Beta-sitosterol (BS) is a phytosterol, widely distributed throughout the plant kingdom and known to be involved in the stabilization of cell membranes. To compile the sources, physical and chemical properties, spectral and chromatographic analytical methods, synthesis, systemic effects, pharmacokinetics, therapeutic potentials, toxicity, drug delivery and finally, to suggest future research with BS, classical as well as on-line literature were studied. Classical literature includes classical books on ethnomedicine and phytochemistry, and the electronic search included Pubmed, SciFinder, Scopus, the Web of Science, Google Scholar, and others. BS could be obtained from different plants, but the total biosynthetic pathway, as well as its exact physiological and structural function in plants, have not been fully understood. Different pharmacological effects have been studied, but most of the mechanisms of action have not been studied in detail. Clinical trials with BS have shown beneficial effects in different diseases, but long-term study results are not available. These have contributed to its current status as an “orphan phytosterol”. Therefore, extensive research regarding its effect at cellular and molecular level in humans as well as addressing the claims made by commercial manufacturers such as the cholesterol lowering ability, immunological activity etc. are highly recommended.

BackgroundLagerstroemia speciosa (L.) Pers. (Family: Lythraceae) is used in traditional medicine in the treatment of diarrhea, diabetes and other diseases. The study was performed to conduct antioxidant, cytotoxic, thrombolytic, membrane stabilizing, antimicrobial, peripheral and central analgesic and hypoglycemic activity assays and phenobarbitone sodium–induced sleeping time test using crude methanol extract of flowers of L. speciosa and its different partitionates.MethodThe antioxidant potential was evaluated by determining the ability of the samples to scavenge 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical. The cytotoxic potential was examined following the procedures of brine shrimp lethality bioassay. Thrombolytic potential was assayed using streptokinase as standard. The samples were subjected to membrane stabilizing activity assay under heat induced condition. Antimicrobial potential was observed by disc diffusion method. The ability of the extract to inhibit writhing induced by acetic acid was determined in peripheral analgesic activity assay. The extract was also tested for central analgesic and hypoglycemic activities by tail flicking and tail tipping methods in Swiss albino mice model, respectively. CNS depressant activity was evaluated by an assay in which sleep was induced in mice using phenobarbitone sodium.ResultsThe chloroform soluble fraction of L. speciosa extract demonstrated the highest antioxidant activity (IC50 = 4.20 ± 0.41 μg/ml) while the most prominent cytotoxic potency was showed by hexane soluble fraction (LC50 = 2.00 ± 0.31 μg/ml). Among the test samples, the carbon tetrachloride soluble fraction induced clot lysis (64.80 ± 0.27%) and prevented heat induced haemolysis (41.90 ± 0.10%) to the maximum extent. The largest zone of inhibition (19.0 mm) against Staphylococcus aureus, was also observed for the same fraction. In peripheral analgesic activity assay, 16.68% inhibition of writhing was documented for the L. speciosa extract (400 mg/kg body weight dose). The extract (400 mg/kg dose) also reduced blood sugar level by 56.12% after three hours of administration of glucose solution. In CNS depressant activity assay, mice of the sample group slept for shorter period of time compared to control group.ConclusionsFrom our investigation, it can be suggested that, the extract should be further studied for possible phytochemicals responsible for the observed biological activities.

ABSTRACT:The methanol extracts of leaves of Nephelium lappaceum L., Pandanus foetidus Roxb., Ludwigia repens Rubin. and the whole plant of Adiantum philippense L. were subjected to assays of antioxidant, cytotoxic, thrombolytic and membrane stabilizing activities. The antioxidant activity was evaluated by DPPH free radical scavenging activity using butylated hydroxytolune and ascorbic acid as standards. The crude extract of N. lappaccam exhibited the highest free radical scavenging activity (IC 50 = 3.93±0.25µg/ml). On the other hand, the crude methanol extracts of A. philippense and P. foetidus demonstrated significant brine shrimp lethality with LC 50 values 0.50±0.84 µg/ml and 0.58±0.73 µg/ml, respectively as compared to the standard anti-neoplastic drug, vincristine sulfate (LC 50 = 0.45 µg/ml). Weak thrombolytic activity was observed for the test samples. The crude methanol extracts of P. foetidus and N. lappaceum showed 17.31±0.82 % and 17.29±0.91 % clot lysis while standard streptokinase and water, used as positive and negative controls, demonstrated 66.77 % and 3.79 % lysis of clot, respectively. The methanol extract of whole plant of A. philippense inhibited hypotonic solution and heat induced haemolysis of RBCs by 53.09±1.01 % and 35.36±1.60 % as compared to 71.77 % and 42.20 % by acetyl salicylic acid, respectively.

ABSTRACT:The methanol extract of leaf of Picrasma javanica as well as its n-hexane, carbon tetrachloride, chloroform and aqueous soluble partitionates were subjected to screening for antioxidant and thrombolytic activities and brine shrimp lethality. The antioxidant potential was evaluated by DPPH, Folin-Ciocalteau reagent and phosphomolybdenum total antioxidant assays using butylatedhydroxytolune (BHT) and ascorbic acid as standards. All fractions showed moderate to strong antioxidant activity, of which the chloroform and aqueous soluble fractions demonstrated the highest activity with the IC 50 value of 14.59 ± 0.73 µg/ml and 18.6 ± 0.15 µg/ml, respectively. The total phenolic content of the chloroform and aqueous soluble fractions was 10.4 ± 0.64 and 5.15 ± 0.22 mg of GAE/g of extractive, respectively. Thus, a positive correlation was found between the total phenolic content and total antioxidant activity of P. javanica. The general toxicity was determined by brine shrimp lethality bioassay where the crude extract (LC 50 1.04 ± 0.31 µg/ml) and its n-hexane (LC 50 1.28 ± 0.45µg/ml) soluble partitionate demonstrated the presence of considerable bioactive principles. Mild to moderate thrombolytic activity was discerned by the methanol extract of leaf of P. javanica and its different fractions. During assay for thrombolytic activity, the carbon tetrachloride soluble materials revealed 34.165±1.57 % of clot lysis while standard streptokinase and water, used as positive and negative controls, demonstrated 66.77% and 3.791% lysis of clot, respectively.

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