Inhibitory effects of Piper betle on production of allergic mediators by bone marrow-derived mast cells and lung epithelial cells

Betelvine (Piper betle L.): A comprehensive insight into its ethnopharmacology, phytochemistry, and pharmacological, biomedical and therapeutic attributes

Piper betle L. (synonym: Piper betel Blanco), or betel vine, an economically and medicinally important cash crop, belongs to the family Piperaceae, often known as the green gold. The plant can be found all over the world and is cultivatedprimarily in South East Asian countries for its beautiful glossy heart-shaped leaves, which are chewed or consumed as betelquidand widely used in Chinese and Indian folk medicine, as carminative, stimulant,astringent, against parasitic worms, conjunctivitis, rheumatism, wound, etc., andis also used for religious purposes. Hydroxychavicol is the most important bioactive compound among the wide range of phytoconstituents found in essential oil and extracts. The pharmacological attributes of P. betle are antiproliferation, anticancer, neuropharmacological, analgesic, antioxidant, antiulcerogenic, hepatoprotective, antifertility, antibacterial, antifungal and many more. Immense attention has been paid to nanoformulations and their applications. The application of P. betle did not show cytotoxicity in preclinical experiments, suggesting that it could serve as a promising therapeutic candidate for different diseases. The present review comprehensively summarizes the botanical description, geographical distribution, economic value and cultivation, ethnobotanical uses, preclinical pharmacological properties with insights of toxicological, clinical efficacy, and safety of P. betle. The findings suggest that P. betle represents an orally active and safe natural agent that exhibits great therapeutic potential for managing various human medical conditions. However, further research is needed to elucidate its underlying molecular mechanisms of action, clinical aspects, structure-activity relationships, bioavailability and synergistic interactions with other drugs.

Indian Medicinal Plants and Formulations and Their Potential Against COVID-19-Preclinical and Clinical Research

The cases of COVID-19 are still increasing day-by-day worldwide, even after a year of its first occurrence in Wuhan city of China. The spreading of SARS-CoV-2 infection is very fast and different from other SARS-CoV infections possibly due to structural differences in S proteins. The patients with severe diseases may die due to acute respiratory distress syndrome (ARDS) caused by systemic inflammatory reactions due to the excessive release of pro-inflammatory cytokines and chemokines by the immune effector cells. In India too, it is spreading very rapidly, although the case fatality rate is below 1.50% (https://www.statista.com), which is markedly less than in other countries, despite the dense population and minimal health infrastructure in rural areas. This may be due to the routine use of many immunomodulator medicinal plants and traditional AYUSH formulations by the Indian people. This communication reviews the AYUSH recommended formulations and their ingredients, routinely used medicinal plants and formulations by Indian population as well as other promising Indian medicinal plants, which can be tested against COVID-19. Special emphasis is placed on Indian medicinal plants reported for antiviral, immunomodulatory and anti-allergic/anti-inflammatory activities and they are categorized for prioritization in research on the basis of earlier reports. The traditional AYUSH medicines currently under clinical trials against COVID-19 are also discussed as well as furtherance of pre-clinical and clinical testing of the potential traditional medicines against COVID-19 and SARS-CoV-2. The results of the clinical studies on AYUSH drugs will guide the policymakers from the AYUSH systems of medicines to maneuver their policies for public health, provide information to the global scientific community and could form a platform for collaborative studies at national and global levels. It is thereby suggested that promising AYUSH formulations and Indian medicinal plants must be investigated on a priority basis to solve the current crisis.

Antioxidant activity of eugenol in Piper betel leaf extract

BACKGROUND

Extracts of Piper betel are used for the treatment of various ailments since ages due to its essential properties like antioxidant, anticancer, anti-allergic etc. In the present study antioxidant activity for Piper betel leaf extract and Eugenol was assessed. Eugenol was taken as marker compound.

METHODS

Nitric oxide, Hydroxyl radical and Reducing power assay methods were carried out for assessment of antioxidant activity of Piper betel.

RESULTS

The antioxidant activity for Nitric oxide, Hydroxyl radical and Reducing power assay at 1000 to 62.5μg/ml was performed. The antioxidant activity of Piper betel leaf extract exhibited the IC50 value for Nitric oxide and Hydroxyl radical >1000 whereas Eugenol exhibited the IC50 value 114.34± 0.46 and 306.44 ± 5.28 respectively, for reducing power assay (RPA) Piper betel leaf extract and Eugenol revealed the RPA value ranging from 0.44-0.08 and 0.53-0.12.

CONCLUSION

The benefits of Piper betel have been mentioned in our ancient texts. Keeping in view the emergence of various diseases and the benefits of Piper betei, there is need that every effort should be made to revive this treasure of nature into our daily supplement.

Phytochemical composition, β-glucuronidase inhibition, and antioxidant properties of two fractions of Piper betle leaf aqueous extract

RATIONALE

Piper betle leaf, used as masticatory in South Asia, is also medicinally important.

OBJECTIVE

This work was done to analyze phytochemical composition of two solvent fractions (chloroform and ethyl acetate) of the aqueous extracts obtained from eight varieties of P. betle leaves and to identify the active components against β-glucuronidase by chemometric analysis.

RESULTS

Twenty-four phenolic compounds, in addition to different organic acids, fatty acids, amino acids, sugars, and polyols, were identified from the solvent fractions. The extracts inhibited the enzyme β-glucuronidase. Piceatannol was the most active constituent against the enzyme (activity 12 times higher than that of silymarin), Chlorogenic acid also inhibited β-glucuronidase (activity 4.4 times higher when compared to silymarin). 2,2'-Diphenyl-1-picrylhydrazyl and superoxide free radical scavenging activities of both the fractions of eight varieties of P. betle leaf extracts showed very strong antioxidant potentiality.

CONCLUSION

The findings validated some medicinal properties of the said leaves.

PRACTICAL APPLICATIONS

Edible leaves of Piper betle are medicinally and economically important. Leaves of different local varieties are reported to be used for the treatment of different diseases. The leaves have many biological properties, hepatoprotection being one of them. A large number of rural population is economically dependent on the cultivation of betel vine. But with a rapid change in lifestyle, the chewing habit of P. betle is decreasing ultimately affecting the livelihood of farmers dependent on betel cultivation. Knowledge on β-glucuronidase inhibitory activity and the mechanism for hepatoprotection of different P. betle varieties may validate the medicinal properties of betel, which would increase consumption of these leaves.

Comparative analysis of mosquito (Diptera: Culicidae: Aedes aegypti Liston) responses to the insecticide Temephos and plant derived essential oil derived from Piper betle L

Resistance to treatments with Temephos or plant derived oil, Pb-CVO, between a field collected Wild Strain (WS) and a susceptible Laboratory Strain (LS) of Ae. aegypti were measured. The Temephos (0.1mg/L) showed the greatest percentage of mosquito mortality compared to Pb-CVO (1.5mg/L) in LS Ae. aegypti. However, WS Ae. aegypti was not significantly affected by Temephos (0.1mg/L) treatment compare to the Pb-CVO (1.5mg/L). However, both strains (LS and WS) when treated with Pb-CVO (1.5mg/L) displayed steady larval mortality rate across all instars. The LC₅₀ of Temephos was 0.027mg in LS, but increased in WS to 0.081mg/L. The LC₅₀ of Pb-CVO treatment was observed at concentrations of 0.72 and 0.64mg/L for LS and WS strains respectively. The enzyme level of α- and β-carboxylesterase was reduced significantly in both mosquito strains treated with Pb-CVO. Whereas, there was a prominent deviation in the enzyme ratio observed between LS and WS treated with Temephos. The GST and CYP450 levels were upregulated in the LS, but decreased in WS, after treatment with Temephos. However, treatment with Pb-CVO caused both enzyme levels to increase significantly in both the strains. Visual observations of the midgut revealed cytotoxicity from sub-lethal concentrations of Temephos (0.04mg/L) and Pb-CVO (1.0mg/L) in both strains of Ae. aegypti compared to the control. The damage caused by Temephos was slightly less in WS compared to LS mosquito strains.

Hydroxychavicol: A phytochemical targeting cutaneous fungal infections

The present study was designed to investigate the potency of hydroxychavicol on selected cutaneous human pathogenic fungi by the use of in vitro and in vivo assays and mechanistic characterization along with toxicological effects. Hydroxychavicol consistently displayed a fungicidal effect against all fungal species tested. Inoculum concentrations over the range of 10⁴ to 10⁷ CFU/ml did not significantly alter its antifungal potential and time–kill curve results revealed concentration–dependent killing. It also inhibited the growth of biofilm generated by Trichophyton mentagrophytes and Candida parapsilosis and reduced the preformed biofilms. Hydroxychavicol was highly effective in the treatment, and mycological eradication of an experimentally induced topical infection model of dermatophytosis (tinea corporis) and cutaneous candidiasis in guinea pigs, respectively. The mode of action of hydroxychavicol appears to originate from the disruption of cell membrane integrity. Administration of hydroxychavicol in mice at 500 mg per kg of body weight by orally produced no overt toxicity. The retention capacity of hydroxychavicol in vitro, in the presence of keratin has attributed to its in vivo effectiveness in the guinea pig model of topical infections. Furthermore, it is suggestive of its potential use as phytochemical for topical use in cutaneous fungal infections.

Developmental response of Spodoptera litura Fab. to treatments of crude volatile oil from Piper betle L. and evaluation of toxicity to earthworm, Eudrilus eugeniae Kinb

Evaluations of biological effects of (Pb-CVO) the crude volatile oil of Piper betle leaves on the tobacco cutworm Spodoptera litura were conducted. Pb-CVO was subjected to GC-MS analysis and twenty vital compounds were isolated from the betel leaf oil. Pb-CVO was tested at four different concentrations (0.25, 0.5, 1.0 and 1.5%) against S. litura. The treated insects exhibited dose depended mortality. The mortality rate was significantly higher at the 1.0 and 1.5% Pb-CVO. The LC50 (Lethal concentration) were observed at 0.48% Pb-CVO. Larval and pupal durations increased in all treatment concentrations (0.25, 0.3, 0.4 and 0.5%) whereas, pupal weight decreased compared to control. Adult longevity of S. litura was reduced in all treatments but predominantly in the 0.4 and 0.5% Pb-CVO. Correspondingly, mean fecundity rate was reduced at all concentrations compared to control. Histological studies of larvae mid-gut profiles of S. litura were severely damaged in 1.0 and 1.5% and showed abnormalities in mid-gut cells with 0.25 and 0.5% Pb-CVO treatments. Earthworm toxicity illustrated that 0.1% of chemical insecticides (monocrotophos and cypermethrin) varied widely in their contact toxicities compared to 0.5 and 1.0% Pb-CVO and control in both contact filter paper and artificial soil test. These findings suggest that twenty essential compounds of betel leaf oil were significant inhibitors of the development and caused behavioral changes of S. litura. Treatment with betel leaf oil at these concentrations had no adverse effect on earthworm populations.

An experimental evaluation of the anti-atherogenic potential of the plant, Piper betle, and its active constitutent, eugenol, in rats fed an atherogenic diet

Hypercholesterolemia is a major risk factor for systemic atherosclerosis and subsequent cardiovascular disease. Lipoperoxidation-mediated oxidative damage is believed to contribute strongly to the progression of atherogenesis. In the current investigation, putative anti-atherogenic and antioxidative properties of an ethanolic extract of Piper betle and of its active constituent, eugenol, were sought in an experimental animal model of chronic hypercholesterolemia. Atherogenic diet-fed rats that received either Piper betle extract orally (500mg/kg b.wt) or eugenol orally (5mg/kg b.wt) for 15days (commencing 30days after the atherogenic diet had been started) exhibited the following variations in different parameters, when compared to atherogenic diet-fed rats that received only saline: (1) significantly lower mean levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol and very low density lipoprotein cholesterol in both serum and hepatic tissue samples; (2) lower mean serum levels of aspartate amino-transferase, alanine amino-transferase, alkaline phosphatase, lactate dehydrogenase and lipid-metabolizing enzymes (lipoprotein lipase, 3-hydroxy-3-methyl-glutaryl-CoA reductase; (3) significantly lower mean levels of enzymatic antioxidants (catalase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase) and non-enzymatic antioxidants (reduced glutathione, vitamin C and vitamin E) and significantly higher mean levels of malondialdehyde in haemolysate and hepatic tissue samples. Histopathological findings suggested a protective effect of the Piper betle extract and a more pronounced protective effect of eugenol on the hepatic and aortic tissues of atherogenic diet-fed (presumed atherosclerotic) rats. These results strongly suggest that the Piper betle extract and its active constituent, eugenol, exhibit anti-atherogenic effects which may be due to their anti-oxidative properties.

A comparative ethnopharmacological analysis of traditional medicine used against respiratory tract diseases in Mauritius

ETHNOPHARMACOLOGICAL RELEVANCE

Despite laudable advances in conventional medicine, respiratory tract diseases (RTD) induced morbidity and mortality continue to inflict a substantial burden on healthcare systems worldwide. Similarly, in the tropical island of Mauritius, 13,320 hospital admissions and 8.2% mortality rates were attributed to RTD solely in the year 2013. Consequently, the therapeutic benefits and relief experienced with traditional medicine (TM) against RTD by the local inhabitants cannot be underestimated. The present study aims to report and quantitatively determine the extent of utilization of plant based therapies and other miscellaneous TM preparations concocted against RTD over the island. Additionally, a similarity index was generated which is indicative of the extent of harmonisation of individual plant species against RTD when the uses mentioned in the study are compared to previous ethnobotanical studies.

MATERIALS AND METHODS

Data was compiled using a semi-structured questionnaire via face-to-face interviews with TM users and practitioners (n=384). Three quantitative ethnopharmacological indices (the use value (UV), informant consensus factor (ICF), and ethnobotanicity index (EI)) were calculated. We also calculated the similarity ratio, similarity percentage, new uses for each plant species and percentage of new use against RTD to compare primary data collected in the present study.

RESULTS

Fifty five plants were documented to be in use against 18 RTD. The most used plant species belonged to the following taxa; Lamiaceae (9%), Fabaceae (7%) and Rutaceae (7%). Thirty two plants recorded in this study have been reported to be used against RTD in previous ethnobotanical studies, of which 22 of these plants have been attributed new uses against RTD based on the results of the present study. The remaining 23 plants species have been recorded for the first time to be used traditionally against RTD. Altogether, 81 different recipes were concocted from the medicinal plants and the most common route of administration was oral intake. Common methods of obtaining medicinal plants were from the wild, cultivation and as imported herbal products. Cough was the most common RTD managed by plant species. The largest proportion of plants were employed against cold. The preference ranking both for UV placed Curcuma longa L., Zingiber officinale Roscoe, Citrus×limonia Osbeck and Cymbopogon citratus (DC.) Stapf as the most useful plant species. Only a small proportion of the indigenous plants (7.73%) proved to be useful in TM.

CONCLUSION

This study provides empirical primary ethnopharmacological data on the use of TM to manage and/or treat RTD and can contribute in preserving indigenous knowledge in Mauritius. It is anticipated that these primary data will open new avenues to identify novel drugs that can help to alleviate sufferings.

Ethnobotanical study of Loloh: Traditional herbal drinks from Bali (Indonesia)

ETHNOPHARMACOLOGICAL RELEVANCE

Loloh are herbal drinks produced and consumed exclusively in Bali (Indonesia) to prevent and treat different ailments. This is the first study to document plants species used as Loloh, reporting the phytochemical components and pharmacological properties of the most cited plants. Documenting the plants used in herbal drinks in Bali by local communities to treat various ailments (providing some information on phytochemistry and pharmacology of the most interesting plants).

MATERIALS AND METHODS

Ethnobotanical data were obtained through semi-structured interviews (individual and group discussions) and questionnaires. Plant specimens were collected, identified and made into herbarium vouchers.

RESULTS

A total of 51 plants species (belonging to 32 families) have been documented for their use in the various preparation of Loloh. Different plants and plant parts are used to prepare Loloh to treat heartburn, fever, diarrhea, hypertension, aphthous stomatitis (canker sores), and other minor health problems. These plants are mainly prepared as decoctions, are juiced or simply added to the preparation. The most cited plants (>30 informants) are Alstonia scholaris (L.) R. Br., Blumea balsamifera (L.) DC., Cinnamomum burmanni Nees ex Bl., and Piper betle L. These plants are well studied with multiple demonstrated pharmacological activities (e.g., antimicrobial, anticancer, antidiabetic).

CONCLUSION

The Balinese communities still preserve a rich ethnobotanical knowledge. Several species are well known for their pharmacological properties, but some [such as Pneumatopteris callosa (Blume) Nakai and Dendrocnide stimulans (L. f.) Chew] are understudied and could be promising candidates for further research.

Piper betle leaves: profiling phenolic compounds by HPLC/DAD-ESI/MS(n) and anti-cholinesterase activity

INTRODUCTION

Piper betle L. is a widely distributed plant in the tropical and subtropical regions, its leaves being largely consumed as a masticator and mouth freshener.

OBJECTIVE

The purposes of this work were to characterise the phenolic profile of this species and to improve knowledge of its anti-cholinesterase properties.

METHODS

The phenolic composition of P. betle leaf aqueous and ethanol extracts was characterised by HPLC coupled with a diode-array detector and combined with electrospray ionisation tandem MS, and in vitro cholinesterase inhibitory capacity of both extracts was assessed by spectrophotometric microassays. The effect on neuronal cells (SH-SY5Y) viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction and lactate dehydrogenase leakage.

RESULTS

Twelve phenolic compounds, comprising a phenylpropanoid, five cinnamoyl and six flavonoids derivatives were identified in P. betle leaves. Hydroxychavicol was the major compound in both extracts; however, the aqueous extract presented a greater diversity of compounds. Both extracts showed strong activity against both acetyl- and butyrylcholinesterase, which can be due, at least partially, to the phenolic composition. Furthermore, the aqueous extract proved to be cytotoxic to human neuroblastoma cells at concentrations higher than 500 µg/mL.

CONCLUSION

The results suggest that the consumption of P. betle leaves as an infusion can have a positive impact in the prevention and treatment of neurodegenerative diseases. Apigenin and luteolin derivatives are reported for the first time in this species.

The phytochemistry, traditional uses and pharmacology of Piper Betel. linn (Betel Leaf): A pan-asiatic medicinal plant

Since antiquity, Piper betel. Linn, commonly known as betel vine, has been used as a religious, recreational and medicinal plant in Southeast Asia. The leaves, which are the most commonly used plant part, are pungent with aromatic flavor and are widely consumed as a mouth freshener. It is carminative, stimulant, astringent and is effective against parasitic worms. Experimental studies have shown that it possess diverse biological and pharmacological effects, which includes antibacterial, antifungal, larvicidal, antiprotozal, anticaries, gastroprotective effects, free radical scavenging, antioxidant, anti-inflammatory hepatoprotective, immunomodulatory, antiulcer and chemopreventive activities. The active principles hydroxychavicol, allylpyrocatechol and eugenol with their plethora of pharmacological properties may also have the potential to develop as bioactive lead molecule. In this review, an attempt is made to summarize the religious, traditional uses, phytochemical composition and experimentally validated pharmacological properties of Piper betel. Emphasis is also placed on aspects warranting detail studies for it to be of pharmaceutical/clinical use to humans.

Effect of Sameera Pannaga Rasa (arsenomercurial formulation) in the management of Tamaka Shwasa (bronchial asthma) - Randomized double blind clinical study

Asthma represents a profound world-wide public health problem. The most effective anti-asthmatic drugs currently available include β2-agonists and glucocorticoids which can controls asthma in about 90-95% of patients. In Ayurveda, this miserable condition is comparable with Tamaka Shwasa type of Shwasa Roga. In the present study, 52 patients were treated with Sameera Pannaga Rasa at a dose of 30 mg twice a day for 4 weeks along with Nagavallidala (leaf of Piper betel Linn.) The results were assessed in terms of clinical recovery, symptomatic relief, pulmonary function improvement and on subjective and objective parameters. A significant improvement in subjective parameters, control on asthma, recurrence of asthma, increase in peak expiratory flow rate, considerable decrease in total and absolute, acute eosinophil count and erythrocyte sedimentation rate were observed. Overall marked improvement was found in 33.33%, moderate improvement in 44.44% and mild improvement in 20.00% was observed. The study reveals that Sameera Pannaga Rasa can be used as an effective drug in bronchial asthma.

Piper nigrum, Piper betle and Gnetum gnemon--natural food sources with anti-quorum sensing properties

Various parts of Piper nigrum, Piper betle and Gnetum gnemon are used as food sources by Malaysians. The purpose of this study is to examine the anti-quorum sensing (anti-QS) properties of P. nigrum, P. betle and G. gnemon extracts. The hexane, chloroform and methanol extracts of these plants were assessed in bioassays involving Pseudomonas aeruginosa PA01, Escherichia coli [pSB401], E. coli [pSB1075] and Chromobacterium violaceum CV026. It was found that the extracts of these three plants have anti-QS ability. Interestingly, the hexane, chloroform and methanol extracts from P. betle showed the most potent anti-QS activity as judged by the bioassays. Since there is a variety of plants that serve as food sources in Malaysia that have yet to be tested for anti-QS activity, future work should focus on identification of these plants and isolation of the anti-QS compounds.

Exoproteome and secretome derived broad spectrum novel drug and vaccine candidates in Vibrio cholerae targeted by Piper betel derived compounds

Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC) for most of the pathogenic Vibrio strains. Two targets (uppP and yajC) are novel to Vibrio, and two targets (uppP and ompU) can be used to develop both drugs and vaccines (dual targets) against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species.

Piper betle shows antioxidant activities, inhibits MCF-7 cell proliferation and increases activities of catalase and superoxide dismutase

BACKGROUND

Breast cancer is the most common form of cancer and the focus on finding chemotherapeutic agents have recently shifted to natural products. Piper betle is a medicinal plant with various biological activities. However, not much data is available on the anti-cancer effects of P. betle on breast cancer. Due to the current interest in the potential effects of antioxidants from natural products in breast cancer treatment, we investigated the antioxidant activities of the leaves of P. betle and its inhibitory effect on the proliferation of the breast cancer cell line, MCF-7.

METHODS

The leaves of P. betle were extracted with solvents of varying polarities (water, methanol, ethyl acetate and hexane) and their phenolic and flavonoid content were determined using colorimetric assays. Phenolic composition was characterized using HPLC. Antioxidant activities were measured using FRAP, DPPH, superoxide anion, nitric oxide and hyroxyl radical scavenging assays. Biological activities of the extracts were analysed using MTT assay and antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) assays in MCF-7 cells.

RESULTS

Overall, the ethyl acetate extract showed the highest ferric reducing activity and radical scavenging activities against DPPH, superoxide anion and nitric oxide radicals. This extract also contained the highest phenolic content implying the potential contribution of phenolics towards the antioxidant activities. HPLC analyses revealed the presence of catechin, morin and quercetin in the leaves. The ethyl acetate extract also showed the highest inhibitory effect against the proliferation of MCF-7 cells (IC50=65 μg/ml). Treatment of MCF-7 cells with the plant extract increased activities of catalase and superoxide dismutase.

CONCLUSIONS

Ethyl acetate is the optimal solvent for the extraction of compounds with antioxidant and anti-proliferative activities. The increased activities of catalase and superoxide dismutase in the treated cells could alter the antioxidant defense system, potentially contributing towards the anti-proliferative effect. There is great potential for the ethyl acetate extract of P. betle leaf as a source of natural antioxidants and to be developed as therapeutics in cancer treatment.

Bacteriostatic effect of Piper betle and Psidium guajava extracts on dental plaque bacteria

In this study, the bacteriostatic effect of Piper betle and Psidium guajava extracts on selected early dental plaque bacteria was investigated based on changes in the doubling time (g) and specific growth rates (micro). Streptococcus sanguinis, Streptococcus mitis and Actinomyces sp. were cultured in Brain Heart Infusion (BHI) in the presence and absence of the extracts. The growth of bacteria was monitored periodically every 15 min over a period of 9 h to allow for a complete growth cycle. Growth profiles of the bacteria in the presence of the extracts were compared to those in the absence and deviation in the g and micro were determined and analyzed. It was found that the g and mu were affected by both extracts. At 4 mg mL(-1) of P. betle the g-values for S. sanguinis and S. mitis were increased by 12.0- and 10.4-fold, respectively (p < 0.05). At similar concentration P. guajava increased the g-value by 1.8- and 2.6 -fold, respectively (p < 0.05). The effect on Actinomyces sp. was observed at a much lower magnitude. It appears that P. betle and P. guajava extracts have bacteriostatic effect on the plaque bacteria by creating a stressed environment that had suppressed the growth and propagation of the cells. Within the context of the dental plaque, this would ensure the attainment of thin and healthy plaque. Thus, decoctions of these plants would be suitable if used in the control of dental plaque.

The n-hexane and chloroform fractions of Piper betle L. trigger different arms of immune responses in BALB/c mice and exhibit antifilarial activity against human lymphatic filarid Brugia malayi

Modulation of immune functions by using herbal plants and their products has become fundamental regime of therapeutic approach. Piper betle Linn. (Piperaceae) is a widely distributed plant in the tropical and subtropical regions of the world and has been attributed as traditional herbal remedy for many diseases. We have recently reported the antifilarial and antileishmanial efficacy in the leaf extract of Bangla Mahoba landrace of P. betle which is a female plant. The present report describes the in vivo immunomodulatory efficacy of the crude methanolic extract and its n-hexane, chloroform, n-butanol fractions of the female plant at various dose levels ranging between 0.3 and 500 mg/kg in BALB/c. Attempts were also made to observe antifilarial activity of the active extracts and correlate it with the antigen specific immune responses in another rodent Mastomys coucha infected with human lymphatic filarial parasite Brugia malayi. The crude methanol extract and n-hexane fraction were found to potentiate significant (p<0.001) enhancement of both humoral (plaque forming cells, hemagglutination titre) as well as cell-mediated (lymphoproliferation, macrophage activation, delayed type hypersensitivity) immune responses in mice. The flow cytometric analysis of splenocytes of treated mice indicated enhanced population of T-cells (CD4(+), CD8(+)) and B-cells (CD19(+)). The n-hexane fraction (3 mg/kg) was found to induce biased type 2 cytokine response as revealed by increased IL-4(+) and decreased IFN-gamma(+) T-cell population while the chloroform fraction (10 mg/kg) produced a predominant type 1 cytokines. Crude methanolic extract (100 mg/kg) demonstrated a mixed type 1 and type 2 cytokine responses thus suggesting a remarkable immunomodulatory property in this plant. The induction of differential T-helper cell immune response appears ideal to overcome immunosuppression as observed in case of lymphatic, filarial Brugia malayi infection which may also be extended to other infections as well.