Chemical Constituents of Vitex Negundo and Evaluation of Their Anti-Inflammatory and Antioxidant Activities

Leaves and stem of Vitex negundo were examined for phytochemicals using various techniques such as normal column chromatography, gel filtration on Sephadex LH-20 and radial chromatography. From the leaves, seven compounds were isolated and identified, by the use of various spectroscopic methods, to be mixture of the flavonoids luteolin, luteolin-3’-O-glucuronide, and isoorientin, the iridoid glycosides 2’-p-hydroxybenzoylmussaenosidic acid and agnuside, and phydroxyl benzoic acid as well as stigmasterol and β-sitosterol. Meanwhile, the stem yielded four lignans which were isolated for the first time from the plant, identified as 6-hydroxy-4-(4-hydroxy-3-methoxyphenyl)3-hydroxymethyl-7- methoxy-3,4-dihydro-2-naphthaldehyde, vitedoin A, vitrofolal E and detetrahydroconidendrin.Nitric oxide (NO) inhibitory assay using RAW 264.7 murine macrophage and soybean lipoxygenase inhibitory assay were carried out in the screening for antiinflamatory properties of the crude methanolic extract, the hexane, dichloromethane and ethyl acetate soluble fractions of the plant. From the leaves, both the hexane and dichloromethane fractions were shown to strongly inhibit nitric oxide production with an IC50 of 14.00 g/ml and 20.00 g/ml respectively. Meanwhile, inhibition of soybean lipoxygenase activity was shown by the ethyl acetate fractions from both plant parts with IC50 of 56.38 g/ml and 63.94 g/ml respectively. Further anti-inflammatory investigation on some of the isolated compounds showed that luteolin was significantly inhibited NO production with an IC50 of 41.50 g/ml (145.10 M), and inhibited formation of (9Z, 11E)-(13S)-13- hydroxyoctadeca-9,11-dienoate with an IC50 of 1.55 g/ml (5.42 M). Luteolin also exhibited high activity in PAF receptor binding assay with 70.20% inhibition at concentration of 18.2 g/ml and xanthine oxidase assay with 98.20% inhibition at concentration of 100 g/ml. The antioxidant evaluation using DPPH radical scavenging assay showed that luteolin and 6-hydroxy-4-(4- hydroxy-3-methoxyphenyl)3-hydroxymethyl-7-methoxy-3,4-dihydro-2- naphthaldehyde at a concentration of 250 g/ml exhibited significant inhibition at 96.2% and 94.7% respectively. The results indicated that luteolin may play a key factor in the plant’s ability to reduce inflammation

Mechanism(s) of action involved in the gastroprotective activity of Muntingia calabura

Ethnopharmacological relevance: Muntingia calabura L. (Muntingiaceae) is locally known as kerukup siam. Its leaves, flowers, barks and roots have been used traditionally in East Asia and South America to treat various diseases including ulcer-related diseases. The present study aimed to investigate the mechanism(s) of gastroprotective effect of methanol extract of Muntingia calabura leaves (MEMC) using the pylorus ligation induced gastric ulceration in rats. Materials and methods: Five groups of rats (n=6) were administered orally once daily for 7 days with 8% Tween 80 (negative control), 100 mg/kg ranitidine (positive control), or MEMC (100, 250 or 500 mg/kg), followed by the ulcer induction via ligation of the pyloric part of the rat’s stomach. This was followed by the macroscopic analysis of the stomach, evaluation of gastric content parameters, and quantification of mucus content. The antioxidant (measured using the superoxide anion and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging, oxygen radical absorbance capacity (ORAC) and total phenolic content (TPC) assays), anti-inflammatory (evaluated using the in vitro lipoxygenase and xanthine oxidase assays), phytoconstituents and HPLC analysis of MEMC were also carried out. Results: The MEMC significantly (p<0.05) reduced gastric lesion in this model. Furthermore, the extract also significantly (p<0.01) reduced the volume of gastric content whereas the total acidity was significantly (p<0.05) reduced in the doses of 100 and 500 mg/kg MEMC. Moreover, the mucus content increased significantly (p<0.01) in MEMC-treated rats. The extract also showed high antioxidant and anti-inflammatory activities in all assays tested, and demonstrated the presence of high tannins and saponins followed by flavonoids. Conclusion: The MEMC exerted gastroprotective effect via several mechanisms including the anti-secretory, antioxidant and anti-inflammatory activities. These activities could be attributed to the presence of tannins, saponins and flavonoids (e.g. rutin, quercitrin, fisetin and dihydroquercetin)

Antioxidant and anti-inflammatory activities of extracts of betel leaves (Piper betle) from solvents with different polarities

The influence of solvents with different polarities on the antioxidant and anti-inflammatory properties of betel leaf extracts (Piper betle) was investigated. The solvents used were water, ethanol, ethyl acetate and hexane. High performance liquid chromatography (HPLC) was used to determine the chemical profiles and concentrations of the active compounds, namely, hydroxychavicol (HC) and eugenol (EU). The antioxidant potential of the extracts was evaluated using two in vitro assays—xanthine/xanthine oxidase superoxide scavenging assay (SOD assay) and 1,2-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay (DPPH assay). The anti-inflammatory assays used were hyaluronidase (HYA), xanthine oxidase (XOD) and lipoxygenase (LOX) inhibition assays. The HPLC results revealed that HC and EU were detected in all types of extracts and the concentrations were highest in the water extract. The highest extraction yield was obtained using water. All the extracts were highly active in both antioxidant assays with water extract showing the strongest inhibition. The extracts also exhibited significant inhibition in XOD and LOX assays. The results indicated that the bioactivity of the extracts was related to HC and EU

Antimicrobial and anti-inflammatory activities of Piper porphyrophyllum (Fam. Piperaceae)

The crude extracts and isolated compounds of Piper porphyrophyllum (Piperaceae) were evaluated for antibacterial and anti-inflammatory activities. The ethyl acetate extract and 3′,4′,5,7-tetramethoxyflavone exhibited the highest activity against Staphylococcus aureus giving values of MIC = 62.5 and 250 μg/mL, respectively. 5-Hydroxy-7-methoxyflavanone and 4′,5-dihydroxy-3′,7-dimethoxyflavone were active against Pseudomonas aeruginosa, both with MIC value 125 μg/mL. The hexane extract and 4′,5-dihydroxy-3′,7-dimethoxyflavone gave the highest anti-inflammatory activity in in vitro quantitative lipoxygenase inhibition assay with inhibitory activity of (IE) 99.72% and 91.81%, respectively

Production of High Quality Planting Materials Through Breeding for Four Important Herbal Species

With the growing interest in these species as a source of new pharmaceutical products and the increasing demand for herbal products in Malaysia, the demand for its raw materials is also increasing. Therefore, initiatives have been taken by Forest Research Institute Malaysia (FRIM) to select and to produce high quality planting materials for future uses. To our knowledge, most of the raw materials used in producing herbal products and its development were being sourced from the wild, with little knowledge on the quality of the raw materials. In order to ensure the quality and sustainability of raw materials in the market, it is important to come out with suitable breeding strategy for the selected species. This paper highlights research by FRIM on collecting, screening, selecting and producing high quality planting materials for the four species based on their growth performance and bioactive compounds. Several research on the production of high quality planting materials for four important medicinal plants has been initiated by FRIM starting from the 11th Malaysian Plan until now. This paper discusses about four selected species namely Chromolaena odorata (kapal terbang), Andrographis paniculata (creat&nbsp;or&nbsp;green chiretta), Beackea frutescens (false ru) and Senna alata (candle bush). These species are found to have a significant benefit to the human’s health. C. odorata (kapal terbang) leaf extract are found to have relatively strong inhibition on platelet-activating factor (PAF) receptor binding in vitro, indicating an anti-inflammatory activity, which is favourable for wound healing. A major bioactive compound in A. paniculata, andrographolide has shown anticancer potential in various research. Whereas, B. frutescens has a potential to be used as anti-gout remedies. Research conducted by FRIM showed that active compound in the leaves and stems of B. frutescens extract are effective in inhibiting uric acid formation and promoting uric acid secretion. Whereas for S. alata, the highest content of major flavonoid glycoside compound, kaempferol-3-O-gentiobioside (K3G), has an anti-inflammatory effect detected in leaf extracts. Germplasm plots for the species were also established in FRIM for future breeding activities. The outputs derived from this study will support the herbal industries in getting quality raw materials in the future. By using high quality plants will also increase the value of pharmaceutical products in the market. It is anticipated that herbal industries and interested party will seek FRIM for high quality seeds and seedlings materials for the development of their products as well as for the establishment of commercial herbal plantation

Hits-to-Lead Optimization of the Natural Compound 2,4,6-Trihydroxy-3-geranyl-acetophenone (tHGA) as a Potent LOX Inhibitor: Synthesis, Structure-Activity Relationship (SAR) Study, and Computational Assignment

A new series of 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA) analogues were synthesized and evaluated for their lipoxygenase (LOX) inhibitory activity. Prenylated analogues 4a-g (half maximal inhibitory concentration (IC50) values ranging from 35 μM to 95 μM) did not exhibit better inhibitory activity than tHGA (3a) (IC50 value: 23.6 μM) due to the reduction in hydrophobic interaction when the alkyl chain length was reduced. One geranylated analogue, 3d, with an IC50 value of 15.3 μM, exhibited better LOX inhibitory activity when compared to tHGA (3a), which was in agreement with our previous findings. Kinetics study showed that the most active analogue (3e) and tHGA (3a) acted as competitive inhibitors. The combination of in silico approaches of molecular docking and molecular dynamic simulation revealed that the lipophilic nature of these analogues further enhanced the LOX inhibitory activity. Based on absorption, distribution, metabolism, excretion, and toxicity (ADMET) and toxicity prediction by komputer assisted technology (TOPKAT) analyses, all geranylated analogues (3a-g) showed no hepatotoxicity effect and were biodegradable, which indicated that they could be potentially safe drugs for treating inflammation

Synthesis and Docking Studies of 2,4,6-Trihydroxy-3-Geranylacetophenone Analogs as Potential Lipoxygenase Inhibitor

The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA) isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX) inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM) where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs) and aromatic groups could significantly affect the enzymatic activity

Genotype Screening and Propagation Techniques of Three Selected Medicinal Plant Species for Production of High-Quality Planting Material

Medicinal plants are a vital source of new bioactive compounds due to their ecological biodiversity and varied chemical properties of each species. Phenotypic selection coupled with the evaluation of genotypes based on the chemical profile can be used for the development of a high-yielding variety. However, most of the raw material that has been used for commercial production of herbal products is mainly derived from wild sources, with little knowledge of the quality of genetic materials. Thus, three medicinal species, Chromolaena odorata (Siam weed), Andrographis paniculata (Creat), and Baeckea frutescens (False ru), were chosen based on their significant benefits to human health. These medicinal species have been traditionally used to treat various illnesses, and have been shown to possess anti-inflammatory, antimicrobial, anticancer, and antioxidant properties. This paper highlights the harvesting method and collection of accessions from natural habitats for the selection of superior genotypes. Individual plants having superior phenotypic characteristics and bioactive compounds were identified. We successfully developed appropriate propagation techniques for each species for the mass production of high-yielding planting material. The establishment of breeding activities for these medicinal plants will provide quality raw materials to support the herbal industry in increasing the value of pharmaceutical products. These efforts will also ensure the sustainable production of high-quality planting materials for the establishment of herbal plantations

Genotype Screening and Propagation Techniques of Three Selected Medicinal Plant Species for Production of High-Quality Planting Material

Medicinal plants are a vital source of new bioactive compounds due to their ecological biodiversity and varied chemical properties of each species. Phenotypic selection coupled with the evaluation of genotypes based on the chemical profile can be used for the development of a high-yielding variety. However, most of the raw material that has been used for commercial production of herbal products is mainly derived from wild sources, with little knowledge of the quality of genetic materials. Thus, three medicinal species, Chromolaena odorata (Siam weed), Andrographis paniculata (Creat), and Baeckea frutescens (False ru), were chosen based on their significant benefits to human health. These medicinal species have been traditionally used to treat various illnesses, and have been shown to possess anti-inflammatory, antimicrobial, anticancer, and antioxidant properties. This paper highlights the harvesting method and collection of accessions from natural habitats for the selection of superior genotypes. Individual plants having superior phenotypic characteristics and bioactive compounds were identified. We successfully developed appropriate propagation techniques for each species for the mass production of high-yielding planting material. The establishment of breeding activities for these medicinal plants will provide quality raw materials to support the herbal industry in increasing the value of pharmaceutical products. These efforts will also ensure the sustainable production of high-quality planting materials for the establishment of herbal plantations