Psidium guajava: a review of its traditional uses, phytochemistry and pharmacology

Guava pomace: a new source of anti-inflammatory and analgesic bioactives

Background

Guava pomace is an example of the processing waste generated after the manufacturing process from the juice industry that could be a source of bioactives. Thus, the present investigation was carried out in order to evaluate the anti-inflammatory and antinociceptive potential and determinate the main phenolic compounds of a guava pomace extract (GPE).

Methods

The anti-inflammatory activity was evaluated by carrageenan, dextran, serotonin, histamine-induced paw edema and neutrophils migration in the peritoneal cavity models. Acetic acid-induced abdominal writhing and formalin test were performed to investigate the antinociceptive effects. In addition, the content of total phenolic and of individual phenolic compounds was determined by GC/MS.

Results

GPE showed anti-inflammatory activity by carrageenan, dextran, serotonin, histamine-induced paw edema and neutrophils migration in the peritoneal cavity models (p < 0.05). GPE also demonstrated antinociceptive activity by acetic acid-induced abdominal writhing and formalin test (p < 0.05). The total phenolic value was 3.40 ± 0.09 mg GAE/g and epicatechin, quercetin, myricetin, isovanilic and gallic acids were identified by GC/MS analysis.

Conclusions

The presence of bioactive phenolic compounds as well as important effects demonstrated in animal models suggest that guava pomace could be an interesting source of anti-inflammatory and analgesic substances.

Ethnobotanical study on medicinal plants around Limu Mountains of Hainan Island, China

AIM OF THE STUDY

The main objectives were to document traditional knowledge on the use of medicinal plants and compare medicinal plant traditions between Li and Hmong living around Limu Mountains of Hainan Island.

MATERIAL AND METHODS

Information was obtained from semi-structured interviews, personal conversation and guided fieldtrips with herbalists. Quantitative methods, such as the coefficient of similarity (S), Chi-square analysis and the 'informant agreement ratio' were applied for the comparison of medicinal plant tradition between Li and Hmong.

RESULTS

In all, 224 plant species grown in the study areas are still traditionally used for the treatment of various diseases. Euphorbiaceae (17 species), Rubiaceae (16 species), Papilionaceae and Poaceae (11 species, respectively), Verbenaceae (10 species) and Compositae (7 species) are predominant families used by herbalists. The most species were reported to be used for injuries (25.1% of all the medicinal use-reports), digestive system disorders (24.8%), infections/infestations (14.7%) and muscular-skeletal system disorders (12.3%). The coefficient of similarity (29.0%) shows a relatively high overlap of medicinal plants used by Li and Hmong. Using Chi-square analysis, it was found that habit mentions were dependent upon the culture. Infections/infestations, injuries and muscular-skeletal system disorders scored high IAR value and mention in both Li and Hmong communities.

CONCLUSIONS

Medicinal plants are of importance to indigenous people around Limu Mountains who still rely on medicinal plants to treat a wide range of illnesses. There is a close relationship of medicinal plant tradition between Li and Hmong who are culturally distinct.

Anti-diarrhoeal and anti-microbial activity of Flos populi (male inflorescence of Populus tomentosa Carrière) aqueous extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Flos populi (male inflorescence of Populus tomentosa Carrière) has been traditionally used in East Asian countries for the treatment of various inflammatory diseases, strengthening the spleen and stomach, anti-rheumatic, anti-tumor and anti-diarrhoeal.

AIM OF THE STUDY

To evaluate the in vivo or in vitro anti-diarrhoeal and anti-microbial activity of Flos populi aqueous extract.

MATERIALS AND METHODS

Acute toxicity of Flos populi aqueous extract (FPAE) was investigated. Castor oil-induced diarrhoea method was used to evaluate the anti-diarrhoeal activity, inhibition of defecation and diarrhoea were determined in mice, effects on castor oil-induced enteropooling, intestinal transit and intestinal fluid secretion in rats or mice. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of FPAE against strains of three clinical bacterial isolates and one reference strain were used to test the anti-microbial activity.

RESULTS

The FPAE reduced the frequency of diarrhoea episodes and decreased the propulsion of charcoal meal through the gastrointestinal tract in a dose dependent manner. FPAE (100-500 mg/kg, p.o.) produced dose-dependent and significant (P<0.01) protection of mice against castor oil-induced diarrhoea. FPAE, dose-dependently and significantly (P< 0.01) delayed the onset of castor-oil induced diarrhoea, decreased the frequency of defecation, and reduced the severity of diarrhoea. Compared with control animals, FPAE, dose-dependently and significantly (P< 0.01) decreased the volume of castor oil-induced intestinal fluid secretion, and reduced the number, weight and wetness of faecal droppings. There was no deaths or abnormalities in behaviour seen in the acute toxicity test. The aqueous extract displayed anti-microbial effects to three species of bacteria in anti-microbial test.

CONCLUSION

The findings of this study indicate that FPAE possesses anti-diarrhoeal property in rats and mice and confirm the ethnomedicinal use of Flos Populi as a valuable natural remedy for the treatment, management and/or control of diarrhoea. These results may support the fact that this plant is traditionally used to cure diarrhoea.

Inhibition of dipeptidyl peptidase activity by flavonol glycosides of guava (Psidium guajava L.): a key to the beneficial effects of guava in type II diabetes mellitus

Based on the traditional use in popular medicine, the effect of extracts from Psidium guajava L. leaves and of the main flavonol-glycoside components on dipeptidyl-peptidase IV (DP-IV), a key enzyme of blood glucose homoeostasis, has been investigated in-vitro. An ethanolic extract was prepared from dried, powdered leaves of guava and was found to contain seven main flavonol-glycosides, which were isolated by semipreparative HPLC and tested individually. The ethanolic guava leave extract was shown to exert a dose-dependent inhibition of DP-IV, with an IC50 of 380 μg/ml test assay solution. Also the individual flavonol-glycosides inhibited DP-IV dose-dependently, with variations of the effects by a factor of 10, and an overall effect accounting for 100% of that observed for the total guava extract. The recovery of individual flavonol-glycosides in CaCo-2 epithelial cells, a model of gastrointestinal tract absorption, amounted to 2.3-5.3% of the amount available for absorption over 60 min at 37°C.

Traditional use of medicinal plants in south-central Zimbabwe: review and perspectives

BACKGROUND

Traditional medicine has remained as the most affordable and easily accessible source of treatment in the primary healthcare system of resource poor communities in Zimbabwe. The local people have a long history of traditional plant usage for medicinal purposes. Despite the increasing acceptance of traditional medicine in Zimbabwe, this rich indigenous knowledge is not adequately documented. Documentation of plants used as traditional medicines is needed so that the knowledge can be preserved and the utilized plants conserved and used sustainably. The primary objective of this paper is to summarize information on traditional uses of medicinal plants in south-central Zimbabwe, identifying research gaps and suggesting perspectives for future research.

METHODS

This study is based on a review of the literature published in scientific journals, books, reports from national, regional and international organizations, theses, conference papers and other grey materials.

RESULTS

A total of 93 medicinal plant species representing 41 families and 77 genera are used in south-central Zimbabwe. These plant species are used to treat 18 diseases and disorder categories, with the highest number of species used for gastro-intestinal disorders, followed by sexually transmitted infections, cold, cough and sore throat and gynaecological problems. Shrubs and trees (38% each) were the primary sources of medicinal plants, followed by herbs (21%) and climbers (3%). The therapeutic claims made on medicinal plants documented in south-central Zimbabwe are well supported by literature, with 82.8% of the plant species having similar applications in other regions of Zimbabwe as well as other parts of the world and 89.2% having documented biological and pharmacological properties.

CONCLUSION

This study illustrates the importance of traditional medicines in the treatment and management of human diseases and ailments in south-central Zimbabwe. Traditional medicines still play an important role in meeting basic health care of local communities in Zimbabwe.

Phenolic-rich extract from the Costa Rican guava (Psidium friedrichsthalianum) pulp with antioxidant and anti-inflammatory activity. Potential for COPD therapy

The potential therapeutic effects of Costa Rican guava (Psidium friedrichsthalianum) extracts for chronic obstructive pulmonary disease were examined. The ethyl acetate fraction displayed the highest antioxidant activity, as compared to the hexane, chloroform, and n-butanol fractions, as well as the crude extract. This fraction was evaluated for its anti-inflammatory activity response relationship against interleukin-8 (IL-8) and inhibition of matrix metalloproteinase-1 (MMP-1) expression before and after treatment with cigarette smoke. The ethyl acetate fraction exhibited inhibitory activity against IL-8 production and MMP-1 expression, showing the most potent inhibitory activities in both assays at 100μg/mL, and nine compounds (1-9) were found. Phenolic compounds 1-O-trans-cinnamoyl-β-d-glucopyranose (2), ellagic acid (3), myricetin (4), quercitrin (7), and quercetin (9) were identified using standard compounds or literature reports from related species. Compounds 1, 5, 6, and 8 were tentatively identified as 1,5-dimethyl citrate (1), sinapic aldehyde 4-O-β-d-glucopyranose (5), 3,3',4-tri-O-methylellagic acid-4'-O-d-glucopyranoside (6), and 1,3-O-diferuloylglycerol (8), All nine compounds are reported for the first time in Costa Rican guava.

Guajadials C-F, four unusual meroterpenoids from Psidium guajava

Abstract

Guajadials C-F (1–4), four sesquiterpenoid-based meroterpenoids with unprecedented skeletons were isolated from the leaves of Psidium guajava. Their structures and relative configurations were established by extensive spectroscopic analysis. A possible biosynthetic pathway for 1–4 was also proposed.

Graphical abstract

Electronic Supplementary Material

Supplementary material is available for this article at 10.1007/s13659-012-0102-4 and is accessible for authorized users.

Protective Effect of Psidium guajava in Arsenic-induced Oxidative Stress and Cytological Damage in Rats

This study was undertaken to evaluate the protective effect of aqueous extract of Psidium guajava leaves against sodium arsenite-induced toxicity in experimental rats. Animals were divided into four groups. Control group received arsenic free distilled water and three treatment groups (II, III, and IV) exposed to the arsenic (NaAsO₂) (20 mg/kg b.wt) through drinking water. Group III and IV were administered a daily oral dose of P. guajava leaf extract 50 and 100 mg/kg b.wt. (AEPG₅₀ and AEPG₁₀₀) for the period of 6 weeks. Blood samples and organs were collected at the end of the experiment. Arsenic exposure resulted in significant rise in lipid peroxidation (LPO) levels in erythrocyte, liver, kidney, and brain. In addition toxin decreased (P<0.05) the level of reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activities in the studied tissues. Residual effect of arsenic in various tissues was also observed. Histopathological results revealed mild to severe type of necrosis and degenerative changes in kidney and liver of arsenic intoxicated animals. Cytological alteration in brain tissue was also observed. Treatment with AEPG₁₀₀ (aqueous extract of P. guajava) @100 mg/kg body weight) significantly restored activities of oxidative stress markers like LPO levels, GSH levels, SOD, and CAT activities but having the limited protective activity of the herbal extract was observed on tissues architecture. It is therefore concluded that prophylactic co-administration of AEPG could provide specific protection from oxidative injury and to some extent on tissue damage.

Bioactivity determination of methanol and water extracts for roots and leaves of Kenyan Psidium guajava L landraces against pathogenic bacteria

Guava (Psidium guajava L) is native to South America and exists as both wild and cultivated. Guava has been used as a source of food and raw materials for pharmaceuticals. The aim of this study was to determine bioactivity of methanol and water extracts from root and leaves of Kenyan guava landraces against selected pathogenic bacteria. Study samples were collected from Western and South Coast of Kenya. One hundred grams of leaf and root ground powders were used for sequential extraction using methanol and water. Extracts were evaporated and 0.2gms dissolved using the extraction solvent and tested against gram positive (Staphylococcus aureus, Bacillus subtilis) and negative bacteria (Escherichia coli). Data on inhibition zone was taken in mm and analyzed at 95% confidence interval. Extracts from Western region had significant inhibition compared to Coastal region. The two regions have different climatic conditions that result in these plants having different compounds even though they are the same species. Roots had higher inhibition compared to the leaves as they contain high levels of tannins compared to leaves. Water as an extracting solvent had higher inhibition than methanol as it is more polar and it absorbs more bioactive compounds. S. aureus was most inhibited followed by E. coli and B. subtilis respectively. There was no significant difference between the gram positive and negative bacteria. Remarkably, some methanol and water root extracts had significant inhibition against bacteria when compared to some commercial antibiotics used. Results of this study indicate that Kenyan guava roots from Western Kenya extracted with methanol and water have a potential to be used as a source of active compounds in treatment of gram positive and gram negative bacteria pathogens.

Protective Effects of Guava Pulp on Cholestatic Liver Injury

Background. Cholestatic liver injury is a leading cause of chronic liver diseases involved with oxidative stress changes and inflammation; thus, antioxidant and anti-inflammation compound-rich guava may play a pivotal role in protecting against the cholestatic liver damages. Our aims for this study are to determine whether guava pulp (GP) has protective effects on cholestatic liver injury-induced mouse model and on interleukin-6 (IL-6) mediated proliferation of QBC939 cholangiocarcinoma cell line. Methods. Mice were induced to cholestatic liver damage by left and median bile duct ligation (LMBDL) surgery and then treated with GP. Plasma and liver samples were collected for biochemical and pathological assays. 5-Bromo-2'-deoxyuridine (BrdU) assay and Western blots were used to detect proliferation and gene expression in QBC939 cells, respectively. Results. Compared with LMBDL only group, in GP-treated mice, the levels of alanine aminotransferase (ALT) and bilirubin decreased, biliary epithelial cell proliferation and liver fibrogenesis were suppressed, Src/MEK/ERK1/2/c-Myc pathway and expressions of transforming growth factor β1(TGF-β1), tissue inhibitor of metalloproteinases TIMP), and procollagen 1α1(COL1α1) were downregulated significantly. Moreover, the GP extract reduced IL-6-enhanced QBC939 cell proliferation, p-ERK, and c-Myc expression as well. Conclusions. GP may provide a new perspective for the treatment of cholestatic liver injury.

The Inhibitory Effects of Aqueous Extract from Guava Twigs,Psidium guajavaL., on Mutation and Oxidative Damage

This study examines the inhibitory effects of the aqueous extract from guava twigs (GTE),Psidium guajavaL., on mutation and oxidative damage. The results show that GTE inhibits the mutagenicity of 4-nitroquinoline-N-oxide (4-NQO), a direct mutagen, and 2-aminoanthracene (2-AA), an indirect mutagen, towardSalmonella typhimuriumTA 98 and TA 100. In addition, GTE shows radical scavenging, reducing activities, tyrosinase inhibition, and liposome protection effects. Meanwhile, GTE in the range of 0.1–0.4 mg/mL protects liver cells fromtert-butyl-hydroperoxide-(t-BHP-) induced cytotoxicity. Furthermore, the cytotoxicity inhibition of GTE in thet-BHP-treated cells was demonstrated in a dose-dependent manner. High-performance liquid chromatography analysis suggests that the major phenolic constituents in GTE are gallic acid, ferulic acid, and myricetin. These active phenolic components may contribute to the biological protective effects of GTE in different models. The data suggest that GTE exhibiting biological activities can be applied to antimutation, antityrosinase, and antioxidative damage.

Medicinal utilization of exotic plants by Bapedi traditional healers to treat human ailments in Limpopo province, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Most exotic plants are usually labelled as alien invasives and targeted for eradication. However, some of these exotic plants play an important role in the traditional primary healthcare sector of the Bapedi culture in the Limpopo Province of South Africa. The medicinal uses of most of these species have neither been documented nor their biological activity evaluated.

AIM OF THE STUDY

To make an inventory of exotic species employed by Bapedi traditional healers to treat different human ailments in the Limpopo Province, South Africa.

MATERIALS AND METHODS

Semi-structured interviews, observation and guided field walks with 52 traditional healers were employed to obtain ethnobotanical data during first half of 2011 on the use of exotic plant species by Bapedi healers to treat human ailments. Based on ethnobotanical information provided by these healers, specimens were collected, numbered, pressed, and dried for identification.

RESULTS

A total of 35 exotics species belonging to 21 families and 34 genera, mostly from the Fabaceae and Solanaceae (11.4% for each), Apocynaceae and Asteraceae (8.5% for each) were used by Bapedi healers to treat 20 human ailments. Trees (45.7%) and herbs (37.1%) are the primary source of medicinal plants. Species most frequently reported were used for the treatment of hypertension (35%), diabetes mellitus, erectile dysfunction and gonorrhoea (25% for each). The highest consensus from individual accounts of the traditional healers on the use of exotic plant remedies in this study was noted for the three ailments. These were for Catharanthus roseus (gonorrhoea, 60%), Punica granatum (diarrhoea, 38.4%) and Ricinus communis (sores, 21.5%). Of the 35 exotic plant species recorded, 34.2% are regulated by the Conservation of Agricultural Resources Act (1983) (CARA) No. 43 of 1983 either as worst weeds or invaders.

CONCLUSION

The present study demonstrated that exotic plant species play an important part as medicinal remedies employed by Bapedi healers to treat different human diseases in the Limpopo Province. The use of these species as alternative sources of medicinal remedies could alleviate harvesting pressure of wild indigenous plants, thereby enhance biodiversity's region. However, there is a need to formulate an appropriate policy to retain some of the useful medicinal exotics (listed under CARA No. 43 of 1983) within the environment before their medicinal value vanishes as they are eradicated through management strategies adopted by the South African government.

A recent update in research on the antihepatotoxic potential of medicinal plants

Hepatic damage is a global metabolic and epidemic disease, affecting essential biochemical activities in almost every age group. Conventional drugs used in the treatment of liver disorders are often inadequate. Also, the spectrum of liver abnormalities caused by allopathic drugs is found to be broad. In view of severely undesirable side effects of synthetic agents, it is necessary to search for alternative drugs for the treatment of liver diseases to replace the currently used drugs, which are of doubtful efficacy and safety. Therefore, there is growing focus to follow systematic research methodology and to evaluate scientific basis for the traditional herbal medicines that are claimed to possess hepatoprotective activities. Use of herbal drugs in the treatment of liver diseases has a long tradition, especially in Eastern medicine and can be traced back as far as 2100 B.C. in ancient China (Xia Dynasty) and India (Vedic period), but evidence for efficacy is sparse. The current study is aimed at providing an overview of clinical and experimental studies carried out on the most effective and commonly used hepatoprotective plants and their beneficial aspects.

Medicinal plants used by the Bapedi traditional healers to treat diarrhoea in the Limpopo Province, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

This paper provides ethnobotanical information on medicinal plants used to treat diarrhoea in the Limpopo Province, South Africa. Documentation of this nature usually provides the basis for selecting medicinal plants for future phytochemical and pharmaceutical studies aimed at developing new, effective and affordable plant-derived diarrhoea remedies.

AIM OF THE STUDY

To record and document medicinal plants used by the Bapedi traditional healers to treat diarrhoea in the Limpopo Province, South Africa.

MATERIALS AND METHODS

In order to record and document medicinal plants used by the Bapedi traditional healers to treat diarrhoea, 51 healers from 17 municipalities covering Capricorn, Sekhukhune and Waterberg districts in the Limpopo Province, South Africa were interviewed between January and July 2011. Data collected included the names of plants, plant part(s) used, methods of herbal preparation, administration, dosage and duration of treatments. Voucher specimens of the plants used by the Bapedi traditional healers to treat diarrhoea were collected, identified and deposited as future reference material at the Larry-Leach Herbarium (UNIN), University of Limpopo.

RESULTS

A total of 20 plant species representing 16 families and 20 genera were found to be commonly used by the Bapedi traditional healers to treat and manage diarrhoea in the Limpopo Province, South Africa. The largest proportion of the medicinal plants belonged to the families Anacardiaceae, Asteraceae, Fabaceae and Malvaceae (10% each). The most frequently used species were Punica granatum (39.2%), Grewia bicolor (33.3%), Dombeya rotundifolia (21.6%), Commiphora marlothii (19.6%) and Acacia senegal (13.7%). The roots were the most commonly used plant part (50%), followed by leaves (20%), bark (15%), fruits (10%), pericarp, seed, tuber and whole plants (5% each). Mono therapies based on preparations made from a single plant species were the most dominant (90%). All medicinal preparations were taken orally for 1 week or until diarrhoea subsided. The therapeutic claims of the medicinal plants documented in this study are well supported by literature, with 70% of the species having anti-diarrhoeal properties or are used as diarrhoea remedies both in South Africa and also in other countries.

CONCLUSION

This study reveals that local communities in the Limpopo Province, South Africa still depend on traditional medicines for basic healthcare; and the use of traditional medicines is still an integral part of their socio-cultural life.

Isolation and biomimetic synthesis of (±)-guajadial B, a novel meroterpenoid from Psidium guajava

(±)-Guajadial B (1), an unusual humulene-based meroterpenoid, was isolated as a racemate from the leaves of Psidium guajava, collected from Vietnam. The structure of this novel secondary metabolite was established on the basis of extensive analysis of NMR spectra and confirmed by biomimetic synthesis in a domino three-component coupling reaction.

Treatment of diarrhoea in rural African communities: an overview of measures to maximise the medicinal potentials of indigenous plants

Diarrhoea is a major cause of morbidity and mortality in rural communities in Africa, particularly in children under the age of five. This calls for the development of cost effective alternative strategies such as the use of herbal drugs in the treatment of diarrhoea in these communities. Expenses associated with the use of orthodox medicines have generated renewed interest and reliance on indigenous medicinal plants in the treatment and management of diarrhoeal infections in rural communities. The properties of many phenolic constituents of medicinal plants such as their ability to inhibit enteropooling and delay gastrointestinal transit are very useful in the control of diarrhoea, but problems such as scarcity of valuable medicinal plants, lack of standardization of methods of preparation, poor storage conditions and incertitude in some traditional health practitioners are issues that affect the efficacy and the practice of traditional medicine in rural African communities. This review appraises the current strategies used in the treatment of diarrhoea according to the Western orthodox and indigenous African health-care systems and points out major areas that could be targeted by health-promotion efforts as a means to improve management and alleviate suffering associated with diarrhoea in rural areas of the developing world. Community education and research with indigenous knowledge holders on ways to maximise the medicinal potentials in indigenous plants could improve diarrhoea management in African rural communities.

Proximate analysis, in vitro organic matter digestibility, and energy content of common guava (Psidium guajava L.) and yellow, strawberry guava (Psidium cattleianum Var. lucidum) tree parts and fruits as potential forage

The nutrient composition of common guava, Psidium guajava L., and strawberry guava (waiwi), Psidium cattleianum var. lucidum, tree parts and fruits was determined during three seasons for six locations in Hawaii to assess guava as a potential feed for cattle. All guava plant parts were higher (p < 0.001) in crude protein than waiwi, but there were no differences in the fiber and energy densities for bark, shoots, and branches. Guava leaves were higher in fiber and had lower energy densities (p < 0.05) than waiwi. Ripe and breaker stage fruits were lower (p < 0.05) in fiber, similar in protein (CP), and higher (p < 0.05) in energy density than immature fruits. Guava fruits were higher in CP (p < 0.05) and organic matter (p < 0.001) and lower in ash (p < 0.001) than waiwi fruits. The primary nutritional concern with guava is low in vitro organic matter digestibility as compared to tropical forage grasses; therefore, it is not recommended as a feedstock for livestock.

Interactions of extracts from selected chewing stick sources with Aggregatibacter actinomycetemcomitans

Background

Aggregatibacter actinomycetemcomitans produces a leukotoxin that activates a pro-inflammatory death of human monocytes/macrophages. A specific clone of this bacterium (JP2) has a 530-base pair deletion in the leukotoxin promoter gene and significantly enhanced expression of leukotoxin. This specific clone of A. actinomycetemcomitans is common in some African populations and has a strong association with periodontal attachment loss in adolescents in these populations. Chewing sticks of plant origin are commonly used as oral hygiene tool in Africa, but their role as a therapeutic agent in periodontal disease is poorly investigated.

Results

Ethanol extracts were made from 7 common plants used as chewing sticks in West-Africa. None of the tested extracts inhibited growth of A. actinomycetemcomitans. However, extracts from Psidium guajava (Guava) completely neutralized the cell death and pro-inflammatory response of human leukocytes induced by the leukotoxin. None of the six other tested chewing stick extracts showed this effect.

Conclusions

The discovery that extracts from Guava efficiently neutralizes A. actinomycetemcomitans leukotoxicity might lead to novel therapeutic agents and strategies for prevention and treatment of aggressive forms of periodontitis induced by infections with the highly leukotoxic JP2 clone of this bacterium.

Inhibitory effect of Psidium guajava water extract in the development of 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice

Atopic dermatitis (AD) is a chronic, relapsing, and inflammatory skin disease associated with eczematous symptoms and IgE hyperproduction. Psidium guajava is an important food crop and medicinal plant with anti-oxidant, anti-inflammatory, and anti-allergic activities, supporting its traditional uses. Our previous studies have shown that P. guajava extract inhibits Th2 chemokine expression by suppressing the activation of NF-κB and STAT1 co-stimulated with TNF-α and INF-γ. In this study, we investigated the inhibitory effect of P. guajava water extract (PGW) on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in NC/Nga mice. Treatment of cream containing PGW onto DNCB-induced AD-like skin lesions in NC/Nga mice ameliorated lesion intensity scores, levels of IgE, thymus and activation-regulated chemokine (TARC), TNF-α, and IL-4 in serum and ears. In contrast, PGW increased level of the immunosuppressive cytokine IL-10. Histological analyses demonstrated decreased thickening of the epidermis/dermis as well as dermal infiltration by inflammatory cells. These results suggest that cream containing PGW may be a potential therapeutic modality for AD and adjunctive agent to control pruritus in AD.

Burden of Stroke in the Philippinesr

Based on disability-adjusted life-years, stroke is the second leading cause of death and among the top five diseases with the greatest burden. Although two community-based studies have been conducted to determine the prevalence of stroke in the Philippines, the incidence has not been nationally recorded to date. The prevalence ranged from 1·9% to 6·59%, and ‘Wiihabilitation’, a rehabilitation stroke therapy, is widely practiced. A clinical trial for stroke rehabilitation using the Chinese Medicine NeuroAid®, which consists of several herbs, is ongoing in many hospitals across the Philippines. Due to their ready availability, phytomedicines are widely used, especially in the rural areas, for the treatment of hypertension, diabetes mellitus, and hypercholesterolemia, which are predisposing factors for stroke in the Philippines. Due to the increasing number of stroke cases annually, the government of the Philippines should emphasize primary and secondary prevention strategies.

Effect of water extracts from edible Myrtaceae plants on uptake of 2-(n-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose in TNF-α-treated FL83B mouse hepatocytes

This study investigated the glucose uptake activity of the water extracts from the leaves and fruit of edible Myrtaceae plants, including guava (Psidium guajava Linn.), wax apples [Syzygium samarangense (Blume) Merr. and L.M. Perry], Pu-Tau [Syzygium jambo (L.) Alston], and Kan-Shi Pu-Tau (Syzygium cumini Linn.) in FL83B mouse hepatocytes. The fluorescent dye 2-(n-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose was used to estimate the uptake ability of the cells. Glucose uptake test showed that pink wax apple fruit extract (PWFE) exhibits the highest glucose uptake activity, at an increment of 21% in the insulin-resistant FL83B mouse hepatocytes as compared with the TNF-α-treated control group. Vescalagin was isolated using column chromatography of PWFE. This compound, at the concentration of 6.25 µg/mL, exhibits the same glucose uptake improvement in insulin-resistant cells as PWFE at a 100-µg/mL dose. We postulate that vescalagin is an active component in PWFE that may alleviate the insulin resistance in mouse hepatocytes.

Antiviral effects of Psidium guajava Linn. (guava) tea on the growth of clinical isolated H1N1 viruses: its role in viral hemagglutination and neuraminidase inhibition

Rapid evolution of influenza RNA virus has resulted in limitation of vaccine effectiveness, increased emergence of drug-resistant viruses and occurrence of pandemics. A new effective antiviral is therefore needed for control of the highly mutative influenza virus. Teas prepared by the infusion method were tested for their anti-influenza activity against clinical influenza A (H1N1) isolates by a 19-h influenza growth inhibition assay with ST6Gal I-expressing MDCK cells (AX4 cells) using fluorogenic quantification and chromogenic visualization. Guava tea markedly inhibited the growth of A/Narita/1/2009 (amantadine-resistant pandemic 2009 strain) at an IC(50) of 0.05% and the growth of A/Yamaguchi/20/06 (sensitive strain) and A/Kitakyushu/10/06 (oseltamivir-resistant strain) at similar IC(50) values ranging from 0.24% to 0.42% in AX4 cells, being 3.4- to 5.4-fold more potent than green tea (IC(50) values: 0.27% for the 2009 pandemic strain and 0.91% to 1.44% for the seasonal strains). In contrast to both teas, oseltamivir carboxylate (OC) demonstrated high potency against the growth of A/Narita/1/09 (IC(50) of 3.83nM) and A/Yamaguchi/20/06 (IC(50) of 11.57nM) but not against that of A/Kitakyushu/10/06 bearing a His274-to-Tyr substitution (IC(50) of 15.97μM). Immunofluorescence analysis under a confocal microscope indicated that both teas inhibited the most susceptible A/Narita/1/2009 virus at the initial stage of virus infection. This is consistent with results of direct inhibition assays showing that both teas inhibited viral hemagglutination at concentrations comparable to their growth inhibition concentrations but inhibited sialidase activity at about 8-times higher concentrations. Guava tea shows promise to be efficacious for control of epidemic and pandemic influenza viruses including oseltamivir-resistant strains, and its broad target blockage makes it less likely to lead to emergence of viral resistance.

Variation in antioxidant attributes at three ripening stages of guava (Psidium guajava L.) fruit from different geographical regions of Pakistan

The present investigation was carried out to appraise the levels of total phenols and vitamin C as well as antioxidant potential at three different ripening stages (un-ripe, semi-ripe and fully-ripe) of guava (Psidium guajava L.) fruit collected from three different geographical regions of Pakistan (Islamabad, Faisalabad and Bhakkar). The antioxidant potential of guava fruit extracts was assessed by means of different in-vitro antioxidant assays, namely inhibition of peroxidation in linoleic acid system, reducing power and radical scavenging capability. Overall, fruit at the un-ripe stage (G1) exhibited the highest levels of TPC, TFC, reducing power and DPPH radical scavenging activity, followed by the semi-ripe (G2) and fully-ripe (G3) stages. On the other hand, vitamin C content increased as the fruit maturity progressed, with highest value seen at the fully-ripe stage (G3) followed by the semi-ripe (G2) and un-ripe stage (G1). The concentration of vitamin C in fruits varied as: Faisalabad (136.4–247.9 mg 100 g⁻¹), Islamabad (89.7–149.7 mg 100 g⁻¹) and Bhakkar (73.1–129.5 mg 100 g⁻¹). The results showed that different stages of maturation and geographical locations had profound effects on the antioxidant activity and vitamin C contents of guava fruit.

Effect of Psidium cattleianum leaf extract on enamel demineralisation and dental biofilm composition in situ

OBJECTIVE

Previous evaluations of Psidium cattleianum leaf extract were not done in conditions similar to the oral environment. The aim of this study was to evaluate the effect of P. cattleianum leaf extract on enamel demineralisation, extracellular polysaccharide formation, and the microbial composition of dental biofilms formed in situ.

DESIGN

Ten volunteers took part in this crossover study. They wore palatal appliances containing 4 enamel blocks for 14 days. Each volunteer dripped 20% sucrose 8 times per day on the enamel blocks. Twice a day, deionised water (negative control), extract, or a commercial mouthwash (active control) was dripped after sucrose application. On the 12th and 13th days of the experiment, plaque acidogenicity was measured with a microelectrode, and the pH drop was calculated. On the 14th day, biofilms were harvested and total anaerobic microorganisms (TM), total streptococci (TS), mutans streptococci (MS), and extracellular polysaccharides (EPS) were evaluated. Enamel demineralisation was evaluated by the percentage change of surface microhardness (%ΔSMH) and integrated loss of subsurface hardness (ΔKHN). The researcher was blinded to the treatments during data collection.

RESULTS

The extract group showed lower TM, TS, MS, EPS, %ΔSMH, and ΔKHN values than the negative control group. There were no differences between the active and negative control groups regarding MS and EPS levels. There were no differences in pH drop between the extract and active control groups, although they were significantly different from the negative control group. For all other parameters, the extract differed from the active control group.

CONCLUSION

Psidium cattleianum leaf extract exhibits a potential anticariogenic effect.

Guava leaf extracts alleviate fatty liver via expression of adiponectin receptors in SHRSP.Z-Leprfa/Izm rats

Background

In recent years, the number of people with metabolic syndrome has continued to rise because of changing eating habits, and accompanying hepatic steatosis patients have also increased. This study examined the effect of guava leaf extract on liver fat accumulation using SHRSP.Z-Leprfa/IzmDmcr rats (SHRSP/ZF), which are a metabolic syndrome model animal.

Method

Seven-week-old male SHRSP/ZF rats were divided into two groups, a control group and a guava leaf extract (GLE) group. We gave 2 g/kg/day GLE or water by forced administration for 6 weeks. After the experimental period, the rats were sacrificed and organ weight, hepatic lipids, serum aminotransferase and liver pathology were examined. To search for a possible mechanism, we examined the changes of key enzyme and transcriptional factors involved in hepatic fatty acid beta-oxidation.

Results

The triglyceride content of the liver significantly decreased in the GLE group in comparison with the control group, and decreased fat-drop formation in the liver tissue graft in the GLE group was observed. In addition, the improvement of liver organization impairments with fat accumulation restriction was suggested because blood AST and ALT in the GLE group significantly decreased. Furthermore, it was supposed that the activity of AMPK and PPARα significantly increased in the GLE group via the increase of adiponectin receptors. These were thought to be associated with the decrease of the triglyceride content in the liver because AMPK and PPARα in liver tissue control energy metabolism or lipid composition. On the other hand, insulin resistance was suggested to have improved by the fatty liver improvement in GLE.

Conclusion

Our results indicate that administration of GLE may have preventive effects of hepatic accumulation and ameliorated hepatic insulin resistance by enhancing the adiponectin beta-oxidation system. Guava leaf may be potentially useful for hepatic steatosis without the side effects of long-term treatments.

Effects of dietary fruits, vegetables and a herbal tea on the in vitro transport of cimetidine: comparing the Caco-2 model with porcine jejunum tissue

CONTEXT

Dietary botanicals are often consumed together with allopathic medicines, which may give rise to pharmacokinetic interactions. In vitro intestinal models are useful to identify botanical-drug interactions, but they may exhibit different expressions of transporters or enzymes.

OBJECTIVE

To compare the effects of selected dietary botanical extracts on cimetidine transport across two in vitro intestinal models.

MATERIALS AND METHODS

Bi-directional transport of cimetidine was measured across Caco-2 cell monolayers and excised porcine jejunum tissue in the absence (control) as well as the presence of verapamil (positive control) and selected plant extracts.

RESULTS

Sclerocarya birrea Hochst. (Anacardiaceae) (marula) and Psidium guajava L. (Myrtaceae) (guava) crude extracts significantly decreased cimetidine efflux in both in vitro models resulting in increased absorptive transport of the drug. On the other hand, Dovyalis caffra Sim. (Flacourtiaceae) (Kei-apple), Prunus persica (L.) Batsch (Rosaceae) (peach), Aspalathus linearis (Burm. f.) R. Dahlgren (Fabaceae) (rooibos tea), Daucus carota L. (Apiaceae) (carrot), Prunus domestica A. Sav. (Rosaceae) (plum), Beta vulgaris L. (Chenopodiaceae) (beetroot) and Fragaria x ananassa (Weston) Duchesne ex Rozier. (Rosaceae) (strawberry) crude extracts exhibited different effects on cimetidine transport between the two models.

DISCUSSION

Caco-2 cells were more sensitive to changes in cimetidine transport by the plant extracts and therefore may overestimate the effects of co-administered plant extracts on drug transport compared to the excised pig tissue model, which is congruent with findings from previous studies.

CONCLUSIONS

The excised porcine jejunum model seemed to provide a more realistic estimation of botanical-drug pharmacokinetic interactions than the Caco-2 cell model.

Psidium guajava L. anti-neoplastic effects: induction of apoptosis and cell differentiation

OBJECTIVES

Curative properties of medicinal plants such as Psidium guajava L. (Myrtaceae) have often been indicated by epidemiological studies on populations in which these fruits are consumed daily. However, complete characterization of the active principles responsible for this ability has never been performed. Here, we have characterized P. guajava's anti-cancer potential and identified the parts of the fruit involved in its anti-neoplastic action.

MATERIALS AND METHODS

We studied morphology of our cells, cell cycle characteristics and apoptosis and performed immunostaining, differentiation and western blot analyses.

RESULTS

We report that the P. guajava extract exerted anti-cancer control on both haematological and solid neoplasias. P. guajava extract's anti-tumour properties were found to be tightly bound to induction of apoptosis and differentiation. Use of ex vivo myeloid leukaemia blasts corroborated that P. guajava was able to induce cell death but did not exhibit anti-cancer effects on all malignant cells investigated, indicating selective activity against certain types of tumour. Analyses of P. guajava pulp, peel and seeds identified the pulp as being the most relevant component for causing cell cycle arrest and apoptosis, whereas peel was responsible for causing cell differentiation. P. guajava itself and its pulp-derived extract were found to induce apoptosis accompanied by caspase activation and p16, p21, Fas ligand (FASL TNF super-family, member 6), Bcl-2-associated agonist of cell death (BAD) and tumour necrosis factor receptor super-family, member 10b (DR5), overexpression.

CONCLUSIONS

Our findings showed that P. guajava L. extract was able to exert anti-cancer activity on cultures in vitro and ex vivo, supporting the hypothesis of its anti malignant pro-apoptotic modulation.

Ethnobotany of the Monpa ethnic group at Arunachal Pradesh, India

BACKGROUND

The present paper documents the uses of plants in traditional herbal medicine for human and veterinary ailments, and those used for dietary supplements, religious purpose, local beverage, and plants used to poison fish and wild animals. Traditional botanical medicine is the primary mode of healthcare for most of the rural population in Arunachal Pradesh.

MATERIALS AND METHODS

Field research was conducted between April 2006 and March 2009 with randomly selected 124 key informants using semi-structured questionnaire. The data obtained was analyzed through informant consensus factor (FIC) to determine the homogeneity of informant's knowledge on medicinal plants.

RESULTS

We documented 50 plants species belonging to 29 families used for treating 22 human and 4 veterinary ailments. Of the medicinal plants reported, the most common growth form was herbs (40%) followed by shrubs, trees, and climbers. Leaves were most frequently used plant parts. The consensus analysis revealed that the dermatological ailments have the highest FIC (0.56) and the gastro-intestinal diseases have FIC (0.43). FIC values indicated that there was high agreement in the use of plants in dermatological and gastro-intestinal ailments category among the users. Gymnocladus assamicus is a critically rare and endangered species used as disinfectant for cleaning wounds and parasites like leeches and lice on livestocks. Two plant species (Illicium griffithii and Rubia cordifolia) are commonly used for traditional dyeing of clothes and food items. Some of the edible plants recorded in this study were known for their treatment against high blood pressure (Clerodendron colebrookianum), diabetes mellitus (Momordica charantia), and intestinal parasitic worms like round and tape worms (Lindera neesiana, Solanum etiopicum, and Solanum indicum). The Monpas of Arunachal Pradesh have traditionally been using Daphne papyracea for preparing hand-made paper for painting and writing religious scripts in Buddhist monasteries. Three plant species (Derris scandens, Aesculus assamica, and Polygonum hydropiper) were frequently used to poison fish during the month of June-July every year and the underground tuber of Aconitum ferrox is widely used in arrow poisoning to kill ferocious animals like bear, wild pigs, gaur and deer. The most frequently cited plant species; Buddleja asiatica and Hedyotis scandens were used as common growth supplements during the preparation of fermentation starter cultures.

CONCLUSION

The traditional pharmacopoeia of the Monpa ethnic group incorporates a myriad of diverse botanical flora. Traditional knowledge of the remedies is passed down through oral traditions without any written document. This traditional knowledge is however, currently threatened mainly due to acculturation and deforestation due to continuing traditional shifting cultivation. This study reveals that the rural populations in Arunachal Pradesh have a rich knowledge of forest-based natural resources and consumption of wild edible plants is still an integral part of their socio-cultural life. Findings of this documentation study can be used as an ethnopharmacological basis for selecting plants for future phytochemical and pharmaceutical studies.

Psidium guajava extract inhibits thymus and activation-regulated chemokine (TARC/CCL17) production in human keratinocytes by inducing heme oxygenase-1 and blocking NF-κB and STAT1 activation

Psidium guajava (P. guajava) is a food and medicinal plant with antioxidant, anti-inflammatory, and anti-allergic activities that support its traditional uses. The aim of this study was to determine the effects of P. guajava ethyl acetate extract (PGEA) on atopic dermatitis and to investigate the possible mechanisms by which PGEA inhibits cytokine-induced Th2 chemokine expression in HaCaT human keratinocyte cells. We found that PGEA suppressed the IFN-γ/TNF-α-co-induced production of thymus and activation-regulated chemokine (TARC) protein and mRNA in HaCaT cells. Additionally, PGEA inhibited the TNF-α/IFN-γ-co-induced activation of NF-κB and STAT1 and increased the expression of heme oxygenase-1 (HO-1) protein and mRNA. HO-1 inhibitor enhanced the suppressive effects of PGEA on TNF-α/IFN-γ-co-induced TARC production and gene expression. Collectively, these data demonstrate that PGEA inhibits chemokine expression in keratinocytes by inducing HO-1 expression and it suggests a possible therapeutic application in atopic dermatitis and other inflammatory skin diseases.

Antidiarrheal activity of Pyrenacantha staudtii Engl. (Icacinaceae) aqueous leaf extract in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Pyrenacantha staudtii Engl. (Icacinaceae) is a plant which is traditionally used for the treatment of blemnorrhea, hernia, insomnia, intestinal pain and diarrhea in Nigeria. Therefore the core aim of the present study is to evaluate antidiarrheal activity of Pyrenacantha staudtii aqueous extract (PSE).

MATERIALS AND METHODS

The antidiarrheal activity was evaluated using castor oil-induced diarrhea method. The effects of Pyrenacantha staudtii aqueous extract on gastrointestinal motility, intestinal transit and enteropooling were also examined in rodents. The acute toxicity effect of the aqueous extract of Pyrenacantha staudtii was also investigated.

RESULTS

Pyrenacantha staudtii aqueous extract (PSE, 100-400mg/kg, p.o.) produced dose-dependent and significant (P<0.05-0.01) protection of rats and mice against castor oil-induced diarrhea, inhibited intestinal transit, and delayed gastric emptying. PSE, produced dose-dependent and significant (P<0.05-0.01) antimotility effect, caused dose-related inhibition of castor-oil-induced enteropooling in animals, comparable to atropine (1mg/kg, p.o.). Like loperamide (10mg/kg, p.o.), PSE, dose-dependently and significantly (P<0.05-0.01) delayed the onset of castor-oil induced diarrhea, decreased the frequency of defecation, and reduced the severity of diarrhea in the rodents. Compared with control animals, PSE, dose-dependently and significantly (P<0.05-0.01) decreased the volume of castor oil-induced intestinal fluid secretion, and reduced the number, weight and wetness of fecal droppings.

CONCLUSION

The findings of this study indicate that PSE possesses antidiarrheal property in rats and mice. These findings confirm the ethnomedicinal use of Pyrenacantha staudtii leaf as a valuable natural remedy for the treatment, management and/or control of diarrhea.

Suppressive effects of quercetin-3-O-(6″-Feruloyl)-β-D-galactopyranoside on adipogenesis in 3T3-L1 preadipocytes through down-regulation of PPARγ and C/EBPα expression

Obesity is a chronic, costly disease, and flavonoids such as quercetin have been proven to play protective roles against it. This study investigated the suppressive effect of quercetin-3-O-(6″-feruloyl)-β-D-galactopyranoside (QFG) on adipogenesis of 3T3-L1 preadipocytes. Quercetin-3-O-(6″-feruloyl)-β-D-galactopyranoside and quercetin were both extracted from Psidium guajava (Myrtaceae, commonly known as guava) leaves and were evaluated for their suppressive effect on adipogenesis by means of oil red O staining and triglyceride assay. It was shown that QFG inhibited adipogenesis in a dose- and time-dependent manner, and it exerted a stronger effect than did quercetin at the same concentration. Quantitative real-time polymerase chain reaction and western blotting were conducted to further examine the differentiation expression of marker genes and transcriptional factors. Both mRNA and protein expression of the key adipogenic transcriptional factors, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT (cytidine-cytidine-adenosine-adenosine-thymidine)/enhancer-binding protein alpha (C/EBPα), were inhibited by QFG. Moreover, the mRNA expression patterns of key participants in the Wnt-β-catenin pathway were not altered during the QFG-induced adipogenesis inhibition. These results suggest that QFG effectively suppresses adipogenesis and that it exerts its role mainly through the significant down-regulation of PPARγ and C/EBPα and, probably, via a Wnt-β-catenin independent pathway.

In vitro antimicrobial activity of methanolic leaf extract of Psidium guajava L

AIM

This study was designed to examine the chemical composition and in vitro antimicrobial potential of methanolic extract of Psidium guajava Linn (Myrtaceae).

MATERIALS AND METHODS

The inhibitory effect of methanolic extract of P. guajava was tested against three bacterial and two fungal strains by using the paper disc diffusion method.

RESULTS

The methanolic extract exhibited antibacterial activity against E. coli with minimum inhibitory concentration, 0.78 μg/ml, minimum bactericidal concentration of 50 μg/ml, and appreciable antifungal activity with minimum inhibitory concentration of 12.5 μg/ml. Preliminary phytochemical analysis of methanolic extract revealed the presence of antimicrobial compounds such as flavonoids, steroids, and tannins, which may contribute for the antimicrobial action of P. guajava.

CONCLUSION

The extract was found to be bacteriostatic and fungistatic in action.