Susceptibility of biofilm forming Pseudomonas aeruginosa and Staphylococcus aureus to antibiotic-adjuvants

Aims@#The objective of the present study is to evaluate the possibility of reversing the resistance of pathogens to antibiotics using phytochemicals from plant extracts as antibiotic-adjuvant.@*Methodology and results@#Twenty-one plants were collected from Podhigai Hills, Tamil Nadu, India and tested in this study. The susceptibility of burn wound isolates (Pseudomonas aeruginosa and Staphylococcus aureus) to antibiotics and the adjuvant activity of the aqueous plant extracts were tested using well diffusion assay. The impact of the plant extracts on quorum sensing was assessed using Chromobacterium violaceum as the model organism. The antibiofilm activity of the adjuvant and antibiotics was determined by crystal violet assay. The isolates which were resistant to more than one class of antibiotics (aminoglycoside, cephalosporin, fluoroquinolone and penicillin) were designated as multidrug resistant bacteria. Combination of cefdinir-Citrullus colocynthis showed 17 mm inhibition zone which is greater than cefdinir (0 mm) against P. aeruginosa. The combination reduced quorum sensing with an inhibition zone of 30 mm. The same combination reduced 96% and 95% of the biofilm formed by P. aeruginosa and S. aureus, respectively at 16 h. Besides, cefdinir with Leucas aspera reduced quorum sensing with an inhibition zone of 28 mm. The combination reduced 94% and 95% of biofilm formed by P. aeruginosa and S. aureus, respectively at 16 h. The aqueous extract of C. colocynthis and L. aspera revealed the presence of flavonoids that possess adjuvant activity. @*Conclusion, significance and impact of study@#Cefdinir-C. colocynthis and cefdinir-L. aspera reversed the resistance of multi drug resistant bacteria to cefdinir. The flavonoids of C. colocynthis and L. aspera served as an adjuvant that potentiates the activity of cefdinir.

Anti-Diabetic, Anti-Cancer Activity And Associated Toxicity Of Leucas Aspera Extract In Wistar Albino Rats

In regenerative medicine, nanotechnology plays a vital role in the diagnosis, the delivery of therapeutic drugs and the treatment of many diseases and disorders. Due to the growing need to develop environmentally friendly technologies in material synthesis, the biosynthesis of Iron Oxide Nanoparticles (IOP) has received considerable attention over the past decades. Therefore, the community is now looking back for traditional medicines for various diseases after the practice of allopathic drugs with tremendous side effects. There are an increasing number of biomedical applications for iron oxide nanoparticles; as such uses are essential for in-vitro characterisation and in-vivo to ensure the bio-safety of these particles. The main complication of diabetes due to frequent lipid peroxidation is liver damage and renal dysfunction, but treatment with Leucas aspera has a pronounced effect on these indicators, which protects the organs from further damage. The current research supports the traditional use of Leucas aspera against diabetes mellitus and cancer, as well as the safety, effectiveness and potency of Leucas aspera leaf extract's anti-diabetic and anti-cancer effect in the in-vivo model. The overall results reveal that Leucas aspera has the potential and can be a candidate of choice without side effect.

Evaluation of wound healing activity of baicalein-7-O- β-D-glucuronide isolated from Leucas aspera.

Leucas aspera (Willd.) Linn. (Lamiaceae), commonly known as “Thumbai,” is distributed throughout India. This study includes the isolation and characterization of flavonoids present in Leucas aspera flowers were compared wound healing activity with standard soframycin ointment. The plant materials were extracted with 95% methanol, petroleum ether, ethyl acetate, and were subjected to column and TLC chromatographic separation analysis. The chemical constituents isolated from the flowers of L. aspera were characterized based on chemical tests and spectral analysis such as UV and NMR spectroscopy. The structure of the isolated compound was confirmed as baicalein-7-O- β-D-glucuronide (baicalin). It has been investigated for wound healing activity by applying on the albino rats. A slow rate of healing was observed earlier which turns to very rapid on the 12th day. The histopathological examination provided additional evidence for the experimental wound healing studies. Protease is a biochemical marker and pH measured to support the wound healing activity. We conclude that the baicalin isolated with the flowers of L. aspera has better wound healing activity.

Selected neurobehavioural evaluation of Leucas Aspera in wistar albino rats.

Background: Leucas Aspera is used in traditional medicine for many ailments. The present study was designed to evaluate the neuro behavioural effects in Wistar albino rats after oral administration of leaves of Leucas Aspera for 28 days. Methods: Wistar albino rats of either sex were treated with the aqueous suspension of dried powdered leaves of L. aspera. Three different groups of animals received L. aspera suspension in doses of 50 mg/kg/day, 100 mg /kg/day or 200mg/kg/day orally for 28 days. The animals were weighed once in a week and the food and water consumption was monitored every day. Behavioural changes in these animals were monitored every week using Rotarod, Actophotometer and William’s maze. Results: A significant increase in body weight, food and water consumption in rats could be recorded after 3rdand 4th week of treatment with 200mg/kg/dayL.aspera. However, there were no changes in any of the behavioural responses in L .aspera treated groups compared to control. Conclusions: The unaltered neuro behavioural responses after L. aspera treatment indicate the safe nature of this medicinal plant. The significant increase in food consumption and body weight changes suggest a potential anabolic/ nutraceutical property of L. aspera.

Antioxidant, antibacterial and cytotoxic effects of the phytochemicals of whole Leucas aspera extract

<p><b>OBJECTIVE</b>To investigate the antioxidant, antibacterial and cytotoxic activity of whole Leucas aspera (Labiatae) (L. aspera) alcoholic extract.</p><p><b>METHODS</b>Whole L. aspera powder was extracted by absolute ethanol (99.50%). The ethanolic extract was subjected to antioxidant, antibacterial and brine shrimp lethality assay.</p><p><b>RESULTS</b>The extract showed potent radical scavenging effect (antioxidant) with IC50 value of (99.58±1.22) µg/mL which was significant (P<0.01) in comparison to ascorbic acid with IC50 value of (1.25±0.95) µg/mL. In case of antibacterial screening, the extract showed notable antibacterial effect against the tested microbial strains. Significant (P<0.05) zone of inhibitions against Gram positive Bacillus subtilis [(12.00±1.32) mm] and Bacillus megaterium [(13.00±1.50) mm], Staphylococcus aureus [(8.00±0.50) mm] and Gram negative Salmonella typhi [(6.00±0.50) mm], Salmonella paratyphi [(8.00±1.00) mm], Shigella dysenteriae [(9.00±1.32) mm] and Vibrio cholerae [(9.00±0.66) mm] was observed. In brine shrimp lethality bioassay, the extract showed the LC50 value as (181.68±2.15) µg/mL which was statistically significant (P<0.01) compared to positive control vincristine sulfate [LC50=(0.76±0.04) µg/mL].</p><p><b>CONCLUSIONS</b>The results demonstrate that the ethanolic extract of L. aspera could be used as antibacterial, pesticidal and various pharmacologic actives.</p>

Antioxidant and antibacterial activity of different parts of Leucas aspera

Objective: To evaluate antioxidant, antimicrobial and cytotoxic activity of different parts (root, flower, leaf and stem) of Leucas aspera (L. aspera) (Labiatae). Methods: Different parts of L. aspera were extracted with 80% (v/v) methanol. The methanol extracts were subjected to antioxidant, antimicrobial and brine shrimp lethality assay. Results: All the extracts showed moderate to potent antioxidant activity, among which the root extract demonstrated the strongest antioxidant activity with the IC50 value of 6.552 μg/mL. Methanol extract of root possessed antioxidant activity near the range of vitamin E and thus could be a potential rich source of natural antioxidant. In case of antimicrobial screening, crude extracts of root, flower, leaf and stem showed notable antibacterial activity against tested microorganisms. The root extract showed the highest mean zone of inhibition ranging from 9.0-11.0 mm against tested microorganisms, at a concentration of 100 mg/mL. In the brine shrimp lethality bioassay, it was evident that the methanol root extract did not show significant toxicity. The LC50 value for 12 h and 24 h observation was 2.890 mg/mL and 1.417 mg/mL, respectively. Conclusions: The present finding suggests that the methanol root extract of L. aspera could be developed as pharmaceutical products.

Antioxidant and antibacterial activity of different parts of Leucas aspera

<p><b>OBJECTIVE</b>To evaluate antioxidant, antimicrobial and cytotoxic activity of different parts (root, flower, leaf and stem) of Leucas aspera (L. aspera) (Labiatae).</p><p><b>METHODS</b>Different parts of L. aspera were extracted with 80% (v/v) methanol. The methanol extracts were subjected to antioxidant, antimicrobial and brine shrimp lethality assay.</p><p><b>RESULTS</b>All the extracts showed moderate to potent antioxidant activity, among which the root extract demonstrated the strongest antioxidant activity with the IC50 value of 6.552 µg/mL. Methanol extract of root possessed antioxidant activity near the range of vitamin E and thus could be a potential rich source of natural antioxidant. In case of antimicrobial screening, crude extracts of root, flower, leaf and stem showed notable antibacterial activity against tested microorganisms. The root extract showed the highest mean zone of inhibition ranging from 9.0-11.0 mm against tested microorganisms, at a concentration of 100 mg/mL. In the brine shrimp lethality bioassay, it was evident that the methanol root extract did not show significant toxicity. The LC50 value for 12 h and 24 h observation was 2.890 mg/mL and 1.417 mg/mL, respectively.</p><p><b>CONCLUSIONS</b>The present finding suggests that the methanol root extract of L. aspera could be developed as pharmaceutical products.</p>