Guava Extract Research Articles

“Comparative evaluation of cytotoxicity of three herbal endodontic irrigants at three intervals of time” – An in vitro study

Aim: The aim of the study was to evaluate and compare the cytotoxicity of 25% of neem leaf extract (Azadirachta indica), 20% of guava leaf extracts (Psidium guajava), and 20% of cinnamon extract (Cinnamomum zeylanicum) irrigants at three intervals of time. Methodology: Four groups were formed (n = 15), Group 1 (control group) – normal saline solution, Group 2 – 25% of neem extract, Group 3 – 20% of guava extract, and Group 4 – 20% of cinnamon extract. Each group was further divided into three subgroups based on intervals (n = 5). Subgroup A – at 10 min, Subgroup B – at 20 min, and Subgroup C – at 30 min. One hundred microliters of each irrigant was added to 2 mL of the diluted red blood cells suspension obtained from a human volunteer. Hemoglobin (Hb) estimation was done with an automated hematology analyzer after incubating the test samples at 10, 20, and 30 min intervals. Results: The reduction in the mean Hb values was not statistically significant in the normal saline, guava, and cinnamon groups. However, in the neem extract group, the mean Hb values reduced significantly at P < 0.001. Among the subgroups, Subgroup A (10 min) showed the least cytotoxicity. Conclusion: In the present study, 20% guava extract had the lowest cytotoxicity and cytotoxicity increased with time. Hence, 20% guava extract can be used as an alternative to conventional irrigants as it has been shown to have the least cytotoxicity.

Physical test and irritation test of water guava leaf extract (Syzygium aqueum) as a natural spray hand sanitizer

This study explores the manufacture of water guava (Syzygium aqueum) leaf extract-based hand sanitizers as an effective and safe natural alternative for maintaining hand hygiene. Given the importance of hand hygiene in preventing the spread of disease, especially amid the COVID-19 pandemic, the use of hand sanitizers has increased significantly. However, alcohol-based products are often irritating to the skin. Therefore, this study aims to evaluate the potential of water guava leaf extract to improve the effectiveness and convenience of hand sanitizers. Water guava leaves contain active compounds such as flavonoids, tannins, and phenolics with antibacterial and anti-inflammatory properties. The research method includes extracting water guava leaves, hand sanitizer formulation, and organoleptic, pH, homogeneity, and irritation testing. The tests carried out were physical tests, including organoleptic tests (shape, smell, and colour), pH, homogeneity, spreadability, adhesiveness, and product irritation tests. The research was designed with a posttest-only control group design with true experimental by analyzing the test object after being given treatment. This research is expected to produce products that are useful for the community. The results showed that all hand sanitizer formulas tested had a pH within the safe range of pH 5 for the skin without irritating the skin of the test animals. Formulas with added guava extract showed improved aroma and anti-irritation, with formulas F1 and F2 gaining the highest preference in aroma and colour. This study concludes that water guava leaf extract can be effectively used in the manufacture of hand sanitizers, providing a gentler and skin-friendly alternative to alcohol-based synthetic products.

Antimicrobial effects and phytochemical analysis of guava leaf extracts on selected microorganisms

The misuse of antimicrobial agents can lead to emergence of resistance to microbes which in turn can lead to the search for alternative therapy. The use of phytopharmaceuticals and herbal medicines have a positive impact and represents a promising alternative. Guava extract has been reported to have antimicrobial properties. However, the aim of this study was to determine the antimicrobial activities of methanol and ethanol extract of guava leave against some certain bacteria (Staphylococus aureus and Escherichia coli) and a fungus (Candida albicans). Qualitative phytochemical screening showed that phenols, tannins, saponins, terpenoids, flavonoids and glycosides are all present in the leaf extract; phenols and tannins are moderately present while others are present in minute quantities. Out of the different concentrations use (50, 100, 200 and 250), The highest concentration which is 250mg/ml showed the highest zone of inhibition for both methanolic and ethanolic extracts against the isolates. Minimum inhibitory concentration and Minimum Bactericidal Concentrations value for both S. aureus and E. coli are 200mg/ml and 250mg/ml respectively; while 50mg/ml and 100mg/ml are for Candida albicans.

Length-weight relationship and condition factor of Nile tilapia (Oreochromis niloticus) fed diets supplemented with guava and star gooseberry leaf extract

Background Nile tilapia (Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Methods Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. Results After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent “b” values in all the GLE, SGLE, and MxLE groups were >3, indicating a positive allometric growth pattern in Nile tilapia compared to the control (b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Conclusions Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

Comparative Antimicrobial Efficacy of Garlic and Guava Extracts on Oral Pathogens Using a Time Kill Assay: An In Vitro Study

Abstract Background: Periodontal disease is characterized by inflammation mediated by the host and related microbes, which leads to the loss of periodontal attachment and tooth loss. Due to an increase in bacterial resistance to antibiotics, there is a shift toward use of herbal medicines. Aim: The aim of the study is to compare the antimicrobial effect of aqueous garlic extract (AGE) and ethanolic guava extract (EGuE) on Tanerella forsythia and Porphyromonas gingivalis using the time kill assay Materials and Methods: AGE and EGuE are prepared. Ciprofloxacin was taken as the control. The MIC was performed for garlic, guava extract, and ciprofloxacin. P. gingivalis and T. forsythia were cultured, and the time kill assay was performed at 0 h, 5 min, 30 min, 1 h, and 2 h. Colonies were counted after 48–72 h for growth. Results: The minimal inhibitory concentration (MIC) results indicated that both EGuE and AGE exhibited superior antibacterial activity compared to ciprofloxacin, suggesting their potential as alternative or complementary antimicrobial agents. In a time kill assay, EGuE demonstrated a significant reduction in colony forming units (CFUs) at 30 min, 1 h, and 2 h, outperforming AGE and ciprofloxacin. Intragroup comparisons revealed that EGuE significantly reduced CFUs at 0 h and 5 min, while AGE showed no notable reduction over time. Conclusion: Overall, the study demonstrates the antimicrobial efficacy of EGuE and AGE against T. forsythia and P. gingivalis at higher concentrations. Hence, these extracts may serve as alternative antimicrobial agents against periodontal pathogens.

Analysis of gauze pad made from coconut tree fiber infused with guava derived phenolic compounds

Abstract Gauze pad wound dressing plays a crucial role in protecting the wound and preventing it from factors that can prolong the healing process. However, due to the porous nature of gauze pads, it cannot completely block microbes from getting into the wound. This study analyzes coconut tree fiber as a gauze pad infused with guava derived phenolic compounds, known for its antimicrobial and antioxidant properties. The research assesses the extract’s effectiveness, focusing on phenolic compounds, antioxidant properties, and antimicrobial effects. By employing the disk diffusion method against Staphylococcus aureus, the study reveals that both 50% and 30% extracts exhibit inhibitory activity, with mean zones of inhibition at 8.5 mm and 8.33 mm, respectively, showing the antimicrobial property for both 50% and 30% extracts. The samples also demonstrated notable DPPH radical scavenging capacities for concentrations ranging from 0.006 to 1.27 (%w/v) for the 50% extract sample and from 0.006 to 1.25 for the 30% extract sample, ranging from 1.98% to 68.5% and 7.94% to 69.5%, respectively, indicating antioxidant property for both samples. The researchers have determined that there is no significant difference (p-value = 0.9187, α = 0.05) between the scavenging activity of both 50% and 30% extract. Furthermore, a minimal disparity in total phenolics was observed, with the former containing 1.25 and the latter 1.24 weight percent gallic acid. To determine if there is any negative skin reaction, a patch test was conducted in collaboration with a dermatologist using Stanford Health Care Medicine Standard. The test revealed no adverse skin reactions after three days of no removal usage of the coconut tree fiber gauze pad infused with phenolic compounds, as compared to a commercially available gauze pad. This study underscores the promise of guava extract and its antibacterial properties, particularly against skin pathogens, and its safe application when integrated with coconut fiber. This combination holds potential as a natural antimicrobial agent with diverse applications.

GABA-fortified synbiotic guava beverage: formulation and evaluation of neuroprotective properties using cell-based assays

In recent years, the use of fermented fruit juices to offer protection against mental illness has been increasing enormously. The present study, aimed at formulating a synbiotic fruit beverage for mental well-being using fructo-oligosaccharide (FOS), Gamma-aminobutyric acid (GABA) and Lactobacillus rhamnosus. Guava extract (abbreviated as fruit extract, FE; 10%) supplemented with FOS (1%) fermented for 48 h using L. rhamnosus, was then fortified with 0.05% GABA (FE + FOS + GABA). This GABA-fortified fermented guava beverage exhibited significant in-vitro antioxidant activity as measured by using 2,2-diphenyl-1-picrylhydrazyl (IC50 value of 0.451 ± 0.05 mg/ml) and ferrous reducing antioxidant capacity (A700 nm value of 0.68 ± 0.06) assays. Fermentation also enhanced total phenolics and flavonoids by 27.63% and 27.41%, respectively. Furthermore, GABA-fortified fermented guava beverage showed a significant neuroprotective effect by negatively modulating oxidative stress and upregulating activity of antioxidant enzymes (superoxide dismutase and catalase) in rotenone treated neuronal cell lines. Taken together, our research findings clearly indicate the propensity of GABA-fortified fermented guava beverage to protect against rotenone mediated neuronal cell damage. Even though the underlying molecular mechanisms need further research, in conclusion, our study demonstrates that the GABA-fortified fermented guava beverage effectively confers neuroprotective effects in vitro, suggesting its potential as a functional beverage for promoting brain health.Graphical

Length-weight relationship and condition factor of Nile tilapia ( Oreochromis niloticus) fed diets supplemented with guava and star gooseberry leaf extract.

Nile tilapia ( Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent " b" values in all the GLE, SGLE, and MxLE groups were >3, indicating a positive allometric growth pattern in Nile tilapia compared to the control ( b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

Karakteristik Kimia dan Daya Simpan Susu Kambing Pasteurisasi dengan Penambahan Ekstrak Jambu Biji Merah (Psidium guajava L.)

The aim of this research is to analyze the effect of adding red guava extract on the chemical characteristics and shelf life of pasteurized goat milk with the addition of red guava extract (Psidium guajava L). This research was carried out using an experimental method using a completely randomized design consisting of 5 treatments and 4 replications. Chemical characteristics were carried out using quantitative descriptive methods. The treatment used was the addition of 0%, 3%, 6%, 9% and 12% red guava extract. The research results showed that the chemical characteristics of pasteurized goat's milk with the addition of red guava extract were the highest water content at P4, 82.91% and the lowest at P3, namely 81.32%, the highest ash content at P1, 1.01% and the lowest at P4, namely 0 .76%, the highest protein content at P1 3.65% and the lowest at P3, namely 3.14%, the highest fat content at P0 4.73% and the lowest at P4, namely 4.32%, the highest carbohydrate content at P3 10.28 % and the lowest was in P4, namely 8.74%, and the highest vitamin C level was in P4, 35.03 mg/100g and the lowest was in P1, namely 26.29 mg/100g. The shelf life of goat milk at 11°C at P0, P1 and P2 is up to 5 days of storage, while for P3 and P4 it can be stored for 3 days. The conclusion is that P1 is the best treatment in producing the chemical characteristics of pasteurized goat's milk, while P4 is the treatment that produces the highest levels of vitamin C.

Gel Formulations of Guava Leaves (Psidium Guajava L) Leaves Ethanol Extract As a Wound Healing Of Burns in Rabbits

The ethanol extract of guava leaves (Psidium guajava L) in previous studies was known to have antiburn, antiinflammatory, antidiarrhea and antibacterial activity. The preparations made are gel preparations which are preferred by the public. The purpose of this study was to determine the activity of guava leaf ethanol extract gel and its effective concentration in healing burns in rabbits. The research method uses rabbits 4 tails made 5 wounds on the back, consisting of negative control, comparison (Bioplacenton®), gel preparations 3%, 5%, and 11%. Wound diameter measurements were carried out on days 3, 6, 9, 12, 15 and 18. The parameters observed were the size of the wound diameter, wound healing such as wound drying, scab formation, closure of the wound and the growth of new hair around the wound. An inflammatory process occurs for 3 days after injury and not processed wound healing. Fibroblasts appeared on day 6 and peaked on day 9, so that on day 9 all treatment and control groups experienced linear healing. On the 9th day the fibroblasts began to peel off on the skin indicating the group has reached the peak of the proliferation phase and wound contractions occur gradually urgent. The results of the guava leaf extract gel activity test (Psidium guajava L) showed a concentration of 11% gave the best effect.

Probiotic Yogurt Supplemented with Lactococcus lactis R7 and Red Guava Extract: Bioaccessibility of Phenolic Compounds and Influence in Antioxidant Activity and Action of Alpha-amylase and Alpha-glucosidase Enzymes.

The industry has increasingly explored the development of foods with functional properties, where supplementation with probiotics and bioactive compounds has gained prominence. In this context, the study aimed to evaluate the influence of in vitro biological digestion on the content of phenolic compounds, antioxidant activity, and inhibition of α-amylase and α-glucosidase activities of probiotic yogurt supplemented with the lactic acid bacteria Lactococcus lactis R7 and red guava extract (Psidium cattleianum). A yogurt containing L. lactis R7 (0.1%) and red guava extract (4%) was characterized for the content of phenolic compounds, antioxidant activity, and potential for inhibition of digestive enzymes after a simulated in vitro digestion process. After digestion, the caffeic and hydroxybenzoic acids remained, and sinapic acid only in the last digestive phase. Antioxidant activity decreased during digestion by 28.93, 53.60, and 27.97% for DPPH, nitric oxide and hydroxyl radicals, respectively, and the inhibition of the α-amylase enzyme decreased only 4.01% after the digestion process. α-glucosidase was more efficient in intestinal digestion, demonstrating an increase of almost 50% in probiotic yogurt with red guava extract before digestion. Possibly, the phenolics change their conformation during digestion, generating new compounds, reducing antioxidant activity, and increasing the inhibitory activity of α-glucosidase digestive enzymes. It was concluded that the probiotic yogurt formulation supplemented with red guava extract could interfere with the concentration of phenolic compounds and the formation of new compounds, suggesting a positive and effective inhibition of the digestive enzymes, even after the digestive process.

Uji Efektivitas Ekstrak Daun Jambu Biji (Psidium guajava) dalam Menurunkan Kadar Gula Darah Mencit (Mus musculus)

Diabetes mellitus is a disorder of blood sugar metabolism chronically characterized by high blood sugar levels resulting from impaired insulin secretion, insulin resistance, or both. Treatment of diabetes mellitus consists of four pillars: education, medical nutrition therapy (MNT), and physical and pharmacological therapies. One of the plants that can be used as a medicinal ingredient is guava leaves. Guava (Psidium guajava L.) leaves are a group of herbal plants with a chemical content that is good for health. Therefore, guava (Psidium guajava L.) leaves are plants that are efficacious as medicine. This plant contains secondary metabolites that act as antidiabetics. Thus, the research aimed to determine the effectiveness of ethanol extract of guava (Psidium guajava L.) leaves on the decrease in blood sugar levels in male mice. The research method employed was maceration, phytochemical screening, and antidiabetic testing with the pre-test and post-test control group design methods to determine if there was a decrease after administration of the extract. The findings indicated that the phytochemical screening test found that guava (Psidium guajava L.) contained secondary metabolites, including alkaloids, flavonoids, and tannins. In contrast, the antidiabetic test revealed that three extracts with concentrations of 50 mg, 100 mg. and 200 mg could decrease blood sugar levels by 15%, 21%, and 47%, respectively. From these findings, it can be concluded that antidiabetic compounds which play a role in the ellanol extrict of guava (Psidium guajava L.) leaves are alkaloids, flavonoids, and tannins.

Guava (Psidium guajava L.) extract inhibits cytokine storm in acute respiratory distress syndrome rats model

Guava (Psidium guajava L.) extract inhibits cytokine storm in acute respiratory distress syndrome rats model

Anti-Arthritis, Antioxidant and Anti - Inflammatory Potential of Ethanolic Extract of Guava Leaves on Rats Exposed to High Fat Diet and Freud Adjuvant

Guava leaves (Psidium guajava) have been used traditionally for years to treat common ailments such as Diabetes, diarrhoea, and hypertension. This study was designed to determine the anti-arthritic, anti-inflammatory, and antioxidant effect of the ethanolic extract of guava leaf (Psidium guajava) on rats fed with a high-fat diet and induced arthritis using complete Freud Adjuvant. Seventy-two male and female albino rats were used in this study, the rats were grouped into 12 with 6 rats in each group, rats were fed a high-fat diet to cause hyperlipidaemia and induced rheumatoid arthritis by injecting 0.1ml of Complete Freund’s Adjuvant into their right hind paw. Group 1 was fed with normal feed and water, group 2 was made of healthy rats, fed with normal feed, water, and guava leaf extract, group 3 was fed with a high-fat diet and induced arthritis with complete Freund’s Adjuvant (CFA) and water, group 4 received dexamethasone (6.75 mg.kg-1 orally), and groups 5 to 12 received the extract at oral doses of 250 and 750 mg/kg, respectively for a period of 28days. ELISA technique was used to analyse the inflammatory markers, antioxidants; SOD, and MDA, while the lipid profile was on a spectrophotometer. The inflammatory markers TNF-α, IL-6, and C-reactive protein were significantly reduced in test subjects at p<0.05, HDL and SOD had no statically significant difference, while MDA was markedly reduced at p<0.05. This study demonstrates that Psidium guajava extract has significant anti-arthritic and lipid-lowering effects. Psidium guajava leaves can be developed into an alternative anti-arthritis and lipid-lowering treatment.

Evaluasi Tingkat Kesukaan Terhadap Sifat Organoleptik Susu Kambing Pasteurisasi Yang Diberi Berbagai Tingkat Ekstrak Jambu Biji Merah (Psidium guajava L.)

The aim of this research is to analyze the effect of adding red guava extract on the level of consumer preference for organoleptic properties including color, aroma, viscosity level, taste and taste of pasteurized goat's milk. This research used an experimental method with a Completely Randomized Design (CRD) pattern consisting of 5 treatments and 4 replications. The treatment used was the addition of red guava extract (P0= milk without red guava extract, P1= milk + 3%, P2= milk + 6%, P3= milk + 9% and P4 milk + 12%). The data obtained were analyzed using analysis of variance (ANOVA) and if the results of the anova test showed that there were significant differences, Duncan's further test was carried out. The results of the research showed that the addition of red guava extract to the manufacture of pasteurized goat's milk had an effect on the level of preference for organoleptic characteristics (color, viscosity level, aroma, flavor and taste). The best counter treatment is the addition of 6% red guava extract with the criteria of yellowish white color, pleasant aroma, light viscosity, sweet taste, slightly savory taste and a liking level of slightly like to like. 6% red guava extract produced the best level of favorability.

Effect of Different Concentrations of Propylene Glycol and Glycerin on the Formulation of Guava Leaf (Psidium Guajava Linn.) Body Scrub with White Rice (Oryza sativa Linn.)

Guava leaves (Psidium guajava Linn.) have contents such as saponins, essential oils, tannins and anti-mutagenic and antioxidants which are ingredients that can reduce free radicals to cells. White rice (Oryza sativa Linn.) is a material that can be used as an abrasiver. Besides being easy to find, white rice also has a relatively cheap price, compared to brown rice or others. This study aims to determine the ethanol extract of guava leaves with white rice can be formulated and the effect of glycerine-propylenglycol in the preparation of body scrub cream with each concentration of 1%, 3%, and 5% and vice versa 5%, 3%, and 1% which are made in 3 formulas. The results obtained from the evaluation of the preparation are: Organoleptical test FI (green), FII and FIII (brown). Homogeneity test obtained by the three formulas is homogeneous, pH test obtained that all formulas meet the pH requirements of 4.5 - 6.5. The spreadability test obtained results in FI (3.1 cm), FII (3.2 cm), FIII (3.0 cm). As for the determination of the type (type) of emulsion obtained that all formulas have type m/a.

The Potential of Ethanol Extract of Guava (Psidium guajava L.) Leaves as Adjuvant-Antibiotic on Salmonella typhi Characterized

The Potential of Ethanol Extract of Guava (Psidium guajava L.) Leaves as Adjuvant-Antibiotic on Salmonella typhi Characterized

The Effects of Fresh Fruit Extracts and Commercially Available Fruit Extracts on the Growth of Streptococcus mutans — An In Vitro Study

Resistance of antibiotics towards pathogenic microorganisms has led to the continuous search of natural plant products as a potential alternative for synthetic antibiotic agents. Many plant produces have shown promising results towards this end. This has led to commercialization and packaging of plant produce especially fruits. However, much research needs to be conducted to assess the potential benefits of commercially available plant produce compared to the natural ones. Consumable food items have both positive and bad effects, and their antibacterial effects on various microorganisms found in the oral cavity are good. To comparatively evaluate the effects of fresh fruit extracts and commercially available juice of Apple, Guava and Pomegranate on the growth of Streptococcus mutans. The present study describes the antibacterial activity of three selected fresh fruit extract and their commercial counterparts (Apple, Pomegranate and Guava) on Streptococcus mutans. Antimicrobial activity of fruit juices (fresh and commercial) was tested by well diffusion assay by an inhibition zone surrounding the well. The aim of the study was to comparatively evaluate the antibacterial activity of three fruit juices on Streptococcus mutans. Analysis of the results revealed the highest antibacterial activity for Fresh fruit extract of Guava towards Streptococcus mutans with a mean diameter of inhibition zone (DIZ) value of 11.26 ± 0.53(P>0.01) and the least was exhibited for commercial juice of pomegranate with a mean diameter of inhibition zone (DIZ) 2.20 ± 0.25 (P>0.01). The results obtained in this study clearly demonstrated a significant antimicrobial effect of fresh fruit extract of guava against Streptococcus mutans. However, preclinical and clinical trials are needed to evaluate biocompatibility and other effects, but in vitro observation of fresh fruit extracts of selected fruits appears promising. Keywords: Antimicrobial, Fruit Juice, Microorganism, Agar well diffusion method, Apple (Malus domestica), Psidium guajava, Pomegranate (Punica granatum)

Antimicrobial Activity of Psidium guajava Aqueous Extract against Sensitive and Resistant Bacterial Strains.

The inappropriate use of antimicrobials, along with environmental conditions, can lead to the emergence of resistant microorganisms. The use of phytopharmaceuticals and herbal medicines has a positive impact and represents a promising alternative. Psidium guajava extracts have been widely reported to have antimicrobial potential; however, studies reporting their activity against resistant bacterial strains are scarce. Because of the emerging resistance, the aim of this study was to analyze the antimicrobial capacity of the aqueous extract of guava leaves against wild-type and resistant bacterial strains. The aqueous extract obtained from the leaves of P. guajava was evaluated by HPLC for the content of total phenolics and tannins, antioxidant activity, and chemical composition. The antimicrobial activity of the extracts was analyzed by the disk diffusion and broth microdilution methods. The results of the chemical analysis of the extracts showed total phenolics content of 17.02 ± 6.87 mg/g of dry extract, total tannin content of 14.09 ± 1.20 mg of tannic acid equivalents/g of dry extract, and moderate antioxidant capacity with an EC50 value of 140 µg/mL. Flavonoids are the major compounds (rutin, hesperidin, and quercetin), followed by phenolic acids. Disk diffusion test results showed the presence of inhibition halos for Gram-positive bacteria (Staphylococcus aureus, sensitive and resistant; Staphylococcus pseudintermedius, sensitive and resistant; and Streptococcus spp., beta-hemolytic), while for Gram-negative bacteria (Escherichia coli, sensitive and resistant), there was no inhibition in the tested concentration range. The Minimal Inhibitory Concentration was 6.8 mg/mL for all Gram-positive strains evaluated. The present study demonstrated the antimicrobial activity of the aqueous extract of P. guajava against sensitive and resistant Gram-positive bacteria. The better antimicrobial activity found in the present study compared with previously reported activity should be highlighted and may be related to the higher concentration of total phenolics present in the tested extract. Moreover, the content of tannins found suggests a species with high quality that produces tannins. These new findings suggest an innovative profile regarding therapeutic resources that can be adopted to combat resistant microbial strains.

Psidium guajava L.- dichloromethane and ethyl acetate fractions ameliorate striped catfish (Pangasianodon hypophthalmus) status via immune response, inflammatory, and apoptosis pathways.

Psidium guajava L. is known to possess immune-modulatory properties in humans and other mammals. Although the positive effects of P. guajava-based diets on the immunological status have been shown for some fish species, the underlying molecular mechanisms of its protective effects remain to be investigated. The aims of this study were to evaluate the immune-modulatory effects of two guava fractions from dichloromethane (CC) and ethyl acetate (EA) on striped catfish with in vitro and in vivo experiments. Striped catfish head kidney leukocytes were stimulated with 40, 20, 10 and 0μg/ml of each extract fraction, and the immune parameters (ROS, NOS, and lysozyme) were examined at 6 and 24h post stimulation. A final concentration of each fraction at 40, 10 and 0 μg/fish was then intraperitoneally injected into the fish. After 6, 24, and 72h of administration, immune parameters as well as the expression of some cytokines related to innate and adaptive immune responses, inflammation, and apoptosis were measured in the head kidney. Results indicated that the humoral (lysozyme) and cellular (ROS and NOS) immune endpoints were regulated differently by CC and EA fractions depending on dose and time in both, in vitro and in vivo experiments. With regards to the in vivo experiment, the CC fraction of the guava extract could significantly enhance the TLRs-MyD88-NF-κB signaling pathway by upregulating its cytokine genes (tlr1, tlr4, myd88, and traf6), following the upregulation of inflammatory (nfκb, tnf, il1β, and il6) and apoptosis (tp53 and casp8) genes 6h after injection. Moreover, fish treated with both CC and EA fractions significantly enhanced cytokine gene expression including lys and inos at the later time points - 24h or 72h. Our observations suggest that P. guajava fractions modulate the immune, inflammatory, and apoptotic pathways.