Characterization of Crude and Processed Pulp Cell Walls of Three Selected Mamey Accessions (Mammea americana L.)

Mamey (Mammea americana L.) is a tropical fleshy fruit native from the West Indies and northern South America. It is very appreciated for its flavor and color but has been little described. The present study investigates the composition and histochemistry of the pulp cell walls of three mamey accessions readily available in Martinique. The impact of pulp processing into puree on cell wall composition is evaluated. The histology and rheology of mamey puree are assessed considering these characterizations. Mamey pulp cell wall composition is dominated by highly methyl-esterified pectins (DM: 66.2-76.7%) of high molecular weight, and show few hemicelluloses, mainly xyloglucans. Processing reduced methyl-esterified uronic acid contents and gave purees with significantly different viscosities. Mamey puree was composed of polydisperse particles (20-2343 µm), which size distributions were different depending on the accession: Ti Jacques was dominated by smaller particles (50% had approximated diameters lower than 160 µm), Sonson's by larger particles (50% had approximated diameters higher than 900 µm), and Galion's had an intermediate profile. This new knowledge on mamey pulp is valuable for future works on mamey processing into new food products, even more so for those including cell wall polysaccharide-degrading enzymes.

flowers: pharmacokinetic and acute toxicity studies

BACKGROUND

The potent antiplasmodial activity of 1-hydroxy-5,6,7-trimethoxyxanthone (HTX), isolated from Mammea siamensis T. Anders. flowers, has previously been demonstrated in vitro. However, its in vivo activity has not been reported. Therefore, this study aimed to investigate the antimalarial activity and acute toxicity of HTX in a mouse model and to evaluate the pharmacokinetic profile of HTX following a single intraperitoneal administration.

METHODS

The in vivo antimalarial activity of HTX was evaluated using a 4-day suppressive test. Mice were intraperitoneally injected with Plasmodium berghei ANKA strain and given HTX daily for 4 days. To detect acute toxicity, mice received a single dose of HTX and were observed for 14 days. Additionally, the biochemical parameters of the liver and kidney functions as well as the histopathology of liver and kidney tissues were examined. HTX pharmacokinetics after intraperitoneal administration was also investigated in a mouse model. Liquid chromatography triple quadrupole mass spectrometry was used to quantify plasma HTX and calculate pharmacokinetic parameters with the PKSolver software.

RESULTS

HTX at 10 mg/kg body weight significantly suppressed parasitemia in malaria-infected mice by 74.26%. Mice treated with 3 mg/kg HTX showed 46.88% suppression, whereas mice treated with 1 mg/kg displayed 34.56% suppression. Additionally, no symptoms of acute toxicity were observed in the HTX-treated groups. There were no significant alterations in the biochemical parameters of the liver and kidney functions and no histological changes in liver or kidney tissues. Following intraperitoneal HTX administration, the pharmacokinetic profile exhibited a maximum concentration (Cmax) of 94.02 ng/mL, time to attain Cmax (Tmax) of 0.5 h, mean resident time of 14.80 h, and elimination half-life of 13.88 h.

CONCLUSIONS

HTX has in vivo antimalarial properties against P. berghei infection. Acute toxicity studies of HTX did not show behavioral changes or mortality. The median lethal dose was greater than 50 mg/kg body weight. Pharmacokinetic studies showed that HTX has a long elimination half-life; hence, shortening the duration of malaria treatment may be required to minimize toxicity.

against Staphylococci Isolated from Skin Lesions

Background

The resistance to antibiotics shown by some dermatological pathogenic microorganisms has increased the interest of pharmaceutical and cosmetic industries in developing natural products that possess different biological activities, including antimicrobial effects.

Methods

In the present investigation, the antibacterial activity of ethanolic extracts of Dodonaea viscosa aerial part and Mammea americana leaves and seed was evaluated against resistant strains of Staphylococcus isolated from skin lesions and against S. aureus ATCC 25923 (reference strain). Column chromatography (CC) and preparative thin-layer chromatography (PTLC) were used to obtain separate fractions of the seed extract of M. americana. We also determined the antimicrobial resistance of the strains against antibiotics using the agar disc diffusion assay. In addition, phytochemical screening was performed by colorimetric standard techniques.

Results

M. americana seed extract showed the highest antibacterial activity with MBC from 2.3 μg/mL to 19.5 μg/mL without differences with gentamicin (p = 0.998). The isolated strain S. epidermidis I showed the highest antimicrobial resistance against the tested antibiotics. PTLC-fractions of M. americana seed extract showed MBC from 3.2 μg/mL to 40.7 μg/mL against S. epidermidis I and S. aureus 25923 (reference), respectively, which suggests a synergistic effect of the secondary metabolites present in the crude ethanolic extract compared to its active PTLC-fractions, where only coumarins and compounds with lactone groups were detected in the phytochemical screening.

Conclusion

M. americana seed extract has promising effects that should be considered in further studies as an alternative or adjuvant in treating skin infections caused by staphylococci.

Natural Compounds with BMI1 Promoter Inhibitory Activity from Mammea siamensis and Andrographis paniculata

A new coumarin derivative (1) and 30 known compounds were isolated from Mammea siamensis and Andrographis paniculata, guided by B cell-specific Moloney murine leukemia virus insertion region 1 (BMI1) promoter inhibitory activity. Among the isolated compounds, 15 compounds showed BMI1 promoter inhibitory activity, and five compounds were found to be cytotoxic. 14-Deoxy-11,12-dehydroandrographolide (18) was highly cytotoxic to DU145 cells with an IC50 value of 25.4 µM. Western blotting analysis of compound 18 in DU145 cells suggested that compound 18 suppresses BMI1 expression.

In vitro cytotoxic activity of Sa-Tri-Lhung-Klod remedy and its herbal ingredients on ovarian and cervical carcinoma cell lines

BACKGROUND

Sa-Tri-Lhung-Klod is a Thai traditional medicine remedy for postpartum in the lists of The National Drug List ofHerbal Medicine Products AD. It consists ofseventeen herbs and were obtained by maceration and used in the form of liquor for women's health care such as treatment ofamenorrhea, menopause and blood tonic. In addition, it also usedfor postpartum care for being anti-inflammation in postpartum and prevention of cancer in women.

OBJECTIVE

To investigate cytotoxic activity ofSa-Tri-Lhung-Klod remedy extracts and its herbal ingredients against human ovarian carcinoma cell line (SKOV-3) and cervical adenocarcinoma (HeLa) cell line.

MATERIAL AND METHOD

Sa-Tri-Lhung-Klod remedy and its plant ingredients were extracted by maceration in 95% ethanol and dried using evaporator. All extracts were testedfor cytotoxic activity by sulforhodamine B (SRB) assay.

RESULTS

Ethanolic extract ofSa-Tri-Lhung-Klod remedy displayed cytotoxic activity against SKOV-3 and HeLa with IC50 values of 72.84±1.07 and 47.24±2.83 μg/ml, respectively. It was classified as "less-active" according to the NCI guideline. However, Caesalpinia sappan, Mammea siamensis and Curcuma comosa showed high cytotoxic activity against SKOV-3 with IC50 values of 9.55±1.38 13.45±0.82 and 14.21±1.30 μg/ml, respectively. The ethanolic extracts ofCaesalpiniasappan and Mammea siamensis also exhibited cytotoxic activity against HeLa with IC50 values of 6.30±0.06 and 7.72±0.11 μg/ml, respectively.

CONCLUSION

These results support the use of Sa-Tri-Lhung-Klod remedy in Thai traditional medicine for preventing of ovarian cancer and cervical cancer Caesalpinia sappan, Curcuma comosa and Mammea siamensis were strikingly active against ovarian and cervical cancer cells. Their extracts have the potential for developing as new anti-cancer drugs for women health.

Hypoglycaemic effects of Mammea africana (Guttiferae) in diabetic rats

AIM OF THE STUDY

The stem bark of Mammea africana Sabine (Guttiferae) is used in African rain forest to treat various diseases, including diabetes mellitus. We investigated whether Mammea africana extract induced hypoglycaemic activity in rats.

MATERIALS AND METHODS

We tested the effects of acute (5h) and sub-acute (21 days) oral administrations of the CH(2)Cl(2)-MeOH stem bark extract of Mammea africana (19-300 mg/kg body weight) on blood glucose levels of normal and streptozotocin (STZ)-induced type 1 diabetic rats. The effects were compared with those of glibenclamide.

RESULTS

Acute administration reduced blood glucose in the diabetic rats only (33.87%, P<0.01). Sub-acute treatment for 21 days also reduced blood glucose level in diabetic rats (73.29%, P<0.01). A reduction or stabilization in total serum protein, triglyceride, cholesterol and alanine amino transferase levels was also observed. No effect was observed on body weight loss but food and water intakes were significantly reduced (P<0.01) in diabetic rats. The maximal anti-diabetic effect was obtained with the dose of 75 mg/kg and was more important than that of glibenclamide.

CONCLUSION

It can be concluded that extracts of Mammea africana exhibited a significant anti-hyperglycaemic activity and improved the metabolic alterations in STZ-diabetic rats. These results provide a rationale for the use of Mammea africana to treat diabetes mellitus and hypercholesterolemia.

Vasodilator and antioxidant effect of xanthones isolated from Brazilian medicinal plants

Vasorelaxant and antioxidant activities are important in the therapy for cardiovascular diseases. We aimed at investigating the vasorelaxant and antioxidant activities of six xanthones isolated from Brazilian medicinal plants. Xanthone ( 1), 1-hydroxyxanthone ( 2), 4-hydroxyxanthone ( 3), 1-hydroxy-8-methoxyxanthone ( 4), 1,3-dihydroxy-7-methoxyxanthone ( 5) and 2,6,8-trihydroxy-1-methoxyxanthone ( 6) induced concentration-dependent vasorelaxant effects in endothelium-intact mice aortic rings. The presence of a hydroxy group in position 1 seemed to decrease the vasodilator effect while a hydroxy in position 4 and an increased number of hydroxy groups improved the vasorelaxatory potential of xanthones. All xanthones showed antioxidant activity but their potencies did not correlate with the vasodilator effect. Our results suggest that the tested xanthones are potentially vasorelaxant and antioxidant compounds but the two activities are not interrelated.

Antioxidant and cytotoxic isoprenylated coumarins from Mammea americana

Antioxidant-guided fractionation of Mammea americana L. seeds resulted in the identification of three new isoprenylated coumarins, mammea B/BA hydroxycyclo F (1), mammea E/BC (2), and mammea E/BD (3). In addition, twelve known isoprenylated coumarins, mammea A/AA (4), mammea A/AA cyclo D (5), mammea A/AA cyclo F (6), mammea A/AC cyclo D (7), mammea A/AD cyclo D (8), mammea B/BA (9), mammea B/BA cyclo F (10), mammea B/BB (11), mammea B/BC (12), mammea B/BD (13), mammea E/BA (14), and mammea E/BB (15), as well as two known flavanols, (+)-catechin (16) and (-)-epicatechin (17) were identified. The fifteen isoprenylated coumarins were screened for their cytotoxicity in the SW-480, HT-29, and HCT-116 human colon cancer cell lines and antioxidant capacities in the DPPH (1,1-diphenyl-2-picrylhydrazyl) free-radical assay. Compounds 1 - 15 exhibited significant cytotoxic activities in the SW-480, HT-29, and HCT-116 human colon cancer cell lines (IC50 ranges 13.9 - 88.1, 11.2 - 85.3, and 10.7 - 76.7 microM, in the three cell lines, respectively) at concentrations comparable to 5-fluorouracil (IC50 = 53.0, 46.1, and 45.1 microM), a drug frequently used for human colon cancer treatment. Compounds 2 - 4, 9, and 11 - 15 displayed high antioxidant activity in the DPPH assay (IC50 range 86 - 135 microM), compounds 1, 5 - 8, and 10, however, had no antioxidant activity (IC50 > 200 microg/mL) in the DPPH assay. The results of these assays were used to study the structure-activity relationships for this class of compounds. In the SW-480 cell line, the three new coumarins, 1 - 3, also exhibited dose-dependent increases in sub-diploid cells by flow cytometry, indicating that they induce apoptosis.

(Guttiferae) bark/latex extract point to an effective antiulcer effect on gastric ulcer models in mice

Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of gastric ulcers. Several folk medicinal plants and herbs have been used to treat gastrointestinal disorders, including gastric ulcers. Mammea americana L. (Guttiferae) fruit is very common in the diet of the population of northern South America. Our research interest in this plant arose because of its potential medicinal value as a tonic and against stomachache, as used in folk medicine. In this paper we evaluated three different extracts (ethanolic/EtOH, methanolic/MeOH and dichloromethane/DCM) obtained from M. americana L., for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCl/60% EtOH), hypothermic restraint stress, nonsteroidal anti-inflammatory drugs (NSAID, indomethacin) and pylorus ligation. In the HCl/EtOH-induced gastric-ulcer model, EtOH and DCM extracts demonstrated significant inhibition of the ulcerative lesion index by 54% (12.0 +/- 2.6 mm) and 86% (3.7 +/- 1.8 mm), respectively, in relation to the control value (26.0 +/- 1.4 mm) (p<0.0001). In the NSAID/cholinomimetic-induced lesion model, both EtOH and DCM extracts showed antiulcerogenic effects with significant reduction in the damage to these gastric lesions of 36% (8.3 +/- 2.0 mm) and 42% (7.5 +/- 1.4 mm), respectively, as compared to the control group (13.0 +/- 0.9 mm) (p<0.0001). In the gastric ulcer induced by hypothermic-restraint stress, both extracts also showed significant activity, and inhibited the gastric lesion index by 58% and 75%, respectively. The EtOH and DCM extracts also changed gastric juice parameters as well as those of cimetidine, decreased gastric acid secretion significantly (p<0.0001), increased pH values and promoted reduced acid output (p<0.0001). In all gastric-ulcer-induced models, MeOH extract did not show any significant antiulcerogenic activity, nor did it change gastric-juice parameters (p>0.05). The results suggest that EtOH and DCM extracts obtained from M. americana possess excellent antisecretory and/or gastrotective effect in all gastric ulcer models. These results suggest that the antiulcerogenic compound(s) present in M. americana may be clustered in the apolar fraction, which will be investigated by our group for the probable mechanisms of action.

Antifungal properties of surangin B, a coumarin from Mammea longifolia

The natural product electron transport inhibitor surangin B was examined for its ability to inhibit in vitro mycelial growth and spore germination in several species of fungi. As an inhibitor of mycelial growth, surangin B showed strongest activity against Rhizoctonia solani (IC50 = 3.8 microM) and Botrytis cinerea (IC50 = 11.2 microM). Inhibitory effects were less pronounced in Alternaria dauci, Fusarium oxysporum and Penicillium sp. (IC50 values > 30 microM) and absent in Trichoderma harzianum. Surangin B reduced the level of spore germination in Fusarium oxysporum (IC50 = 2.3 microM) and Botrytis cinerea (IC50 = 1.4 microM), although Alternaria dauci was considerably more tolerant of this coumarin (IC50 = 500 microM). Our results indicate that surangin B may have potential as an antifungal agent.

Occurrence of antioxidant and radical scavenging proanthocyanidins from the Indian minor spice nagkesar (Mammea longifolia planch and triana syn)

Nagkesar (buds of Mammea longifolia) is extensively used in culinary preparations especially in spice blend in India. Previously thirteen compounds were identified from the medium polar fractions of methanol extract of buds of M. longifolia. In continuation of the study, the polar fraction of methanol extract exhibited stronger antioxidative and radical scavenging activities. An attempt was made to separate and identify the active compounds and found that those were proanthocyanidin oligomers with mean degree of polymerisation ranges from 2 to 10. This is the first report to indicate that Mammea buds contain antioxidant and radical scavenging procyanidin oligomers.

Cytotoxic coumarins from Mammea harmandii

Two new naturally occurring coumarins, isomesuol (1) and mammearin A (2), together with nine known Mammea coumarins 3-11 were isolated from the EtOAc extract of the leaves and twigs of Mammea harmandii. Coumarins 1, 3 and 4 showed cytotoxicity against a panel of mammalian cancer cell lines. Their structures were determined by spectroscopic methods. The assignments of 13C-NMR signals of isomesuol (1), which was isolated for the first time as a natural product, have been revised.