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Background: Syzygium palodense is an unexplored species endemic to the southern Western Ghats in India. Purpose: Here we report the chemical profiles of essential oils (EOs) of the leaves and fruit pericarps of S. palodense and their antiproliferative activities against C6 glioma and Dalton's Lymphoma Ascites (DLA) cells. Methods: S. palodense leaves and fruit pericarp EOs were isolated by hydrodistillation and characterized by gas chromatographic (GC/FID, GC/MS) techniques. Antiproliferative activities of EOs were elucidated by MTT, phase contrast/fluorescent microscopic and flow cytometric assays. Results: Thirty six (99.92%) constituents were identified from S. palodense fruit pericarp EO, with (E)-β-ocimene (63.20%), myrcene (15.79%) and (Z)-β-ocimene (9.70%) as its major constituents. Sixty nine (99.40%) constituents were identified in the leaf EO, and the major ones were (E)-β-ocimene (30.58%), (E)-caryophyllene (14.23%), δ-selinene (13.89%), γ-himachalene (7.59%), myrcene (8.38%) and (Z)-β-ocimene (5.68%). Both leaf and fruit pericarp EOs showed significant cytotoxicity in C6 glioma and Dalton's Lymphoma Ascites (DLA) cells with very low CD50 values of 1.8, 1.2 µg/ml and 4.8, 1.1 µg/ml, respectively. MTT, phase contrast/fluorescent microscopic and flow cytometric assays revealed the cytotoxic mechanism of these EOs in C6 glioma and DLA cells as induction of apoptosis. Conclusion: This is the first report of the chemical profiles and biological activities of EOs of S. palodense. Both leaf and fruit pericarp EOs displayed strong antiproliferative activity (very low CD50 values) against C6 glioma and DLA cells.

Mast seeding and associated events in Melocanna baccifera, the largest fruit producing bamboo, is an enigma. So far there are no comprehensive accounts on its flowering phenology, fruiting dynamics and animal interactions. In this study, spanning over 13 years (2009 to 2022), we observed eight M. baccifera clumps in JNTBGRI Bambusetum from flowering initiation, fruiting to eventual death. Flowering phenology, floral characteristics, floret types, breeding system, bee visitation, pollination, fruit production and predators were recorded; predation patterns were correlated with fruit chemistry. Flowering duration of clumps ranged from 20 (March 2009—October 2010) to 120 (September 2012—August 2022) months. Bisexual florets are dichogamous and protogynous; and female duration (22–72 h) is many times higher than male duration (2–6 h). The highest ever fruit production for an individual bamboo clump (456.67 Kg) was recorded. Of the total fallen fruits (38371), 38.11% were predated, 43.80% good fruits (no predator hits) and 18.09% immature fruits. A positive correlation between reward (fruits) versus predation was observed, especially in short intervals of high fruit production. Pollen predators (Apis cerana indica, Halictus taprabonae, Braunsapis cupulifera, Trigona iridipennis), fruit predators, ranging from arthropods to mammals, viz., millipede (Spinotarsus colosseus), slug (Mariaella dussumieri), snails (Cryptozona bistrialis, Macrochlamys sp.), borers (Achroia grisella, Blattella germanica), mammals (monkeys Macaca radiata, rats Rattus rattus, porcupine Hystrix indica, wild boar Sus scrofa, palm civet Paradoxurus hermaphroditus), seedling predators (rabbit Lepus nigricollis, deer Axis axis), and insect/pest predators (ants Crematogaster biroi, Oecophylla smaragdina, mantis Euchomenella indica) were identified. Fruit predation is linked to its age and chemistry. Apart from new insights on flowering phenology, breeding system, pollination and fruiting dynamics, this study demonstrates the vibrant interaction between M. baccifera flowers/fruits and visitors/predators, and provides significant leads towards elucidating the cause of rat multiplication and other events associated with its gregarious flowering. [ABSTRACT FROM AUTHOR]

Ethnopharmacological Relevance: Melicope lunu-ankenda leaves are used to treat diabetes in folklore medicinal practices in India and Malaysia. Here we report the isolation of an O-prenylated flavonoid (3,5,4'-trihydroxy-8,3'-dimethoxy-7-(3-methylbut-2-enoxy)flavone; OPF) from the leaves of M. lunu-ankenda and its antidiabetes activity against type-2 diabetes mellitus (T2DM)., Materials and Methods: OPF was isolated from M. lunu-ankenda leaves by extraction and repeated column chromatography and its structure was elucidated by IR, UV-vis, 1D-, 2D-NMR and mass spectral analyses. Blood glucose lowering activity of OPF was tested in normal rats by oral glucose tolerance test and its efficacy was tested in STZ-induced type-2 diabetic rats. SGOT, SGPT, ALP, serum urea, total triglycerides, total cholesterol and reduction in HDLC, protein and serum insulin levels in normal rats and STZ-induced type-2 diabetic rats were measured. Acute toxicity of OPF was tested at 500 mg/kg dose. Mechanism of antidiabetes action of OPF was elucidated by insulin release from RIN 5F cells., Results: OPF isolated from M. lunu-ankenda showed significant blood glucose lowering activity in oral glucose tolerance test on overnight fasted, glucose loaded normal rats and the optimum activity was observed at a dose of 10mg/kg body weight. In neonatal streptozotocin (STZ) induced diabetic rats, the OPF treatment for 20 days significantly ameliorated the derailed blood glucose levels, liver glycogen and serum biological parameters including insulin to normal levels. OPF on acute toxicity evaluation did not show any conspicuous toxic symptoms even at a higher dose of 500 mg/kg body weight in mice. On evaluating the mechanism of antidiabetes action, it was observed that, OPF induced insulin release from cultured RIN 5F cells in vitro from which it was evident that the OPF acts on pancreatic β-cells for insulin release thereby correcting the derailed blood glucose levels, serum biochemical parameters and ameliorate various diabetic complications in STZ-induced diabetic rats., Conclusions: This study shows the potent antidiabetes activity of OPF and describes its mechanism of action. OPF is a promising candidate for the development of new generation anti-DM drugs. Isolation of the O-prenylated flavonoid justifies the use of M. lunu-ankenda for diabetic treatments in folklore practices., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Hemionitis arifolia, a folklore anti-diabetes fern, was evaluated for its hypoglycaemic and anti-diabetic properties using rats. Glucose lowering effect and anti-diabetes activity were studied using glucose tolerance test in normal rats and alloxan diabetic rats, respectively. When different extracts were tested, the ethanol and, to some extent, the water extracts were found to lower the levels of blood glucose in glucose fed rats. The ethanol extract showed optimum activity at 200 mg/kg. The extract exhibited only marginal hypoglycaemic activity in overnight fasted normal rats and it was devoid of conspicuous toxic symptoms in sub-acute toxicity evaluation in mice. When the alcohol extract was fractionated by sequential solvent extraction, the activity was found in ethyl acetate fraction (50 mg/kg). This fraction containing steroids and coumarins showed anti-diabetes activity in alloxan diabetic rats as judged from serum glucose levels, liver glycogen content and body weight. This fraction is an attractive material for further research vis-à-vis drug development.