Browsing by Author "Dharmasiri, M.G."

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Anti-inflammatory activity of decoction of leaves and stems of Anisomeles indica at pre-flowering and flowering stages
(Informa Healthcare, 2002) Dharmasiri, M.G.; Ratnasooriya, W.D.; Thabrew, M.I.
A decoction of leaves and stems of Anisomeles indica (Lamiaceae) is claimed to possess anti-inflammatory activity in Sri Lankan traditional medicine. The plants at both preflowering and flowering stages are used as an anti-inflammatory agent. However, the anti-inflammatory activity of the plant has not been scientifically evaluated thus far. The aims of this study were to evaluate scientifically the anti-inflammatory activity of decoctions of leaves and stems of A. indica at pre-flowering and flowering stages and possible toxic effects of the decoctions. Three doses of the freeze-dried decoction of a pre-flowering plant (E1) (125, 250 and 500 mg/kg) and one dose of the decoction of a plant at flowering stage (E2) (500 mg/kg) were orally administered to rats. The anti-inflammatory activity was evaluated using the carrageenan-induced paw edema, formaldehyde-induced paw edema and adjuvant-induced paw edema models in rats. E1 demonstrated a significant (P < 0.01) and dose-dependent anti-inflammatory effect in all three models, while E2 did not demonstrate significant anti-inflammatory activity. E1 demonstrated a significant (P < 0.01) and dose-dependent antihistamine activity and free radical scavenging activities in addition to the previously reported membrane stabilising and cyclooxygenase-I inhibitory activities. However, E1 failed to impair significantly the in vitro activity of lipoxygenase. A 30-day treatment with 500 mg/kg of E1 was not liver toxic or renotoxic, and it did not have a significant effect on body weights. It was concluded that the anti-inflammatory activity of E1 is contributed by cyclooxygenase-1 inhibition, plasma membrane stabilisation, antihistamine and free radical scavenging activities, but not by the inhibition of lipoxygenase. These observations prove scientifically the anti-inflammatory activity of A. indica, mentioned in the Sri Lankan traditional medicine, while revealing a loss of the activity after flowering.
Anti-inflammatory and analgesic activity in the polyherbal formulation maharasnadhi quathar
(Elsevier, 2003) Thabrew, M.I.; Dharmasiri, M.G.; Senaratne, L.
Maharasnadhi Quathar (MRQ) is a polyherbal preparation recommended by Ayurvedic medical practitioners for treatment of arthritic conditions. An investigation has been carried out with rats and human rheumatoid arthritis (RA) patients, to determine the anti-inflammatory and analgesic potential of MRQ. Results obtained demonstrate that MRQ can significantly and dose-dependently inhibit carrageenan-induced rat paw oedema (the inhibition at 3h was greater than at 1h after induction of oedema). MRQ could also increase the reaction time of rats in the hot-plate test (by 57% after the first hour of treatment), although it had no effect on the reaction time in the tail-flick test, indicating that MRQ possesses analgesic activity that is probably mediated via a supra-spinal effect.MRQ also exerted a dose-dependent (a) protective effect on heat-induced erythrocyte lysis, and (b) inhibition of 5-lipoxygenase activity. In RA patients, after 3 months of MRQ treatment, there was a marked improvement in the pain and inflammation experienced by the patients as well as in the mobility of the affected joints. From the overall results obtained, it may be concluded that MRQ possesses significant anti-inflammatory and analgesic activities. Alteration in synthesis of prostaglandins and leukotrienes, membrane stabilization and anti-oxidant activity are some of the possible mechanisms through which MRQ mediates its anti-arthritic effects.
Diuretic activity of leaf and stem decoctions of Anisomeles indica
(2003) Dharmasiri, M.G.; Ratnasooriya, W.D.; Thabrew, M.I.
Anisomeles indica (Lamiaceae) is a wild perennial herb growing in South and South East Asia. A decoction of leaves and stems of this plant is said to be diuretic but this point has not been verified in a controlled scientific investigation. The aim of the study was to scientifically investigate the diuretic activity of the decoctions of leaves and stems of both preflowering (E1) and flowering (E2) plants. Rats were used for experiments. The results showed that A. indica has powerful diurecti action and justify the use of the plant in traditional medicine in Sri Lanka. It is concluded that only the preflowering plants possessed marked diuretic activity. The selection of proper stage of the plant is vital for the induction of diuresis.
Gastroportective effects Anisomeles Indica Kuntze
(Medknow Publications, 2007) Dharmasiri, M.G.; Ratnsooriya, W.D.; Thabrew, M.I.
Haematological parameters of three species of wild caught microchiropteran bats, Miniopterus schreibersii, Taphozous melanopogon and Hipposideros lankadiva in Sri Lanka
(Journal of Science of the University of Kelaniya Sri Lanka, 2005) Ratnasooriya, W.D.; Udagama-Randeniya, P.V.; Yapa, W.B.; Digana, P.M.C.B.; Dharmasiri, M.G.
This study,for the first time in South Asia, examines haematological parameters of thre species of wild caught Sri Lankan microchiropteran bats, belonging to three different families having different global zoogeographical distributions; Miniopterus schreibersii (Vespertilionidae: n=12), Taphozous melanopogon (Emballonuridae; n=19) and Hipposideros lankadiva (Hipposiderosidae; n=15). Blood samples were obtained from the median vein and the total white blood cell (WBC) count, red blood cell (RBC) count, packed cell volume (PCV), haemoglobin content(Hb), mean corpuscular volume (MCV) and mean corpuscular haemoglobin content (MCHC) were determined using standard haematological techniques. lnterspecies differences existed in some of the parameters monitored, i.e. PCV, MCV, WBC and RBC counts. % of neutrophils and lymphocytes. On the other hand, a gender discrepancy was recorded for T.melanopgon with respect to neutrophils and lymphocytes, and for M. schreibersii with respect to the total WBC count. The highest WBC count and the lowest PCV and MCV were found in M. schreibersii. T.melanopgon registered the highest percentage of lymphocytes and the lowest percentage of neutrophils, while H. lankadiva possessed the highest MCV. Haematological values were recorded also for a single lactating T.melanopogon.
Water extracts of leaves and stems of pre-flowering but not flowering plants possess analgesic and antihyperalgesic activities in rat
(Informa Healthcare, 2003) Dharmasiri, M.G.; Ratnasooriya, W.D.; Thabrew, M.I.
According to Sri Lankan traditional medicine, a decoction made from stems and leaves of Anisomeles indica Kuntze (Lamiaceae) possesses analgesic activity. However, the validity of this claim has not been scientifically tested. The aim of this study was to investigate analgesic and antihyperalgesic activities of this plant using a water extract made from the leaves and stems. The water extracts were made from leaves and stems of both preflowering (E1) and flowering plants (E2). E1 showed a dose-dependent analgesic effect up to 6 h of treatment when tested in rats using the hot plate and the tail flick techniques. Further, the analgesic effect of E1 was not accompanied by toxic effects. This effect was neither gender dependent nor dependent on the stage of the estrous cycle. E1 also showed a dose-dependent antihyperalgesic activity in the hot plate test. In contrast, E2 did not show any analgesic effect (500 mg/kg). The analgesic effect produced by E1 was not abolished by naloxone. E1 dose-dependently retarded the amplitude of the spontaneous contractions of isolated dioestrous rat uterus. Further, E1 induced a dosedependent plasma membrane stabilisation effect on rat erythrocytes. Collectively, these observations suggest that the analgesic and antihyperalgesic effects of E1 are mediated from inhibition of COX-1, thus impairing the synthesis of prostaglandins. A change in chemical contents that accompanies flowering could be one possible reason for the inability of E2 to demonstrate analgesic effect.