinine over hours to days. Urinary analysis of all patients demonstrated oxalate crystals. Histopathologic examination of renal tissues of all 4 patients revealed acute tubular damage with calcium oxalate crystals, interstitial edema, and inflammatory cellular infiltration. The presence of calcium oxalate crystals was further confirmed with the brilliant birefringence seen under polarized light. Two patients needed intermittent hemodialysis over a week owing to oliguria and uremia. The other 2 patients did not require hemodialysis and had improvement of renal function with supportive treatment. All had high renal function on discharge but were back to normal within a month. This study highlights AKI as a serious complication of star fruit ingestion. The type and quantity of star fruit ingested and some patient factors may play a role in the pathogenesis of AKI. Public education about this serious uncommon complication is important.

Rapid Structure-Based Annotation and Profiling of Dihydrochalcones in Star Fruit (Averrhoa carambola) Using UHPLC/Q-Orbitrap-MS and Molecular Networking.

Dihydrochalcones are a subclass of flavonoids. There has been growing interest in dihydrochalcones for their health benefits and potential to modulate flavor, but their comprehensive profile in diverse plant species is lacking. Star fruit is a tropical fruit rich in dihydrochalcones. In this study, a systematic annotation using UHPLC/Q-Orbitrap-MS and molecular networking was established to rapidly identify dihydrochalcones in 12 star fruit cultivars. A total of 53 dihydrochalcones were characterized within a short retention time including one novel compound (phloretin-3'-C-(2-O-trans-p-coumaroyl)-ß-d-fucopyranoside) and 23 compounds identified from the Averrhoa genus for the first time. 3-Hydroxyphloretin was the most abundant dihydrochalcone in star fruit. All the identified dihydrochalcones had a higher abundance in leaves compared to fruits. This is the first report that systematically investigates dihydrochalcones in star fruit of multiple cultivars, and the results could provide a useful reference for the future development and utilization of plant genetic resources.

Averrhoa Carambola L. Roots DMDD alleviates myocardial injury in diabetes mellitus mice by regulating ROS-mediated autophagy pathway / 中国药理学通报

Aim To evaluate the protective effect of Averrhoa Carambola L. Roots DMDD alleviating myocardial injury in diabetes mellitus (DM) mice and its mechanism. Methods SD mice were given high-glucose-high-fat diet combined with streptozotocin to induce DM model, and were administered with DMDD. The fasting blood glucose (FBG) was recorded. The left ventricular end-diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP), maximum upstroke velocity of left ventricular pressure (+ dp/dt

Mechanisms of star fruit (Averrhoa carambola) toxicity: A mini-review.

The star fruit (Averrhoa carambola) is consumed in high amounts in Asia and Central/South America. It contains oxalic acid and caramboxin. In some individuals, its ingestion may lead to nephrotoxicity and neurotoxicity. The nephrotoxic effect is due to oxalate deposition in renal tubules resulting in acute tubular necrosis and interstitial nephritis. Although uraemic encephalopathy secondary to acute kidney injury may play a role, a shift to an excitatory state of the central nervous system (CNS) by caramboxin through activation of excitatory neuroreceptors and inhibition of GABA receptors leads to mental confusion, seizures and status epilepticus seen with star fruit intoxication. In this mini-review, we discuss the mechanisms of star fruit-related toxicity.

Protective Effect of Benzoquinone Isolated from the Roots of Averrhoa carambola L. on Streptozotocin-Induced Diabetic Mice by Inhibiting the TLR4/NF-κB Signaling Pathway.

BACKGROUND: Studies have demonstrated that the roots of Averrhoa carambola L. (Oxalidaceae), a traditional Chinese medicine, can be used to treat diabetes and diabetes-related diseases. Nevertheless, the potential beneficial effects and mechanism of benzoquinone isolated from the roots of Averrhoa carambola L. (BACR) on diabetes remain unclear. METHODS: Diabetic Kunming mice were injected with STZ (120 mgkg-1) in the tail vein. Fasting blood glucose (FBG) and the change of body weight were measured after oral administration of BACR (120, 60, 30 mg/kg/d) every week. The levels of the total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), glucosylated hemoglobin (GHb), fasting insulin (FINS), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured. The histological examination of pancreatic tissues and the TLR4/NF-κB pathway was analyzed by RT-PCR, immunohistochemistry and Western blot. RESULTS: The study found that clearly the BACR obviously reduced the blood glucose, serum lipids, GHb and FINS. In addition, BACR treatment markedly reduced the release of inflammatory factors, including IL-6 and TNF-α, and down-regulated the expression of the TLR4/NF-κB pathway. CONCLUSION: BACR has potential benefits for the treatment of diabetes by ameliorating metabolic functions and attenuating the inflammatory response via inhibition of the activation of theTLR4/NF-κB pathway.

Identification of secondary metabolites in Averrhoa carambola L. bark by high-resolution mass spectrometry and evaluation for α-glucosidase, tyrosinase, elastase, and antioxidant potential.

In this study, paper spray ionization (PSI) coupled to high-resolution mass spectrometry has been used to identify secondary metabolites from ethanol extracts of Averrhoa carambola L. bark (ABE). Various phytoconstituents including phenolic acids, flavonoids, xanthones and terpenoids were identified from the bark. ABE shows potential antioxidant activity as well as markedly inhibited α-glucosidase, elastase, and tyrosinase enzyme activities in a concentration-dependent fashion, respectively. ABE significantly inhibited α-glucosidase at lower concentration (IC50: 7.15 ± 0.06 µg/mL). Identified compounds were tested to understand the biological activity of ABE. Experimental results suggest that norathyriol, one of the identified compounds, has significant α-glucosidase (IC50: 0.81 ± 0.01 µg/mL) inhibition and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (IC50: 4.90 ± 0.09 µg/mL). At a dose of 100 mg/kg, ABE significantly decreased the postprandial blood glucose level in oral glucose tolerance test (OGTT). This study shows that carambola bark can be a potential source of bioactive compounds.

Dihydrochalcone C-glycosides from Averrhoa carambola leaves.

Ten undescribed dihydrochalcone C-glycosides, carambolasides R1‒R3, S1, S2, T1‒T3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P were isolated along with carambolasides I and P from the leaves of Averrhoa carambola L. (Oxalidaceae). Their structures were determined by spectroscopic and chemical methods. Among them, carambolasides P, T1, T2, and I with contents of 22.78, 14.39, 4.93, and 1.87 mg g-1 dry wt., respectively, were shown to be abundant in the leaves by HPLC analysis. All the compounds showed more potent ABTS radical cation scavenging activity than l-ascorbic acid. 3-Hydroxycarambolaside T1 and 3-hydroxycarambolaside P also demonstrated moderate DPPH radical scavenging activity. Further, carambolaside R3, 3-hydroxycarambolaside T1, and 3-hydroxycarambolaside P exhibited weak in vitro porcine pancreatic lipase inhibitory activity.

Flavan-3-ols and 2-diglycosyloxybenzoates from the leaves of Averrhoa carambola.

Averrhoa carambola L. (Oxalidaceae) was widely cultivated for fruits (star fruit), whereas the value of leaves remains to be discovered. Our study on the leaves yielded five flavan-3-ols (1-5) and two 2-diglycosyloxybenzoates. Their structures were determined by spectroscopic and chemical methods. Epicatechin-(5,6-bc)-4ß-(p-hydroxyphenyl)-dihydro-2(3H)-pyranone (1) and benzyl 2-ß-d-apiofuranosyl-(1 â†’ 6)-ß-d-glucopyranosyloxybenzoate (6) were new structures. 6-(S-2-Pyrrolidinone-5-yl)epicatechin (4) and 6-(R-2-pyrrolidinone-5-yl)epicatechin (5) were obtained as monomeric diastereomer for the first time and their absolute configurations were determined by electronic circular dichroism (ECD) computation. Epicatechin-(7,8-bc)-4α-(p-hydroxyphenyl)-dihydro-2(3H)-pyranone (2), epicatechin-(7,8-bc)-4ß-(p-hydroxyphenyl)-dihydro-2(3H)-pyranone (3), and methyl 2-ß-d-apiofuranosyl-(1 â†’ 6)-ß-d-glucopyranosyloxybenzoate (7) were not previously reported from the genus Averrhoa. Compounds 1-5 showed more potent 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities and ferric reducing antioxidant power (FRAP) than l-ascorbic acid. Meanwhile 1 and 3 exhibited lipase and α-glucosidase inhibitory activities, respectively. The results clarified the structures of flavan-3-ols and 2-diglycosyloxybenzoates in the leaves and their antioxidant, lipase, and α-glucosidase inhibitory activities.

Extract of Averrhoacarambola L. (Oxalidaceae) roots ameliorates carbon tetrachloride-induced hepatic fibrosis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The root of Averrhoa carambola L. (Oxalidaceae), a traditional Chinese medicine, was mainly used in ancient times in the treatment of urinary calculi, recurrent headache and joint pain. AIM OF THE STUDY: Our aims were to explore the potential therapeutic effect of the extract of Averrhoa carambola L. (Oxalidaceae) roots (EACR) against hepatic fibrosis in CCl4-treated rats and to understand the underlying molecular mechanism. MATERIALS AND METHODS: Six groups of male Sprague Dawley rats were treated as follows: vehicle (olive oil), CCl4 alone, CCl4+colchicine, CCl4+EACR 1.0 g/kg, CCl4+EACR 0.5 g/kg and CCl4+EACR 0.25 g/kg. At the end of the 12th week, biomarkers of liver function, liver fibrosis, hepatic oxidative stress and antioxidant status were assayed, and histopathological and immunohistochemical evaluation of liver tissue were conducted to investigate the liver damage and fibrosis degree. Furthermore, expressions of COL-1a1, α-SMA, TGF-ß1, Smad2, smad3, Smad4 and TIMP2 were examined by qPCR and/or western blot. The expressions of apoptosis-related proteins were also detected using western blot analysis. RESULTS: EACR treatment markedly reduced the CCl4-induced elevation of serum aminotransferase activities, liver fibrosis indexes, and the extent of oxidative stress. EACR treatment also significantly reduced the accumulation of collagen and the immunostaining of α-SMA, TGF-ß1 and Smad2, 4 and 7 in the liver of CCl4 treated rats. In addition, EACR treatment markedly reversed the CCl4-induced increase in mRNA expression of COL-1a1, α-SMA, TIMP2, TGF-ß1, Smad2 and Smad4 and suppressed the expressions of α-SMA, TIMP2, TGF-ß1, smad2, 3 and 4, BAX and cleaved caspase-3 proteins. Meanwhile, EACR treatment also significantly elevated the mRNA expression of Smad7 and the protein expression of Smad7 and Bcl-2. CONCLUSION: These results suggest that EACR has protective activity against liver fibrosis. The anti-fibrotic activity of EACR in vivo is associated with enhanced antioxidant, apoptosis-inhibition and increased MMP-2/TIMP-2 expression ratio, and with modulation of TGF-ß1/Smad signaling pathway.

Refrigeration and modified atmosphere to the conservation of 'Malasia' Star fruit / Refrigeração e atmosfera modificada na conservação da carambola 'Malasia'

ABSTRACT: Despite the fact that cold storage and modified atmosphere techniques have already been studied for fresh cut Star fruit, little has been done considering the whole fruit. Besides that, each cultivar has its peculiarities, so the efficiency of combined postharvest treatments should be studied. The objective of this study was to evaluate the effect of polyvinyl chloride (PVC), 8.5 µm thick and low-density polyethylene (LDPE), 33 µm thick associated with cold storage (10 ± 1 °C and 5 ± 1 °C / 85 ± 5% RH) on the conservation of 'Malasia' Star fruit. Storage at 25 oC maintained Star fruit overall quality, regardless of the film type, up to four days. The weight loss was higher in fruit packed with PVC, but this fact was not noticed by the sensory analysis. The storage in 5 and 10 oC did not caused chilling injury but fruit presented retention of yellow color development and firmness reduction; these aspects were positively assessed by the sensory analysis. The film type did not influence the conservation of the fruit. The storage at 5 and 10 °C, regardless of the package film, prolonged 'Malasia' star fruit shelf life up to 16 days, followed by two days at 25 °C.

RESUMO: Apesar das técnicas de armazenamento refrigerado e atmosfera modificada já terem sido estudadas para carambolas processadas, pouco foi feito considerando a fruta inteira. Além disso, cada cultivar possui peculiaridades, dessa forma a eficiência dos tratamentos pós-colheita combinados deve ser estudada. O objetivo deste trabalho foi avaliar o efeito do cloreto de polivinila (PVC), 8,5 µm de espessura e polietileno de baixa densidade (PEBD), 33 µm de espessura associados ao armazenamento refrigerado (10 ± 1 °C e 5 ± 1 °C / 85 ± 5% de UR) na conservação da carambola Malasia. O armazenamento a 25 °C manteve a qualidade da carambola, independentemente do tipo de filme, até quatro dias. A perda de massa foi maior nos frutos embalados em PVC, mas esta não foi percebida pela análise sensorial. As temperaturas de armazenamento de 5 e 10 °C não causaram dano de frio, mas os frutos apresentaram retenção no desenvolvimento da coloração amarela e na redução da firmeza; esses aspectos foram avaliados positivamente na análise sensorial. O tipo de filme não influenciou a conservação do fruto. O armazenamento a 5 e 10 °C, independente do filme da embalagem, prolongou a vida útil da carambola 'Malasia' até 16 dias, seguido por dois dias a 25 °C.