Bioactive compounds, and bio-activities common to three natural products expected to boost the treatment of the comorbidities of COVID-19: A review

COVID-19, with many variants of its causative virus, has been and is still causing ravages and claiming many lives all over the globe. Currently, there are no therapeutic agents against the disease except for a few already existing ones that are used to manage the symptoms and comorbidities associated with the disease. Even some currently developed vaccines cannot efficiently handle various variants of the causative agent for COVID-19. This review is aimed at utilizing the possible synergy that might exist in the combination therapy of Nigella sativa, Curcuma longa, and honey for better management of COVID-19 and the associated comorbidities. The literature search was performed by inputting some relevant keywords into important search engines and websites such as Google, Google Advanced Search, PubMed, and so on. In vitro studies on some bioactive compounds isolated from N. sativa and C. longa have demonstrated activity against SARS-CoV-2. The three natural products, N. sativa, C. longa, and honey have exhibited wonderful activities against some of the health conditions associated with COVID-19; such include; antiviral, immunomodulatory, antioxidant, anti-inflammatory, bronchodilatory, antihistamine, antitussive, antimicrobial and other activities. Some of the major active compounds responsible for the bioactivities of these products and their mechanisms of action have been highlighted. The products individually have exhibited strong biological activities against conditions associated with COVID-19 and so are expected to exert a synergistic effect when combined in the treatment of the disease even with many variants of the causative organism

Anti-inflammatory and antioxidant activities of ethylacetate fraction of Sida linifolia L. (Malvaceae)

Sida linifolia L., a known weed found in West Africa and other parts of the world, is being used in African traditional medicine for many purposes, including the relief of uncomfortable teething, and the prevention of malaria. This study aimed to fractionate the crude extract of S. linifolia and determine the anti-inflammatory, and antioxidant properties of the most potent fraction. In the examination of anti-inflammatory compounds, in vitro tests for platelet aggregation, albumin denaturation, protease, and phospholipase A2 were utilized. To assess the in vivo anti-inflammatory effects, rat paw edema was induced with carrageenan and egg albumin. The total antioxidant capacity (TAC), 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing power (FRAP), and nitric oxide (NO) assays were used in the in vitro antioxidant assessment. The result of the phytochemical screening revealed that there were varying concentrations of terpenoids, saponins, steroids, alkaloids, flavonoids, tannins, and other phenols. The ethylacetate leaf fraction of S. linifolia EALFSL displayed robust, concentration-dependent anti-inflammatory effects by significantly inhibiting hypotonicity-and heat-induced hemolysis, platelet aggregation, protein denaturation, protease activity, and phospholipase A2 activity, which were comparable to those of the reference drugs (aspirin/prednisolone). In vivo studies also revealed that EALFSL was able, at different doses, to inhibit the progress of carrageenan-induced rat paw edema and egg albumin models. Though it was less active than the butylated hydroxytoluene BHT (0.30 mg/ml), ascorbic acid (0.32-0.50 mg/ml), and gallic acid (0.47 mg/ml), the EALFSL fraction's IC50 values ranged from 0.93 to 1.20 mg/ml. The results demonstrated that EALFSL has significant concentration-dependent antioxidant activity. These suggest that the ethylacetate leaf fraction of S. linifolia possesses anti-inflammatory and antioxidant effects

A polyherbal formulation reverses hydrogen peroxide-induced hematological and biochemical aberrations in rats

DRHM® is a polyherbal formulation [composed of Cymbopogon citratus (17%), Carica papaya leaves (16%), Mangifera indica bark (15%), Moringa oleifera leaves (14%), Citrus limon (12%), Psidium guajava (11%), Zingiber officinale root (9%) and Allium sativum (6%)] that is indicated for many disease conditions and as a detoxifier. In this study, the effects of DRHM® on hydrogen peroxide (3 mL/kg b.w of 5% H2O2, i.p)-induced hematological and biochemical aberrations in rats were evaluated. H2O2 significantly (p<0.05) reduced hemoglobin level, packed cell volume and red blood cell, white blood cell and platelet counts. It elevated the activities of aspartate and alanine aminotransferases and levels of total bilirubin and malondialdehyde. In addition, H2O2 also decreased superoxide dismutase, catalase and glutathione peroxidase activities and reduced glutathione and antioxidant vitamins levels. However, after 14 days of treatment at 1, 2 and 3 mL/kg/d b.w. p.o, DRHM® reversed aberrations in hematological status, enhanced antioxidant status and attenuated lipid peroxidation and hepatic damage induced by H2O2, in a dose-dependent manner comparable to silymarin (100 mg/kg/d. b.w.). These findings suggest that the phytoconstituents in DRHM® might be responsible for these ameliorative effects by boosting antioxidant defense system. DRHM® was tolerable up to 10 mL/kg. b.w

A polyherbal formulation reverses hydrogen peroxide-induced hematological and biochemical aberrations in rats

927-933DRHM® is a polyherbal formulation [composed of Cymbopogon citratus (17%), Carica papaya leaves (16%), Mangifera indica bark (15%), Moringa oleifera leaves (14%), Citrus limon (12%), Psidium guajava (11%), Zingiber officinale root (9%) and Allium sativum (6%)] that is indicated for many disease conditions and as a detoxifier. In this study, the effects of DRHM® on hydrogen peroxide (3 mL/kg b.w of 5% H2O2, i.p)-induced hematological and biochemical aberrations in rats were evaluated. H2O2 significantly (p<0.05) reduced hemoglobin level, packed cell volume and red blood cell, white blood cell and platelet counts. It elevated the activities of aspartate and alanine aminotransferases and levels of total bilirubin and malondialdehyde. In addition, H2O2 also decreased superoxide dismutase, catalase and glutathione peroxidase activities and reduced glutathione and antioxidant vitamins levels. However, after 14 days of treatment at 1, 2 and 3 mL/kg/d b.w. p.o, DRHM® reversed aberrations in hematological status, enhanced antioxidant status and attenuated lipid peroxidation and hepatic damage induced by H2O2, in a dose-dependent manner comparable to silymarin (100 mg/kg/d. b.w.). These findings suggest that the phytoconstituents in DRHM® might be responsible for these ameliorative effects by boosting antioxidant defense system. DRHM® was tolerable up to 10 mL/kg. b.w

Salvia africana-lutea L.:: a review of ethnobotany, phytochemistry, pharmacology applications and future prospects

Plants are nature’s reserve for vitality and health-boosting agents. Despite ever-rising interest and research on plant medicinal chemistry, many stones are still being left unturned. Moreover, many traditional medicinal plants are yet to be discovered or functionally characterized. This study presented an up-to-date review of a poorly explored member of the Salvia genus indigenous to Africa—Salvia africana-lutea L. (synonymous with Salvia aurea L.) with details on its geographical distribution, ethnobotany, and pharmacological applications. We reviewed all literature published on Salvia africana-lutea up to January 2023, retrieved from PubMed, Scopus, and ScienceDirect as primary databases and google scholar as the secondary source. From our literature search, we found 38 documents published on S. africana-lutea, despite the popularity of the Salvia genus as a medicinal plant (having over 15,000 articles published to date). From the retrieved literature, only a few studies focused on exploiting the ethnobotanical features of the plants, such as the morphology, flowering and existence, and nature of its trichomes. Some studies have reported S. africana-lutea as an excellent source of essential oils trapped within their leaf trichomes with numerous phytochemicals and bioactivities. Other studies have reported some interesting pharmacological activities of plant extracts and isolated phytochemicals, such as their antimicrobial, anti-oxidative, analgesic, antipyretic, anticancer, cytotoxic, and other bioactivities. We identified some limitations of the few published studies, highlighting future research needs that should draw more scientific interest to foster more study on this under-explored and valuable plant species of Salvia, to harness its medicinal and industrial potential fully

A polyherbal formulation reverses hydrogen peroxide-induced hematological and biochemical aberrations in rats

927-933DRHM® is a polyherbal formulation [composed of Cymbopogon citratus (17%), Carica papaya leaves (16%), Mangifera indica bark (15%), Moringa oleifera leaves (14%), Citrus limon (12%), Psidium guajava (11%), Zingiber officinale root (9%) and Allium sativum (6%)] that is indicated for many disease conditions and as a detoxifier. In this study, the effects of DRHM® on hydrogen peroxide (3 mL/kg b.w of 5% H2O2, i.p)-induced hematological and biochemical aberrations in rats were evaluated. H2O2 significantly (p<0.05) reduced hemoglobin level, packed cell volume and red blood cell, white blood cell and platelet counts. It elevated the activities of aspartate and alanine aminotransferases and levels of total bilirubin and malondialdehyde. In addition, H2O2 also decreased superoxide dismutase, catalase and glutathione peroxidase activities and reduced glutathione and antioxidant vitamins levels. However, after 14 days of treatment at 1, 2 and 3 mL/kg/d b.w. p.o, DRHM® reversed aberrations in hematological status, enhanced antioxidant status and attenuated lipid peroxidation and hepatic damage induced by H2O2, in a dose-dependent manner comparable to silymarin (100 mg/kg/d. b.w.). These findings suggest that the phytoconstituents in DRHM® might be responsible for these ameliorative effects by boosting antioxidant defense system. DRHM® was tolerable up to 10 mL/kg. b.w

Zanthoxylum Species: A Comprehensive Review of Traditional Uses, Phytochemistry, Pharmacological and Nutraceutical Applications

Zanthoxylum species (Syn. Fagara species) of the Rutaceae family are widely used in many countries as food and in trado-medicinal practice due to their wide geographical distribution and medicinal properties. Peer reviewed journal articles and ethnobotanical records that reported the traditional knowledge, phytoconstituents, biological activities and toxicological profiles of Z. species with a focus on metabolic and neuronal health were reviewed. It was observed that many of the plant species are used as food ingredients and in treating inflammation, pain, hypertension and brain diseases. Over 500 compounds have been isolated from Z. species, and the biological activities of both the plant extracts and their phytoconstituents, including their mechanisms of action, are discussed. The phytochemicals responsible for the biological activities of some of the species are yet to be identified. Similarly, biological activities of some isolated compounds remain unknown. Taken together, the Z. species extracts and compounds possess promising biological activities and should be further explored as potential sources of new nutraceuticals and drugs