Spasmolytic effect of aqueous extract of Tagetes erecta L. flowers is mediated through calcium channel blockade on the guinea-pig ileum

Antiulcer mechanisms of the hydroalcoholic extract from Aztec marigolds' medicinal and edible flowers (Tagetes erecta L.)

The antiulcer mechanisms of the dry extract of T. erecta flowers (DETe) were studied here. The acute ulcers induced by acidified ethanol or indomethacin were reproduced in mice pretreated with DETe (3 - 300 mg/kg). The antiulcer activity of DETe was also verified in mice pretreated with NEM, L-NAME, indomethacin, or yohimbine. The antisecretory effect of DETe was verified in rats, and its anti-Helicobacter pylori activity was determined in vitro. DETe (300 mg/kg, p.o) reduced the ethanol- or indomethacin-induced ulcer by 49 and 93%, respectively. The pre-treatment with L-NAME, NEM or yohimbine abolished the gastroprotective effect of DETe. However, DETe did not change the volume, acidity, or peptic activity in rats and did not affect H. pylori. This study expands knowledge about the antiulcerogenic potential of DETe, evidencing the role of nitric oxide, non-protein sulfhydryl groups, α2 adrenergic receptors, and prostaglandins, but not antisecretory or anti-H. pylori properties.

Ethnobotanical Research and Compilation of the Medicinal Uses in Spain and the Active Principles of Chiliadenus glutinosus (L.) Fourr. for the Scientific Validation of Its Therapeutic Properties

The species Chiliadenus glutinosus (L.) Fourr. has a large number of therapeutic uses reported in the traditional Spanish medicine. The growing interest in preserving the ethnopharmacological knowledge related to the botanical diversity existing in Spain and the interest in achieving scientific validation of the therapeutic properties of medicinal species has led to the development of this study. To do it, all the known medicinal uses of Ch. glutinosus in Spain were compiled, then an exhaustive bibliographic research on its chemical composition was carried out, and finally, an in silico validation of the bioactive phytochemicals present in a higher proportion in the essential oil of Ch. glutinosus: camphor, borneol, lucinone, glutinone, quercetin, kutdtriol, and kaempferol; in an attempt to justify the reported traditional uses of the species. It was found that much of the traditional medicinal uses of Ch. glutinosus, along with the biological activity of its phytochemicals, are supported by scientific evidence. The results place this species in a prominent position to initiate possible lines of research to develop new, more effective drugs and improve therapies to treat conditions and diseases that affect the different organic systems of the human being.

Modulatory effect of Tagetes erecta flowers essential oils via Nrf2/HO-1/NF-κB/p65 axis mediated suppression of N-methyl-N'nitro-N-nitroguanidine (MNNG) induced gastric cancer in rats

Protective effect of Tagetes erecta flowers essential oils was investigated on oxidative stress, immune response, inflammation, and apoptosis against N-methyl-N'nitro-N-nitroguanidine (MNNG) induced gastric cancer in rats. Essential oil were extracted from Tagetes erecta flowers and analyzed using gas chromatography-mass spectrometry (GC-MS). For observing a protective effect against MNNG induced gastric cancer, we divided rats into 4 groups (group A to D) having 10 rats in each group. Performed various experiments and measured a different parameters to investigate antioxidant activity, immune response, anti-inflammatory and anti-apoptotic activity. The levels of malondialdehyde were markedly increased in the presence of N-methyl-N'nitro-N-nitroguanidine, whereas, the antioxidant activities of superoxide dismutase, and catalase were lowered in the treated rats in contrast with the control. Intervention with TEEO to gastric cancer-induced rats upregulated the redox status and the activity of the immune system to decrease cancer risk. The proinflammatory cytokines (IL-6 and TNF-α) secretions that were induced by MNNG were markedly inhibited by TEEO. Administration of TEEO also significantly reduced terminal deoxynucleotidyl transferase dUTP nick end labeling positive gastric cancer cells, expression of mRNA of caspase-3, and Bax. Whereas, the expression of Bcl-2 was increased. Additionally, downregulation of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) and IκBα degradation and the nuclear factor-κB (NF-κB) p65 expression in tissues of the stomach of MNNG-induced-rats were markedly elevated due to TEEO. This suggested possession of TEEO with a protective shield against MNNG induced gastric cancer by the exertion of antioxidative stress, anti-apoptotic response, the anti-inflammatory response through Nrf2/HO-1, and NF-κB signaling pathways.

Study of Antispasmodic and Antidiarrheal Activities of Tagetes lucida (Mexican Tarragon) in Experimental Models and Its Mechanism of Action

Tagetes lucida has been used in traditional medicine as a remedy to alleviate several gastrointestinal disorders that provoke stomachaches, abdominal cramps, and diarrhea. However, there is not enough scientific evidence that supports these effects. Therefore, the purpose of this study was to evaluate antispasmodic and antidiarrheal activities of aqueous extract of T. lucida (AqExt-TL) as well as its mechanism of action in experimental models. Antispasmodic activity and the mechanism of action of AqExt-TL were assessed on segments of the guinea pig ileum precontracted with KCl, acetylcholine (ACh), or electrical field stimulation (EFS). Furthermore, the antispasmodic effect of two coumarins (umbelliferone and herniarin) previously identified in this species was evaluated. Antidiarrheal activity of AqExt-TL was determined using the charcoal meal test in mice. AqExt-TL showed antispasmodic activity in segments of the guinea pig ileum precontracted with KCl (83.7 ± 1.9%) and ACh (77.2 ± 5.3%) at the maximal concentration; however, practically, it did not alter the contractions induced by EFS (10.1 ± 2.2%). Antispasmodic activity of AqExt-TL was not significantly altered by hexamethonium (a ganglionic blocker) or L-NAME (an inhibitor of nitric oxide synthase). However, this extract decreased the maximal contractile response to calcium (82.7 ± 8.5%), serotonin (68.1 ± 8.5%), and histamine (63.9 ± 5.9%) in their concentration-response curves. Umbelliferone and herniarin also induced an antispasmodic effect on tissues precontracted with KCl. In addition, low doses of AqExt-TL reduced to 50% the distance traveled by charcoal meal in the gastrointestinal transit model in mice as loperamide, an antidiarrheal agent, did. These results provided evidence of the antispasmodic and antidiarrheal activity of T. lucida, which supports its use in the folk medicine in relieving symptoms in some gastrointestinal disorders. In the antispasmodic effect, the blockade of histaminergic and serotoninergic pathway as well as the calcium channels seems to be involved. Finally, umbelliferone and herniarin could be partially responsible for the antispasmodic activity induced by T. lucida.

Flavonoids in a crude extract of Catha edulis inhibit rat intestinal contraction via blocking Ca2+ channels

BACKGROUND

Animal studies show that Catha edulis inhibits gastrointestinal tract motility. However, there is little or no information on its effect on colon motility and the mechanism of action and active constituents responsible for this effect. This study therefore attempted to discern the effect, suggest the mechanism, and identify the active compounds from the crude extract.

METHODS

A crude extract of Catha edulis was fractionated and subfractionated using column chromatography and HPLC. The activity of all fractions and subfractions was evaluated on rat colon longitudinal muscle. Nuclear magnetic resonance (NMR) spectroscopic data elucidations were used to identify the active compounds. An ileal segment preparation was used to investigate the possible mechanism of action.

RESULTS

The crude extract of Catha edulis (0.05-0.5 mg/mL) inhibited spontaneous contraction of rat colon and ileum (P < 0.05), and tetrodotoxin (TTX, 10 µmol/L) failed to block this effect. Similar to verapamil (0.01-0.1 μmol/L), the Catha edulis extract (0.05-0.5 mg/mL) inhibited high K⁺ (80 mmol/L)-induced sustained ileal contraction and decreased the response to Ca²⁺ . Analysis of the NMR data showed that quercetin, kaempferol, and myricetin were the active phytochemicals. All the identified compounds were flavonoids and significantly inhibited (P < 0.05) spontaneous contraction of the rat colon longitudinal muscle compared to controls.

CONCLUSIONS

The crude extract of Catha edulis has a spasmolytic effect on the rat ileum, which is mediated through blocking Ca²⁺ channels, and quercetin, kaempferol, and myricetin were found to be the causative compounds.

Bioactive Phytochemicals from Mercurialis spp. Used in Traditional Spanish Medicine

Plants from the genus Mercurialis have a long history of use as herbal remedies in traditional Spanish medicine. The growing interest in the conservation of knowledge related to biodiversity has encouraged us to review the bioactive phytochemicals from the four most widespread Mercurialis species in the Iberian Peninsula (M. annua L., M. ambigua L., M. perennis L., and M. tomentosa L.). First, the medicinal uses of these four species throughout Spain were compiled, and then a bibliographical search on their chemical composition was conducted in an attempt to justify their reported traditional uses. We found that most of the medicinal uses of Mercurialis spp. are supported by scientific evidence. This includes its antidiabetic and antihypertensive properties attributable to the flavonoid rutin and narcissin, respectively; its benefits in the treatment of skin dark spots, attributable to mequinol; and its anti-inflammatory activity, attributable to scopoletin, kaempferol, squalene, and cycloartenol. This review contributes to the validation of the medicinal uses of Mercurialis spp. in Spain and provides some new avenues for further investigations on the biological activity of this interesting medicinal plant.

Hydroalcoholic extract of Tagetes erecta L. flowers, rich in the carotenoid lutein, attenuates inflammatory cytokine secretion and improves the oxidative stress in an animal model of ulcerative colitis

Given the role of oxidative stress in ulcerative colitis (UC) etiology, and the amount of lutein (a carotenoid with antioxidant properties) in the dry hydroalcoholic extract of Tagetes erecta flowers (DHETE), this study investigated the intestinal anti-inflammatory properties of DHETE in an animal model of UC. The amount of lutein in the extract was determined by ¹H-nuclear magnetic resonance spectroscopy, and total phenols, radical scavenger capability, cytotoxicity, and effects on reactive oxygen species and nitric oxide production were evaluated in vitro. Experimental UC was established by adding 5% dextran sulfate sodium (DSS) to drinking water, with the effects of DHETE (30-300 mg/kg, once a day for 7 days) on the morphological (colon length and weight), clinical (disease activity index and body weight loss), microscopic (histological score and mucin levels), and biochemical parameters analyzed. The lutein concentration found in DHETE was 8.2%, and DHETE scavenged 2,2-diphenyl-1-picrylhydrazyl radicals at 1000 μg/mL The exposure of intestinal epithelial cells to DHETE did not change its viability but reduced reactive oxygen species and nitric oxide production after lipopolysaccharide stimulation. In vivo, DHETE (300 mg/kg) attenuated weight loss, disease activity index, colon shortening, and histopathological changes promoted by DSS intake. Moreover, DHETE increased mucin colonic staining. The treatment with DHETE decreased myeloperoxidase activity as well as tumor necrosis factor and interleukin-6 levels. The extract also increased reduced glutathione levels and catalase activity and normalized superoxide dismutase and glutathione-S-transferase activities. In conclusion, DHETE reduced colitis severity by attenuating inflammatory cytokine secretion and improved the endogenous antioxidant defense in DSS-induced UC in mice.