Garcinielliptone FC, a polyisoprenylated benzophenone fromPlatonia insignisMart., promotes vasorelaxant effect on rat mesenteric artery

Inhibitory effects against SARSCoV-2 main protease (Mpro) of biflavonoids and benzophenones from the fruit of Platonia insignis

The SARS-CoV-2 mutation and the limitation of the approved drug against COVID-19 are still a challenge in many country healthcare systems and need to be affronted despite the set of vaccines to prevent this viral infection. To contribute to the identification of new antiviral agents, the present study focused on natural products from an edible fruit with potential inhibitory effects against the SARS-CoV-2 main protease (Mpro). First, LC-ESIMS analysis of Platonia insignis fruits was performed and showed the presence of biflavonoids and benzophenones in the seed and pulp, respectively. Then, maceration and chromatographic purification led to the identification of two triglycerides (1 and 2) alongside chamaejasmine (3) and volkensiflavone (4) from the seed and isogarcinol (5) and cycloxanthochymol (6), from the pulp. Compounds 1-6 after evaluating their inhibitory against Mpro, displayed from no to significant activity. Compound 5 was the most potent with an IC50 value of 0.72 μM and was more active than the positive control, Ebselen (IC50 of 3.4 μM). It displayed weak and no cytotoxicity against THP-1 (CC50 of 116.2 μM) and Vero cell lines, respectively. Other active compounds showed no cytotoxicity against THP-1. and Vero cell lines. Molecular docking studies revealed interactions in the catalytic pocket between compound 5 and amino acid residues that composed the catalytic dyads (His 41 and Cyst 145).

Total synthesis and structural reassignment of garcinielliptone FC, a polycyclic polyprenylated acylphloroglucinol with diverse bioactivity

Garcinielliptone FC (GFC) was assigned to be a type A polycyclic polyprenylated acylphloroglucinol (PPAP) and was found to exhibit diverse biological activities. Now we revise the structure of GFC to xanthochymol, a type B PPAP, via NMR and total synthesis methods. The total syntheses of (±)-xanthochymol and (±)-cycloxanthochymol were accomplished in 12 and 13 steps, respectively.

Effects of “Bacuri” Seed Butter (Platonia insignis Mart.), a Brazilian Amazon Fruit, on Oxidative Stress and Diabetes Mellitus-Related Parameters in STZ-Diabetic Rats

Simple Summary

The abnormal glucose metabolism present in diabetes mellitus causes several complications in different metabolic pathways and different organs. Chronic hyperglycemia promotes an imbalance between ROS production and antioxidant defense, causing oxidative stress, which contributes to damage in the body. The properties of natural products in diabetes mellitus research have been investigated to assist in the treatment. In this study, the effects of 28 days of oral administration of bacuri seed butter (Platonia insignis Mart.) was investigated on blood glucose, HbA1c, and liver and kidney function, as well as antioxidant defense in streptozotocin-induced female rats. Bacuri seed butter presented a positive effect on glycemic control, evidenced by a decrease in the percentage of glycated hemoglobin. Interestingly, the treatment also promoted increased hepatic antioxidant defenses and reduced liver damage, demonstrating a hepatoprotective effect.

Abstract

This study aimed to investigate the effects of oral administration of Platonia insignis Mart. (“bacuri”) seed butter (BSB) on oxidative stress and diabetes mellitus-related parameters in streptozotocin-induced (STZ) diabetic rats. Diabetes mellitus was induced in female Wistar rats (180–250 g) by the intraperitoneal administration of STZ (45 mg/kg, b.w). BSB (25, 50, and 100 mg/kg) was administered to animals for four weeks. The effect on weight gain, food intake, blood glucose, glycated hemoglobin, hepatic transaminases, plasma and liver TBARS and MPO activity, erythrocyte SOD activity, non-protein sulfhydryl groups (SH-NP), and histopathology of the liver tissue was investigated. BSB at the dose of 100 mg/kg had a positive effect on the reduction in glycated hemoglobin percentage and increased albumin concentration, as well as decreased ALT and AST levels and increased SH-NP liver levels in treated animals compared to normal control rats. Moreover, BSB had no effects on weight gain, food intake, and fasting glucose. Thus, the BSB presented marked properties in improvement of hepatic antioxidant defenses, which demonstrates BSB as a potential hepatoprotective agent in metabolic disorders.

The ethnobotanical relevance of the tribe Symphonieae (Clusiaceae) around the world

ETHNOPHARMACOLOGICAL RELEVANCE

The tribe Symphonieae (Clusiaceae) encompasses 48 species accommodated in seven genera (Lorostemon, Montrouziera, Moronobea, Pentadesma, Platonia, Symphonia and Thysanostemon). Parts of these plants, mainly the exudates and the seeds oil are useful for different purposes, especially for treating dermatological conditions. In addition to the role in the folk medicine, some species are of great economic and cultural importance for native people from different continents.

AIM OF THE REVIEW

The goal of this review is to critically summarize the current knowledge on systematics, ethnobotanical, chemical and pharmacological aspects of species from the tribe Symphonieae, as well as to provide support for future taxonomic and phylogenetic studies on the Clusiaceae family.

MATERIALS AND METHODS

The available information was gathered from many different databases (Web of Science, ScienceDirect, Scopus, Pubmed, ChemSpider, SciFinder, ACS Publications, Wiley Online Library, Useful Tropical Plants Database, Google Scholar). Additional data from books, theses and dissertations were also included in this review.

RESULTS

Chemical studies of Symphonieae have demonstrated that the genera are a source of benzophenones, xanthones and biflavonoids. Components as sesquiterpenoids, triterpenoids, flavonoids, free fatty acids, among others, have also been reported. Extracts and compounds isolated from a variety of species have been exhibiting antimicrobial, cytotoxic and antiprotozoal activities, corroborating part of their medicinal uses. In addition, certain species produce edible fruits and a kind of "butter" with economic importance. All species produce exudate, which often has great relevance in the daily lives of local people.

CONCLUSION

Several species of Symphonieae have potential therapeutic applications and some of them have been investigated to scientifically validate their popular uses. In addition, a number of species have proved to be a rich source of promising pharmacologically active compounds. Finally, the value of fruits, exudate and butter, for instance, should serve as a stimulus for the sustainable development of products that aim to take advantage of these natural resources.

Toxicity, cytotoxicity, mutagenicity and in vitro antioxidant models of 2-oleyl-1,3-dipalmitoyl-glycerol isolated from the hexane extract of Platonia insignis MART seeds

2-oleyl-1,3-dipalmitoyl-glycerol (ODG) was obtained from Platonia insignis (bacurizeiro) seeds. There are no studies on its toxicity and protective activities against oxidative stress. This study was aimed to evaluate antioxidant effects in vitro, as well as to evaluate the toxicological and mutagenic effects of the ODG. ODG showed a median lethal dose (LD₅₀) greater than 1200 μg mL^-1 in A. salina. In the assay of A. cepa (0.2-0.002 mg mL^-1) the ODG compound at the highest concentration was slightly cytotoxic with decrease in the size of roots and mitotic indexes, but did not induce chromosomal alterations. ODG (8.75-140.00 μg mL^-1) was found to reduce nitric oxide production by 41.6 %, while the antioxidant standard ascorbic acid (AA) reduced 54.14 %. ODG (15.625-250.00 μg mL^-1) promoted removal of the hydroxyl radical by 35.69 % at the highest concentration and was able to prevent lipid peroxidation induced by 2,2'-azobis-2-amidinopropane (AAPH), inhibiting the amount of TBARS formed, up to 35.69 %, a result close to that obtained with AA. Thus, ODG moderately reduced the levels of hydroxyl radicals, nitric oxide, and TBARS in vitro and was nontoxic at low concentrations.

Garcinielliptone FC: Selective anti-amastigote and immunomodulatory effects on macrophages infected by Leishmania amazonensis

The present study was directed to the in vitro antileishmanial, cytotoxic and immunomodulatory effects of Garcinielliptone FC (GFC) against promastigote and macrophage-internalized amastigote forms of Leishmania amazonensis. GFC showed in vitro cytotoxicity against BALB/c peritoneal macrophages with CC₅₀ of 74.90 μM. The hemolytic activity against sheep erythrocytes only demonstrated a decrease of 20.42% in cell viability at the highest tested concentration tested (1326.0 μM). GFC promoted in vitro growth inhibition of both promastigote and intracellular amastigotes with IC₅₀ values of 14.06 and 1.91 μM, respectively, with 7.3-fold higher Selectivity Index (SI) for intracellular amastigotes (SI = 39.21) than for promastigotes (SI = 5.33). Interestingly, the pre-treatment of macrophages or promastigotes with GFC promoted decrease of infected macrophages and number of recovered amastigotes, respectively. Also, GFC was able to markedly promote macrophages activation by increase of phagocytic capability and nitrite production at concentrations able to solve infection of macrophages by L. amazonensis, suggesting the possible involvement of immunomodulatory modulation of macrophages leading to solve the infection. GFC is an emerging and promising chemical compound for the studies focused on the assessment of its therapeutic potential on in vivo experimental models of leishmaniasis.

A 28-day Sub-acute Genotoxic and Behavioural Assessment of Garcinielliptone FC

Garcinielliptone FC (GFC) is a polyisoprenylated benzophenone isolated from Platonia insignis Mart (Clusiaceae) with promising anticonvulsant properties. However, its safe use and other effects on the central nervous system require assessment. This study assessed the toxicological effects of GFC using the comet assay and the micronucleus test in mice treated for 28 days. A behavioural model was employed to detect possible injuries on the central nervous system. Mice treated with GFC (2, 10 and 20 mg/kg; i.p.) daily for 28 days were submitted to rotarod test, open-field test and tail suspension test (TST). After the behaviour tasks, biological samples were assessed to evaluate genotoxic and mutagenic effects using the comet assay and the micronucleus test. Garcinielliptone FC did not impair the performance of the animals in the rotarod and open-field tests, with no antidepressant-like effect in TST. No genotoxic effects in blood and cerebral cortex were observable in the comet assay; however, there was a significant increase in index and frequency of damage in liver after treatment with GFC 20 mg/kg. Garcinielliptone FC did not increase micronucleus frequency in bone marrow. At the tested doses, GFC was not toxic to the CNS and did not induce genotoxic damage to blood or bone narrow cells. DNA damage to liver tissue was caused only by the highest dose, although no mutagenic potential was observed.

Research Progress of Polycyclic Polyprenylated Acylphloroglucinols

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of hybrid natural products sharing the mevalonate/methylerythritol phosphate and polyketide biosynthetic pathways and showing considerable structure and bioactivity diversity. This review discusses the progress of research into the chemistry and biological activity of 421 natural PPAPs in the past 11 years as well as in-depth studies of biological activities and total synthesis of some PPAPs isolated before 2006. We created an online database of all PPAPs known to date at http://www.chem.uky.edu/research/grossman/PPAPs . Two subclasses of biosynthetically related metabolites, spirocyclic PPAPs with octahydrospiro[cyclohexan-1,5'-indene]-2,4,6-trione core and complicated PPAPs produced by intramolecular [4 + 2] cycloadditions of MPAPs, are brought into the PPAP family. Some PPAPs' relative or absolute configurations are reassigned or critically discussed, and the confusing trivial names in PPAPs investigations are clarified. Pharmacologic studies have revealed a new molecular mechanism whereby hyperforin and its derivatives regulate neurotransmitter levels by activating TRPC6 as well as the antitumor mechanism of garcinol and its analogues. The antineoplastic potential of some type B PPAPs such as oblongifolin C and guttiferone K has increased significantly. As a result of the recent appearances of innovative synthetic methods and strategies, the total syntheses of 22 natural PPAPs including hyperforin, garcinol, and plukenetione A have been accomplished.