1'S-1'-acetoxychavicol acetate isolated from Alpinia galanga inhibits human immunodeficiency virus type 1 replication by blocking Rev transport

Influence of Thermal Treatment on the Composition of Alpinia officinarum Rhizome

Alpinia officinarum is a representative of the Zingiberaceae family, which is known for its wide use in the food and pharmaceutical industries also due to its precious pharmacological potential. The major aim of the present study was to evaluate the influence of thermal treatment on the composition of the rhizome of Alpinia officinarum and its antioxidant activity. The fresh rhizome was subjected to various thermal treatment processes-boiling, frying and microwave heating during various time intervals-and their composition and antioxidant activity were determined using chromatographic (HPLC - High Performance Liquid Chromatography and HPLC-MS - High Performance Liquid Chromatography Mass Spectrometry) and spectrophotometric (DPPH and TPC - Total Phenolic Content) methods. Pinobanksin was the main compound found in the extract of the fresh rhizome (537.79 mg/kg), followed by galangin (197.7 mg/kg) and zingerone (185.5 mg/kg). The effect of thermal treatment on the rhizome composition was varied. In general, thermal processing significantly decreased the content of active compounds in the rhizome. However, there were some exceptions-boiling for 4 min significantly increased the content of pinobanksin (1162.4 mg/kg) and galangin (280.7 mg/kg), and microwave processing for 4 min increased the content of pinocembrin (213 mg/kg). It was found that boiling and microwave treatment significantly increased the antioxidant activity of the processed rhizomes.

A Review on the Potential Species of the Zingiberaceae Family with Anti-viral Efficacy Towards Enveloped Viruses

Natural products are a great wellspring of biodiversity for finding novel antivirals, exposing new interactions between structure and operation and creating successful defensive or remedial methodologies against viral diseases. The members of Zingiberaceae traditional plant and herbal products have robust anti-viral action, and their findings will further lead to the production of derivatives and therapeutic. Additionally, it highlights the insight of utilizing these phytoextracts or their constituent compounds as an emergency prophylactic medicine during the pandemic or endemic situations for novel viruses. In this connection, this review investigates the potential candidates of the Zingiberaceae family, consisting of bioactive phytocompounds with proven antiviral efficacy against enveloped viruses. The present study was based on published antiviral efficacy of Curcuma longa, Zingiber officinale, Kaempferia parviflora, Aframomum melegueta Elettaria cardamomum, Alpina Sps (belongs to the Zingiberaceae family) towards the enveloped viruses. The relevant data was searched in Scopus”, “Scifinder”, “Springer”, “Pubmed”, “Google scholar” “Wiley”, “Web of Science”, “Cochrane “Library”, “Embase”, Dissertations, theses, books, and technical reports. Meticulously articles were screened with the subject relevancy and categorized for their ethnopharmacological significance with in-depth analysis. We have comprehensively elucidated the antiviral potency of phytoextracts, major composition, key compounds, mode of action, molecular evidence, immunological relevance, and potential bioactive phytocompounds of these five species belonging to the Zingiberaceae family. Conveniently, these phytoextracts exhibited multimode activity in combating the dreadful enveloped viruses.

Karyopherin-mediated nucleocytoplasmic transport

Efficient and regulated nucleocytoplasmic trafficking of macromolecules to the correct subcellular compartment is critical for proper functions of the eukaryotic cell. The majority of the macromolecular traffic across the nuclear pores is mediated by the Karyopherin-β (or Kap) family of nuclear transport receptors. Work over more than two decades has shed considerable light on how the different Kap family members bring their respective cargoes into the nucleus or the cytoplasm in efficient and highly regulated manners. In this Review, we overview the main features and established functions of Kap family members, describe how Kaps recognize their cargoes and discuss the different ways in which these Kap-cargo interactions can be regulated, highlighting new findings and open questions. We also describe current knowledge of the import and export of the components of three large gene expression machines - the core replisome, RNA polymerase II and the ribosome - pointing out the questions that persist about how such large macromolecular complexes are trafficked to serve their function in a designated subcellular location.

Investigation of HIV-1 Viral Protein R Inhibitory Activities of Twelve Thai Medicinal Plants and Their Commercially Available Major Constituents

Viral protein R (Vpr) is an accessory protein in Human immunodeficiency virus-1 (HIV-1) and has been suggested as an attractive target for HIV disease treatment. Investigations of the ethanolic extracts of twelve Thai herbs revealed that the extracts of the Punica granatum fruits, the Centella asiatica aerials, the Citrus hystrix fruit peels, the Caesalpinia sappan heartwoods, the Piper betel leaves, the Alpinia galangal rhizomes, the Senna tora seeds, the Zingiber cassumunar rhizomes, the Rhinacanthus nasutus leaves, and the Plumbago indica roots exhibited the anti-Vpr activity in HeLa cells harboring the TREx plasmid encoding full-length Vpr (TREx-HeLa-Vpr cells). Moreover, the investigation of the selected main constituents in Punica granatum, Centella asiatica, A. galangal, and Caesalpinia sappan indicated that punicalagin, asiaticoside, ellagic acid, madecassic acid, madecassoside, zingerone, brazilin, and asiatic acid possessed anti-Vpr activities at the 10 μM concentration. Among the tested extracts and compounds, the extracts from Centella asiatica and Citrus hystrix and the compounds, punicalagin and asiaticoside, showed the most potent anti-Vpr activities without any cytotoxicity, respectively.

A New Monoterpene from the Rhizomes of Alpinia galanga and Its Anti-Vpr Activity

A new menthane-type monoterpene, alpigalanol (1), together with four known terpenes (2-5) were isolated from the ethyl acetate soluble fraction of the 70 % ethanol extract of the Alpinia galanga rhizomes. The structure of 1 was determined by spectroscopic analyses, including 1D- and 2D-NMR. The extract of the A. galanga rhizomes and all isolated compounds (1-5) possessed Vpr inhibitory activities against the TREx-HeLa-Vpr cells at a concentration of 1.25 μM without showing any cytotoxicity.

Antiviral screening on Alpinia eremochlamys, Etlingera flexuosa, and Etlingera acanthoides extracts against HIV-infected MT-4 cells

Alpinia eremochlamys K. Schum, Etlingera flexuosa A.D. Poulsen, and Etlingera acanthoides A.D. Poulsen are endemic Zingiberaceae plants from Central Sulawesi, Indonesia. This study is the first report on screening the potential antiviral activity of ethanol extracts of the leaves, pseudostems, and rhizomes parts on HIV-infected MT-4 cells and identifying chemical constituents by GC-MS. The plants were extracted by the maceration method using 96% ethanol as a solvent. The antiviral activity was measured using Viral-ToxGlo colorimetric method and using the extracts at concentrations ranging from 7.8 to 1000 μg/mL. GC-MS was used to identify the secondary metabolites of potential extracts. The results showed that ethanol extract of E. acanthoides rhizome was the most potent antiviral activity (IC₅₀ of 1.74 ± 2.46 μg/mL) and less toxic on lymphocyte (MT-4) cells (CC₅₀ of 204.90 ± 106.35 μg/mL), affording the highest value of selectivity index (SI) of 117.76. A. eremochlamys rhizomes also showed promising antiviral activity with IC₅₀ of 64.18 ± 2.58 μg/mL and no toxicity on MT-4 cells affording a high SI value 19.05. Preliminary GC-MS identification showed the presence of terpenoids and fatty acids as major compounds. Zerumbone, ar-turmerone, caryophyllene, and caryophyllene oxide were also detected. Chemical constituents identified by GC-MS might be responsible for the antiviral activity of extracts, suggesting further isolation and antiviral testing of the purified compounds.

Bioactive Molecules from the Alpinia Genus: A Comprehensive Review

BACKGROUND

Floral has diversity and unique nature due to the complex structure and component. Alpinia is an important genus of the Zingiberaceae family having complex taxonomical diversity. The presence of many unique bioactive molecules makes this genus, a pharmaceutically important genus. They provide a wide range of medicinal properties, including traditional remedies to modern therapeutic applications.

METHODS

Extracts of Alpinia mostly contain bioactive molecules and secondary metabolites such as polyphenolics, tannins, flavonoids and other therapeutically important compounds. These bioactive molecules are biologically active, treating against inflammation, cancer, arterial hypertension, and other deadly diseases.

RESULTS

These bioactive molecules can act as natural enzyme inhibitors for some of the deadly diseases and can block the pathway for metabolic activities. In addition, these genera have played a major role in multidisciplinary studies of phytochemistry, ethnobotany, and pharmacological aspects in day-to-day life.

CONCLUSION

Therefore, this review highlights the fewer known facts of the genus Alpinia in terms of bioactive molecules and its significant therapeutic applications to help in combating major diseases of humans.

Docking Study on Anti-HIV-1 Activity of Secondary Metabolites from Zingiberaceae Plants

Introduction:

Human immunodeficiency virus type-1 (HIV-1) that causes acquired immunodeficiency syndrome (AIDS) has become a worldwide health problem today. There are approximately 30 anti-HIV-1 drugs that have been used in the treatment of AIDS. However, effective anti HIV-1 agents with less side affect and high inhibition potency are still in demand.

Objective:

The objective of this study was to identify the potential compounds from Zingiberaceae plants that might be active as anti-HIV-1 by molecular docking.

Materials and Methods:

Molecular docking simulation was performed by using AutoDock 4.2 on Linux operation system. Docking protocol was validated by using root mean square deviation (RMSD) value using redocking and cross-docking methods. The reported metabolites from Zingiberaceae plants were docked on HIV-1 protease, integrase, and reverse transcriptase protein enzymes.

Results:

The docking result showed that the genera of Zingiber, Etlingera, Alpinia, Hedychium, and Boesenbergia have potential metabolites that inhibit HIV protease, integrase, and reverse transcriptase enzymes by possessing lower docking energy than native ligand of amprenavir, raltegravir, and nevirapine. Among the metabolites, noralpindenoside B and alpindenoside A from Alpinia densespicata inhibited protease enzymes with the lowest docking energy of -18.02 and -17.90 kcal/mol, respectively. Meanwhile, panduratin E from Boesenbergia pandurata Roxb. and 5α,8α-epidioxyergosta-6,22-dien-3β-ol from Etlingera elatior showed the lowest docking energy on integrase protein with docking energy of -11.97 and -11.41 kcal/mol, respectively. Pahangensin A from Alpinia pahangensis Ridley showed the lowest docking energy on reverse transcriptase enzyme with docking energy of -13.76 kcal/mol.

Conclusion:

The docking molecular study has identified the possible potential compounds from Zingiberaceae plants that might be used for anti-HIV-1 treatment. So, this study suggested further isolation and purification of the predicted compounds.

Small Molecule Inhibitors of CRM1

The transport through the nuclear pore complex is used by cancer cells to evade tumor-suppressive mechanisms. Several tumor-suppressors have been shown to be excluded from the cell nucleus in cancer cells by the nuclear export receptor CRM1 and abnormal expression of CRM1 is oncogenic. Inhibition of CRM1 has long been postulated as potential approach for the treatment of cancer and to overcome therapy resistance. Furthermore, the nuclear export of viral components mediated by the CRM1 is crucial in various stages of the viral lifecycle and assembly of many viruses from diverse families, including coronavirus. However, the first nuclear export inhibitors failed or never entered into clinical trials. More recently CRM1 reemerged as a cancer target and a successful proof of concept was achieved with the clinical approval of Selinexor. The chemical complexity of natural products is a promising perspective for the discovery of new nuclear export inhibitors with a favorable toxicity profile. Several screening campaigns have been performed and several natural product-based nuclear export inhibitors have been identified. With this review we give an overview over the role of CRM1-mediated nuclear export in cancer and the effort made to identify and develop nuclear export inhibitors in particular from natural sources.

Analysis of Alpina officinarum Hance, chemically and biologically

Alpinia officinarum Hance is one of the most commonly used herbs belongs to Family Zingiberaceae. The current work deals with the qualitative and quantitative chemical study of this plant rhizomes in addition to the investigation of its anticancer activities. The results of the qualitative analysis showed a variation of phytochemical contents in this plant. While quantitative analysis showed a very promising percentage of active materials and Pharmacopeial constants. Analysis of elements like Cu, Zn & Mg were variable chromium was the lowest (0.680 ppm). The active constituents showed the highest percentage of carbohydrate (20.25 ± 1.11) and the lowest was of lipid (2.79 ± 1.03), other constituents percentage ranged from 5.11 ± 1.31 to 18.26 ± 1.24 for protein and flavonoids respectively. The pharmacopeial constant determinations reported the highest in moisture content (11.02 ± 1.05), Total ash, water-soluble ash, and acid insoluble ash were varied in values (5.64 ± 1.31 to 2.01 ± 1.12).

The evaluation of the antitumor activities (in vitro) of the investigated plant rhizomes extract showed that; it exhibited a direct cytotoxic effect on the growth of some cell lines compared to the standard drug vinblastine sulphate. The activities were recorded against two cell lines; A-549 (Lung carcinoma) and CACO (colorectal carcinoma) with IC50 6.72 ± 0.5 and 7.6 ± 0.3 µg/ml respectively, these effects were better than the standard drug vinblastine sulphate (IC₅₀ were 24.6 ± 0.7& 30.3 ± 1.4 µg/ml). Moreover, the effect of the investigated extract was also promising on the other three cell lines (HCT-116 (Colon carcinoma, Hela (Cervical carcinoma) & Pc3 (prostate cancer) the best effect was on Hela with IC₅₀ of 24.5 ± 1.1 µg/ml better than vinblastine sulphate (59.7 ± 2.1 µg/ml).

Chemical Constituents and Bioactivities of Several Indonesian Plants Typically Used in Jamu

This article reviews the chemical constituents and bioactivities of several Indonesian plants typically used in Jamu prescriptions in Indonesia. Jamu is Indonesia traditional medicine: it consists of either a single ingredient or a mixture of several medicinal plants. One plant family always used in Jamu is Zingiberaceae (ginger), such as Curcuma domestica/C. longa, C. xanthorrhizae, C. heyneana, C. zedoaria, C. aeruginosa, Zingiber aromaticum, Alpinia galanga. We also report other commonly used plant families such as Justicia gendarussa and Cassia siamea, whose activities have been extensively explored by our department.

In Vitro Activities of Enantiopure and Racemic 1'-Acetoxychavicol Acetate against Clinical Isolates of Mycobacterium tuberculosis

In the process of evaluating the effect of several plant extracts against Mycobacterium tuberculosis using the Microplate Alamar Blue Assay (MABA), an extract of Thai herb Alpinia galanga rhizome and its major component, 1'-acetoxychavicol acetate (ACA), exhibited marked anti-tuberculosis activity. The minimal inhibition concentrations (MICs) of the S-enantiomer of ACA (S-ACA) against M. tuberculosis H37Ra ATCC 25177 and H37Rv ATCC 27294 strains were 0.2 µg/mL and 0.7 µg/mL, respectively. More than 95% of 100 drug-sensitive and 50 drug-resistant mycobacterial clinical isolates were inhibited by extracted S-ACA at 1.0 µg/mL. All of the remaining isolates were inhibited at 2.0 µg/mL. In contrast to the S-enantiomer, synthetic racemic 1'-R,S-ACA (rac-ACA) showed MICs of 0.5 µg/mL and 2.7 µg/mL for M. tuberculosis H37Ra ATCC 25177 and H37Rv ATCC 27294, respectively, suggesting that the anti-tuberculosis effect might be primarily due to the S-form. These observations were in line with the MICs of rac-ACA against 98% of 93 drug-resistant clinical isolates, which showed the effective inhibitory dose at 2.0 µg/mL. After exposure to 2.7 µg/mL of rac-ACA for at least 3 h, the tubercle bacilli were completely killed. These demonstrated that ACA had potent anti-TB activity.

An overview of chemical constituents from Alpinia species in the last six decades

Alpinia species is one of the most important genera of the Zingiberaceae family. Up to 2015, 544 compounds with various bioactivities were isolated, the major components are diarylheptanoids (143) and sesquiterpenoids (132).

Structural Basis of Targeting the Exportin CRM1 in Cancer

Recent studies have demonstrated the interference of nucleocytoplasmic trafficking with the establishment and maintenance of various cancers. Nucleocytoplasmic transport is highly regulated and coordinated, involving different nuclear transport factors or receptors, importins and exportins, that mediate cargo transport from the cytoplasm into the nucleus or the other way round, respectively. The exportin CRM1 (Chromosome region maintenance 1) exports a plethora of different protein cargoes and ribonucleoprotein complexes. Structural and biochemical analyses have enabled the deduction of individual steps of the CRM1 transport cycle. In addition, CRM1 turned out to be a valid target for anticancer drugs as it exports numerous proto-oncoproteins and tumor suppressors. Clearly, detailed understanding of the flexibility, regulatory features and cooperative binding properties of CRM1 for Ran and cargo is a prerequisite for the design of highly effective drugs. The first compound found to inhibit CRM1-dependent nuclear export was the natural drug Leptomycin B (LMB), which blocks export by competitively interacting with a highly conserved cleft on CRM1 required for nuclear export signal recognition. Clinical studies revealed serious side effects of LMB, leading to a search for alternative natural and synthetic drugs and hence a multitude of novel therapeutics. The present review examines recent progress in understanding the binding mode of natural and synthetic compounds and their inhibitory effects.

Structure-activity relationships of benzhydrol derivatives based on 1'-acetoxychavicol acetate (ACA) and their inhibitory activities on multiple myeloma cell growth via inactivation of the NF-κB pathway

1'-Acetoxychavicol acetate (ACA), which was isolated from the rhizomes of Zingiberaceae, exhibits various biological actions, including anti-inflammatory, anti-human immunodeficiency virus (HIV), and anti-cancer activities. ACA represents an attractive candidate for the treatment of many cancers. We herein examined the structure-activity relationships of ACA derivatives based on the benzhydrol skeleton in human leukemia cells (HL-60). Our results revealed that the ACA derivatives synthesized (ACA, 1, and 18) had inhibitory effects on the growth of multiple myeloma cells (IM-9 cells) by inactivating the NF-κB pathway.

Direct and indirect organogenesis of Alpinia galanga and the phytochemical analysis

Alpinia galanga is a rhizomatous herb rich in essential oils and various other significant phytoconstituents. Rapid direct regeneration was obtained from the rhizome explants (15.66 ± 0.57 shoots) on MS media supplemented with zeatin at a concentration of 2 mg/l. The callus cultures of A. galanga were initiated from the rhizome explants on MS media supplemented with 2 mg/l each of BAP, 2,4-D, and NAA. The callus was analyzed for the presence of a vital phytoconstituent--acetoxychavicol acetate (ACA) associated with various biological properties. ACA was detected in the young friable callus as well as the stationary phase callus. Moreover, the induction of morphogenetic response in callus resulted in higher accumulation of ACA. The phytohormone withdrawal from the propagation media and the subsequent transfer of callus to BAP (2 mg/l) containing MS media has resulted in multiple shoot induction. The regenerated (indirect) plants have shown 1.6-fold higher ACA content (1.253%) when compared to the control plant (0.783%). Micropropagation of such conventionally propagated plants is very essential to meet the commercial demand as well as to ensure easy storage and transportation of disease free stocks.

HIV-1 integrase and neuraminidase inhibitors from Alpinia zerumbet

AIDS and influenza are viral pandemics and remain one of the leading causes of human deaths worldwide. The increasing resistance of these diseases to synthetic drugs demands the search for novel compounds from plant-based sources. In this regard, the leaves and rhizomes of Alpinia zerumbet, a traditionally important economic plant in Okinawa, were investigated for activity against HIV-1 integrase (IN) and neuraminidase (NA). The aqueous extracts of leaves and rhizomes had IN inhibitory activity with IC(50) values of 30 and 188 μg/mL, whereas against NA they showed 50% inhibition at concentrations of 43 and 57 μg/mL, respectively. 5,6-Dehydrokawain (DK), dihydro-5,6-dehydrokawain (DDK), and 8(17),12-labdadiene-15,16-dial (labdadiene) were isolated from the rhizomes and were tested for enzyme inhibitions. DK and DDK strongly inhibited IN with IC(50) of 4.4 and 3.6 μg/mL, respectively. Against NA, DK, DDK, and labdadiene exhibited mixed type of inhibition with respective IC(50) values of 25.5, 24.6, and 36.6 μM and K(i) values ranging from 0.3 to 2.8 μM. It was found that DDK is a slow and time-dependent reversible inhibitor of NA, probably with a methoxy group as its functionally active site. These results suggest that alpinia could be used as a source of bioactive compounds against IN and NA and that DK and DDK may have possibilities in the design of drugs against these viral diseases.

1'-Acetoxychavicol acetate suppresses angiogenesis-mediated human prostate tumor growth by targeting VEGF-mediated Src-FAK-Rho GTPase-signaling pathway

Cancer therapeutic agents that are safe, effective and affordable are urgently needed. We describe that 1'-acetoxychavicol acetate (ACA), a component of Siamese ginger (Languas galanga), can suppress prostate tumor growth by largely abrogating angiogenesis. ACA suppressed vascular endothelial growth factor (VEGF)-induced proliferation, migration, adhesion and tubulogenesis of primary cultured human umbilical vascular endothelial cells (HUVECs) in a dose-dependent manner. ACA also inhibited VEGF-induced microvessel sprouting from aortic rings ex vivo and suppressed new vasculature formation in Matrigel plugs in vivo. We further demonstrated that the mechanisms of this chavicol were to block the activation of VEGF-mediated Src kinase, focal adhesion kinase (FAK) and Rho family of small guanosine triphosphatases (GTPases) (Rac1 and Cdc42 but not RhoA) in HUVECs. Furthermore, treatment of human prostate cancer cells (PC-3) with ACA resulted in decreased cell viability and suppression of angiogenic factor production by interference with dual Src/FAK kinases. After subcutaneous administration to mice bearing human prostate cancer PC-3 xenografts, ACA (6 mg/kg/day) remarkably inhibited tumor volume and tumor weight and decreased levels of Src, CD31, VEGF and Ki-67. As indicated by immunohistochemistry and TUNEL analysis, microvessel density and cell proliferation were also dramatically suppressed in tumors from ACA-treated mice. Taken together, our findings suggest that ACA targets the Src-FAK-Rho GTPase pathway, leading to the suppression of prostate tumor angiogenesis and growth.

Antibacterial activity of Thai herbal extracts on acne involved microorganism

Ethyl acetate and methanol extracts of 18 Thai medicinal plants were investigated for their antibacterial activity against Propionibacterium acnes, Stapylococcus aureus, and S. epidermidis. Thirteen plant extracts were capable of inhibiting the growth of P. acnes and S. epidermidis, while 14 plant extracts exhibited an inhibitory effect on S. aureus. Based on the broth dilution method, the ethyl acetate extract of Alpinia galanga (L.) Wild. (Zingiberaceae) rhizome showed the strongest antibacterial effect against P. acnes, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 156.0 and 312.0 microg/mL, respectively. On the basis of bioassay-guided purification, the ethyl acetate extract was isolated to afford the antibacterial active compound, which was identified as 1'-acetoxychavicol acetate (1'-ACA). 1'-ACA had a strong inhibitory effect on P. acnes with MIC and MBC values of 62.0 and 250.0 microg/mL, respectively. Thus, 1'-ACA was used as an indicative marker for standardization of A. galanga extract using high performance liquid chromatography. These results suggest that A. galanga extract could be an interesting agent for further studies on an alternative treatment of acne.

Median lethal dose, antimalarial activity, phytochemical screening and radical scavenging of methanolic Languas galanga rhizome extract

The methanolic extract of Languas galanga rhizomes was investigated for antimalarial activity against Plasmodium berghei (NK65) infections in mice. The median lethal dose was determined to ascertain the safety of the extract in ICR mice of both sexes. The antimalarial activities during early and established infections, as well as the prophylactic activity were evaluated. Phytochemical screening and radical scavenging activity of the extract were also investigated to elucidate the possible mechanism of the antimalarial properties. The acute oral toxicity (LD₅₀) of Languas galanga extract in mice was established to be 4.998 mg/kg. The extract of Languas galanga rhizomes demonstrated significant antiplasmodial activity in all the three models of the antimalarial evaluations. Phytochemical screening revealed the presence of some vital antiplasmodial constituents such as terpenoids and flavonoids. The extract also exhibited a moderate capacity to scavenge the free radicals. The rhizome extract of Languas galanga thus possesses antimalarial activity, which explains the rational usage of this plant in traditional Malaysian medicine.

Antiplasmid activity of 1'-acetoxychavicol acetate from Alpinia galanga against multi-drug resistant bacteria

ETHNOPHARMACOLOGICAL RELEVANCE

Alpinia galanga (L.) Swartz is traditionally used in the treatment of various ailments across India, China, and Southeast Asian countries. In India it is a reputed drug in indigenous system of medicine and largely used as antibacterial and antiseptic. In southern India the rhizomes has been used as a domestic remedy against bacterial infections.

AIM OF THE STUDY

To identify a potential antiplasmid compound from Alpinia galanga against multi-drug resistant bacteria.

MATERIALS AND METHODS

The crude rhizome extract of Alpinia galanga was prepared in acetone. Antibacterial activity was checked by MIC and antiplasmid activity was checked by SIC. The principal compound responsible for the antiplasmid activity, in the crude extract, was identified by bioassay guided fractionation using hexane-acetone. Antibiotic resistance profile of plasmid harboring strains and plasmid cured strains was determined by disc diffusion method.

RESULTS

The crude acetone extract of the rhizomes of Alpinia galanga exhibited antiplasmid activity against Salmonella typhi, Escherichia coli and vancomycin resistant Enterococcus faecalis with an efficiency of 92%, 82% and 8% respectively at 400 microg/ml SIC. The principal compound responsible for the activity was identified as 1'-acetoxychavicol acetate. 1'-Acetoxychavicol acetate demonstrated the ability to cure plasmid encoded antibiotic resistance in various multi-drug resistant bacterial strains of clinical isolates such as Enterococcus faecalis, Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli and Bacillus cereus with curing efficiency of 66%, 75%, 70%, 32% and 6% respectively at SIC of 400-800 microg/ml.

CONCLUSION

1'-Acetoxychavicol acetate mediated R-plasmid curing significantly reduced the minimal inhibitory concentration of antibiotics required to inhibit growth of bacteria, thus making the antibiotic treatment more effective.

Rev regulates translation of human immunodeficiency virus type 1 RNAs

Full-length human immunodeficiency virus type 1 (HIV-1) RNA acts as both mRNA, encoding Gag and Gag–Pol polyproteins, and genomic RNA. Translation of this RNA must be tightly controlled to allow sufficient protein synthesis prior to a switch to particle production. The viral protein Rev stimulates nuclear export of unspliced HIV-1 RNAs containing the Rev response element, but may also stimulate translation of these RNAs. We previously identified an additional Rev binding site in the 5′ untranslated region of the HIV-1 RNA. We show that Rev inhibits translation non-specifically at high concentrations and stimulates translation of HIV-1 RNAs at intermediate concentrations in vitro. Stimulation is dependent on the presence of the Rev binding site within the 5′ untranslated region and not on the Rev response element. In COS-1 cells, translation from an HIV-1 reporter is specifically increased by coexpression of Rev.

Rev: beyond nuclear export

Rev remains a hot topic. In this review, we revisit the insights that have been gained into the control of gene expression by the retroviral protein Rev and speculate on where current research is leading. We outline what is known about the role of Rev in translation and encapsidation and how these are linked to its more traditional role of nuclear export, underlining the multifaceted nature of this small viral protein. We discuss what more is to be learned in these fields and why continuing research on these 116 amino acids and understanding their function is still important in devising methods to combat AIDS.

Effect of naturally occurring hydroxychavicol acetate on the cytokine production in T helper cells

Naturally occurring phenolic compounds, such as chavicol analogues, have been shown to have potent antioxidant and anti-inflammatory activities. We have previously isolated two chavicol acetate analogues, acetoxychavicol acetate (ACA) and hydroxychavicol acetate (HCA) from the rhizomes of Alpinia galanga. Although the function of ACA has been studied in many systems, the function of HCA has yet to be systemically examined. In this study, we have comparably examined the functions of ACA and HCA on the cytokine production in Th cells. ACA exhibited potent antioxidant activity and increased cell apoptosis; therefore, cytokine production by Th cells was diminished. Although HCA had neither antioxidant activity nor pro-apoptotic function, it was shown to increase IL-2 production and attenuate IFNgamma expression in Th cells. In addition, we demonstrated that HCA suppressed T-bet expression, which is responsible for IL-2 suppression and IFNgamma induction in Th cells and inhibited T-bet-mediated Th1 cell differentiation. Therefore, we suggest that HCA may be beneficial as therapeutics for treating inflammatory immune disorders caused by extravagant activation of Th1-mediated immune responses.