Analysis of the chemical composition of root essential oil from Indian sarsaparilla (Hemidesmus indicus) and its application as an ecofriendly insecticide and pharmacological agent

GC-MS analysis and nutra-pharmaceutical potential of Mentha piperita essential oil extracted by supercritical fluid extraction and hydro-distillation

This study reports the comparative evaluation of yield, physico-chemical composition and biological attributes (antioxidant activity, antimicrobial activity, biofilm inhibition and hemolytic activity) of peppermint (Mentha piperita L.) essential oil (EO) obtained by hydro-distillation (HD) and supercritical fluid (CO2) extraction (SCFE) methods. The yield (%) of EO obtained by HD (0.20 %) was significantly (p < 0.05) higher than that of SCFE (0.13 %) while the variation in the physical parameters like solubility, color, density (at 25 °C) and refractive index (at 25 °C) was not significant between the tested oils. The data of chemical compositional analysis revealed that menthol was the key component in the EO obtained by HD (52.85 %) and SCFE (45.51 %), followed by menthone [HD (25.93 %) and SCFE (27.3 %)] and eucalyptol [HD (8.59 %); SCFE (8.92 %)]. The EO extracted with supercritical fluid (SCFE-EO) exhibited superior (p < 0.05) DPPH free radical inhibition potential (52 %) with an IC50 value of 15.65 μg/mL and reducing power compared to that of HD-EO. The highest antimicrobial activity was exhibited by SCFE-EO against Pasturella multocida with an inhibition zone of 18.00 mm (MIC value of 86 μg/mL). The results of biofilm inhibition and hemolytic activity revealed that the SCFE method was superior to recover high quality EO in comparison to the HD method. The peppermint EO obtained by SCFE, owing to potent bioactive components, can be a potential candidate to develop nutra-pharmaceuticals.

Insecticidal property of Ocimum essential oil embedded polylactic acid packaging films for control of Sitophilus oryzae and Callosobruchus chinensis

Naturally derived essential oils (EOs) from Ocimum basilicum (OB) and Ocimum gratissimum (OG) were incorporated in polylactic acid (PLA) matrix with concentration of 2.5 % and 5 % respectively by solvent casting method, with an aim to develop insecticidal polymer pouches (insect proof polymer pouches). The major components following GC-MS analysis revealed the presence of EOs as estragole (69.998 %) in OB and thymol (29.843 %) in OG. The developed films with EOs showed remarkable insecticidal activity with 100 % and 80 % mortality rate for OB and OG respectively at 2.5 % concentration against rice weevil (Sitophilus oryzae). While, both OB and OG EOs observed 100 % mortality against pulse beetle (Callosobruchus chinensis) after 96 h exposure in presence of grain conditions and the insecticidal efficacy was equivalent to the commercial hermetic bags (CSB). The physical property of film showed increase in the film thickness in EO-PLA films whereas the mechanical properties of EO-PLA films matrix have increased the polymer flexibility with decreasing tensile strength (TS) and Youngs modulus (EM) as TS OB 5 %, OG 5 % - 15.64 MPa, 17.66 MPa respectively. While, water vapour transmission rate (WVTR) was reduced to 0.015 g/m2.hr, optical characteristics showed slight significant change in colour and FTIR spectra exhibited a change in -OH stretching compared to blank PLA matrix. The surface morphology of the blank and EO embedded PLA films visualized by SEM depicted a complete homogenization of essential oils in the PLA matrix.

New combination of drugs to combat Escherichia coli DSM1103 QCDSM by reducing antibiotic ciprofloxacin standard dose using response surface methodology

BACKGROUND

Microbial diseases are emerged as a concern for the global health and are responsible for increased mortality among different age groups. It is therefore essential to control the microbial population with novel antimicrobial agents. Antibiotic-phytochemicals mixtures are used for improving the antibacterial efficiency against bacterial pathogens to decrease their microbial resistance development. This study compared the inhibitory potentials of ciprofloxacin antibiotic and phytochemical mixtures of Syzygium aromaticum (clove), Allium sativum (garlic) and Cinnamomum verum (cinnamon) against Escherichia coli DSM1103 QCDSM using Minimal inhibitory concentrations (MICs) and Bactericidal inhibitory concentrations (MBCs) methods.

OBJECTIVE

Inhibitory activity of ciprofloxacin and three oil plant extracts of the selected plants (clove, garlic, cinnamon) were tested against E. coli DSM1103 QCDSM using well diffusion method on Muller-Hinton agar plates by studying MIC and MBC tests. The software "Design Expert® 12" Stat-Ease was used to analyze the experimental mixture design.

RESULTS

A mixture design of twenty mixture combination runs using different concentration levels of ciprofloxacin and the three oil plants extracts were performed against E. coli DSM1103 QCDSM growth. Results revealed that the standard recommended ciprofloxacin dose 5 μg/100 ml may be replaced by the oil extracts of S. aromaticum 4.75 % (v/v), A. sativum 5.0% (v/v), C. verum 5.0%(v/v) and ciprofloxacin 0.25% (w/v) as alternative drugs.

CONCLUSION

The proposed mixture containing Syzygium aromaticum (clove), Allium sativum (garlic) and Cinnamomum verum (cinnamon) was found to be an effective antimicrobial agent and may signifies the role of traditional knowledge in drug discovery.

Chemical Composition of Cinnamomum verum Leaf and Flower Essential Oils and Analysis of Their Antibacterial, Insecticidal, and Larvicidal Properties

Cinnamomum verum is widely used in traditional medicines, and the different parts of the plant, such as bark, leaves, and flowers, are used for essential oil production. The present study compared the chemical composition of the essential oil of C. verum extracted from the leaves and flowers. In addition, efficacy of these essential oils against the two common pests Sitophilus oryzae and Callosobruchus maculatus was also evaluated. The results indicated the presence of cinnamaldehyde, eugenol, caryophyllene, and linalool in these essential oils, however, at different concentrations. The leaf essential oil was found to be 10-20% more effective as a fumigant against both the pests. Likewise, the leaf essential oil found to repel these pests even at lower concentrations than that of flower essential oil of C. verum. Besides, these essential oils were also effective in controlling the growth of various gram positive and gram negative microbial pathogens and possibly a safeguard for human health. On contrary, both the essential oils were found to be safe for the application on grains, as indicated by their germination potentials. It was also observed that these essential oils do not cause any significant toxicity to guppy fishes, thus confirming their ecological safety for use as a biopesticide.

Antimicrobial and anti-biofilm activities of polyphenols extracted from different Saudi Arabian date cultivars against human pathogens

BACKGROUND

Microbial diseases have emerged as a serious threat to the healthcare system globally and also in Saudi Arabia; various diseases are associated with higher mortality and increased spreading rates. Dietary sources are often entertained to improve the immune system of the body to fight against these infections. The date fruit (Phoenix dactylifera L) is one such functional food that is less explored for its actual potentials.

METHODS

The polyphenols isolated from the different cultivars of dates in Saudi Arabia (Ajwa, Safawi, Khalas, and Sukkary) was evaluated for their antibacterial, anti-fungal and anti-biofilm forming abilities. The anti-radical properties of the phenolic extract were conducted in terms of the scavenging of diphenyl-1-picrylhydrazyl radical, hydrogen peroxide radicals and ABTS radicals. The anti-inflammatory potential was analyzed in terms of lipoxygenase activity inhibition.

RESULTS

The phenolic compounds of different dates were spectrophotometrically estimated and cultivars such as Ajwa and Sukkary had the highest polyphenol content. It was also noteworthy that they exerted potent antibacterial activities against Staphylococcus aureus, Streptococcus pyogenes, and Pseudomonas aeruginosa as estimated by the least minimal inhibitory concentration (MIC) or minimal bactericidal concentration (MBC) values. Besides, these polyphenols reduced the biofilm formation by these bacterial pathogens; it is thus possible that the polyphenols from dates can be a promising antimicrobial agent against various pathogenic strains. Corroborating with these, the polyphenol extracts from different Saudi Arabian dates were found to inhibit the growth of mycelium in strains of Candida albicans and Aspergillus niger. Apart from these, the polyphenol isolates also exhibited significant anti-radical properties against different reactive radical systems.

CONCLUSION

Overall, the efficacy of phenolic compounds extracted from the dried date fruits are not only restricted to the functional food features; instead, these molecules are capable of preventing the growth of microbial pathogens of humans. Hence, it may emerge as potent antibacterial, anti-fungal and anti-biofilm forming candidates.