Automatic Classification of Antimalarial Herbal Drugs Exposed to Ultraviolet Radiation from Unexposed Ones Using Laser-Induced Autofluorescence with Chemometric Techniques.

Exposure of antimalarial herbal drugs (AMHDs) to ultraviolet radiation (UVR) affects the potency and integrity of the AMHDs. Instant classification of the AMHDs exposed to UVR (UVR-AMHDs) from unexposed ones (Non-UVR-AMHDs) would be beneficial for public health safety, especially in warm regions. For the first time, this work combined laser-induced autofluorescence (LIAF) with chemometric techniques to classify UVR-AMHDs from Non-UVR-AMHDs. LIAF spectra data were recorded from 200 ml of each of the UVR-AMHDs and Non-UVR-AMHDs. To extract useful data from the spectra fingerprint, principal components (PCs) analysis was used. The performance of five chemometric algorithms: random forest (RF), neural network (NN), support vector machine (SVM), linear discriminant analysis (LDA), and k-nearest neighbour (KNN), were compared after optimization by validation. The chemometric algorithms showed that KNN, SVM, NN, and RF were superior with a classification accuracy of 100% for UVR-AMHDs while LDA had a classification accuracy of 98.8% after standardization of the spectra data and was used as an input variable for the model. Meanwhile, a classification accuracy of 100% was obtained for KNN, LDA, SVM, and NN when the raw spectra data was used as input except for RF for which a classification accuracy of 99.9% was obtained. Classification accuracy above 99.74 ± 0.26% at 3 PCs in both the training and testing sets were obtained from the chemometric models. The results showed that the LIAF, combined with the chemometric techniques, can be used to classify UVR-AMHDs from Non-UVR-AMHDs for consumer confidence in malaria-prone regions. The technique offers a non-destructive, rapid, and viable tool for identifying UVR-AMHDs in resource-poor countries.

The Aqueous Stem Bark Extract of Alstonia boonei Exhibits Anticataract Activity in Sprague Dawley Rat.

In Africa, Alstonia boonei is used folklorically for the management of the multitude of conditions including cataract, which accounts for 50% of cases of blindness in the region. The current study set out to probe the traditional use of the aqueous extract of Alstonia boonei stem bark (ABE) as an anticataract remedy using Sprague Dawley rat models. We investigated the probable phytochemical constituents in the extract, in vitro antioxidant potential, and its in vitro aldose reductase inhibition. For the anticataract investigations, diabetic cataract was induced using galactose in 3-week-old Sprague Dawley rats, and age-related cataract was induced by the administration of sodium selenite to 10-day-old rat pups. Cataract scores in both models were determined after treatment with 30, 100, and 300 mgkg-1 doses of ABE and 10 mlkg-1 of distilled water. Lens glutathione, total lens protein, soluble lens proteins (alpha-A) crystallin, and aquaporin 0 levels in the enucleated lens homogenates were determined. Changes in lens to body weight were also determined with histopathological analysis done on the lenses in the selenite-induced cataract model. The presence of alkaloids, tannins, flavonoids, glycosides, and triterpenoids was identified in the extract. The extract inhibited aldose reductase activity with IC50 of 92.30 µgml-1. The 30, 100, and 300 mgkg-1ABE-treated rats recorded significantly (p < 0.05) reduced cataract scores indicating a delay in cataractogenesis in galactose-induced cataract and in selenite-induced cataractogenesis as well. Markers of lens transparency such as AQP0, alpha-A crystallin, and total lens proteins and lens glutathione levels were significantly (p < 0.05) preserved. In conclusion, this study establishes the anticataract potential of the aqueous stem bark extract of Alstonia boonei in Sprague Dawley rat models.

Synthesis of 1,2,3-triazole-thymol derivatives as potential antimicrobial agents.

Background: Thymol as a natural biological template can be modified chemically since the hydroxyl group makes it a candidate for structural modification. Thus, this study incorporated the triazole moiety on thymol and the chlorination of thymol moiety to help improve its biological potency. Materials and methods: A series of ten 1,2,3-triazole-thymol derivatives 1-10 were synthesized from thymol, by a click reaction between O-propargyl terminal alkyne of thymol and its chlorothymol with benzyl azide and substituted benzyl azides. Their structures were confirmed by spectroscopic methods (1H-NMR, 13C-NMR, IR, GC-MS-EI/CI and LC-ESI-QTOF-MS). The Well diffusion method using Müeller-Hinton agar plates was used to demonstrate the antimicrobial activities of the synthesized triazole-thymol derivatives on selected bacterial strains; Escherichia coli ATCC 25922, Staphylococcus aureus ATCC25923, Methicillin resistant S. aureus (MRSA), Pseudomonas aeruginosa ATCC 29853, E. coli ESBL, K l ebsiella pneumoniae NCTC 13438 and Meropenem Resistant E. coli. Results: All the synthesized triazole-thymol derivatives showed significant but variable antibacterial activity against the seven medically important bacterial strains tested. The compound 4-((4-chloro-2-isopropyl-5-methylphenoxy)methyl)-1-(2-nitrobenzyl)-1H-1,2,3triazole (9) demonstrated a higher antibacterial activity with a mean zone of inhibition (38.7 mm) compared with ampicillin as the positive control which gave a zone size of 30.0 mm. In addition, the compound showed a three-fold potency than the parent compound, thymol (11.0 mm) against MRSA at a concentration of 100 µg/ml. Conclusion: These results provide additional evidence of the exploitation of natural products like thymol as leads for drug development against medically important bacterial pathogens.

Wound Healing Properties and Antimicrobial Effects of Parkia clappertoniana Keay Fruit Husk Extract in a Rat Excisional Wound Model.

Background: Parkia clappertoniana Keay (Family: Fabaceae) (P. clappertoniana) fruit husk is commonly used in northern Ghana for wound treatment. However, this folk claim remains to be confirmed scientifically. Objective: This study investigated wound healing and antimicrobial effects of P. clappertoniana fruit husk extract (PCFHE) by using excision wound model in rats. Materials and Methods: After preparation and phytochemical analysis of PCFHE, it was reconstituted in purified water and emulsifying ointment yielding a wound healing formula (0.3, 1, and 3%). Excision wounds were established in healthy male Sprague-Dawley rats (aged 8-10 weeks; weighing 150-200 g). Rats were randomly assigned into six groups (model, 1% silver sulfadiazine [SSD], vehicle, and PCFHE [0.3, 1, and 3%, respectively]) and topically treated daily until complete wound healing. The endpoints (period of epithelialization, wound contraction, collagen content, erythema index, oedema index, inflammatory cell infiltration, and antimicrobial activity) were assessed for all groups. Minimum fungicidal concentration (MFC), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill were assessed. Results: Quercetin and catechin were detected in PCFHE. Compared to model and vehicle groups, PCFHE-treatment groups improved wound healing and antimicrobial (MBC, MFC, and MIC) endpoints. PCFHE demonstrated bacteriostatic and fungicidal effects against identified wound contaminants (Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Candida albicans). Conclusion: P. clappertoniana fruit husk possesses wound healing and antimicrobial effects in excisional wounds in rats that confirms its folk use, and the reported pharmacological properties of PCFHE are attributable to its quercetin and catechin phyto-constituents.

Zanthoxylum zanthoxyloides Alkaloidal Extract Improves CCl4-Induced Hepatocellular Carcinoma-Like Phenotypes in Rats.

BACKGROUND: Despite the enrollment of new small molecules such as Sorafenib for the treatment of hepatocellular carcinoma (HCC), HCC still remains a significant contributor to cancer-related mortality and morbidity globally. Zanthoxylum zanthoxyloides is long suspected of possessing anticancer bioactive compounds that may hold the prospect of adjunctive therapy against inflammation-related cancers such as HCC. OBJECTIVE: This study assessed the effects of an alkaloidal extract of the leaves of Zanthoxylum zanthoxyloides on CCl4/olive oil (1 : 1 v/v)-induced HCC-like phenotypes in rats. MATERIALS AND METHODS: Zanthoxylum zanthoxyloides alkaloidal extract (ZZAE) was prepared using Soxhlet and liquid-liquid extraction methods. Subsequently, ZZAE was characterized phytochemically. In the curative method, experimental HCC was established in adult (8-10 weeks old) male Sprague-Dawley rats weighing 150-300 g by twice-daily administration of CCl4/olive oil (1 : 1 v/v) (2 mL/kg ip). After confirmation of experimental HCC in rats, the rats were randomly reassigned into seven (7) groups of seven (7) rats each and treated daily for 12 weeks as follows: control (normal saline, 5 ml/kg po), model (CCl4, 5 ml/kg, ip), ZZAE (50, 100, and 200 mg/kg po), carvedilol (6.25 mg/kg po), and 20% Tween20 (1 mL/rat, po). To assess whether ZZAE has a prophylactic (preventive) effect, rats were first treated with ZZAE and later exposed to CCl4 reconstituted in olive oil. RESULTS: ZZAE (100 and 200 mg/kg) and carvedilol decreased tumor incidence compared to that of control. Compared to control, ZZAE (100 and 200 mg/kg) significantly (P < 0.05) improved serum GGT. Compared to control, ZZAE improved hepatohistological distortions induced by CCl4/olive oil and also improved liver/body weight ratio. Compared to water, ZZAE arrested mitosis in the Allium cepa assay. CONCLUSION: ZZAE ameliorated CCl4/olive oil-induced HCC-like phenotype in rats and demonstrated general hepatoprotective effects by improving liver and kidney function markers. This finding rationalizes the need for further studies on ZZAE as a potential source of bioactive anti-HCC compounds.

Glucose lowering and pancreato-protective effects of Abrus Precatorius (L.) leaf extract in normoglycemic and STZ/Nicotinamide - Induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Abrus precatorius (L.) leaves are used as folk medicine by the local communities in the western region of Ghana to treat diabetes mellitus; however, this health claim remains unverified scientifically. OBJECTIVE: The study investigated glucose lowering and pancreato-protective effects of Abrus precatorius leaf extract (APLE) in normoglycemic and STZ/nicotinamide (NIC)-induced diabetic rats. METHOD: after preparation of APLE, it was subjected to phytochemical screening, proximate composition and elemental assessments by using standard methods. Oral glucose tolerance test (OGTT) and maltose, lactose and sucrose oral challenge were assessed in normoglycemic rats post-APLE. Morphological characteristics of glucose response curve (time of glucose peak and shape of glucose response curve) were determined. Subsequently, diabetes mellitus was experimentally established in normoglycaemic adult Sprague-Dawley rats (weighing 150-250 g) of both sexes by sequential injection of Streptozotocin (STZ, 60 mg/kg ip)-reconstituted in sodium citrate buffer and NIC (110 mg/kg ip)-reconstituted in normal saline (1:1 v/v) for 16 weeks. Except control rats (normal saline 5 ml/kg ip; baseline fasting blood glucose [FBG] of 6.48 mmol/L), rats having FBG (stable at 11.1 mmol/L or ≥ 250 mg/dL) 3 days post-STZ/NIC injection were randomly re-assigned to one of the following groups: model (STZ/NIC-induced diabetic rats), APLE (100, 200 and 400 mg/kg respectively po) and metformin (300 mg/kg po) and treated daily for 28 days. Bodyweight and FBG were measured on weekly basis. FBG was measured by using standard glucometers. On day 28, rats were sacrificed under chloroform anesthesia, blood collected via cardiac puncture; kidney, liver and pancreas surgically harvested. While the pancreas was processed, sectioned and H&E-stained for histological examination, fresh kidney and liver were homogenized for assessment of total anti-oxidant capacity. Median cross-sectional area of pancreatic islets of Langerhans was determined for each group by using Amscope. RESULTS: Cumulatively, APLE (100, 200 and 400 mg/kg respectively) dose-dependently decreased the initial FBG by 55.22, 76.15 and 77.77% respectively compared to model (-1.04%) and metformin (72.29%) groups. APLE treatment recovered damaged pancreatic ß-cells and also increased median cross-sectional area (x106 µm2) of pancreatic islets compared to that of model group. APLE significantly (P < 0.05) increased total anti-oxidant capacity (5.21 ± 0.02 AscAE µg/mL) of plasma, kidney and liver compared to model (4.06 ± 0.04 AscAE µg/mL) and metformin (4.87 ± 0.03 AscAE µg/mL) groups. CONCLUSION: APLE has demonstrated glucose lowering and pancreato-protective effects in rats and arrested the characteristic loss in bodyweight associated with diabetes mellitus. This finding preliminarily confirms folk use of APLE as an anti-diabetic herbal medicine, whiles providing a rationale for further translational studies on APLE.

The hydroxyl moiety on carbon one (C1) in the monoterpene nucleus of thymol is indispensable for anti-bacterial effect of thymol.

BACKGROUND: Thymol, a natural monoterpene phenol is not only relevant clinically as an anti-microbial, anti-oxidant and anti-inflammatory agent but also holds the prospect as a natural template for pharmaceutical semi-synthesis of therapeutic agents. It is a major component of essential oils from many plants. Evidence abound linking overall bioactivity of thymol to its monoterpene nucleus, specifically, the hydroxyl (-OH) substituent on carbon number one (C1) on the monoterpene nucleus. Other studies have posited that the overall bioactivity of thymol is not substantially altered by chemical modification of - OH on the C1 of the monoterpene nucleus. In view of this, it is still unclear as to whether removal or modification of the -OH on C1 of the monoterpene nucleus relates generally or context-dependently to bioactivity of thymol. OBJECTIVE: The present study investigated anti-bacterial effects of ester-and-ether substituted derivatives of thymol on S. aureus, P. aeruginosa and E. coli. MATERIALS AND METHODS: twelve ester-and-ether substituted derivatives of thymol (6TM1s and 6TM2s) were synthesized and characterized by using HPLC, Mass spectrometry, and IR techniques. Anti-bacterial activity of the 12 thymol derivatives was evaluated using broth macrodilution and turbidimetric methods against pure clinical isolates (S. aureus, P. aeruginosa and E. coli). Standard anti-biotics used were Thymol Streptomycin and flucloxacillin, while DMSO was used as vehicle for thymol derivatives. MIC and MBC were determined. RESULTS: Thymol produced broad-spectrum growth inhibition on all isolates. At equimolar concentrations, thymol and reference drugs produced concentration-dependent growth inhibition against the isolates (Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli) compared to DMSO. Although the growth inhibitory effects of the ester-and-ether derivatives of thymol was significant (P ≤ 0.05) compared to DMSO, it was however insignificant (P ≥ 0.05) compared to thymol and reference antibiotics. Comparatively, at equimolar concentrations, ester-substituted derivatives of thymol, particularly the branched chain derivative (TM1C) produced more effective growth inhibition on the isolates than the ether-substituted derivatives of thymol. Thymol was twice as potent (MIC and MBC, 500 µg/ml) than both ester-and-ether substituted derivatives of thymol (MIC and MBC, > 1000 µg/ml) on all the three clinical isolates. Increase in side chain bulkiness of -OH moiety on the monoterpene nucleus of thymol decreased growth inhibition on isolates. CONCLUSION: Thymol has demonstrated broad-spectrum anti-bacterial effects attributable to the hydroxyl moiety on C1 of the monoterpene nucleus. Structural modification of the hydroxyl moiety on C1 of the monoterpene nucleus of thymol with either ether-or-ester substitutions yielded no significant anti-bacterial effects.