Norepinephrine-augmenting lipolytic effectors from Astilbe thunbergii rhizomes

Application of one-step inner-recycling counter-current chromatography for the preparative separation and purification of chemical constituents from the rhizome of Bergenia ciliate (haw.) Sternb

Bergenia ciliata (haw.) Sternb, the renowned pharmaceutical plant in Jammu and Kashmir of Pakistan, is widely applied in treating different illnesses including diabetes, diarrhea, and vomiting. This work employed an efficient one-step inner-recycling counter-current chromatography for preparative separating and purifying compounds with similar partition coefficients from the rhizome of Bergenia ciliate (haw.). Five compounds, including quercetin rhamnodiglucoside (1), quercetin-3-O-rutinoside (2), bergenine (3), kaempferol (4), and palmatic acid (5), were successfully separated using the optimized biphasic solvent system that contained ter-butylmetylether/n-butanol/acetonitrile/water (2:2:1:5, v/v) with the purities over 98%. Mass spectrometry and nuclear magnetic resonance were conducted for structural identification. As a result, our proposed strategy might be applied in separating compounds with similar partition coefficients, which was advantageous with regard to the less solvent and time consumption, and the increased number of theoretical plates.

Smilax glabra Roxb.: A Review of Its Traditional Usages, Phytochemical Constituents, Pharmacological Properties, and Clinical Applications

Smilax glabra Roxb. (SGB) is a medicinal plant widely distributed in 17 countries worldwide. It is the primary raw material of the world-famous and best-selling functional food and beneficial tea. SGB was first recorded in Ben Cao Jing Ji Zhu of the Southern and Northern Dynasties (420–589 AD) and was reported for nutritional and medicinal properties for thousands of years. This review searched PubMed, Web of Science, and other databases for relevant literature on SGB species until April 2022. It aims to provide more integrated thinking, detailed awareness, and better knowledge of SGB. More than 200 chemical components have been discovered, including flavonoids, phenolic, phenolic acids, stilbenes, organic acids, phenylpropanoids, and others. Previous studies have demonstrated that SGB and its active ingredients show a wide range of pharmacological effects, including anti-infective, anti-cancer, anti-inflammatory, antioxidant, cardiovascular protection, etc. However, many studies on the biological activity of this plant were mainly based on crude extracts and active ingredients, and there is a lack of clinical studies and toxicity studies to support the development of drug design, development, and therapy. In summary, this review will provide specific and valuable suggestions and guidelines for further research and application of this plant in the medicinal field.

LC-HRMS-Based Profiling: Antibacterial and Lipase Inhibitory Activities of Some Medicinal Plants for the Remedy of Obesity

Globally, obesity is a serious health concern that causes numerous diseases, including type 2 diabetes, hypertension, cardiovascular diseases, etc. Medicinal plants have been used to aid in weight loss since ancient times. Thus, this research is focused on the exploration of pancreatic lipase inhibitory activity and secondary metabolite profiling of Bergenia ciliata, Mimosa pudica, and Phyllanthus emblica, selected based on an ethnobotanical survey. The lipase inhibition was investigated using 4-nitrophenyl butyrate (p-NPB) as a substrate. To uncover further therapeutic potentials of these medicinal plants, antimicrobial activity and minimum inhibitory concentration (MIC) of the extracts were also determined. The ethyl acetate plant extracts showed higher antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Shigella sonnei. The MIC of ethyl acetate extracts of medicinal plants considered in this study ranges from 1.56 to 6.25 mg/mL. The hexane fraction of Mimosa pudica and Phyllanthus emblica showed a higher lipase inhibitory activity as compared to others, with IC50 values of 0.49 ± 0.02 and 2.45 ± 0.003 mg/mL, respectively. In the case of Bergenia ciliata, the methanolic extract inhibited lipase more effectively than others, with an IC50 value of 1.55 ± 0.02 mg/mL (IC50 value of orlistat was 179.70 ± 3.60 µg/mL). A mass spectrometry analysis of various solvent/solvent partition fractions (extracts) revealed 29 major secondary metabolites. The research offers a multitude of evidence for using medicinal plants as antiobesity and antimicrobial agents.

Naturally Occurring Chromone Glycosides: Sources, Bioactivities, and Spectroscopic Features

Chromone glycosides comprise an important group of secondary metabolites. They are widely distributed in plants and, to a lesser extent, in fungi and bacteria. Significant biological activities, including antiviral, anti-inflammatory, antitumor, antimicrobial, etc., have been discovered for chromone glycosides, suggesting their potential as drug leads. This review compiles 192 naturally occurring chromone glycosides along with their sources, classification, biological activities, and spectroscopic features. Detailed biosynthetic pathways and chemotaxonomic studies are also described. Extensive spectroscopic features for this class of compounds have been thoroughly discussed, and detailed 13C-NMR data of compounds 1-192, have been added, except for those that have no reported 13C-NMR data.

Bergenin - a biologically active scaffold: Nanotechnological perspectives

Bergenin, 4-O-methyl gallic acid glucoside, is a bioactive compound present in various plants belonging to different families. The present work compiles scattered information on pharmacology, structure activity relationship and nanotechnological aspects of bergenin, collected from various electronic databases such as Sci Finder, PubMed, Google scholar, etc. Bergenin has been reported to exhibit hepatoprotective, anti-inflammatory, anticancer, neuroprotective, antiviral and antimicrobial activities. Molecular docking studies have shown that isocoumarin pharmacophore of bergenin is essential for its bioactivities. Bergenin holds a great potential to be used as lead molecule and also as a therapeutic agent for development of more efficacious and safer semisynthetic derivatives. Nanotechnological concepts can be employed to overcome poor bioavailability of bergenin. Finally, it is concluded that bergenin can be emerged as clinically potential medicine in modern therapeutics.

ASTILBIN: A PROMISING UNEXPLORED COMPOUND WITH MULTIDIMENSIONAL MEDICINAL AND HEALTH BENEFITS

BACKGROUND

Many flavonoids have various beneficial actions like anti-inflammatory, anti-carcinogenic properties and many other clinical conditions. Astilbin is one such flavanoid compound having many physiological as well as pharmacological actions.

PURPOSE

To summarize the important findings from the research conducted using astilbin having significance to its physiological and pharmacological activities as well as the patents filed using astilbin.

STUDY DESIGN

Systematic review and compilation of the collected literature.

METHOD

An extensive investigation of literature was done using several worldwide electronic scientific databases like PUBMED, SCOPUS, Science Direct and Google Scholar etc. All the article available in the English language that used our compound of interest i.e. astilbin, on the basis of inclusion criteria decided were retrieved from these databases, thoroughly reviewed and were summarized.

RESULT

It has been established that astilbin can play a vital in the management of diseases associated with immune system. It also possesses antibacterial, anti-oxidative and hepatoprotective activity.

CONCLUSION

These researches provide evidence that astilbin possesses great potential and thus can be utilized in the management of various disorders, thus establishing itself as a potential candidate for novel drug development. Also, there is still room for research on astilbin like it can be evaluated for anticancer potential, protective effect in various diabetic complications and many more. Overall observations from data suggested that astilbin is a promising compound and proved its efficacy in every preclinical study which is conducted till date. Some of the pharmacological activity is still unexplored. After successful preclinical trials, astilbin can go for further clinical trials.

Bergenia ciliata: A comprehensive review of its traditional uses, phytochemistry, pharmacology and safety

Bergenia ciliata is a medicinal plant used for the treatment of kidney stones. The presented review is the first attempt to gather utmost information about the distribution, ethno-medicines, phytochemical analysis, pharmacology and toxicology of B. ciliata. This review was designed with the aim to compile fragmented information about B. ciliata in addition to explore its therapeutic potential and future research opportunities. A total of 185 research papers were reviewed using several data sources such as; Web of Science, Scopus, Google scholar, Science direct and PubMed. Results of this review revealed that B. ciliata is being used to cure 104 different types of ailments. Although among reported disorders B. ciliata showed high potential in the treatment of gastrointestinal disorders but it is well known for the treatment of kidney disorders particularly kidney stones. Literature review showed that traditional healers mostly utilize it in powder form. Moreover, B. ciliata was reported to possess high antifungal, antiviral, anti plasmodial and antibacterial activities. Pharmacological studies reported that it has good antioxidant, anti-inflammatory, anti-tussive, anti-ulcer and anti-neoplastic activities. Variety of secondary metabolites belonging to different classes of compounds such as phenols, alcohols, terpenoids and fatty acid were reportedly isolated from B. ciliata. In spite of having better efficiency of ethno medicines and good pharmacological potential, B. ciliata has also shown toxic effects on living system in several studies. We invite the attention of researchers to carry out detailed ethno-pharmacological and toxicological studies on this valuable plant species in order to provide reliable knowledge to the patients and discover more novel compounds for the development of new drugs with fewer side effects on the living system as compare to modern medicines.

Astilbe thunbergii reduces postprandial hyperglycemia in a type 2 diabetes rat model via pancreatic alpha-amylase inhibition by highly condensed procyanidins

Type 2 diabetes mellitus (T2DM) is a common global health problem. Prevention of this disease is an important task, and functional food supplements are considered an effective method. We found potent pancreatic α-amylase inhibition in Astilbe thunbergii root extract (AT) and confirmed that AT treatment in a T2DM rat model reduces post-starch administration blood glucose levels. Activity-guided isolation revealed procyanidin (AT-P) as the α-amylase inhibitory component with IC₅₀ = 1.7 μg/mL against porcine pancreatic α-amylase. Structure analysis of AT-P revealed it is a B-type procyanidin comprised of four types of flavan-3-ols, some with a galloyl group, and catechin attached as the terminal unit. The abundant AT-P content and its comparable α-amylase inhibition to acarbose, the anti-diabetic medicine, suggest that AT is a promising food supplement for diabetes prevention.

Hints of Western Medicine from Chinese Medicine

As a biochemist, I have been studying lipolytic and lipogenic pathways in fat cells since 1963. In 1966, I proposed a hormone-sensitive substrate theory in which catecholamines might not act on lipase but on substrate during their lipolytic processes. The lipolytic and lipogenic pathways are negative and positive processes in triglyceride content of fat cells. Insulin inhibits the negative process (lipolysis) and stimulates the positive process (lipogenesis from glucose). On the other hand, catecholamine stimulates the negative process and inhibits the positive one. These hormones discriminate the negative and positive rules and regulate opposite ways. We tried to find these hormone-like substances in various natural products. We isolated tea saponins, chitosan, and others as insulin-like substances and dimethyl-xanthine as a catecholamine-like one. It is well known that extracellular fluid pH changes from 7.4 to 6.8. Reduction of the pH from 7.4 causes insulin resistance. Insulin failed to stimulate glucose uptake at pH 7.0 of the extracellular fluid. We found minus ions, which stimulated lipogenesis from glucose by raising extracellular fluid pH to 7.4. These are our approaches to find functional substances that prevent lifestyle-related diseases.

Astilbin alleviates LPS-induced ARDS by suppressing MAPK signaling pathway and protecting pulmonary endothelial glycocalyx

Acute respiratory distress syndrome (ARDS) is a devastating disorder that is characterized by increased vascular endothelial permeability and inflammation. Unfortunately, no effective treatment beyond supportive care is available for ARDS. Astilbin, a flavonoid compound isolated from Rhizoma Smilacis Glabrae, has been used for anti-hepatic, anti-arthritic, and anti-renal injury treatments. This study examined the effects of Astilbin on pulmonary inflammatory activation and endothelial cell barrier dysfunction caused by Gram-negative bacterial endotoxin lipopolysaccharide (LPS). Endothelial cells from human umbilical veins or male Kunming mice were pretreated with Astilbin 24h before LPS stimulation. Results showed that Astilbin significantly attenuated the pulmonary histopathological changes and neutrophil infiltration 6h after the LPS challenge. Astilbin suppressed the activities of myeloperoxidase and malondialdehyde, as well as the expression of tumor necrosis factor-α and interleukin-6 in vivo and in vitro. As indices of pulmonary edema, lung wet-to-dry weight ratios, were markedly decreased by Astilbin pretreatment. Western blot analysis also showed that Astilbin inhibited LPS-induced activation of mitogen-activated protein kinase (MAPK) pathways in lung tissues. Furthermore, Astilbin significantly inhibited the activity of heparanase and reduced the production of heparan sulfate in the blood serum as determined by ELISA. These findings indicated that Astilbin can alleviate LPS-induced ARDS, which potentially contributed to the suppression of MAPK pathway activation and the degradation of endothelial glycocalyx.

Chemistry and Pharmacognosy of the Genus Durio

Durio is well known as one of the sources of seasonal fruit production in Southeast Asia with its center of diversity in Borneo. Thailand, Indonesia, and Malaysia are the main Durio producers in the world. Besides having much information about the utilization and benefit from its timber and fruits as a food substance, traditionally some parts of this plant, such as leaves, bark and root, can also be used for medical purposes. This review deals with chemical constituents and the biological activities of Durio plants.

Diversity, pharmacology and synthesis of bergenin and its derivatives: potential materials for therapeutic usages

Bergenin, a natural secondary metabolite, has been isolated from different parts of a number of plants. It is one of active ingredients in herbal and Ayurvedic formulations. It exhibits antiviral, antifungal, antitussive, antiplasmodial, antiinflammatory, antihepatotoxic, antiarrhythmic, antitumor, antiulcerogenic, antidiabetic and wound healing properties. It has been analyzed and estimated in different plant extracts, blood and drug samples using chromatographic techniques, and pharmacokinetic studies have been made. Several bergenin derivatives were isolated and/or synthesized and were found to possess pharmacological activities. Total synthesis of bergenin and its derivatives were reported. This review article covers literature on bergenin and its derivatives until 2013. Ethnomedicinal value of bergenin containing plant materials is also highlighted. This comprehensive review provides information on the potentiality of bergenin and its derivatives for therapeutic usages.

Cancer chemopreventive effect of bergenin from Peltophorum pterocarpum wood

The aqueous extract of Peltophorum pterocarpum (Fabaceae) wood exhibited potent inhibitory effects against EpsteinBarr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells and against melanogenesis in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16 melanoma cells, as well as potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. Two phenolic acid derivatives, bergenin (1) and gallic acid (2), were isolated from the ethyl acetate (AcOEt)-soluble fraction obtained from the extract. Compound 1 exhibited potent inhibitory effect against EBV-EA activation and against skin tumor promotion in an in vivo two-stage mouse skin carcinogenesis test based on 7,12-dimethylbenz[a]anthracene (DMBA) as initiator, and with TPA as promoter. Both compounds 1 and 2 exhibited melanogenesis-inhibitory activities in α-MSH-stimulated B16 melanoma cells, and, in addition, compound 2 showed strong DPPH radical-scavenging activity.

Astilbin inhibits proliferation of rat aortic smooth muscle cells induced by angiotensin II and down-regulates expression of protooncogene

This study examined the effect of astilbin on the proliferation of rat aortic smooth muscle cells (RASMCs) induced by angiotensin II (AngII) and explored the possible mechanisms. Cell proliferation model of RASMCs was induced by treatmente with AngII. Cells were randomly divided to 8 groups. Normally cultured VSMCs serves as blank control group; in AngII model group, cells were treated with AngII at 10(-7) mol/L; in three astilbin groups, cells were treated with 10, 15, 30 mg/L of astilbin; in three AngII+astilbin groups, cells were treated with AngII (at 10(-7) mol/L) and astilbin at 10, 15, 30 mg/L. Cell proliferation ability was detected by MTT method and the cell cycles and proliferation index were flow cytometrically determined. The expression of c-myc mRNA was assessed by using reverse transcription polymerase chain reaction (RT-PCR), and the expression of NF-κB in RASMCs was immunocytochemically observed. Our results showed that MTT metabolism in RASMCs in the basic and AngII stimulated situation was inhibited by astilbin, and the cells numbers of G(0)/G(1) phase were increased and that of G(2)/S phase were decreased markedly. Not only highly expression of c-myc gene stimulated by AngII could be inhibited by Astilbin significantly, but also the expression of NF-κB protein can be down regulated by Astilbin. We are led to conclude that astilbin astilbin can inhibit the AngII-mediated proliferation of RASMCs by blocking the transition of RASMCs from G(0)/G(1) phase to S phase and by down-regulating the expression of NF-κB, c-myc gene.

Synthesis of new bergenin derivatives as potent inhibitors of inflammatory mediators NO and TNF-α

Bergenin is an isocoumarin natural product which aides in fat loss, healthy weight maintenance, enhancing the lipolytic effects of norepinephrine, inhibiting the formation of interleukin 1α and cyclooxygenases-2. Here we describe the anti-inflammatory activity of new bergenin derivatives 1-15 in the respiratory burst assay. Bergenin was isolated from the crude extract of Mallotus philippenensis after repeated column chromatography and was then subjected to chemical derivatization. The structures of all compounds were elucidated by NMR and mass spectroscopic techniques. Compound 2 was also studied using single crystal X-ray diffraction. Compounds 4, (54.5±2.2%) 5 (47.5±0.5%) 5, and 15 (86.8±1.9%) showed significant (P≤0.005) NO inhibitory activities whereas 6, 7, 11, 12 and 13 displayed moderate inhibitory activities that ranges between 16% and 31%. Furthermore compounds 4 and 15, were discovered as significant (P≤0.005) TNF-α inhibitors with 98% and 96% inhibition, respectively, while compounds 3, 5, 7, 8, 11, and 12 showed low level of TNF-α inhibition (0.4-28%). Compounds 8, 13 and 15 exhibited moderate anti-inflammatory IC(50) activities with 212, 222, and 253 μM, respectively, compared to the standard anti-inflammatory drug indomethacin as well as the parent bergenin compound. No cytotoxic effects could be detected when the compounds were tested on 3T3 cells up to concentrations of 100 μM.

Enhancing effects of a chromone glycoside, eucryphin, isolated from Astilbe rhizomes on burn wound repair and its mechanism

We previously reported that three compounds isolated from Astilbe thunbergii rhizomes accelerated burn wound healing. Among the three substances, eucryphin enhanced burn wound healing most strongly; however, the biological mechanisms of eucryphin are not yet well understood and here we examined the effects on chemokine, growth factor, and cytokine productions in in vivo and in vitro experiments. We have set burn wounds on the backs of mice and topically applied either vehicle alone or vehicle containing low doses of eucryphin to the burn wound. We examined the effects of eucryphin on chemokine, cytokine, and growth factor production at the wound site and in various cells. Eucryphin (10(-4) to 10(-8)% ointment) facilitated burn wound repair compared to the vehicle control. Eucryphin (100 ng per wound) increased IL-1beta, MCP-1, VEGF, and TGF-beta1 levels in the exudates from the wound area. Eucryphin increased VEGF, TGF-beta1, and HIF-1alpha expression levels in keratinocytes. These findings suggest that the enhancement of burn wound healing by eucryphin might be due to promotional angiogenesis during skin wound repair as a result of the stimulation of VEGF and TGF-beta1 production caused by the increase in HIF-1alpha expression in keratinocytes.

The inhibitory effect of astilbin on the arteriosclerosis of murine thoracic aorta transplant

The inhibitory effect of astilbin on transplant arteriosclerosis in murine model of thoracic aorta transplantation was examined. Model of rat thoracic aorta transplantation was established. Ninety rats were divided into three groups. In isograft group, the thoracic aorta of Brown Norway (BN) rat was anastomosed with the abdominal aorta of another BN rat. In allograft group, the thoracic aorta of BN rat was anastomosed with the abdominal aorta of Lewis rat. In astilbin group, the rats receiving allo-transplantation were given astilbin 5 mg/kg per day for a time of 28 days. The donor thoracic aorta and the recipient abdominal aorta were anastomosed by means of a polyethylene cannula (inner diameter: 1.5 mm, length: 3 mm length). The grafts were histologically examined for structural changes. The areas of arterial lumen and endatrium were calculated. Our results showed that, in the allograft group, 28 days after allografting, conspicuous proliferation of smooth muscles and infiltration with a great number of inflammatory cells were found in the tunica intima and tunica media. Astilbin significantly inhibited the proliferation of smooth muscles and ameliorated the infiltration of inflammatory cells thereby prevent against the development of transplant arteriosclerosis. It is concluded that asltilbin can effectively prevent the development of arteriosclerosis in allotransplant by inhibiting the proliferation of smooth muscles and inhibit the proliferation of smooth muscles in tunica of intima and media and reducing infiltration of the inflammatory cells.

Secondary metabolites of Hypericum monogynum from Pakistan

4-Chlorobenzoic acid (1), quercitrin (2), astilbin (3), along with ?-sitosterol, ?-sitosterol, friedelin and ?-amyrin were isolated from the aerial parts of Hypericum monogynum. Whereas compound 1 was isolated for the first time from natural sources, flavanonol 3 was not found before in these species.

Effects of Astilbe thunbergii rhizomes on wound healing Part 1. Isolation of promotional effectors from Astilbe thunbergii rhizomes on burn wound healing

The dried rhizomes of Astilbe thunbergii (Sieb. et Zucc) Miq (Saxifragaceae) have been traditionally used for the treatments of a sword cut, wound bitten by animals, frost-bite, burn, suppurative dermatitis or skin inflammatory diseases from the Tang period (about 8th century) in China. The physiological actions, especially the wound-healing effects of this drug are not yet well understood. In this study, we examined the effects of an ethanol extract of Astilbe thunbergii rhizomes on burn wound healing in mice. The topical application at a dose of 100mg ointment per wound of 70% ethanol extract (0.5 or 1.0% (w/w) ointment) of this drug promoted the burn wound healing. The ethanol extract was divided into two fractions (ethyl acetate-soluble and -insoluble fractions), and it was found that the topical application at a dose of 100mg ointment per wound of the ethyl acetate-soluble fraction (0.5 and 1.0% ointment) promoted the burn wound healing. Based on this finding, we attempted to isolate the active substance(s) from the ethyl acetate-soluble fraction. Three active substances 1, 2 and 3, were obtained from A. thunbergii rhizomes as promotional effectors of burn wound healing in mice. Based on the analysis of (1)H and (13)C NMR spectra, compounds 1, 2 and 3 were identified as eucryphin (1), bergenin (2) and astilbin (3), respectively. The effective dose (ED(50)) of compounds 1, 2 and 3 on burn wound healing were 4, 190 and 64 microg/wound, respectively. Among these three compounds, eucryphin (1) promoted the burn wound healing most strongly.

Synthesis and immunosuppressive activity of l-rhamnopyranosyl flavonoids

Astilbin, a flavonoid isolated from different plants, shows diverse biological activities. This paper reports the synthesis and immunosuppressive activity of seven analogues of astilbin, which may shed light on the structure-activity relationship of the compounds. The following glycosyl flavonoids, 6-alpha-L-rhamnopyranosyloxyflavanone (20), 3-alpha-L-rhamnopyranosyloxyflavone (22), 3-alpha-L-rhamnopyranosyloxyflavanone (24), 3-alpha-L-rhamnopyranosyloxychromanone (26), 4-alpha-L-rhamnopyranosyloxychromanol (27), 7-hydroxy-3-alpha-L-rhamnopyranosyloxyflavanone (30) and 4'-hydroxy-3-alpha-L-rhamnopyranosyloxyflavanone (32) were prepared respectively by glycosylation of 6-hydroxyflavanone (1), 3-hydroxyflavone (2), 3-hydroxyflavanone (5), 3-hydroxychromanone (8), 4-chromanol (9), 7-benzyloxy-3-hydroxyflavanone (12), 4'-benzyloxy-3-hydroxyflavanone (15). Among them, compounds 5, 8, 12 and 15 were synthesized from flavanone (3), 4-chromanone (6), 7-hydroxyflavanone (10) and 4'-hydroxyflavanone (13) respectively. Similar to astilbin (4), compounds 22, 24, 26, 30 and 32 significantly inhibited the single mixed lymphocytes reaction (sMLR) and enhanced the apoptosis of spleen cells isolated from mice with sheep red blood cell-induced delayed-type hypersensitivity respectively. However, compound 20 only showed a slight tendency to inhibit sMLR at higher concentration. Both compounds 20 and 27 did not influence the cell apoptosis. These data suggest that the following factors play essential roles in determining the biological activity of the flavonoids: the position at which the sugar is linked to the flavone, the presence of carbonyl on C-4 and phenol hydroxyl group in A or B ring. However, the presence of a B ring is unfavorable for the biological activity and the double bond at C2-C3 in C-ring shows little effect on the activity.

Evaluation of selected South African medicinal plants for inhibitory properties against human immunodeficiency virus type 1 reverse transcriptase and integrase

Seventeen aqueous and methanol extracts from nine South African medicinal plants, ethnobotanically selected, were screened for inhibitory properties against HIV-1 reverse transcriptase (RT). Isolated compounds were additionally evaluated on HIV-1 integrase (IN). The strongest inhibition against the RNA-dependent-DNA polymerase (RDDP) activity of RT was observed with the methanol extract of the stem-bark of Peltophorum africanum Sond. (Fabaceae) (IC(50) 3.5 microg/ml), while the methanol extract of the roots of Combretum molle R.Br. ex G. Don (Combretaceae) was the most inhibitory on the ribonuclease H (RNase H) activity (IC(50) 9.7 microg/ml). The known compounds bergenin and catechin, and a red coloured gallotannin composed of meta-depside chains of gallic and protocatechuic acids esterified to a 1-O-isobutyroly-beta-D-glucopyranose core, were isolated from the methanol extract of the roots and stem-bark of Peltophorum africanum. The gallotannin inhibited the RDDP and RNase H functions of RT with IC(50) values of 6.0 and 5.0 microM, respectively, and abolished the 3'-end processing activity of IN at 100 microM. Catechin showed no effect on RT but had a moderate activity on HIV-1 IN. Bergenin was inactive on both enzymes. The aqueous and methanol extracts were non-toxic in a HeLaP4 cell line at a concentration of 400 microg/ml.

Biological activity of astilbin from Dimorphandra mollis against Anticarsia gemmatalis and Spodoptera frugiperda

Astilbin was isolated in high yield from Dimorphandra mollis, and its insecticidal and growth inhibiting activity by stomach ingestion were evaluated against Anticarsia gemmatalis and Spodoptera frugiperda. The insecticidal activity of astilbin, the weight reduction of the larval phase and the prolongation of the larval and pupal phases were verified for both species. Astilbin was identified on the base of its NMR, MS and physical data.