ICAPS-2021
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/23880
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Item Perceptions of urban residents on the cultural and ecological roles of residential gardens in Gampaha district, Sri Lanka(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Subashini, J. K. W. N.; Yakandawala, K.; Minor, E. S.Urban residential gardens provide recreational, socio cultural and environmental services to urban communities. However, the degree to which the urban residents recognize, and value of these services is unclear where a complex assortment of interacting socio-economic factors govern the perceptions of urban residents towards the role of residential gardens. Due to the limited attention on urban residential landscapes in Sri Lanka, the present study was conducted targeting the urban community in the Gampaha Divisional Secretariat (DS) to evaluate the perceptions towards cultural, environmental and conservation values of the residential gardens. A pre-tested, interviewer-administrated questionnaire was used to collect the socio-economic details of 50 randomly selected households located within the 2 km radius of the city center of the Gampaha DS. Perceptions on environmental, cultural and the conservation services of residential gardens were evaluated based on a 5-point Likert scale. The Chi-square test of association was used to identify the significant socio-economic factors that influence the perceptions of the respondents. The majority of the respondents were 51-65 years old (41.7%), followed by >65 years (25%) and 36–50 years old (25%). About 45.8% of the respondents had completed a basic degree qualification, while 41.7% had completed Advanced Level qualification. Retired household heads dominated the sample (37.5%), followed by those occupied in the private sector (29.2%). The highest fraction (32%) of the respondents received a monthly income ranging from USD 400 – USD 600. Stress release/health benefits, pollution control, and aesthetic value of plants/flowers, were ranked as the highest benefits of residential gardens, with mean scores of 4.90, 4.84 and 4.82, respectively. The majority of respondents (84%) strongly agreed with the statement that residential gardens can connect people with nature (Mean Score=4.82). Among the respondents, 24% had a highly positive attitude on the importance of residential gardens as entities of ecosystem conservation, while 34% of the respondents showed a neutral attitude. According to the Chi-square test, income, age, education and employment were significantly associated with the attitudes of the respondents towards the socio cultural services of residential gardens. Meanwhile, only the education was significantly associated with attitudes on the conservation values of residential gardens (p<0.05). The results reflect the desire of urban dwellers to experience a pleasant and fresh natural environment even in the middle of an urban lifestyle. Since people tend to feel the nature in the direct and the closest living environment in their everyday lives, residential gardens should be considered as the primary unit of concern in urban green space planning. Hence, understanding people’s perceptions of gardens could be help in designing and improving the urban green spaces.Item In vitro antidiabetic activity of Spondias pinnata aqueous extract and encapsulated chitosan-TPP nanoparticles(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Wadasinghe, R. R.; Attanayake, A. P.; Kalansuriya, P.Spondias pinnata (L. f.) Kurz is a medicinal plant used in complementary medicine. Decoctions prepared using stem-bark of S. pinnata find applications in treating diabetes mellitus. However, low bioavailability of bioactive metabolites (polyphenols and flavonoids) and lack of appropriate release of metabolites delimit the antidiabetic activity of S. pinnata aqueous extract (SAE). Encapsulation of SAE with chitosan-tripolyphosphate (CS-TPP) could enhance its therapeutic potential and provide controlled release. The objective of this work to determine in vitro antidiabetic activity of S. pinnata stem-bark extracts and SAE-encapsulated CS-TPP nanoparticles using α-amylase inhibitory, α-glucosidase inhibitory, glucose uptake and glucose adsorption assay. The extracts were prepared by extracting dried and powdered stem-bark of S. pinnata into distilled water, acetone, ethyl acetate, dichloromethane under ultrasonication (40 kHz, 37 °C, 30 min) separately. The total phenol content (TPC) and flavonoid content (TFC) of the extracts were determined using Folin-Ciocalteu and aluminium chloride methods, respectively. Based on the results of α-amylase inhibitory assay, SAE was selected for the encapsulation with CS-TPP. The SAE had TPC of 4.18±0.02 mg gallic acid equivalents per gram of dry weight (GAE/g DW) and TFC of 0.37±0.01 mg quercetin equivalents per gram of dry weight (QE/g DW) and showed the highest α-amylase inhibitory activity (IC50 53.34±7.43 µg/mL). The acetone extract had TPC of 34.43±0.35 mg GAE/g DW and TFC of 4.06±0.05 mg QE/g DW and showed the highest α-glucosidase inhibitory activity (IC50 8.82±1.42 µg/mL). The highest glucose uptake and glucose adsorption were shown by acetone extract and aqueous extract, respectively. SAE-encapsulated nanoparticles were prepared from CS-TPP at varying concentrations (0.250, 0.375, 0.500 and 0.625% w/v) of SAE using ionic gelation method under magnetic stirring; the highest encapsulation efficiency (68.21% ± 0.66%) and loading capacity (0.79% ± 0.17%) were obtained at 0.625% w/v of SAE. Loaded nanoparticles were separated by centrifugation and free polyphenols were determined by Folin-Ciocalteu method. The Z-average particle diameter of SAE-encapsulated CS-TPP nanoformulations was 417±86 nm with polydispersity index of 0.574 and zeta potential of +20.63 mV. The IC50 values corresponding to α-amylase inhibitory activity and α-glucosidase inhibitory activity of SAE-encapsulated CS-TPP nanoparticles were 1.10±0.03 mg/mL and 3.16±0.15 mg/mL, respectively. Although the percentage of glucose uptake and adsorption in SAE encapsulated CS-TPP nanoparticles is lower than the crude extract, it had shown 11.59±1.03 % glucose uptake at 5 mM glucose concentration and 1.47 mmol/g glucose adsorption at 100 mM glucose concentration. The SAE, acetone extract and SAE-encapsulated CS-TPP nanoparticles showed higher antidiabetic activity than the positive control, acarbose. Further investigations on the releasing profiles of SAE-encapsulated CS-TPP nanoparticles would reveal the rates at which the active metabolites are released to the media during the timeframes of the conducted assays.Item Optimization of high-fat diet fed streptozotocin induced Wistar rat model for screening antidiabetic agents(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Wickramasinghe, A. S. D.; Attanayake, A. P.; Kalansuriya, P.High-fat diet (HFD) fed streptozotocin (STZ) induced Wistar rats are frequently used as animal models of type 2 diabetes mellitus for screening novel antidiabetic agents. As the composition of HFD, age and strain of rats, dose of STZ and the intended degree of pathophysiological changes vary among studies, the development of a model that best fits to a particular research setting is pivotal. Furthermore, ensuring the long-term stability and establishment of an adequate biochemical profile of the model are necessities which have been addressed by limited studies to date. This study attempted the development of a model which mimics type 2 diabetes mellitus for screening of novel antidiabetic drugs. Wistar rats were fed with a HFD (60% calories from fat) for four weeks, followed by STZ intraperitoneal injection (30, 40 and 50 mg/kg). Rats with fasting serum glucose >11.1 mmol/L were enrolled for the study. There were five groups (n=10/group); healthy rats, HFD fed rats, HFD+STZ (30 mg/kg) rats, HFD+STZ (40 mg/kg) rats, HFD+STZ (50 mg/kg) rats. The glycemic status of the rats was monitored weekly by the routine conduct of oral glucose tolerance tests. Experimental rats were euthanized after 28 days and blood samples were collected for biochemical investigations. Glycemic status of the model was assessed by determining fasting serum glucose, insulin, glycated hemoglobin (HbA1c) and homeostatic model assessment-insulin resistance (HOMA-IR). Lipid profiles were assessed by determining total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C) levels. STZ induced rats (30, 40 and 50 mg/kg) showed a significant dose dependent increase in fasting serum glucose (by 67, 61 and 136%) and insulin (by 19, 15 and 13%) concentrations (p<0.05). HOMA-IR was above 2.5 and increased in a dose dependent manner by 98, 108 and 176% in STZ induced rats (30, 40 and 50 mg/kg). However, only the STZ (50 mg/kg) induced group of rats showed fasting serum glucose concentration of 13.71 ± 1.01 (>11.1 mmol/L) and a significant increase in HbA1c by 66% compared to the healthy rats (p<0.05). Further, the STZ 50 mg/kg rats showed stable hyperglycemia throughout the study period. STZ induced rats (30, 40 and 50 mg/kg) also showed a significant dose dependent increase in TC (by 6, 7 and 9%), and TG (by 16, 15 and 23%) respectively (p<0.05). However, only the STZ induced (50 mg/kg) group of rats showed significant increase in serum concentrations of LDL-C (by 12%) and VLDL-C (by 16%) compared to the healthy rats (p<0.05). Only slight changes in HDL-C levels were observed in the STZ induced groups of rats however, the values were not significant (p>0.05). The results revealed that the Wistar rats fed with HFD rich in saturated fat for four weeks followed by a single intraperitoneal dose of STZ (50 mg/kg) would produce stable diabetic model which closely mimic pathophysiological features of type 2 DM characterized by insulin resistance and dyslipidemia.Item Determination of cytotoxicity and antifungal activity of different solvent extracts obtained from coconut testa flour of selected Sri Lankan coconut cultivars(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Gunarathne, K. M. R. U.; Marikkar, J. M. N.; Mendis, E.; Yalegama, C.; Jayasinghe, L.Coconut testa is reported as a rich source of phyto-constituents that claim various bioactivities. In this study, selected bioactivities of flour obtained from partially defatted coconut testa (CTF) of five Sri Lankan coconut cultivars namely, Gon Thembili (GT), Ran Thembili (RT), San Raman Tall (SR), Tall x Tall (TT) and commercial hybrid (COM) were investigated. CTF was sequentially extracted with hexane, ethyl acetate (EtOAc), and methanol (MeOH). The obtained crude extracts were subjected to cytotoxicity assay using the 2nd instar nauplii of Artemia salina while the antifungal activity was assessed using TLC bioautographic method against Cladosporium cladosporioides. Results showed that the majority of the extracts did not show inhibitory activity against C.cladosporioide except for the hexane and EtOAc fractions of COM cultivar. According to the result of the cytotoxicity assay, the hexane, EtOAc and MeOH extracts of CTF of different cultivars showed low to moderate toxicity (LC50 ˃ 2000 ppm) towards A. salina whereas the overall lethality % was found to be dependent on the concentration of CTF extracts within the selected range of 50-2000 ppm. When comparing the results obtained for the highest CTF concentration level (2000 ppm), a significantly (p<0.05) higher percentage of lethality was observed for hexane extracts of RT (33.33±5.77%), EtOAc extracts of COM (46.67±5.77%), TT (43.33±5.77%) and MeOH extract of COM (33.33±5.77%) compared to other cultivars. The results of this study confirmed the poor antifungal activity of CTF while demonstrating the degree of the potential of CTF to function as a cytotoxic agent and their varied activities among different Sri Lankan coconut cultivars. However, sample preparation method might have affected the results showed by hexane extract as partial defatting may remove potential antifungal and cytotoxic compound up to certain extent. It is clear that selective in-depth studies for cytotoxicity of CTF are needed for further elaborations. However, the results of this study would provide sound preliminary knowledge for future research aspects.Item Mosquito larvicidal effect of Annona glabra fruit extract on dengue vector, Aedes aegypti(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Wijebandara, N. R. Y.; Ranasinghe, H. A. K.; Amarasinghe, L. D.; Wickramarachchi, S. R.Annona glabra is a plant of Family Annonaceae and many plant species belong to this family have been intensively studied since they were discovered to contain compounds with important biological properties. These properties include cytotoxic, antitumor, antiparasitic, antifungal, antispasmodic, repellent, and insecticidal activities. Insecticidal effects of plant extracts vary depending on the plant parts (leaf, seed, fruit, bark) used for the extraction. Larvicidal effect of A. glabra aqueous extract from leaves and seeds have been evaluated against Aedes aegypti mosquitoes in Sri Lanka, and larvicidal effect of fruit is not determined yet. Therefore, the present study was conducted to evaluate the effect of A. glabra fruit extract for its larvicidal efficacy on third instar larvae of Ae. aegypti. Fresh ripen fruits of A. glabra plant were collected from Hunupitiya, (N 06º 58.904/, E 079° 54.281/) in Gampaha district, Sri Lanka. The aqueous crude extract was prepared from powdered A. glabra fruits. Seven concentrations were prepared between the range of 3 g/L – 300 g/L. Batches of 25 third instar larvae of Ae. aegypti were used for larval bioassays. Ae. aegypti mosquito larvae were evaluated in accordance with guidelines of World Health Organization. The experimental setup was repeated four times per each concentration. Probit analysis was used to evaluate the relationship of mortality with the concentration of aqueous crude extract. The A. glabra fruit extract showed a dose-dependent effect against Ae. aegypti larvae after the 48-hour exposure period. The percentage mortality rates have shown a significant variance among different concentrations (P = 0.000). The recorded LC50 and LC90 values for aqueous crude extract were 87.71 ± 5.41 gL-1 and 510.79 ± 12.56 gL-1 respectively, after 48 hours of exposure period. Larvicidal activity of A. glabra plant is supported by previous literature, where the presence of phytochemicals such as saponins, flavonoids, steroids and tannins have shown combined effects in terms of larvicidal action against mosquitoes. Hence, there is a potential of A. glabra aqueous fruit extract as a potential source for the development of an environment-friendly plant-based larvicide against Aedes aegypti.Item A preliminary study on the utilization of coconut paring residue as an antioxidant and a food preservative(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Thilakarathna, G. T. M.; Jayathilaka, N.; Seneviratne, K. N.Coconut paring is the brownish outer layer of the coconut kernel, which is removed when desiccated coconut is produced. Coconut Paring Residue (CPR) is the residue remaining after expulsion of coconut oil from the coconut parings. The present study was conducted to evaluate the potential of the ethanolic extract of CPR as an antioxidant mixture capable of preserving edible oils and milk. Phenolic compounds of CPR were extracted using ethanol: water (70:30 v/v) solvent system as 70% ethanol has shown the highest oxygen radical absorption capacity for the phenolic mixture. Total phenolic content and antioxidant activity of CPR extracts were measured using Folin-Ciocalteu and α, α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging assays respectively. The potential of the phenolic extract to inhibit lipid oxidation in soybean oil, sesame oil, sunflower oil and palm oil was determined by monitoring peroxides using ferric thiocyanate method. Microbial count was used to evaluate the ability of the phenolic extract to inhibit or delay the action of microorganisms in milk. All the tests were conducted in duplicates. Total phenolic content of the coconut paring residue extract was 1947 ± 12 mg/kg as gallic acid equivalents. The phenolic extract showed higher antioxidant activity between the concentration range 5-90 µg/mL and lower IC50 value (10.40 ± 0.36 μg/mL) compared to the ascorbic acid standard. Peroxide values of the phenolic-added oil samples were lower than those of the control with no added extract during the storage time period of 15 days. Colony Forming Units of yeast and molds per mL of milk (CFU/mL) were estimated using test samples with phenolic extract at 200 μg/mL). Milk without phenolic extract served as the control. The initial CFU count in both control and test samples was 4.5 × 104 ± 2.1 x 104 CFU/mL and the CFUs on the day two were 4.6 x 109 ± 1.7 x 109 CFU/mL and 2 x 108 ± 1.41 x 108 CFU/mL, respectively. The results suggest that the phenolic extracts of CPR can be used for improving the shelf life of edible oils and milk.Item Effect of oviposition-site deprivation on reproductive performance and life history parameters of dengue vector Aedes aegypti(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Gunathilaka, R. A. K. M.; Ganehiarachchi, G. A. S. M.Dengue and dengue hemorrhagic fever is the most important arthropod-borne viral disease that occurs in tropical and subtropical regions in the world. Annually 390 million new dengue cases are being reported from the 128 dengue-endemic countries. Aedes aegypti belonging to the family Culicidae is the primary vector that transmits the disease. Since there is no vaccine or a drug to prevent the disease, controlling programs are mainly focused on the vector controlling strategies. The primary vector is a container breeder and the widely used control method, source reduction, interrupts the oviposition of females. This will prevent or delay the oviposition of females leading to oviposition-site deprivation. Therefore, it is hypothesized that oviposition-site deprivation may affect the reproductive performance, life history parameters and longevity of Ae. aegypti. Thus, the objective of the study was to determine the effect of oviposition-site deprivation on fecundity, fertility, larval mortality, total larval duration, pupal duration and longevity of Ae. aegypti. Oviposition-site deprivation was done by blocking the access to the oviposition substrate. Mosquito batches were allowed to access an oviposition substrate separately on the day of blood feeding, 2, 4, 6 and 8 days after blood feeding. They were regularly fed with a 10 % sugar solution as the energy source. According to the results the mean number of eggs laid by the females subjected to different egg retention periods varied significantly. The highest number of eggs (99.53 ± 5.02) were laid by the females subjected to 8-day egg retention period and it was a 69% increase compared with the females who were not subjected to oviposition-site deprivation. However, the fertility (84.93 ± 0.47), percentage larval mortality (14.33 ± 1.16), total larval duration (105.60 ± 2.40 hours), pupal duration (41.60 ± 0.98 hours) and longevity (19.40 ± 0.29 days) did not show any significant difference (One-Way ANOVA, DF = 4, P > 0.05) with the oviposition-site deprivation. Increase of fecundity leads to an increase of vector population. Therefore, an increase of fecundity will act opposite to the desired goal of source reduction. However, the effect of the oviposition-site deprivation driven increased fecundity to the next gonotrophic cycle is not known. Alternatively, complete elimination of breeding sites in an area may support the mosquitoes to develop adaptations to use alternative breeding habitats such as estuaries. So, from the scientific viewpoint, complete elimination of breeding sites through source reduction may be disadvantageous. Also, oviposition-site deprivation through source reduction alone may not be an effective way to control vector populations of Ae. aegypti. Thus, it is important to have a clear knowledge on the effect of oviposition-site deprivation on mosquito physiology, reproductive performance, life history parameters and the longevity of the vector mosquitoes when adopting vector controlling strategies.Item Drought risk reduction by small tank cascade systems and isolated small tanks in the dry zone of Sri Lanka: an ecosystem based approach(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Prematilaka, L. A.; Wickramasinghe, D.; Vidanage, S.Sri Lanka is a proud owner of a flamboyant irrigation based history with a wide array of tanks. A cascade of water tanks (Small Tank Cascade System -STCS) which recycles water to help paddy cultivation, act as the backbone of the dry zone irrigation. The STCS are gaining attention not only as a water source but also as a resource to reduce drought risk in the dry zone. Droughts have been recognized as a major disaster in the Sri Lankan context. Owing to various anthropogenic influences, the occurrence of droughts in the dry zone of Sri Lanka is now rapidly exacerbating. The aim of this study was to investigate how tanks in a STCS and isolated reservoirs contribute to retain water during the dry season. This investigation was carried upon two selected tanks of the Kapiriggama STCS and two selected individual isolated small tanks in the Anuradhapura district of Sri Lanka. The cascade tanks were compared with the isolated tanks to determine whether the two systems differ in minimizing the drought risk in the dry zone. The present study adopted the use of Remote Sensing (RS) and Geographic Information System (GIS) techniques. The analysis was conducted using Normalized Difference Vegetation Index (NDVI) for the years 2006, 2014 and 2018. The NDVI images for the study sites were processed and analyzed for the two driest months of the selected years. The results revealed that the tanks in the STCS contribute more than the isolated small tanks to reduce the risk of droughts by retaining more water during the dry season. During April 2014, the two cascade tanks retained a water extent of 2.14% and 22.92% while the two isolated tanks retained a water extent of only 0%. In addition, during May 2018, two cascade tanks retained a water extent of 0.36% and 0.54% while the two isolated tanks retained a water extent of only 0% and 0.12%. Further, the present study highlights the significance of sustainable management and operation of both cascade and isolated tanks, since a growing body of evidence indicates that both tank systems are under heavy anthropogenic pressure. In addition, our study indicates the successful use of NDVI as a tool to assess water availability in reservoirs which can be beneficial in decision making related to water management.Item Development and characterization of biodegradable films of cornstarch filled with methylcellulose and gelatin(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Ranasinghe, W. R. A. D. S.; Jayasuriya, C. K.; Premachandra, J. K.Synthetic plastics play a vital role in many applications such as packaging, electrical, electronics, medical, textiles, furniture, and structural applications due to desirable properties like light- weight, high strength, flexibility, and chemical inertness. However, when the products made from many synthetic plastics are discarded to the natural environment it takes a very long time for degradation. This results in environmental pollution. Therefore, the use of biodegradable plastics in place of non-degradable plastics has gained significant interest as one of the main plastic waste management methods. However, biodegradable plastics such as starch and Polylactic acid do not show desired mechanical properties. In this research, it was expected to synthesize biodegradable films with improved mechanical properties using cornstarch (CS) filled with methylcellulose (MC). Microcrystalline cellulose (MCC) was extracted from cotton fibers through alkali treatment and bleaching, followed by sulphuric acid hydrolysis. Then, MCC was converted to MC using dimethyl sulfate in the presence of acetone as the solvent. This conversion was analyzed by Fourier transform infrared spectroscopy (FTIR). Their FTIR spectra showed significant differences in the regions 2960-3650 cm-1, 2780-2950 cm-1, and 960-1160 cm-1, which indicates that the conversion has occurred. The degree of substitution of the methyl group for H in MCC was determined by an acid-base titration and the resulting value was 1.36 ± 0.02. Then, an aqueous solution of MC (0.5 g/100 mL) was prepared. In the presence of water, CS (4% w/v) was dissolved in different amounts of the prepared MC solution in order to have six solutions with the ratio of MC to CS as 0.00%, 0.625%, 1.25%, 3.125%, 6.125%, 12.125% (w/w). Acetic acid (1% v/v) was added to all these solutions. Afterwards, two series of solutions, series 1 and 2, were prepared by mixing 1% and 2% (v/v) of glycerol, respectively, into the resulting solutions. Similarly, the third series was prepared by mixing glycerol (1% v/v) and gelatin (1% w/v). Three series of films were prepared using these solutions following the casting method. The dried films were characterized on physical, chemical, mechanical, and thermal properties. The film with 0.625% (w/w) MC in series 3, showed the highest tensile strength of 14.06 MPa. Films with MC-1.25% (w/w) in each series showed the lowest water absorptivity, swelling, and solubility properties. All the films produced were transparent. The films tend to twist and swell when treated with chemicals such as NaOH, HCl, NaCl, and ethanol. Also, the transparency of some of the films was reduced after this chemical treatment. FTIR analysis, thermo-gravimetric analysis, and differential scanning calorimetry were performed on the films having optimum properties. These films showed thermal degradation between 323-335 °C, melting temperatures between 267-293 °C, and glass transition temperatures between 84-120 °C. The biodegradability of films was determined by performing a soil burial test. After three months, the films had disappeared. It can be concluded that the biodegradable films developed in this study have the potential to replace polyethylene in some short-term packaging applications.Item Herbicidal properties of invasive alien plants Dillenia suffruticosa and Prosopis juliflora against Brassica juncea and Pennisetum polystachion(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Kaushalya, W. D. D.; Bandara, N. C.; Damunupola, J. W.; Madawala, H. M. S. P.; Jayasuriya, K. M. G. G.; Wijesundara, D. S. A.; Bandara, B. M. R.Synthetic pesticides can cause deleterious effects on human health and the environment. The rapid spread of invasive alien plants (IAPs) threatens biodiversity and the natural and semi-natural ecosystems. A strategy to address these problems is to develop eco-friendly plant-based pesticides from IAPs. In this study, the two IAPs, Dillenia suffruticosa (Griff.) Martelli. and Prosopis juliflora (Sw.) DC., were evaluated for their herbicidal properties against Brassica juncea (L.) Czern. (Bj) and Pennisetum polystachion (L.) Schult. (Pp). The dry leaf powders of IAPs, were separately extracted into dichloromethane-methanol (1:1) using a bottle extractor. The leaf powders and the concentrated leaf extracts were assayed for their inhibitory effects on seed germination and early seedling growth (shoot length, root length and biomass) of Bj and Pp using a Petri dish assay; 2-methyl-4-chlorophenoxyacetic acid (MCPA) and glufosinate were used as positive controls and distilled water and aqueous dimethyl sulfoxide as negative controls. Each treatment was done on 25 seeds in four replicates, in three trials. The IC50 values of the leaf powders and extracts expressed in equivalent amount of leaf powder for the inhibition of seed germination of Bj and Pp were as follows: 3.70 ± 0.38 and 3.10 ± 0.52 mg cm-2 (D. suffruticosa leaf powder against Bj and Pp, respectively); 1.55 ± 0.05 and 0.23 ± 0.06 mg cm-2 (P. juliflora leaf powder against Bj and Pp, respectively); 1.47 ± 0.07 mg cm-2 (D. suffruticosa leaf extract against Bj); 1.19 ± 0.53 mg cm-2 (P. juliflora leaf extract against Bj). Both IAPs were more effective on Pp than Bj (ANOVA, F = 70, p < 0.001). According to the results of the Kruskal- Wallis test, the leaf powders of P. juliflora (at 3.52 mg cm-2, 2 = 25.7, p < 0.001) and D. suffruticosa (at 17.62 mg cm-2, 2 = 24.3, p < 0.001) and the leaf extracts of P. juliflora (at 5.56 mg cm-2, 2 = 26.2, p < 0.001) and D. suffruticosa (at 8.27 mg cm-2, 2 = 25.6, p < 0.001) displayed more potent inhibitory effects on seed germination than glufosinate (at 4.4 µg cm-2) and MCPA (at 10.6 µg cm-2). Growth parameters of Bj and Pp decreased with increasing concentrations of leaf powders and extracts of IAPs (one-way ANOVA, p < 0.05). The leaves of P. juliflora and D. suffruticosa can be exploited to develop eco-friendly herbicides.