Role of taraxerone isolated from Leucas lavandulifolia, as an immunomodulator.

ETHNOPHARMACOLOGICAL RELEVANCE: The Indian tradition system of medicine enlists a large number of plants for basic health care. Leucas lavandulifolia is mentioned in the ayurvedic medicinal system and also used among the folklores. The plant is used for the treatment of fever, asthma, psoriasis, dermatitis and healing snake bites. The scientific validation of the plant for their traditional use in different immune related disorders are yet to be explored. AIM OF THE STUDY: The study aims to isolate immunomodulatory active compound from Leucas lavandulifolia and evaluating its efficiency in immune related disorders. MATERIALS AND METHODS: The immunomodulatory activity of the phytocompound is evaluated through in vitro and in vivo studies. The compound purification and identification were done by chromatography and LC/Q-TOF respectively. Its immunomodulatory activity was evaluated in cells like PBMC, neutrophils and macrophages by MTT assay and cell cycle analysis. Animal studies were performed on Swiss albino mice. The levels of IL-4 and IL-6 cytokines were also evaluated in both in vitro and in vivo models. RESULTS: Leucas lavandulifolia stem portion was found to have good modulatory property. An active immunomodulator was isolated from the methanol extract of the plant. LC/Q-TOF data revealed the isolated compound to be taraxerone. In PBMC, the compound was capable of suppressing the proliferation rate of the compound indicated by a decrease in cell numbers. The activated IL-4 and IL-6 production was also suppressed actively at 25 µg/ml of taraxerone. Similar inhibitory effects were seen in RAW 264.7 and THP-1 macrophage cell lines. An IC50 value of 17.5 µg/ml was obtained for taraxerone in LPS stimulated RAW 264.7 macrophage cell lines. The NO level, IL-4, IL-6 and phagocytosis in the LPS stimulated macrophage was effectively lowered by 25 µg/ml of taraxerone. In PMA stimulated THP-1 Macrophage Cell Lines, taraxerone was capable of suppressing the cell number and IL-6. The compound didn't show any effect on IL-4 levels. The compound exhibited an immunosuppressive activity in PHA induced PMN cells by suppressing the respiratory burst and interleukins IL-4 and IL-6. TX could also suppress the proliferation of DNCB induced monocyte cells and IL-4. The haematological parameters exhibited a significant suppression for the high dose group of taraxerone. The antibody titre and phagocytic index was suppressed by the high dose group, whereas the low dose group did not have any effect. So taraxerone at 50 mg/kg body weight is capable of modulating the B-lymphocytes and macrophages. But the compound has exhibited insignificant effect on the DTH hypersensitivity response and organ index. CONCLUSION: Taraxerone at high concentration was capable of suppressing stimulated PBMC, macrophage and PMN. The activated nitric oxide, IL-4, IL-6 production and phagocytosis was also suppressed. The haematological parameters, antibody titre and phagocytic index was also lowered in antigenically challenged mice. The terpenoid taraxerone exhibits a good modulatory effect on the immune system and proves to be a potent drug for the treatment of many allergic disorders.

Structural characterization of a novel derivative of myricetin from Mimosa pudica as an anti-proliferative agent for the treatment of cancer.

The study was initiated to determine the anticancer activity of a novel compound isolated from the plant Mimosa pudica. The structure of the compound was identified as a derivative of myricetin having alkyl, hydroxy alkyl and methyl substitutions on the basis of spectral evidences (UV-vis, FT-IR, 1H NMR and Mass spectra). The isolated compound was interpreted as 2-(2',6'-dimethyl-3',4',5'-alkyl or hydroxy alkyl substituted phenyl)-3-oxy-(alkyl or hydoxy alkyl)- 5,7-dihydroxy-chromen-4-one. In vitro evaluation of anticancer activity against human lung adenocarcinoma cell line (A549) and human erythroleukemic cell line (K562) were conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. In vivo anticancer activity was determined against Dalton's Ascites Lymphoma (DAL) in Swiss albino mice. The mice were treated with intraperitoneal administration of the compound at 25mg/kg and 100mg/kg body weight and were compared with the normal, DAL control and standard drug cyclophosphamide treated groups. The histology revealed that the compound could protect the cellular architecture of liver and kidney. The results from the in vitro, in vivo and histological examinations confirmed the ethnopharmacological significance of the isolated compound and could be considered further for the development of an effective drug against cancer.