Open Access Original Research Article

Antibiotics Sensitivity Profile of Wounds’ Bacterial Isolates and Antibacterial Assessment of Chromolaena odorata Aqueous and Ethyl Acetate Extracts

Mercy Adewumi Alabi

South Asian Research Journal of Natural Products, Page 1-9

Aim: To study the in vitro inhibitory effect of C. odorata extracts on bacterial isolates from wound swab samples.

Place of Study: University of Medical Sciences Teaching Hospital, Akure, Ondo State, Nigeria, between January and June 2019.

Methodology: Wound swabs were collected from patients of University of Medical Sciences Teaching Hospital, Akure. Air-dried and powdered C. odorata leaves were extracted using distilled water and ethyl acetate and concentrated using a rotary evaporator. Qualitative phytochemical screening of C. odorata extracts was done by standard methods. Antibiotics susceptibility pattern of bacterial isolates to a panel of ten (10) conventional antibiotics was determined by disc diffusion method. Antibacterial activity of C. odorata extracts were determined using agar diffusion  method.

Results: Pseudomonas aeruginosa was the most abundant bacteria isolated (40.30%) in this study. Chromolaena odorata aqueous extract had higher extraction yield (24.1%) than ethyl acetate extract. Phytochemical screening revealed the presence of saponin, flavonoids, terpenoids, steroids, tannin, glycoside and phenol of C. odorata extracts. Proteus vulgaris exhibited 100% resistance against augmentin. The highest zone of inhibition observed with the C. odorata ethyl acetate extract was against P. aeruginosa (18.67±0.67 mm).

Conclusion: This study reveals the in vitro inhibitory effect of C. odorata extracts on bacteria isolated from wounds thus presenting them as potential antibacterial agents.

Open Access Original Research Article

Phytochemical Screening, Antimicrobial and Antioxidant Activity of Lepidium sativum Seeds Extract

Awdalla B. Omer, Azhari H. Nour, Mahmoud M. Ali, Omer Adam Omer Ishag, Ibrahim Yaagoub Erwa, Mohammed Abdelwahhab Ali

South Asian Research Journal of Natural Products, Page 10-17

Plants play a significant role in drug discovery and development of pharmaceuticals process. In many countries, medicinal plants consider the main source of primary health care.

Aims: This study aimed to investigate the phytochemical screening, antimicrobial and antioxidant activities of Lepidium sativum seeds extracts and fractions.

Methodology: Seeds of L. sativum were collected and extracted by maceration in methanol and the extract was fractionated using hexane, chloroform, ethyl acetate and an aqueous solvent. Phytochemical screening of crude extract was performed using standard methods. The crude extracts and the fractions were tested against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans. The radical scavenging (DPPH) was determined according to the standard methods.

Results: The phytochemical screening result of the crude extract showed the presence of flavonoids, alkaloids, tannins, saponins, phenols, glycosides and terpenoids. Antimicrobial activities results were showed variation in the inhibition zones from 8-20 mm; the best activity was in A. niger 20 mm at concentration 100 mg/mL of crude extract, however in S. Aureus 16 mm at the same concentration of ethyl acetate fraction. The results of free radical scavenging activity results obtained were higher at ethyl acetate fraction (76±0.02%), chloroform fraction (74±0.01%) and aqueous fraction (70±0.09%), while moderate at the crude extracts (46±0.07%) and low at hexane fraction (21±0.04%).

Conclusion: It could be concluded that the crude extracts and fractions of L. sativum had high potential as an antibacterial and antioxidant agent, which can be used for medicinal purposes.

Open Access Original Research Article

Use of Polyphenol Extracts from Dioscorea steriscus and Plecranthus esculentus N.E.Br Tubers to Curb Oxidative Deterioration of Sunflower Oil

Masimba Tapera, Ruth Wanjau, Alex K. Machocho, Pamhidzai Dzomba

South Asian Research Journal of Natural Products, Page 18-28

Aim: The aim of the present study was to determine the possibility of using polyphenol extracts from Dioscorea steriscus and Plecranthus esculentus N.E.Br tubers of Zimbabwe as preservatives for sunflower oil under oven and kitchen storage conditions.

Methodology: Polyphenols were extracted from Dioscorea steriscus and Plecranthus esculentus tubers, screened using polyphenol screening assays and added to virgin sunflower oil at 100 ppm dose.  Oxidative stability was determined using peroxide values and UV-Vis absorbances a 232 nm.

Results: Polyphenol screening assays of aqueous acetone extracts from Dioscorea steriscus and Plecranthus esculentus tubers revealed the presence of flavonoids, phenolic acids, tannins, lignans and anthocyanins. Oxidative stability of sunflower oil under kitchen storage conditions (room temperature) and oven storage conditions (65°C) as measured by peroxide values and UV-Vis absorbances at 232 nm followed the order D. steriscus fortified ˃ BHT fortified ˃ P. esculentus fortified ˃ unfortified. The lowest mean peroxide value (17.72±0.05 mEq/kg oil) over a 5 week storage duration under kitchen storage conditions was recorded in D.steriscus fortified sunflower oil and the highest (31.17±0.16 mEq/kg oil) was recorded in unfortified sunflower oil.

Conclusion: Polyphenol extracts from Dioscorea steriscus and Plecranthus esculentus tubers showed high preservative potential on virgin sunflower oil under both kitchen and oven storage conditions. Polyphenol extracts from D. steriscus and P. esculentus tubers may be used as alternative sources of antioxidants for the preservation of sunflower oil.

Open Access Original Research Article

In vitro Inhibitory Effects of Protein Isolates from Unripe Plantain (Musa paradisiaca) on Key Enzymes Linked to Type-2 Diabetes and Obesity

Adedayo Emmanuel Ogunware, Yetunde Ebunlomo Oyende, Samuel Arawu, Olusegun Omolade Fajana

South Asian Research Journal of Natural Products, Page 29-40

Aims: This study was carried out to examine and characterize the effects of protein isolates from unripe plantain on enzymes linked with type-2 diabetes(α-amylase) and obesity (Pancreatic Lipase) using an in vitro model.

Place and Duration of Study: Department of Biochemistry, Lagos State University, Ojo, Lagos, Nigeria between July 2019 and January 2020.

Methodology: Proteins were isolated from dried raw flour of unripe plantain, and enzyme inhibition assays were conducted in the presence of protein isolates using α-amylase from Saccharomyces cerevisiae and porcine pancreatic lipase. Acarbose and Orlistat were used as the standard inhibitors respectively. Percentage inhibition of the two enzymes and the IC50 values were determined. The effects of pH, temperature and salts on the inhibitory activity of the protein isolates were also determined. 

Results: The protein isolates showed maximum percentage inhibition on α-amylase activity at 87% (IC50 value 0.46±1.9 mg/mL) compared with acarbose with a maximum inhibitory potential of 86% (IC50 value 0.51±3.6 mg/mL) and maximum percentage inhibition on pancreatic Lipase at 91% (IC50 value 0.73±3.2 mg/mL) compared with Orlistat with a maximum inhibitory potential of 97% (IC50 value 0.61±9.4 mg/mL). The optimum pH for both α-amylase and pancreatic lipase inhibitory activity was observed to be pH 9.0 and, the optimum temperature for α-amylase and pancreatic lipase inhibitory activity was observed to be at 40oC. At certain concentrations the inhibitory activities of the unripe plantain protein isolates were affected by the salts.

Conclusion: These results showed the presence of α-amylase and pancreatic lipase inhibitors in unripe plantain which indicates that this plant can be beneficial in the construction of anti-diabetes and anti-obesity medications.

Open Access Original Research Article

Inhibitory Activity of Protein Isolate from Bambara Groundnut (Vigna subterranean) on Alpha-amylase and Pancreatic Lipase

Yetunde Ebunlomo Oyende, Adedayo Emmanuel Ogunware, Samuel Arawu, Olusegun Omolade Fajana

South Asian Research Journal of Natural Products, Page 41-51

Aim: This research was carried out to examine the inhibitory activity of protein isolate from bambara groundnut on alpha-amylase and lipase in vitro, and to study the effect of temperature, pH and substrate concentration on the enzymes in vitro.

Place and Duration of Study: Department of Biochemistry, Lagos State University, Ojo, Lagos, Nigeria between August 2019 and January 2020.

Methodology: Protein was isolated from bambara groundnut using alkaline extraction (isoelectric precipitation). Alpha-amylase and pancreatic lipase inhibitory assays were performed using starch solution and a stock solution of PNPB (p-nitrophenyl butyrate) as substrates respectively. The effect of variation of substrate concentration, temperature and pH on the inhibition of alpha-amylase and pancreatic lipase activity was also studied.

Results: At a concentration of 1.0 mg/mL, the protein isolate from Bambara groundnut exhibited 91% inhibition of alpha-amylase activity with an IC50value of 0.40±1.85 mg/mL (in comparison with acarbose which exhibited 86% inhibition at the same concentration) and 91% inhibition of lipase activity with an IC50value of 0.73±3.7 mg/mL (in comparison with Orlistat which exhibited 97%  inhibitionat the same concentration). The most favorable temperature for the inhibition of alpha-amylase and lipase was 40°C. The optimum pH for alpha-amylase and lipase inhibitory activity was 10.5 and 9.0 respectively.

Conclusion: These results showed the presence of alpha-amylase and pancreatic lipase inhibitors in bambara groundnut which indicates that this plant can be used as a feed supplement in the control of high blood-glucose level of diabetes patients.