In vivo antitumor effect, induction of apoptosis and safety of Remirea maritima Aubl. (Cyperaceae) extracts

A highly selective 2''-O-glycosyltransferase from Ziziphus jujuba and De novo biosynthesis of isovitexin 2''-O-glucoside

A novel and efficient 2''-O-glycosyltransferase ZjOGT38 was identified from Ziziphus jujuba. It could regio-selectively glycosylate 2-hydroxyflavanone C-glycosides. ZjOGT38 allowed de novo biosynthesis of isovitexin 2''-O-glucoside in E. coli.

Evaluation of the anti-inflammatory, antipyretic and antinociceptive activities of the hydroalcoholic extract of Rhynchospora nervosa (Vahl) Boeckeler (Cyperaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Rhynchospora nervosa (Vahl) Boeckeler (Cyperaceae), popularly known as "capim-estrela", is a native species widely distributed in Brazil. The whole plant has been used in local traditional medicine in the form of teas or syrups to treat inflammation, flu, nasal congestion, fever, swelling, and venereal disease. This is the first study to investigate the pharmacological properties of this species.

AIM OF THE STUDY

The present study aimed to evaluate the in vivo anti-inflammatory, antipyretic and antinociceptive potential of the lyophilized hydroalcoholic extract of R. nervosa in heterogenic Swiss mice. In addition to pharmacological studies, the total phenol and flavonoid contents of the extract were determined.

MATERIAL AND METHODS

The anti-inflammatory effect was evaluated through carrageenan-induced paw edema and peritonitis models. For the antinociceptive assay, the number of acetic acid-induced writhing responses in the animals was counted. Antipyretic activity was tested by yeast-induced pyrexia in mice and evaluated for 4 h. Nitric oxide (NO) concentration and leukocyte migration in the peritoneal fluid were quantified. The acute toxicity of the extract was also calculated. Quantitative analyses of total phenols and flavonoids in the extract were performed by spectrophotometric methods.

RESULTS

In short, the lyophilized hydroalcoholic extract of R. nervosa showed low acute toxicity in the preclinical tests (LD₅₀ = 3807 mg/kg). A significant anti-inflammatory effect was observed, with an average reduction of carrageenan-induced paw edema of 96.37%. Comparatively, indomethacin inhibited the development of the carrageenin paw edema by 97.52%. In the peritonitis test, a significant reduction in NO levels was recorded. A reduction in the number of white cells, notably monocytes, was also observed, confirming the anti-inflammatory effect. Writhing was reduced by 86.53%, which indicates antinociceptive activity. As for antipyretic activity, no positive effects of the extract were observed. The lyophilized hydroalcoholic extract of R. nervosa presented a high content of phenolic compounds (322.47 μg GAE/mg) and total flavonoids (440.50 μg QE/mg).

CONCLUSION

The lyophilized hydroalcoholic extract of R. nervosa showed significant in vivo anti-inflammatory and antinociceptive activity in mice. These preliminary findings support the indication of the use of this species in folk medicine in Brazil for the treatment of inflammation.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Cytotoxic, Antitumor and Toxicological Profile of Passiflora alata Leaf Extract

Passiflora alata or passion fruit is a native flowering plant from Amazon, geographically spread from Peru to Brazil. The plant has long been used in folks medicine for its pharmacological properties and is included in the Brazilian Pharmacopoeia since 1929. The aim of this study was to evaluate the potential cytotoxic and antitumor activities of Passiflora alata leaf extract (PaLE) in S180-tumor bearing mice. The percentage of cell proliferation inhibition (% CPI) and IC₅₀ in relation to 4 tumor cell lines were determined in PC3, K-562, HepG2 and S180 cell lines using the MTT assay. PaLE showed a CPI > 75% and greater potency (IC₅₀ < 30 µg/mL) against PC3 and S180 cell lines. PaLE showed antitumor activity in treatments intraperitoneally (36.75% and 44.99% at doses of 100 and 150 mg/kg/day, respectively). Toxicological changes were shown in the reduced body mass associated with reduced food consumption, increased spleen mass associated with histopathological increase in the white pulp of the spleen and increased number of total leukocytes with changes in the percentage relationship between lymphocytes and neutrophils. Our outcomes corroborate the conclusion that PaLE has antitumor activity in vitro and in vivo with low toxicity.

Atranorin, an antimicrobial metabolite from lichen Parmotrema rampoddense exhibited in vitro anti-breast cancer activity through interaction with Akt activity

Atranorin (ATR), lichenized secondary metabolite and depside molecule with several biological potentials such as antimicrobial, anticancer, anti-inflammatory, antinociceptive, wound healing and photoprotective activities. Cytotoxic reports of ATR are documented in several cancer cells and in vivo models but its molecular interaction studies are poorly understood. Therefore, in this present investigation, we have used the in silico studies with biological validation of the molecular targets for the anti-breast cancer mechanism of ATR. The molecular docking studies with the breast cancer oncoproteins such as Bcl-2, Bax, Akt, Bcl-w and Bcl-xL revealed the highest interaction was observed with the Akt followed by Bax, Bcl-xL and Bcl-2 & least with the Bcl-w proteins. The cytotoxicity studies showed ATR selectively inhibited MDA MB-231 and MCF-7 breast cancer cells in differential and dose-dependent manner with the IC₅₀ concentration of 5.36 ± 0.85 μM and 7.55 ± 1.2 μM respectively. Further mechanistic investigations revealed that ATR significantly inhibited ROS production and significantly down-regulated the anti apoptotic Akt than Bcl-2, Bcl-xL and Bcl-w proteins with a significant increase in the Bax level and caspases-3 activity in the breast cancer cells when comparison with Akt inhibitor, ipatasertib. In vitro biological activities well correlated with the molecular interaction data suggesting that atranorin had higher interaction with Akt than Bax and Bcl-2 but weak interaction with Bcl-w and Bcl-xL. In this present study, the first time we report the interactions of atranorin with molecular targets for anti-breast cancer potential. Hence, ATR represents the nature-inspired molecule for pharmacophore moiety for design in targeted therapy.Communicated by Ramaswamy H. Sarma.

Targeted enzyme gene re-positioning: A computational approach for discovering alternative bacterial enzymes for the synthesis of plant-specific secondary metabolites

Plant-biosynthesised secondary metabolites are unique sources of pharmaceuticals, food additives, and flavourings, among other industrial uses. However, industrial production of these metabolites is difficult because of their structural complexity, dangerousness and unfriendliness to natural environment, so the development of new methods to synthesise them is required. In this study, we developed a novel approach to identifying alternative bacterial enzyme to produce plant-biosynthesised secondary metabolites. Based on the similarity of enzymatic reactions, we searched for candidate bacterial genes encoding enzymes that could potentially replace the enzymes in plant-specific secondary metabolism reactions that are contained in the KEGG database (enzyme re-positioning). As a result, we discovered candidate bacterial alternative enzyme genes for 447 plant-specific secondary metabolic reaction. To validate our approach, we focused on the ability of an enzyme from Streptomyces coelicolor strain A3(2) strain to convert valencene to the grapefruit metabolite nootkatone, and confirmed its enzymatic activity by gas chromatography-mass spectrometry. This enzyme re-positioning approach may offer an entirely new way of screening enzymes that cannot be achieved by most of other conventional methods, and it is applicable to various other metabolites and may enable microbial production of compounds that are currently difficult to produce industrially.

In vitro and in vivo anti-leukemia activity of the stem bark of Salacia impressifolia (Miers) A. C. Smith (Celastraceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Salacia impressifolia (Miers) A. C. Smith (family Celastraceae) is a traditional medicinal plant found in the Amazon Rainforest known as "miraruíra", "cipó-miraruíra" or "panu" and is traditionally used to treat dengue, flu, inflammation, pain, diabetes, male impotency, renal affections, rheumatism and cancer.

AIM OF THE STUDY

The aim of this study was to investigate in vitro and in vivo anti-leukemia activity of the stem bark of S. impressifolia in experimental models.

MATERIALS AND METHODS

The in vitro cytotoxic activity of extracts, fractions and quinonemethide triterpenes (22-hydroxytingenone, tingenone and pristimerin) from the stem bark of S. impressifolia in cultured cancer cells was determined. The in vivo antitumor activity of the ethyl acetate extract (EAE) and of its fraction (FEAE.3) from the stem bark of S. impressifolia was assessed in C.B-17 severe combined immunodeficient (SCID) mice engrafted with human promyelocytic leukemia HL-60 cells.

RESULTS

The extract EAE, its fraction FEAE.3, and quinonemethide triterpenes exhibited potent cytotoxicity against cancer cell lines, including in vitro anti-leukemia activity against HL-60 and K-562 cells. Moreover, extract EAE and its fraction FEAE.3 inhibited the in vivo development of HL-60 cells engrafted in C.B-17 SCID mice. Tumor mass inhibition rates were measured as 40.4% and 81.5% for the extract EAE (20 mg/kg) and for its fraction FEAE.3 (20 mg/kg), respectively.

CONCLUSIONS

Ethyl acetate extract and its fraction from the stem bark of S. impressifolia exhibit in vitro and in vivo anti-leukemia activity that can be attributed to their quinonemethide triterpenes. These data confirm the ethnopharmacological use of this species and may contribute to the development of a novel anticancer herbal medicine.

Redox-Active Profile Characterization of Remirea maritima Extracts and Its Cytotoxic Effect in Mouse Fibroblasts (L929) and Melanoma (B16F10) Cells

Remirea maritima is a tropical plant with a reticulated root system belonging to the family Cyperaceae, also known to have biologically active secondary metabolites. However, very few data on R. maritima’s biological actions are available and there are no reports regarding the redox-active profile of this plant. In this study, we examined the total phenolic content of Remirea maritima hydroalcoholic (RMHA) extracts, redox properties against different reactive species generated in vitro and their cytotoxic effect against fibroblasts (L929) and melanoma (B16F10) cells. Total reactive antioxidant potential index (TRAP) and total antioxidant reactivity (TAR) results revealed that RMHA at all concentrations tested showed significant antioxidant capacity. RMHA was also effective against hydroxyl radical formation, reduction of Fe³⁺ to Fe²⁺ and in scavenging nitric oxide (NO) radicals. In vitro, the level of lipid peroxidation was reduced by RMHA extract and the data showed significant oxidative damage protection. The RMHA cytotoxicity was evaluated by a neutral red assay in fibroblast (L929) and melanome (B16F10) cells. The obtained results showed that the RMHA (40 and 80 µg/mL, respectively) reduced 70% of the viable cells. In conclusion, this study represents the first report regarding the antioxidant and anti-proliferative potential of R. maritima against B16F10 melanoma cells.