Cytoprotective and antisecretory properties of methanolic extract of Distemonanthus benthamianus (Caesalpiniaceae) stem bark on acute gastric ulcer in rats

OBJECTIVES

In African traditional medicine, Distemonanthus benthamianus (Caesalpiniaceae) is used to treat many diseases including gastric ulcers. We evaluated in this study, the cytoprotective and antisecretory properties of the methanolic extract of the stem bark of this plant using different technics of gastric lesion induction.

METHODS

Cytoprotective and antisecretory activity of the methanolic extract of D. benthamianus stem bark was evolved through six methods of gastric lesion induction in experimental Wistar male rats (150-200 g): (1) gastric lesions induced by HCl/ethanol, (2) gastric lesions induced by Indomethacin- HCl/ethanol, (3) gastric lesion induced by Indomethacin, (4) gastric lesions induced by Pylorus ligation, (5) gastric lesions induced by histamine-Pylorus ligation, (6) gastric lesions induced by carbachol-Pylorus ligation. Mucus and gastric mucosal ulceration were evaluated. pH, gastric volume, and acidity were quantified in all pylorus ligation induction technics. Nitric oxide (NO) level was determined in indomethacin induced gastric ulcers.

RESULTS

At different doses (125, 250 and 500 mg/kg), extract reduced significantly the ulcer index. In all models used, that is 100.00% with HCl/ethanol; 100.00% with HCl/ethanol/indomethacin; 95.70% with Indomethacin; 74.79% with pylorus ligation, 95.94% histamine-Pylorus ligation, 99.54% carbachol-Pylorus ligation at the highest dose of 500 mg/kg. The lesion formation reduces in all the methods used followed by a significant increase of mucus production. The pylorus ligation technic revealed that the extract has an antisecretory activity.

CONCLUSIONS

The methanolic extract of D. benthamianus stem bark has both cytoprotective and antisecretory effects. This extract exerts its antisecretory effect trough cholinergic and histaminergic pathways.

Trunk-bark extracts on enteropathogenic Escherichia coli 31-induced diarrhea in rats

Background Distemonanthus benthamianus is used in the Western part of Cameroon to treat diarrheal episodes and infections. This study assessed its trunk-bark extracts activity against enteropathogenic Escherichia coli 31 (EPEC 31)-induced diarrhea in rats. Methods Aqueous and methanolic extracts were analyzed through high-performance liquid chromatography (HPLC). In vitro minimum inhibitory and bactericidal concentrations (MICs/MBCs) were evaluated on Enterococcus faecalis (ATCC 10,541), E. coli (ATCC 6539), Klebsiella pneumoniae (ATCC 13,883), Salmonella typhi (ATCC 6539) strains and on Proteus mirabilis, Pseudomonas aeruginosa (PA 01) and Shigella flexneri isolates using the microdilution method. Diarrhea was induced by inoculating rats with EPEC 31 (1.5 × 108 CFU/mL; p.o). Serum transaminases level assay and enzyme-linked immunosorbent assay (ELISA) for cytokines determination were performed. Hematoxylin-eosin (H-E) staining was used for intestinal tissue analysis. Results HPLC fingerprints of extracts showed presence of gallic acid and other unidentified compounds. The lowest MIC of 256 µg/mL was obtained with methanolic extract. At 100 mg/kg, both extracts significantly (p<0.001) inhibited diarrhea, with the methanolic extract being the most active. In addition, the methanolic extract significantly (p<0.001) increased the relative mass of the liver compared to negative control (Tween-DMSO 8%). The aqueous extract (100 mg/kg) significantly (p<0.01) increased alanine aminotransferase (ALT) serum concentration; while the methanolic extract (100 mg/kg) exhibited similar effect over aspartate aminotransferase (AST). At 50 and 100 mg/kg, the methanolic extract significantly (p<0.05 and p<0.01) decreased the Interleukin-1β (IL-1β) serum level, compared to negative control (Tween-DMSO 8%). Serum level of tumor necrosis factor alpha (TNF-α) significantly (p<0.001) decreased with 100 mg/kg of aqueous extract and all doses of methanolic extract. Inhibition of inflammatory cells tissue infiltration and epithelial regeneration was highly noticed in the ileum and colon of extracts-treated rats than in ciprofloxacin-treated animals. Conclusion These findings suggest that D. benthamianus trunk-bark extracts displayed therapeutic effects against infectious diarrhea in rats.

A multidirectional investigation of stem bark extracts of four African plants: HPLC-MS/MS profiling and biological potentials

The practice of traditional medicine, especially herbal medicine, is still prevalent across the African continent. Yet, their in-depth pharmacological and chemical exploitation by the scientific community remain a necessity. The aim of the present study was to investigate into the phenolic components, antioxidant, and enzyme-inhibitory activities of three solvent extracts (ethyl acetate, methanol, and water) of the stem bark of four African plant species (Senna siamea, Distemonanthus benthamianus, Harrisonia abyssinica, and Pycnanthus angolensis). It was found that D. benthamianus followed by P. angolensis, displayed the highest DPPH and ABTS scavenging, ferric and cupric reducing, and total antioxidant capacity in the phosphomolybdenum assay. A similar result was observed for AChE, BChE, and tyrosinase inhibition. The two plants also showed comparable α-amylase inhibitory effect. On the other hand, H. abyssinica showed high metal chelating and α-glucosidase inhibition. Among the solvents used, the methanol extract seemed to be the most bioactive. In addition, TPC was highest in D. benthamianus (135.33-192.29 mg GAE/g) while P. angolensis was richest in TFC (7.68-12.48 mg RE/g). A range of bioactive compounds were identified in the extracts, with variations observed among the plants. Senna siamea stem bark showed the presence of nine compounds; where flavonoids (e.g. naringenin, kaempferol, dihydroquercetin) were recorded. Genistein (m/z 271.06), procyanidin B (m/z 577.13) and C (m/z 865.19) isomers were common in stem barks extracts of D. benthamianus and P. Angolensis. To conclude, D. benthamianus and P. angolensis can be considered as potential pharmaceutical agents or functional food components that could reduce the risks of oxidative stress-related disorders.

Whole genome sequencing of Rhodotorula mucilaginosa isolated from the chewing stick (Distemonanthus benthamianus): insights into Rhodotorula phylogeny, mitogenome dynamics and carotenoid biosynthesis

In industry, the yeast Rhodotorula mucilaginosa is commonly used for the production of carotenoids. The production of carotenoids is important because they are used as natural colorants in food and some carotenoids are precursors of retinol (vitamin A). However, the identification and molecular characterization of the carotenoid pathway/s in species belonging to the genus Rhodotorula is scarce due to the lack of genomic information thus potentially impeding effective metabolic engineering of these yeast strains for improved carotenoid production. In this study, we report the isolation, identification, characterization and the whole nuclear genome and mitogenome sequence of the endophyte R. mucilaginosa RIT389 isolated from Distemonanthus benthamianus, a plant known for its anti-fungal and antibacterial properties and commonly used as chewing sticks. The assembled genome of R. mucilaginosa RIT389 is 19 Mbp in length with an estimated genomic heterozygosity of 9.29%. Whole genome phylogeny supports the species designation of strain RIT389 within the genus in addition to supporting the monophyly of the currently sequenced Rhodotorula species. Further, we report for the first time, the recovery of the complete mitochondrial genome of R. mucilaginosa using the genome skimming approach. The assembled mitogenome is at least 7,000 bases larger than that of Rhodotorula taiwanensis which is largely attributed to the presence of large intronic regions containing open reading frames coding for homing endonuclease from the LAGLIDADG and GIY-YIG families. Furthermore, genomic regions containing the key genes for carotenoid production were identified in R. mucilaginosa RIT389, revealing differences in gene synteny that may play a role in the regulation of the biotechnologically important carotenoid synthesis pathways in yeasts.

Hepatoprotective and in vivo antioxidant activity of Olax subscorpioidea Oliv. (Olacaceae) and Distemonathus benthamianus Baill. (Caesalpiniaceae)

Background:

Liver diseases are on rise and remain a serious health problem. Olax subscorpioidea and Distemonanthus benthamianus are two plants used in Ivorian traditional medicine in the treatment of many diseases including jaundice and hepatitis.

Objective:

The present study was carried out to assess the hepatoprotective and in vivo antioxidant potentials of the hydro-ethanolic leaf extracts of these plants in carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats.

Materials and Methods:

The plant extracts at doses of 25 and 100 mg/kg bw, and silymarin (25 mg/kg bw) were intraperitoneally (i.p.) injected once daily for 7 days to different groups of rats. Hepatotoxicity was induced on the 7^th day in all the group animals except control. Rats were sacrificed on the 8^th day and blood was collected. Serum biochemical parameters and antioxidant activity were measured using standard procedures. Histopathological examinations of liver rats were also performed.

Results and Discussion:

Hepatotoxicity induced with CCl₄ was well manifested by significant increase in serum activities of GOT, GPT, ALP and GGT, and enhancement of total bilirubin and TBARS levels. On the other hand, the level of total protein, albumin, α₁-globulin significantly decreased, and DPPH-free radical scavenging activity and TAP were lowered. Pretreatment with plant extracts and silymarin prevent the toxic effects of CCl₄ by decreasing serum enzyme activities, total bilirubin and TBARS levels and improving serum TAP and DPPH-free radical scavenging potential. Histopathological observations showed almost normal hepatic cells with a mild degree of inflammation, lesser fatty infiltration and absence of necrosis among the rats treated at 100 mg/kg of extracts of both the plants.

Conclusion:

The results suggest that the hydro-ethanolic leaf extracts of O. subscorpioidea and D. benthamianus possesses hepatoprotective and in vivo antioxidant activity.