Study on the Antinociceptive Activity and Mechanism of Action of Isolated Saponins from Siolmatra brasiliensis (Cogn.) Baill

Antinociceptive in vivo activity and chemical profiling by UHPLC-MS/MS of stem bark and leaves extracts of Ficus maxima Mill. (Moraceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Ficus maxima is a medicinal plant extensively used in traditional medicine by Indigenous peoples across Central and South America. It is a member of the family Moraceae, subgenus Pharmacosycea, employed in treating various conditions, including intestinal parasites, gingivitis, internal inflammations, and snake bites. Despite its significant pharmacological potential, the species remains underrepresented in scientific literature.

AIM OF THE STUDY

This study aimed to evaluate the in vivo antinociceptive properties of leaf (ELFM) and stem bark (EBFM) extracts from Ficus maxima. Additionally, the chemical composition of these extracts was determined using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).

MATERIALS AND METHODS

Plant material was collected in Abaetetuba, Pará, Brazil, in October 2013 and subjected to static maceration to obtain crude ELFM and EBFM. Bio-guided fractionation was performed by sequential liquid-liquid partitioning with hexane (Hex), dichloromethane (DCM), and ethyl acetate (EtOAc), yielding the following fractions: ELFM-Hex and EBFM-Hex, ELFM-DCM and EBFM-DCM, and ELFM-EtOAc and EBFM-EtOAc. The biological activity of EBFM, ELFM, and their respective fractions were evaluated using the formalin-induced pain test and the hot plate test, followed by an assessment of their mechanisms of action. The UHPLC-MS/MS analysis was conducted using electrospray ionization (ESI) in both positive and negative modes. Metabolite annotation was facilitated by MS/MS libraries and molecular networks constructed on the GNPS platform.

RESULTS

The reactivity time to formalin in the neurogenic phase was reduced from 84.7 ± 7.6 s (100%) to 37.3 ± 4.7 s (44%), 33.1 ± 6.3 s (39%), 40.7 ± 7.4 s (48%), 57.2 ± 2.6 s (77%), 49.7 ± 4.1 s (58%), 46.8 ± 8.1 s (55%), and 52.4 ± 5.3 s (61%) after treatment with ASA, morphine, EBFM, ELFM, ELFM-Hex, ELFM-DCM, and ELFM-EtOAc at doses of 30 mg/kg, respectively. In the inflammatory phase, the reactivity time to formalin was reduced from 124.3 ± 25.9 s (100%) to 49.7 ± 4.7 s (40%), 9.8 ± 4.3 s (8%), 32.5 ± 8.5 s (26%), 59.8 ± 16.8 s (48%), and 54.4 ± 7.3 s (44%) after treatment with ASA, morphine, EBFM, ELFM, and ELFM-Hex at doses of 30 mg/kg, respectively. A reversal of the antinociceptive action of EBFM and ELFM was observed in the inflammatory phase after treatment with atropine, a muscarinic antagonist, and naloxone, an opioid antagonist, respectively. In the hot plate test, EBFM showed Antinociceptive Activity (AA) of 62.6 ± 9.2% after 90 min; however, there was a reversal of AA to 8.6 ± 2.8% when naloxone was used. The UHPLC-MS/MS metabolite analysis revealed the presence of loliolide (3), luteolin (13), lupeol (14), gallic acid (15), chlorogenic acid (16), pygenic acid A (17), and other metabolites from the alkaloids and fatty acids classes.

Mechanisms of action of ethyl acetate fractions of Liparis nervosa (Thunb.) Lindl. as potential central anti-nociceptive agents

Opioids/non-steroidal anti-inflammatory drugs are used to alleviate pain; however, they are expensive and can have adverse effects, especially when used over extended periods. Therefore, there is immense demand for innovative, non-addictive analgesics. Here, we report a novel plant-derived central anti-nociceptive agent, Liparis nervosa (Thunb.) Lindl. (LN), validated in animal pain models. Ethyl acetate fractions of L. nervosa (EALN) exhibited central anti-nociceptive activity in hot plate, tail immersion, formalin-induced paw oedema, and acetic acid-induced abdominal writhing tests. The chemical composition of the EALN was determined using ultra-high-performance liquid chromatography-mass spectrometry. Reserpine (monoamine transmitter-depleting agent) and naltrexone (opioid antagonist) partially suppressed the anti-nociceptive effect of EALN in both phases of the formalin test. Oral administration of EALN activated the endogenous opioid and central descending inhibitory systems by increasing β-endorphin, 5-hydroxytryptamine, and norepinephrine expression. EALN treatment increased the expression of γ-aminobutyric acid B; inhibited the expression of prostaglandin E2, substance P, calcitonin gene-related peptide, and c-Fos; and blocked the transmission of pain signals in the spinal cord. EALN treatment reduced the activity of nitric oxide and nitric oxide synthase in the central region and inhibited the nitric oxide-cyclic guanosine monophosphate signal transduction pathway, thereby attenuating the transmission of nociceptive information in the descending inhibitory pathways. The central anti-nociceptive effect of EALN was achieved by integrating these pathways. This study provides new insights into the pharmacologic action of LN and provide a therapeutic approach as a promising candidate for central anti-nociceptive agents.

A Comprehensive Review of Ethnomedicinal Uses, Phytochemistry, Pharmacology, and Toxicity of Prunus africana (Hook. F.) Kalkman from Africa

Prunus africana, a widely utilized medicinal plant in various African ethnic communities, continues to hold significant importance in traditional healing practices. Research has identified phytochemical compounds in this plant, exhibiting diverse pharmacological activities that offer potential for pharmaceutical development. Notably, P. africana is employed in treating various ailments such as wounds, diabetes mellitus, malaria, benign prostatic hyperplasia, chest pain, and prostate cancer. Its pharmacological properties are attributed to a spectrum of bioactive compounds, including tannins, saponins, alkaloids, flavonoids, terpenoids, phytosterols, and fatty acids. Multiple studies have documented the anti-inflammatory, antimicrobial, antiandrogenic, antiangiogenic, antioxidant, antidipeptidyl peptidase-4 activity, analgesic, and astringent properties of P. africana extracts. This review offers a comprehensive compilation of ethnomedicinal applications, phytochemical composition, pharmacological effects, and toxicity assessments of P. africana, serving as a foundation for future preclinical and clinical investigations. By understanding its traditional uses and chemical constituents, researchers can target specific medical conditions with greater precision, potentially expediting the development of safe and effective pharmaceuticals. Moreover, toxicity assessments provide crucial insights into the safety profile of P. africana extracts, ensuring the development of safe pharmaceuticals to treat various diseases.

Safety Assessment and Pain Relief Properties of Saffron from Taliouine Region (Morocco)

Saffron is the most expensive spice in the world. In addition to its culinary utilization, this spice is used for medicinal purposes such as in pain management. In this study, the analgesic activity of Crocus sativus stigma extract (CSSE) was evaluated in rodents and its possible physiological mechanism was elucidated. The anti-nociceptive effect of CSSE was evaluated using three animal models (hot plate, writhing, and formalin tests). The analgesic pathways involved were assessed using various analgesia-mediating receptors antagonists. The oral administration of CSSE, up to 2000 mg/kg, caused no death or changes in the behavior or in the hematological and biochemical blood parameters of treated animals nor in the histological architecture of the animals’ livers and kidneys. CSSE showed a central, dose-dependent, anti-nociceptive effect in response to thermal stimuli; and a peripheral analgesic effect in the test of contortions induced by acetic acid. The dual (central and peripheral) analgesic effect was confirmed by the formalin test. The anti-nociceptive activity of CSSE was totally or partially reversed by the co-administration of receptor antagonists, naloxone, atropine, haloperidol, yohimbine, and glibenclamide. CSSE influenced signal processing, by the modulation of the opioidergic, adrenergic, and muscarinic systems at the peripheral and central levels; and by regulation of the dopaminergic system and control of the opening of the ATP-sensitive K⁺ channels at the spinal level. The obtained data point to a multimodal mechanism of action for CSSE: An anti-inflammatory effect and a modulation, through different physiological pathways, of the electrical signal generated by the nociceptors. Further clinical trials are required to endorse the potential utilization of Moroccan saffron as a natural painkiller.

Anti-inflammatory, Analgesic, and Cytotoxic Effects of The Phytexponent: A Polyherbal Formulation

The Phytexponent is used to treat pain and inflammation in complementary and alternative medicine practices; however, empirical data supporting its pharmacological efficacy and safety is scanty, hence the present study. We used the carrageenan-induced paw oedema and the acetic acid-induced writhing techniques to determine the anti-inflammatory and analgesic efficacies, respectively, of the Phytexponent in Swiss albino mice models. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay technique was used to investigate the in vitro cytotoxic effects of the Phytexponent in the Vero E6 cell line. The Phytexponent exerted significant (P < .05) anti-inflammatory effects in the carrageenan-induced paw oedema mouse model in a dose- and time-dependent manner, with significantly higher efficacy at 250 mg/Kg BW, than indomethacin (4 mg/Kg BW), in the first, second, and third hour (P < .05). Besides, the Phytexponent significantly reduced the acetic acid-induced writhing frequency in mice (P < .05), in a dose-dependent manner, depicting its analgesic efficacy. Notably, the Phytexponent (at doses: 125 mg/Kg BW and 250 mg/Kg BW) exhibited significantly higher analgesic efficacy than the Indomethacin (P<.05). Moreover, the Phytexponent was not cytotoxic to Vero E6 cells (CC₅₀ >1000 µg/ml) compared to cyclophosphamide (CC₅₀ = 2.48 µg/ml). Thus, the Phytexponent has significant in vivo anti-inflammatory and analgesic efficacy in mice models and is not cytotoxic to Vero E6 cell line, depicting its therapeutic potential upon further empirical investigation.

Special Issue "Plant Extracts: Biological and Pharmacological Activity"

The use of plant extracts for therapeutic purposes knows a wide diffusion [...].

Machaerium hirtum (Vell.) Stellfeld Alleviates Acute Pain and Inflammation: Potential Mechanisms of Action

Machaerium hirtum (Vell.) Stellfeld (Fabaceae) known in Brazil as “jacaranda de espinho” or “espinheira santa nativa” is a medicinal plant commonly used in folk medicine to treat ulcers, cough and diarrhea. This study aimed to investigate the anti-inflammatory and antinociceptive effects of hydroalcoholic extracts from M. hirtum twig (HEMh) using in vivo experimental models of nociception through the involvement of transient receptor potential channels, acid-sensing ion channel (ASIC), nitrergic, opioidergic, glutamatergic, and supraspinal pathways. Our results revealed an antinociceptive effect of HEMh mediated by the opioidergic, l-arginine-nitric oxide and glutamate systems, as well as by interactions with TRPA1/ASIC channels. The anti-inflammatory effect of HEMh evaluated with a xylene-induced ear edema and by the involvement of arachidonic acid and prostaglandin E2 (PGE₂) showed involvement of the COX pathway, based on observed decreases in PGE₂ levels. A phytochemical investigation of the HEMh led to the isolation of α-amyrin, β-amyrin, allantoin, apigenin-7-methoxy-6-C-β-d-glucopyranoside, and apigenin-6-C-β-d-glucopyranosyl-8-C-β-d-xylopyranoside. In conclusion, the acute oral administration of HEMh inhibits the nociceptive behavioral response in animals through the nitrergic, opioid, glutamatergic pathways, and by inhibition of the TRPA1 and ASIC channels, without causing locomotor dysfunction. In addition, its anti-inflammatory effect is associated with the COX pathway and decreased PGE₂ levels.