Characterization of anti-inflammatory effect and possible mechanism of action of Tibouchina granulosa

Toxicity Potential of Nutraceuticals

During the past few decades and especially during and after the COVID-19 pandemic, the use of nutraceuticals has become increasingly popular in both humans and animals due to their easy access, cost-effectiveness, and tolerability with a wide margin of safety. While some nutraceuticals are safe, others have an inherent toxic potential. For a large number of nutraceuticals, no toxicity/safety data are available due to a lack of pharmacological/toxicological studies. The safety of some nutraceuticals can be compromised via contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, drugs of abuse, etc. Knowledge of pharmacokinetic/toxicokinetic studies and biomarkers of exposure, effect, and susceptibility appears to play a pivotal role in the safety and toxicity assessment of nutraceuticals. Interaction studies are essential to determine efficacy, safety, and toxicity when nutraceuticals and therapeutic drugs are used concomitantly or when polypharmacy is involved. This chapter describes various aspects of nutraceuticals, particularly their toxic potential, and the factors that influence their safety.

Tibouchina granulosa Leaves Present Anti-Inflammatory Effect

The ethanol extract (EE) prepared from the leaves of Tibouchina granulosa, and its fraction in ethyl acetate (fEA) were evaluated concerning their capacity to reduce inflammation in different experimental models. fEA was also studied concerning its chemical constituents. EE and fEA were assayed for their anti-inflammatory potential, using formalin-induced licking behavior and carrageenan-induced inflammation into the subcutaneous air pouch (SAP) models. Reduction in polymorphonuclear cells (PMN) activation was performed in freshly isolated PMN. Chromatographic analysis of fEA was performed by HPLC-DAD. Hispiduloside was isolated as the main constituent in fEA, and its quantity was estimated to be 39.3% in fEA. EE (30 mg/kg) significantly reduced the second phase of formalin-induced licking. fEA demonstrated a reduction in leukocyte migration into the SAP. EE and fEA drastically reduced cytokines (TNF-α, IL-1β, and IFN-γ), nitric oxide (NO) production, in vitro PMN migration induced by C5a and IL-8, and TNF-α and IL-1β gene expression. Taken together, our data indicate that either ethanol extract or its fEA fraction from leaves of T. granulosa present an anti-inflammatory effect, contributing to the pharmacological and chemical knowledge of this species and confirming the rationale behind its traditional use.

Proanthocyanidins Inhibit the Transmission of Spinal Pain Information Through a Presynaptic Mechanism in a Mouse Inflammatory Pain Model

Inflammatory pain is one of the most common symptoms of clinical pain that seriously affects patient quality of life, but it currently has limited therapeutic options. Proanthocyanidins, a group of polyphenols enriched in plants and foods, have been reported to exert anti-inflammatory pain-alleviating effects. However, the mechanism by which proanthocyanidins relieve inflammatory pain in the central nervous system is unclear. In the present study, we observed that intrathecal injection of proanthocyanidins inhibited mechanical and thermal pain sensitivity in mice with inflammatory pain induced by Complete Freund’s Adjuvant (CFA) injection. Electrophysiological results further showed that proanthocyanidins inhibited the frequency of spontaneous excitatory postsynaptic currents without affecting the spontaneous inhibitory postsynaptic currents or the intrinsic properties of parabrachial nucleus-projecting neurons in the spinal cord. The effect of proanthocyanidins may be mediated by their inhibition of phosphorylated activation of the PI3K/Akt/mTOR pathway molecules in dorsal root ganglia neurons. In summary, intrathecal injection of procyanidin induces an obvious anti-inflammatory pain effect in mice by inhibiting peripheral excitatory inputs to spinal neurons that send nociceptive information to supraspinal areas.

Phytochemical composition and biological activities of extracts from ten species of the family Melastomataceae Juss

Plants possess a renewable source of metabolites with enormous chemical structural diversity, which may have potential therapeutic relevance. Furthermore, this chemical diversity favors the possibility of finding new and different chemical constituents with antimicrobial, antioxidant and anti-tumor activities. This work analyzed preliminary phytochemical profiles and evaluated the antimicrobial, antioxidant and cytotoxic activities of hexane extracts of leaves of ten species of the family Melastomataceae. Phytochemical screening was performed using staining methods while total phenols and flavonoids were quantified by spectrophotometry. Antimicrobial activity was evaluated using the disk diffusion method. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazil (DPPH) method. Toxicity was recorded using the lethality test with Artemia salina Leach (1819). Cytotoxic activity of the extracts was assessed in vitro with acute monocytic leukemia cells (THP-1). Phytochemical analysis detected the presence of tannins, terpenes, steroids, polyphenols and flavonoids and the absence of alkaloids. Clidemia capitellata (Bonpl.) D. Don had the greatest amount of polyphenols (205.95 mg/g ± 4.14) while Clidemia hirta (L.) D. Don had the highest content of total flavonoids (143.99 mg/g ± 4.18). The hexane extracts did not show antimicrobial activity nor toxicity against Artemia salina. The extract of Tibouchina francavillana Cogn. was the most active in sequestering the DPPH radical. The extracts showed cytotoxicity in THP-1 cells with the appearance of apoptotic bodies and cell death. The extracts of Miconia amoena, Clidemia sericea and Clidemia capitellata are non-toxic against Artemia salina and induce the formation of apoptotic bodies and cell death of the THP-1 lineage.

Nutraceuticals: Transformation of Conventional Foods into Health Promoters/Disease Preventers and Safety Considerations

Nutraceuticals are essential food constituents that provide nutritional benefits as well as medicinal effects. The benefits of these foods are due to the presence of active compounds such as carotenoids, collagen hydrolysate, and dietary fibers. Nutraceuticals have been found to positively affect cardiovascular and immune system health and have a role in infection and cancer prevention. Nutraceuticals can be categorized into different classes based on their nature and mode of action. In this review, different classifications of nutraceuticals and their potential therapeutic activity, such as anti-cancer, antioxidant, anti-inflammatory and anti-lipid activity in disease will be reviewed. Moreover, the different mechanisms of action of these products, applications, and safety upon consumers including current trends and future prospect of nutraceuticals will be included.

Tibouchina granulosa (Vell.) Cogn (Melastomataceae) as source of endophytic fungi: isolation, identification, and antiprotozoal activity of metabolites from Phyllosticta capitalensis

Endophytes are microorganisms that form symbiotic relationships with their own host. Included in this group are the species Phyllosticta capitalensis, a group of fungi that include saprobes that produce bioactive metabolites. The present study aimed to identify the cultivable endophytic fungal microbiota present in healthy leaves of Tibouchina granulosa (Desr.) Cogn. (Melastomataceae) and investigate secondary metabolites produced by a strain of P. capitalensis and their effects against both Leishmania species and Trypanossoma cruzi. Identification of the strains was accomplished through multilocus sequencing analysis (MLSA), followed by phylogenetic analysis. The frequency of colonization was 73.66% and identified fungi belonged to the genus Diaporthe, Colletotrichum, Phyllosticta, Xylaria, Hypoxylon, Fusarium, Nigrospora, and Cercospora. A total of 18 compounds were identified by high-resolution mass spectrum analysis (UHPLC-HRMS), including fatty acids based on linoleic acid and derivatives, from P. capitalensis. Crude extracts had activity against Leishmania amazonensis, L. infantum, and Trypanosoma cruzi, with inhibitory concentration (IC50) values of 17.2 μg/mL, 82.0 μg/mL, and 50.13 μg/mL, respectively. This is the first report of the production of these compounds by the endophytic P. capitalensis isolated from T. granulosa.

Chemistry and Pharmacology of the Kazakh Crataegus Almaatensis Pojark: An Asian Herbal Medicine

Crataegus almaatensis, an endemic ornamental plant in Kazakhstan is used in popular medicine due to its cardiotonic properties. The most studied species of the same genus are commonly found in Europe, which shows the importance of having the Kazakh species validated via its chemical and pharmacological studies. High-speed countercurrent chromatography (HSCCC) operated under optimized conditions enabled an isolation of the three main compounds from the aqueous phase of the leaves ethanol extract, further identified by nuclear magnetic resonance (NMR), as quercetin 3-O-rhamnoside (quercitrin) (4.02% of the crude extract-CECa); quercetin 3-O-β-galactoside (hyperoside) (1.82% of CECa); kaempferol 3-O-α-L-rhamnoside (afzelin) (0.94% of CECa). The CECa, the aqueous phase of the crude extract (APCa) together with the isolates were evaluated for their vascular (vascular reactivity in human internal mammary artery-HIMA), anti-nociceptive (formalin-induced liking response and hot plate) and anti-inflammatory (subcutaneous air-pouch model-SAP) activities. CECa at the concentrations of 0.014 and 0.14 mg/mL significantly increased the maximum contractility response of HIMA to noradrenaline. The APCa CR curve (0.007–0.7 mg/mL) showed an intrinsic relaxation effect of the HIMA. APCa at the dose of 100 mg/kg i.p. significantly decreased the total leukocyte count and the IL-1β release in the SAP wash.

Acylated Flavonoid Glycosides are the Main Pigments that Determine the Flower Colour of the Brazilian Native Tree Tibouchina pulchra (Cham.) Cogn

Tibouchina pulchra (Cham.) Cogn. is a plant native to Brazil whose genus and family (Melastomataceae) are poorly studied with regards to its metabolite profile. Phenolic pigments of pink flowers were studied by ultra-performance liquid chromatography with a photodiode array detector and electrospray ionization quadrupole time-of-flight mass spectrometry. Therein, twenty-three flavonoids were identified with eight flavonols isolated by preparative high-performance liquid chromatography and analysed by one- and two-dimensional nuclear magnetic resonance. Kaempferol derivatives were the main flavonols, encompassing almost half of the detected compounds with different substitution patterns, such as glucoside, pentosides, galloyl-glucoside, p-coumaroyl-glucoside, and glucuronide. Concerning the anthocyanins, petunidin p-coumaroyl-hexoside acetylpentoside and malvidin p-coumaroyl-hexoside acetylpentoside were identified and agreed with previous reports on acylated anthocyanins from Melastomataceae. A new kaempferol glucoside was identified as kaempferol-(2''-O-methyl)-4'-O-α-d-glucopyranoside. Moreover, twelve compounds were described for the first time in the genus with five being new to the family, contributing to the chemical characterisation of these taxa.

Toxicity Potential of Nutraceuticals

By the turn of the twenty-first century, the use of nutraceuticals became increasingly popular in both humans and animals due to their easy access, cost-effectiveness, and tolerability with a wide margin of safety. While some nutraceuticals are safe, others have a toxic potential. For a large number of nutraceuticals, no toxicity/safety data are available due to a lack of pharmacological/toxicological studies. The safety of some nutraceuticals can be compromised via contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, drugs of abuse, etc. Knowledge of pharmacokinetic/toxicokinetic studies appears to play a pivotal role in safety and toxicity assessment of nutraceuticals. Interaction studies are essential to determine efficacy, safety, and toxicity when nutraceuticals and therapeutic drugs are used concomitantly. This chapter describes various aspects of nutraceuticals, particularly their toxic potential, and the factors influencing their safety.