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Abstract: Ethnopharmacological relevance: Preparations from Munronia pinnata (Wall.) Theob. are extensively used in traditional medicine in Sri Lanka for the treatment of inflammatory conditions. However, neither the pharmacological features nor the phytochemistry of this plant are explored in order to understand and rationalize the reported ethnobotanical significance. As 5-lipoxygenase (5-LO) and microsomal prostaglandin E2 synthase (mPGES)-1 are crucial enzymes in inflammatory disorders, we evaluated their inhibition by M. pinnata extracts and studied the chemical profile of the plant for the identification of relevant constituents. Materials and methods: Cell-free and cell-based assays were employed in order to investigate the suppression of 5-LO and mPGES-1 activity. Cell viability, radical scavenger activities, and inhibition of reactive oxygen species formation (ROS) in neutrophils were studied to assess cytotoxic and antioxidant effects. Gas and liquid chromatography coupled to mass spectrometric analysis enabled the characterization of secondary metabolites. Results: The n-hexane extract of M. pinnata efficiently suppressed 5-LO activity in stimulated human neutrophils (IC50 =8.7µg/ml) and potently inhibited isolated human recombinant 5-LO (IC50 =0.48µg/ml) and mPGES-1 (IC50 =1.0µg/ml). In contrast, no significant radical scavenging activity or suppression of ROS formation was observed, and neutrophil viability was unaffected. The phytochemistry of the plant was unveiled for the first time and phytosterols, fatty acids, sesquiterpenes and several other types of secondary metabolites were identified. Conclusions: Together, potent inhibition of 5-LO and mPGES-1 activity, without concomitant antioxidant activity and cytotoxic effects, rationalizes the ethnopharmacological use of M. pinnata as anti-inflammatory remedy. Detailed chromatographic/mass spectrometric analysis reveals discrete chemical structures of relevant constituents. [Copyright &y& Elsevier]

Traditional folk medicine in Sri Lanka is mostly based on plants and plant-derived products, however, many of these medicinal plant species are scientifically unexplored. Here, we evaluated the anti-inflammatory and antimicrobial potency of 28 different extracts prepared from seven popular medicinal plant species employed in Sri Lanka. The extracts were subjected to cell-based and cell-free assays of 5-lipoxygenase (5-LO), microsomal prostaglandin E2 synthase (mPGES)-1, and nitric oxide (NO) scavenging activity. Moreover, antibacterial and disinfectant activities were assessed. Characterization of secondary metabolites was achieved by gas chromatography coupled to mass spectrometric (GC-MS) analysis. n-Hexane- and dichloromethane-based extracts of Garcinia cambogia efficiently suppressed 5-LO activity in human neutrophils (IC50 = 0.92 and 1.39 µg/mL), and potently inhibited isolated human 5-LO (IC50 = 0.15 and 0.16 µg/mL) and mPGES-1 (IC50 = 0.29 and 0.49 µg/mL). Lipophilic extracts of Pothos scandens displayed potent inhibition of mPGES-1 only. A methanolic extract of Ophiorrhiza mungos caused significant NO scavenging activity. The lipophilic extracts of G. cambogia exhibited prominent antibacterial and disinfectant activities, and GC-MS analysis revealed the presence of fatty acids, sesquiterpenes and other types of secondary metabolites. Together, our results suggest the prospective utilization of G.cambogia as disinfective agent with potent anti-inflammatory properties. [ABSTRACT FROM AUTHOR]

Ethnopharmacological Relevance: Leucas zeylanica (L.) W.T. Aiton is a popular, multi-purpose medicinal plant in Sri Lanka but the pharmacological potential and the chemical profile have not been systematically investigated to understand and rationalize the reported ethnobotanical significance., Aim of the Study: The present study was undertaken to scientifically validate the traditional usage of this plant for the treatment of inflammatory conditions, gout and microbial infections. Inhibition of 5-lipoxygenase (5-LO), microsomal prostaglandin E 2 synthase (mPGES)-1 and xanthine oxidase (XO) by different extracts of L. zeylanica was investigated to determine the anti-inflammatory and anti-gout activity, respectively. The antibacterial and antifungal activities were also studied and the relevant constituents in the bioactive extracts were tentatively identified., Materials and Methods: Cell-free and/or cell-based assays were employed in order to investigate the effects of the extracts against the activity of human 5-LO, mPGES-1 and XO as well as to assess antioxidant properties. The antibacterial activity of the extracts was determined by the broth micro-dilution method against Gram positive and Gram negative bacteria including methicillin-resistant Staphylococcus aureus while the agar dilution method was employed to determine the anti-Candida activity. Gas chromatography coupled to mass spectrometric (GC-MS) analysis enabled the characterization of secondary metabolites in the extracts., Results: The dichloromethane extract of L. zeylanica efficiently inhibited 5-LO activity in stimulated human neutrophils (IC 50 = 5.5 µg/mL) and isolated human 5-LO and mPGES-1 (IC 50 = 2.2 and 0.4 µg/mL). Potent inhibition of XO was observed by the same extract (IC 50 = 47.5 μg/mL), which is the first report of XO-inhibitory activity of a Sri Lankan medicinal plant. Interestingly, significant radical scavenging activity was not observed by this extract. Only the n-hexane extract exhibited antibacterial activity against Staphylococcus aureus and Staphylococcus saprophyticus with a MIC of 250 µg/mL while the anti-Candida activity was moderate. GC-MS analysis revealed the presence of phytosterols, fatty acids, sesquiterpenes, diterpenes and several other types of secondary metabolites., Conclusions: Potent inhibition of 5-LO, mPGES-1 and XO rationalizes the ethnopharmacological use of L. zeylanica as anti-inflammatory and anti-gout remedy. Interestingly, the antimicrobial activities were not prominent, despite its wide utility as an antimicrobial medication., (Copyright © 2018 Elsevier B.V. All rights reserved.)