Phytochemical and Antinociceptive, Anti-Inflammatory, and Antioxidant Studies of Smilax larvata (Smilacaceae)

Phenolic compounds profile in extracts of Smilax spp., antioxidant activity, and inhibition of advanced glycation end products

Smilax genus possesses bioactive properties attributed to phenolic compounds, which may exhibit antioxidant effects and inhibit the advanced glycation end products (AGEs). However, identifying these phenolic compounds and AGEs has become increasingly relevant to understanding such activities. This study aimed to identify phenolic compounds in extracts of Smilax spp. and evaluate their antioxidant and AGEs inhibitory activities. To achieve this, the Smilax genus was identified via PCR, and phenolic compounds including chlorogenic acid, naringenin-6-C-glucoside, quercetin, quercetin-3-O-glucoside, and myricetin were identified using HPLC-MS/MS. Antioxidant activity was assessed by ferric reducing antioxidant power (FRAP), and radicals such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azino-bis-[3-ethyl-benzothiazoline]-6-sulfonic acid (ABTS), while AGEs inhibition was evaluated using a model system formed by bovine serum albumin-glucose. The highest antioxidant activity was 3612.18 mM TE/g, and the inhibition of AGEs was 52.44 %. These results demonstrate that Smilax spp. can inhibit AGEs, neutralize free radicals, and reduce compounds associated with antioxidant capacity.

Variation in Terpenoid and Flavonoid Content in Different Samples of Salvia semiatrata Collected from Oaxaca, Mexico, and Its Effects on Antinociceptive Activity

Salvia semiatrata Zucc. (Lamiaceae) is endemic to Oaxaca, Mexico, and is known for its analgesic properties. Terpenoids and phenolic compounds with antinociceptive potential have been characterised from this species. The aim of this research was to determine the variation in terpenoids and flavonoids in ethyl acetate extracts of S. semiatrata collected from ten different localities, as well as to evaluate the antinociceptive effect between plants with higher and lower contents of these secondary metabolites. Quantification of S. semiatrata compounds was performed via HPLC-DAD, whereas in vivo evaluation of the antinociceptive effect was performed via formalin test. The results showed that the most abundant groups of metabolites are oleanolic acid (89.60-59.20 µg/mg), quercetin (34.81-16.28 µg/mg), catechin (11.30-9.30 µg/mg), and 7-keto-neoclerodan-3,13-dien-18,19:15,16-diolide (7-keto) (8.01-4.76 µg/mg). Principal component and canonical correspondence analysis showed that the most contrasting localities in terms of compound content and climatic variables are Miahuatlán and Santiago Huauclilla. The differences in metabolite content between the two locations did not affect the antinociceptive effects evaluated at a dose of 300 mg/kg, p.o. In conclusion, the results indicate that S. semiatrata is effective in relieving pain, regardless of the site of collection, reinforcing its traditional use as analgesic.

Mansoa alliacea extract presents antinociceptive effect in a chronic inflammatory pain model in mice through opioid mechanisms

In some chronic disorders, as in arthritis, the inflammatory pain persists beyond the inflammation control becoming pathological. Its treatment shows limited efficacy and adverse effects which compromises patients' quality of life. Mansoa alliacea, known as 'cipo alho', is popularly used as analgesic and others species of this genus show anti-inflammatory actions. We investigated the anti-inflammatory and antinociceptive potential of M. alliacea extract in an inflammatory pain model which presents inflammatory characteristics similar to those caused by arthritis, through of the intraplantar injection of complete Freund's adjuvant (CFA) in mice. The extract chromatographic analysis revealed the presence of ρ-coumaric, ferulic and chlorogenic acids, luteolin, and apigenin. The treatment with M. alliacea prevented and reversed the CFA-induced mechanical allodynia with maximum inhibition (I_max) of 100% and 90 ± 10%, respectively. The co-administration of M. alliacea extract plus morphine enhanced the anti-allodynic effect with I_max of 100%. The M. alliacea extract also reverted the CFA-induced thermal hyperalgesia with I_max of 3.6 times greater compared to the vehicle and reduced the thermal threshold under physiological conditions. However, M. alliacea extract did not reduce the CFA-induced edema and myeloperoxidase activity. Additionally, non-selective and δ-selective opioid receptor antagonists, but not κ-opioid, prevented extract anti-allodynic effect with I_max of 98 ± 2% and 93 ± 2%, respectively. Moreover, M. alliacea extract did not induce adverse effects commonly caused by opioids and other analgesic drugs, at least in the tested pharmacological doses after the acute treatment. M. alliacea extract presents antinociceptive activity in an inflammatory pain model, which presents inflammatory characteristics similar to those arthritis-induced, without causing adverse effects in tested pharmacological doses. These effects seem to be mediated mainly via δ-opioid receptors.

Acute toxicity study and anti-nociceptive activity of Bauhinia acuminata Linn. leaf extracts in experimental animal models

Bauhinia acuminata commonly known as dwarf white orchid tree is traditionally used to treat acute and chronic pain, skin ailments, cancer, diabetes, throat infections and asthma. As there were no scientific reports on use of Bauhinia acuminata for anti-nociceptive activity, the present study was designed to evaluate possible effects of aqueous and alcoholic extracts in experimentally induced pain in animals. Acute toxicity was carried out as per OECD guideline 423. The anti-nociceptive activity was evaluated in Swiss albino mice by hot plate, acetic acid induced writhing and tail immersion tests at three different dose levels (250, 500 and 1000mg/kg) of aqueous and alcoholic extracts. Formalin induced nociception test was performed in Sprague Dawley rats at three dose levels. Both aqueous and alcoholic extracts were found safe at dose of 5000mg/kg. In hot plate test, both extracts showed significant (p<0.001) anti-nociceptive activity. In acetic acid writhing test, both aqueous and alcoholic extracts significantly reduced number of writhes (p<0.001). In Tail immersion test, both the extracts showed significant increase in tail withdrawal response (p<0.001). Treatment with aqueous and alcoholic extracts significantly reduced nociception in formalin induced nociception model (p<0.001). From the results it can be concluded that aqueous and alcoholic extracts possesses potent anti-nociceptive activity.

Smilax glabra Rhizoma affects the pharmacokinetics and tissue distribution of methotrexate by increasing the P‑glycoprotein mRNA expression in rats after oral administration

Methotrexate (MTX) is a widely used immunosuppressant and anticancer agent with high toxicity. Smilax glabra Rhizoma (SGR) has the effect of detoxification and immunoregulation, and has been used as both food and folk medicine in many countries. Co‑administration of MTX and SGR occurs in several diseases. However, whether they work synergistically or are incompatible remains unknown. In the present study, MTX was administrated to rats alone or combined with SGR. Blood and tissue samples were collected at designated times. The concentrations of MTX were determined by high‑performance liquid chromatography. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detected the gene expression. SGR decreased the AUC0‑t and Cmax of MTX by 44.5 and 48.2%, but in a tissue‑dependent manner. The total exposure of MTX was significantly decreased in the small intestine, stomach, plasma, and kidney by 61.6, 34.7, 63.3 and 46.1%, respectively, but was increased in the lung and spleen by 82.9 and 21.0%, respectively. RT‑qPCR demonstrated that SGR increased the mean P‑glycoprotein (gp) mRNA expression in the small intestine 2.54 times, but had a marginal effect on the expression of organic anion transporting polypeptide 2, and organic anion transporter (OAT)1 and OAT2. These results suggested that SGR affects the pharmacokinetics of MTX in a tissue‑dependent manner by affecting P‑gp, and the clinical effect of co‑administration depended on the disease site.