Caesalpinia palmeri: First Report on the Phenolic Compounds Profile, Antioxidant and Cytotoxicity Effect

This study aimed to determine the phenolic compounds profile, antioxidant potential and cytotoxicity of extracts and fractions of Caesalpinia palmeri. Methanolic extracts were generated from C. palmeri berries, stems and flowers. The latter was subjected to liquid-liquid partition, obtaining hexane, ethyl acetate and residues fractions. Results showed that the flower extract and ethyl acetate fraction had a larger concentration of phenolic compounds (148.9 and 307.9 mg GAE/g, respectively), being ellagic acid (6233.57 and 19550.08 μg/g, respectively), quercetin-3-β-glycoside (3023.85 and 8952.55 μg/g, respectively) and gallic acid (2212.98 and 8422.34 μg/g, respectively) the most abundant compounds. Flower extract and ethyl acetate fraction also presented the highest antioxidant capacity on all tested methods (DPPH, ABTS, ORAC and FRAP) and low cytotoxicity against ARPE-19 cells (IC₅₀ >170 μg/mL). C. palmeri possessed high antioxidant potential, associated with the presence of phenolic compounds and low cytotoxicity, suggesting that they could represent an option to counter oxidative stress.

Antiproliferative activity of Haematoxylum brasiletto H. Karst

BACKGROUND

Haematoxylum brasiletto is a tree that grows in Central America, commonly known as "Palo de Brasil," which is used in the traditional medicine for the treatment of cancer and gastric ulcers.

OBJECTIVE

The aim of this study was to isolate the compounds responsible for antiproliferative activity of H. brasiletto.

MATERIALS AND METHODS

A bioassay-guided fractionation of ethanol extract of H. brasiletto was performed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide cell proliferation assay to measure the antiproliferative activity on six human cancer cell lines (A549, LS180, HeLa, SiHa, MDA-MB-231, and NCI-H1299) and one human noncancer cell line (ARPE-19). The ethanol extract was partitioned with hexane, dichloromethane, and ethyl acetate. The active dichloromethane fraction was fractioned by silica-column chromatography, and active subfractions were separated using preparative-thin layer chromatography. The chemical structure of an isolated compound was elucidated with different chemical and spectroscopic methods.

RESULTS

The flavonoid brazilin (1) was isolated from the heartwood of H. brasiletto. The measurement of antiproliferative activity showed that brazilin can inhibit the growth of SiHa, MDA-MB-231, A549, and NCI-H1299 cell lines by 50% at doses of 44.3, 48.7, 45.4, and 48.7 μM, respectively. Furthermore, the flavonoid showed a high antiproliferative activity on LS 180 and HeLa with IC50 values of 62.2 and 71.9 μM, respectively. Brazilin also exhibited a high antiproliferative activity on the human noncancer cell line ARPE-19 with an IC50 value of 37.9 μM.

CONCLUSIONS

Brazilin: (6aS, 11bR)-7,11b-Dihidro-6H-indeno[2,1-c] cromeno-3,6a, 9,10-tetrol was isolated; this compound demonstrated antiproliferative activity against several human cancer cell lines. This work demonstrated that brazilin, a flavonoid isolated and characterized of H. brasiletto, has antiproliferative activity against cancer cell lines.

SUMMARY

The flavonoid brazilin was isolated from the heartwood of H. brasilettoBrazilin is able to inhibit the growth of SiHa, MDA-MB-231, A549 and NCI- H1299 cancerous cell linesBrazilin exhibited a moderate antiproliferative activity on the human non-cancer cell line ARPE-19Brazilin demonstrated to have antiproliferative activity against human cancer cell lines and could be a potential source of anticancer agents. Abbreviations used: MTT: [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium]; FBS: Fetal bovine serum; TLC: Thin layer chromatography.

Apoptotic activities of cardenolide glycosides from Asclepias subulata

ETHNOPHARMACOLOGICAL RELEVANCE

Asclepias subulata Decne. (Apocynaceae) is a shrub occurring in Sonora-Arizona desert. The ethnic groups of Sonora, Mexico, Seris and Pimas, use this plant for the treatment of sore eyes, gastrointestinal disorders and cancer.

AIM OF THE STUDY

To determine the cell death pathways that the cardenolide glycosides with antiproliferative activity found in the methanol extract of A. subulata are able to activate.

MATERIALS AND METHODS

The effect of cardenolide glycosides isolated of A. subulata on induction of apoptosis in cancer cells was evaluated through the measuring of several key events of apoptosis. A549 cells were treated for 12h with doses of 3.0, 0.2, 3.0 and 1.0µM of 12, 16-dihydroxicalotropin, calotropin, corotoxigenin 3-O-glucopyranoside and desglucouzarin, respectively. Apoptotic and necrotic cell levels were measured by double staining with annexin V-FITC/PI. Mitochondrial membrane depolarization was examined through JC-1 staining. Apoptosis cell death and the apoptosis pathways activated by cardenolide glycosides isolated of A. subulata were further characterized by the measurement of caspase-3, caspase-8 and caspase-9 activity.

RESULTS

Apoptotic assays showed that the four cardenolide glycosides isolated of A. subulata induced apoptosis in A549 cells, which was evidencing by phosphatidylserine externalization in 18.2%, 17.0%, 23.9% and 22.0% for 12, 16-dihydroxicalotropin, calotropin, corotoxigenin 3-O-glucopyranoside and desglucouzarin, respectively, compared with 4.6% of control cells. Cell death was also associated with a decrease in mitochondrial membrane potential, which was more than 75% in the treated cultures respect to control. The activation of caspase-3 was observed in all cardenolide glycosides-treated cancer cells indicating the caspase-dependent apoptosis of A549 cells. Extrinsic and intrinsic apoptosis pathways were activated by cardenolide glycosides treatment at the doses tested.

CONCLUSION

In this study was found that cardenolide glycosides, 12, 16-dihydroxicalotropin, calotropin, corotoxigenin 3-O-glucopyranoside and desglucouzarin, isolated from A. subulata induced the cell death trough caspase-dependent apoptosis, which was activated, preferably, by extrinsic pathway.

Antiproliferative activity of cardenolide glycosides from Asclepias subulata

ETHNOPHARMACOLOGICAL RELEVANCE

Asclepias subulata Decne. is a shrub occurring in Sonora-Arizona desert (Mexico-USA). The ethnic groups, Seris and Pimas, use this plant for the treatment of sore eyes, gastrointestinal disorders and cancer.

AIM OF THE STUDY

To isolate the compounds responsible for antiproliferative activity of the methanol extract of A. subulata.

MATERIALS AND METHODS

A bioguided fractionation of methanol extract of A. subulata was performed using MTT assay to measure the antiproliferative activity of different compounds on three human cancer cell lines (A549, LS 180 and PC-3), one murine cancer cell line (RAW 264.7) and one human normal cell line (ARPE-19). The methanol extract was partitioned with hexane, ethyl acetate and ethanol. The active fractions, ethanol and residual, were fractioned by silica-column chromatography and active sub-fractions were separated using HPLC. The chemical structures of isolated compounds were elucidated with different chemical and spectroscopic methods.

RESULTS

A new cardenolide glycoside, 12, 16-dihydroxycalotropin, and three known, calotropin, corotoxigenin 3-O-glucopyranoside and desglucouzarin, were isolated of active sub-fractions. All isolated compounds showed a strong antiproliferative activity in human cancer cells. Calotropin was the more active with IC50 values of 0.0013, 0.06 and 0.41 µM on A549, LS 180 and PC-3 cell lines, respectively; while 12, 16-dihydroxycalotropin reached values of 2.48, 5.62 and 11.70 µM, on the same cells; corotoxigenin 3-O-glucopyranoside had IC50 of 2.64, 3.15 and 6.62 µM and desglucouzarin showed values of 0.90, 6.57 and 6.62, µM. Doxorubicin, positive control, showed IC50 values of 1.78, 6.99 and 3.18 µM, respectively. The isolated compounds had a weak effect on murine cancer cells and human normal cells, exhibiting selectivity to human cancer cells.

CONCLUSION

In this study, we found that 12, 16-dihydroxicalotropin, calotropin, corotoxigenin 3-O-glucopyranoside and desglucouzarin are responsible of antiproliferative properties of A. subulata, and that these compounds are highly selective to human cancer cells. Further studies are needed in order to establish the action mechanisms of the isolated compounds.

Plant folk medicines for gastrointestinal disorders among the main tribes of Sonora, Mexico

This paper describes the herbal remedies used by ethnic groups from Sonora, Mexico, for treatment of gastrointestinal diseases. Twelve types of these illnesses are cured using 85 different species which belong to 38 families. Thirty nine spp. are used to treat diarrhea, 28 for stomach-ache, 12 for constipation, 9 for intestinal parasites, 6 for indigestion, 3 for stomach or intestinal cancer, 3 for stomach inflammation and only 1 to treat gastrointestinal sicknesses, ulcers, gastritis, colitis and colic. Regarding the use of species of plant per ethnic group the following was observed: Mayo 47; Seri, 27; Yaqui, 13; Guarijio, 12, Pima, 5 and Papago, 3. The plants are used by two or more tribes, for the same or different illness but always related to the gastrointestinal system.