A Critical Appraisal of the Most Recent Investigations on Ora-Pro-Nobis (Pereskia sp.): Economical, Botanical, Phytochemical, Nutritional, and Ethnopharmacological Aspects.

Pereskia aculeata Miller and Pereskia grandfolia Haw, known as 'ora-pro-nobis', are unconventional vegetables belonging to the Cactaceae family, native to the Americas and common in the northeast and southeast regions of Brazil. This review attempts to present a balanced account of both the methods used for obtaining extracts from the diverse parts of the plants and the results that were obtained in terms of their applicability to foods and other products with biological activities. Attention will also be devoted to the properties of their bioactives and their applications to real food products. Methods for obtaining extracts from the diverse parts of the plants will be analyzed, as well as the chemical nature of the bioactives that were hitherto identified. Next, the applicability of ora-pro-nobis in either its integral form or in the form of extracts or other products (mucilages) to the production of food and dietary supplements will be analyzed. The species have been extensively investigated during the last few decades. But, the determination of chemical structures is frequently incomplete and there is a need for new studies on texture determination and color evaluation. Further studies exploring the fruit and flowers of P. aculeata are also required.

Inhibition of Gluconeogenesis by Boldine in the Perfused Liver: Therapeutical Implication for Glycemic Control.

The alkaloid boldine occurs in the Chilean boldo tree (Peumus boldus). It acts as a free radical scavenger and controls glycemia in diabetic rats. Various mechanisms have been proposed for this effect, including inhibited glucose absorption, stimulated insulin secretion, and increased expression of genes involved in glycemic control. Direct effects on glucose synthesis and degradation were not yet measured. To fill this gap, the present study is aimed at ensuring several metabolic pathways linked to glucose metabolism (e.g., gluconeogenesis) in the isolated perfused rat liver. In order to address mechanistic issues, energy transduction in isolated mitochondria and activities of gluconeogenic key enzymes in tissue preparations were also measured. Boldine diminished mitochondrial ROS generation, with no effect on energy transduction in isolated mitochondria. It inhibited, however, at least three enzymes of the gluconeogenic pathway, namely, phosphoenolpyruvate carboxykinase, fructose-bisphosphatase-1, and glucose 6-phosphatase, starting at concentrations below 50 µM. Consistently, in the perfused liver, boldine decreased lactate-, alanine-, and fructose-driven gluconeogenesis with IC50 values of 71.9, 85.2, and 83.6 µM, respectively. Conversely, the compound also increased glycolysis from glycogen-derived glucosyl units. The hepatic ATP content was not affected by boldine. It is proposed that the direct inhibition of hepatic gluconeogenesis by boldine, combined with the increase of glycolysis, could be an important event behind the diminished hyperglycemia observed in boldine-treated diabetic rats.

Purple tea: chemical characterization and evaluation as inhibitor of pancreatic lipase and fat digestion in mice.

A variety of the classic green tea plant, Camellia sinensis, was developed and is exclusive to Kenya. Due to high content of anthocyanin polyphenols in its leaves, the beverage obtained from this variety is purple in color and is the origin of the name purple tea. This work had two main purposes. The first one was to identify and quantify the major anthocyanin polyphenols in a hot water aqueous extract of the purple tea leaves. The second one was to test the hypothesis if this extract is capable of inhibiting triglyceride absorption considering that anthocyanin polyphenolics have been frequently associated to antilipidemic effects. Parallel experiments were always done with a similar green tea extract for comparison purposes. The antioxidant, anti-inflammatory, and cytotoxic activities of both tea varieties are similar. The purple tea extract, however, was strongly inhibitory toward the pancreatic lipase (minimal IC50 = 67.4 µg mL-1), whereas the green tea preparation was a weak inhibitor. Triglyceride digestion in mice was inhibited by the purple tea extract starting at 100 mg kg-1 dose and with a well-defined dose dependence. Green tea had no effect on triglyceride digestion at doses up to 500 mg kg-1. The latter effect is probably caused by several components in the purple tea extract including non-anthocyanin and anthocyanin polyphenols, the first ones acting solely via the inhibition of the pancreatic lipase and the latter by inhibiting both the lipase and the transport of free fatty acids from the intestinal lumen into the circulating blood. The results suggest that the regular consumption of Kenyan purple tea can be useful in the control of obesity.

Potential of plant extracts in targeting SARS-CoV-2 main protease: an in vitro and in silico study.

The deaths caused by the covid-19 pandemic have recently decreased due to a worldwide effort in vaccination campaigns. However, even vaccinated people can develop a severe form of the disease that requires ICU admission. As a result, the search for antiviral drugs to treat these severe cases has become a necessity. In this context, natural products are an interesting alternative to synthetic medicines used in drug repositioning, as they have been consumed for a long time through traditional medicine. Many natural compounds found in plant extracts have already been shown to be effective in treating viral and bacterial diseases, making them possible hits to exploit against covid-19. The objective of this work was to evaluate the antiviral activity of different plant extracts available in the library of natural products of the Universidade Estadual de Maringá, by inhibiting the SARS-CoV-2 main protease (Mpro), and by preventing viral infection in a cellular model. As a result, the extract of Cytinus hypocistis, obtained by ultrasound, showed a Mpro inhibition capacity greater than 90%. In the infection model assays using Vero cells, an inhibition of 99.6% was observed, with a selectivity index of 42.7. The in silico molecular docking simulations using the extract compounds against Mpro, suggested Tellimagrandin II as the component of C. hypocistis extract most likely to inhibit the viral enzyme. These results demonstrate the potential of C. hypocistis extract as a promising source of natural compounds with antiviral activity against covid-19.Communicated by Ramaswamy H. Sarma.

Antiviral activity of Cenostigma pluviosum var. peltophoroides extract and fractions against SARS-CoV-2.

Few extracts of plant species from the Brazilian flora have been validated from a pharmacological and clinical point of view, and it is important to determine whether their traditional use is proven by pharmacological effects. Cenostigma pluviosum var. peltophoroides is one of those plants, which belongs to the Fabaceae family that is widely used in traditional medicine and is very rich in tannins. Due to the lack of effective drugs to treat severe cases of Covid-19, the main protease of SARS-CoV-2 (Mpro) becomes an attractive target in the research for new antivirals since this enzyme is crucial for virus replication and does not have homologs in humans. This study aimed to prospect inhibitor candidates among the compounds from C. pluviosum extract, by virtual screening simulations using SARS-CoV-2 Mpro as target. Experimental validation was made by inhibitory proteolytic assays of recombinant Mpro and by antiviral activity with infected Vero cells. Docking simulations identify four compounds with potential inhibitory activity of Mpro present in the extract. The compound pentagalloylglucose showed the best result in proteolytic kinetics experiments, with suppression of recombinant Mpro activity by approximately 60%. However, in experiments with infected cells ethyl acetate fraction and sub-fractions, F2 and F4 of C. pluviosum extract performed better than pentagalloylglucose, reaching close to 100% of antiviral activity. The prominent activity of the extract fractions in infected cells may be a result of a synergistic effect from the different hydrolyzable tannins present, performing simultaneous action on Mpro and other targets from SARS-CoV-2 and host.Communicated by Ramaswamy H. Sarma.

Biological Characterization and Antimicrobial Bioactives of Mycelium Extracts from Medicinal Mushrooms Phellinus linteus and Pleurotus albidus (Agaricomycetes).

Bioactivity is defined as the intrinsic property of compounds that enables their participation in specific biological reactions. This study aimed to evaluate the antimicrobial capacity and to separate and characterize bioactives from aqueous and hydroalcoholic extracts obtained from the mycelium of medicinal mushrooms Pleurotus albidus and Phellinus linteus. Antimicrobial activity, through the disc diffusion method, was found against strains of Bacillus cereus, B. subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus. P. albidus extracts showed better activity against Bacillus strains, whereas Ph. linteus extracts had greater effectiveness against S. aureus and P. aeruginosa. Aqueous extraction was best for obtaining bioactive compounds of P. albidus, whereas 30% hydralcoholic extraction performed best for obtaining Ph. linteus. Mass spectrometry analyses allowed the identification of the main chemical compounds extracted from the fungal biomasses, including glutathione oxidase, leucovorin, and riboflavin. Taking these findings into consideration, P. albidus and Ph. linteus might be used as sources of bioactive molecules for the development of novel drugs or nutraceuticals, contributing to the improvement of public health.

Biochemical characterization and biological properties of mycelium extracts from Lepista sordida GMA-05 and Trametes hirsuta GMA-01: new mushroom strains isolated in Brazil.

The objective of this study was to evaluate the antioxidant activity, determine and quantify the phenolic compounds and other compounds, and evaluate the cellular cytotoxicity of mycelium extracts of two new Basidiomycete mushrooms strains isolated in Brazil and identified as Lepista sordida GMA-05 and Trametes hirsuta GMA-01. Higher amounts of proteins, free amino acids, total and reducing carbohydrates, and phenolic compounds as chlorogenic, ferulic, caffeic, and gallic acids were found in extracts of T. hirsuta and L. sordida. Protocatechuic acid was found only in aqueous extracts of L. sordida. The TLC of the extracts showed the predominance of glucose and smaller amounts of xylose. It was observed through UPLC-MS higher amounts of phenolic compounds. The aqueous extract from T. hirsuta had the most noteworthy results in the antioxidant assays, especially the ABTS test. The cytotoxic activity was evaluated using two different cell lineages and showed higher toxicity for L. sordida in macrophages J774-A1. However, in Vero cells, it was 12.6-fold less toxic when compared to T. hirsuta. Thus, both mushrooms show potential as functional foods or additives, presenting phenolic content, antioxidant activity, and low cytotoxic activity in the tested cells.

The inhibitory action of purple tea on in vivo starch digestion compared to other Camellia sinensis teas.

In order to contribute to improve knowledge about the actions of Camellia sinensis extracts on starch digestion, several varieties were compared. The latter were green, oolong, white, black, and purple teas. The results are hoped to contribute to our understanding of the mode of action and potency of the various tea preparations as possible adjuvants in the control of post-prandial glycemia. The extracts were prepared in way similar to their form of consumption. All extracts decreased starch digestion, but the purple tea extract was the strongest inhibitor, their inhibitory tendency started at the dose of 50 mg/kg and was already maximal with 250 mg/kg. Maltose tolerance was not significantly affected by the extracts. Glucose tolerance was not affected by purple tea, but black tea clearly diminished it; green tea presented the same tendency. Purple tea was also the strongest inhibitor of pancreatic α-amylase, followed by black tea. The green tea, oolong tea, and white tea extracts tended to stimulate the pancreatic α-amylase at low concentrations, a phenomenon that could be counterbalancing its inhibitory effect on starch digestion. Based on chemical analyses and molecular docking simulations it was concluded that for both purple and black tea extracts the most abundant active component, epigallocatechin gallate, seems also to be the main responsible for the inhibition of the pancreatic α-amylase and starch digestion. In the case of purple tea, the inhibitory activity is likely to be complemented by its content in deoxyhexoside-hexoside-containing polyphenolics, especially the kaempferol and myricetin derivatives. Polysaccharides are also contributing to some extent. Cyanidins, the compounds giving to purple tea its characteristic color, seem not to be the main responsible for its effects on starch digestion. It can be concluded that in terms of postprandial anti-hyperglycemic action purple tea presents the best perspectives among all the tea varieties tested in the present study.

Evaluation of the Antioxidant and Antimicrobial Activity of the Culinary-Medicinal Mushroom Lentinula boryana (Agaricomycetes) from Brazil.

Mushrooms can be used in culinary applications, as a source of antioxidants, and for many therapeutic purposes. Foods are a natural source of antioxidant compounds, molecules that can inhibit oxidation of other molecules through the removal of free radicals, and thus play an important role in the protection of an organism's health. Phenolic compounds are secondary metabolites widely present in vegetables and mushrooms. Some studies highlight the capacity of mushrooms to produce antioxidant, antimicrobial, and antitumoral substances. This study aimed to evaluate the antioxidant capacity (with the ABTS, Trolox equivalent antioxidant capacity, and ferric reducing antioxidant power methods) and antimicrobial activity (disc diffusion method) of an Lentinula boryana isolate, using its mycelium as the primary material of study. The results showed that L. boryana has benefits such as antioxidant activity in medicinal and culinary uses.

Effects of a Myrciaria jaboticaba peel extract on starch and triglyceride absorption and the role of cyanidin-3-O-glucoside.

The purpose of this study was to perform a parallel and comparative investigation of the effects of a Myrciaria jaboticaba (common name jabuticaba) peel extract and of its constituent cyanidin-3-O-glucoside on the overall process of starch and triglyceride intestinal absorption. The peel extract inhibited both the porcine pancreactic α-amylase and the pancreatic lipase but was 13.6 times more potent on the latter (IC50 values of 1963 and 143.9 µg mL-1, respectively). Cyanidin-3-O-glucoside did not contribute significantly to these inhibitions. The jabuticaba peel extract inhibited starch absorption in mice at doses that were compatible with its inhibitory action on the α-amylase. No inhibition of starch absorption was found with cyanidin-3-O-glucoside doses compatible with its content in the extract. The extract also inhibited triglyceride absorption, but at doses that were considerably smaller than those predicted by its strength in inhibiting the pancreatic lipase (ID50 = 3.65 mg kg-1). In this case, cyanidin-3-O-glucoside was also strongly inhibitory, with 72% inhibition at the dose of 2 mg kg-1. When oleate + glycerol were given to mice, both the peel extract and cyanidin-3-O-glucoside strongly inhibited the appearance of triglycerides in the plasma. The main mechanism seems, thus, not to be the lipase inhibition but rather the inhibition of one or more steps (e.g., transport) in the events that lead to the transformation of free fatty acids in the intestinal tract into triglycerides. Due to the low active doses, the jabuticaba peel extract presents many favourable perspectives as an inhibitor of fat absorption and cyanidin-3-O-glucoside seems to play a decisive role.

Actions of multiple doses of resveratrol on oxidative and inflammatory markers in plasma and brain of healthy and arthritic rats.

The actions of resveratrol in brain and plasma of rats with adjuvant-induced arthritis were investigated. Resveratrol was administered orally during a period of 23 days. A major concern of the present work was to explore an ample range of daily doses (10-200 mg/kg). Several oxidative and inflammatory markers were measured. Important effects of resveratrol treatment were the normalization of the plasma myeloperoxidase activity (inflammatory marker), the normalization of the brain xanthine oxidase activity (reactive oxygen species source) and the near-normalization of the catalase activity in the brain (antioxidant defence). These effects presented obvious dose dependencies in the range up to 200 mg/kg. Resveratrol also reduced protein and lipid damage within the lowest dose ranges investigated, and its action as a free radical scavenger activity was enhanced in brain mitochondria of arthritic rats. Resveratrol failed in restoring the diminished albumin levels and plasma protein thiols in arthritic rats. The latter, however, were substantially increased in healthy rats at low doses (up to 50 mg/kg), a sign of antioxidant action. This increase was reversed at higher doses, a sign of pro-oxidant action. The observations agree with the notion that low doses of resveratrol might be useful as an adjuvant to the conventional antirheumatic drugs.

Potential anti-diabetic properties of Merlot grape pomace extract: An in vitro, in silico and in vivo study of α-amylase and α-glucosidase inhibition.

A practical approach to control glycemia in diabetes is to use plant natural products that delay hydrolysis of complex sugars and promote the diminution of the release of glucosyl units into the blood plasma. Polyphenolics have been described as being effective in inhibiting amylases and α-glucosidases. Grape pomace is an important sub product of the wine industry, still rich in many compounds such as polyphenolics. In this context, the purpose of this study was to search for possible effects of a grape pomace extract on salivary and pancreatic α-amylases and α-glucosidase, as well as on intestinal glucose absorption. The Merlot grape pomace extract (MGPE) was prepared using a hydroalcoholic mixture (40% ethanol + 60% water). In vitro inhibition was quantified using potato starch (for amylases) and maltose (for α-glucosidase) as substrates. In vivo inhibition was evaluated by running starch and maltose tolerance tests in rats with or without administration of MGPE. Ranking of the extract compounds for its affinity to the α-amylases was accomplished by computer simulations using three different programs. Both α-amylases, pancreatic and salivary, were inhibited by the MGPE. No inhibition on α-glucosidase, however, was detected. The IC50 values were 90 ± 10 µg/mL and 143 ± 15 µg/mL for salivary and pancreatic amylases, respectively. Kinetically this inhibition showed a complex pattern, with multiple binding of the extract constituents to the enzymes. Furthermore, the in silico docking simulations indicated that several phenolic substances, e.g., peonidin-3-O-acetylglucoside, quercetin-3-O-glucuronide and isorhamnetin-3-O-glucoside, besides catechin, were the most likely polyphenols responsible for the α-amylase inhibition caused by MGPE. The hyperglycemic burst, an usual phenomenon that follows starch administration, was substantially inhibited by the MGPE. Our results suggest that the MGPE can be adequate for maintaining normal blood levels after food ingestion.

Pigments and vitamins from plants as functional ingredients: Current trends and perspectives.

The food manufacturing industry has increasingly focused in the development of wholesome and safer products, including certified labeled "super foods," "healthy foods" and "functional foods," which are currently under great demand worldwide. Plant pigments and vitamins are amidst the most common additives incorporated to foodstuff, not only for improving their nutritional status but also for coloration, preservation, and even therapeutic purposes. The recovery of pigments from agro industrial wastes using green emerging approaches is a current trend and clearly the best alternative to ensure their sustainable obtainment and make these ingredients more popular, although still full of challenging aspects. Stability and bioavailability limitations of these active molecules in food matrices have been increasingly studied, and a number of methods have been proposed to minimize these issues, among which the incorporation of a co-pigment, exclusion of O2 during processing and storage, and above all, microencapsulation and nanoencapsulation techniques. The most recent advances and challenges in the application of natural pigments and vitamins in functional foods, considering only reports of the last 5 years, were the focus of this chapter.

Effects of Cooking and In Vitro Digestion on Antioxidant Properties and Cytotoxicity of the Culinary-Medicinal Mushroom Pleurotus ostreatoroseus (Agaricomycetes).

In this study we evaluated the antioxidant capacity, antimicrobial activity, and cytotoxicity of an aqueous extract of the Pleurotus ostreatoroseus mushroom, which was cooked. Fresh basidiocarps were heated and steamed at 100°C and the resulting aqueous extract was assessed before and after in vitro digestion. Cooking reduced the amounts of phenolic compounds in the extract. The antioxidant activity of the extract was evaluated through the use of 4 methods. The lowest half-maximal effective concentration (EC50) against ABTS radicals was 0.057 ± 0.002 mg/mL for the uncooked basidiocarp extract. Cooking and the digestive process led to decreased activity (P > 0.05) against ABTS and DPPH radicals. A significant increase in chelating activity (P > 0.05) occurred after the basidiocarps were cooked (EC50 = 0.279 ± 0.007 mg/mL). The reducing power did not significantly change among the different extracts. The uncooked basidiocarp extract was cytotoxic to Vero cells. After cooking and subsequent in vitro digestion, the cytotoxicity of the extracts decreased (P < 0.05). Bacillus subtilis, Staphylococcus aureus, and Candida albicans were sensitive to the fresh mushroom extract. The data showed that after being cooked and digested, the P. ostreatoroseus mushroom maintains antioxidant activity and has a low cytotoxic effect.

Antioxidant Action of an Aqueous Extract of Royal Sun Medicinal Mushroom, Agaricus brasiliensis (Agaricomycetes), in Rats with Adjuvant-Induced Arthritis.

The purpose of this study was to evaluate possible effects of the administration of an aqueous Agaricus brasiliensis extract on the oxidative state of the liver, brain, and plasma in adjuvant-induced arthritic rats, a model for human rheumatoid arthritis. Daily doses of 400 mg · kg-1 were administered by gavage for 23 days. This treatment produced significant diminutions in protein carbonylation and lipid damage in the liver, brain, and plasma. It also diminished the tissue reactive oxygen species and increased the antioxidant capacity of the plasma. Antioxidant defenses, which are diminished by arthritis, were improved by treatment with the A. brasiliensis extract, as revealed by preservation of the reduced glutathione and protein thiol levels and by the tendency of the activities of some antioxidant enzymes to normalize. The increased glucose-6-phosphate dehydrogenase activity was also almost normalized by the treatment. In addition, there were indications that A. brasiliensis can inhibit the initiation of structural events that can lead to hepatocyte necrosis. In conclusion, A. brasiliensis aqueous preparations can, in principle, be visualized as potential auxiliaries in the treatment of patients with rheumatoid arthritis as a result of their capacity to reduce oxidative stress. This effect was exerted in multiple organs, as can be judged from the results obtained in the liver, brain, and plasma. The continuous ingestion of A. brasiliensis as specific preparations or as a food supplement can possibly help to attenuate the systemic effects of rheumatoid arthritis and improve the quality of life of patients affected by this disease.

Development of a technique for psyllium husk mucilage purification with simultaneous microencapsulation of curcumin.

This study focused on evaluating a technique for the psyllium husk mucilage (PHM) purification with simultaneous microencapsulation of curcumin. PHM was extracted with water and purified with ethanol. For the mucilage purification and simultaneous microencapsulation, an ethanolic solution of curcumin was used. After dehydration, the samples were analysed by instrumental techniques and evaluated for thermal stability. The presence of curcumin in the solution did not impair the yield of precipitated polysaccharide. Interactions of the dye and carbohydrates were confirmed by displacement of peaks in FT-IR and FT-Raman spectroscopy. The onset temperature of degradation of microcapsules was superior to that of curcumin. Thermal stability in solution at 90°C also improved. After 300 minutes of heating, the microcapsules had a remnant curcumin content exceeding 70%, while, in standard sample, the remaining curcumin content was 4.46%. Thus, the developed technique was successful on purification of PHM and microencapsulation of curcumin.

The Metabolic Responses to L-Glutamine of Livers from Rats with Diabetes Types 1 and 2.

There are several claims about the beneficial effects of supplementing L-glutamine to both type 1 and type 2 diabetes. The purpose of the present study was to provide detailed knowledge about the fate of this amino acid in the liver, the first organ that receives the compound when ingested orally. The study was done using the isolated perfused rat liver, an experimental system that preserves the microcirculation of the organ and that allows to measured several parameters during steady-state and pre steady-state conditions. L-Glutamine was infused in the portal vein (5 mM) and several parameters were monitored. Livers from type 1 diabetic rats showed an accelerated response to L-glutamine infusion. In consequence of this accelerated response livers from type 1 diabetic rats presented higher rates of ammonia, urea, glucose and lactate output during the first 25-30 minutes following L-glutamine infusion. As steady-state conditions approached, however, the difference between type 1 diabetes and control livers tended to disappear. Measurement of the glycogen content over a period of 100 minutes revealed that, excepting the initial phase of the L-glutamine infusion, the increased glucose output in livers from type 1 diabetic rats was mainly due to accelerated glycogenolysis. Livers from type 2 diabetic rats behaved similarly to control livers with no accelerated glucose output but with increased L-alanine production. L-Alanine is important for the pancreatic ß-cells and from this point of view the oral intake of L-glutamine can be regarded as beneficial. Furthermore, the lack of increased glucose output in livers from type 2 diabetic rats is consistent with observations that even daily L-glutamine doses of 30 g do not increase the glycemic levels in well controlled type 2 diabetes patients.

Analysis of a whole diet in terms of phenolic content and antioxidant capacity: effects of a simulated gastrointestinal digestion.

This work compares the phenolic contents and the total antioxidant capacity of the 36 most popular Brazilian foods submitted to aqueous extraction or in vitro digestion. The purpose was to evaluate the extent by which digestion differs from the simple aqueous extraction procedures of several food matrices. After in vitro digestion, cereals, legumes, vegetables, tuberous vegetables, chocolates and fruits showed higher phenolic contents and higher antioxidant activities than those obtained by aqueous extraction. Contrarily, the digestion caused a reduction in the phenolic contents and antioxidant activities of beverages (red wine, coffee and yerba mate). Our results suggest that the phenolics of food groups with solid and complex matrix are protected against enzymatic action and alteration in pH during the digestion, what does not occur in liquid food matrices such as the beverages. This fact would overestimate the antioxidant activities of beverages submitted solely to aqueous extraction.

Fast hepatic biotransformation of p-synephrine and p-octopamine and implications for their oral intake.

Citrus aurantium (bitter orange) extracts have been used in products for weight management and sports performance. These extracts contain large amounts of p-synephrine and much smaller amounts of p-octopamine. Both protoalkaloids exert lipolytic and glycogenolytic activities at similar concentrations. The biotransformation of p-synephrine and p-octopamine is not as well-known as those of other adrenergic amines. For this reason transformation of these amines was investigated in the isolated perfused liver. Special attention was devoted to the single pass extraction of each compound as well as to the kinetics of uptake. The assay of the amines in the outflowing perfusate was done by means of high performance liquid chromatography (HPLC). The single pass extraction of p-synephrine was higher than 90% at a portal concentration of 10 µM. It declined with the concentration, but was still around 30% at the concentration of 500 µM. At low concentrations (10-50 µM) the decreasing sequence of single pass extractions was p-synephrine > p-octopamine ≈ epinephrine > norepinephrine. Rates of uptake versus p-synephrine concentration resulted in a Michaelis-Menten type of relationship, with a KM value of 290.7 ± 32.1 µM and a Vmax of 0.762 ± 0.042 µmol min(-1) g(-1). The rates of uptake of p-octopamine did not present clear saturation and could be approximated by a linear relationship with a first order rate constant of 1.5 min(-1). The rapid hepatic transformation of p-synephrine and p-octopamine means that their concentration in the portal vein exceeds that in the systemic circulation during absorption. Their metabolic effects will, thus, be exerted predominantly in the liver.

Oxidative changes in the blood and serum albumin differentiate rats with monoarthritis and polyarthritis.

Adjuvant arthritis in rats, as rheumatoid arthritis in humans, may be of greater or lesser severity, namely polyarthritis and monoarthritis, respectively. The present study was planned to evaluate the oxidative changes in the blood and specifically in the serum albumin of rats with adjuvant-induced mono- and poly-arthritis. Total antioxidant capacity, thiols, carbonyl groups, albumin, uric acid and ascorbic acid were measured in the total serum. The specific oxidative status of albumin was also measured after separation by affinity chromatography. All serum oxidative parameters were close to normal in monoarthritic rats with the exception of the ascorbic acid concentration, which was 23 % lower, and albumin carbonyl groups, which were 64 % higher. Many modifications were found in polyarthritic rats, specially the ascorbic acid concentration (35 % lower) and albumin carbonyl groups (102 % higher). The results revealed that the levels of ascorbic acid in the serum and carbonyl groups in the albumin molecule can be regarded as indicators of the severity of arthritis since they were modified by both monoarthritis and polyarthritis, but to different degrees.