The evidence framework of traditional Chinese medicine injection (Aidi injection) in controlling malignant pleural effusion: A clustered systematic review and meta-analysis.

INTRODUCTION: Aidi injection (Aidi), a traditional Chinese medicine injection, is often practiced to control malignant pleural effusion (MPE). OBJECTIVES: We performed a registered systematic review and meta-analysis (PROSPERO: CRD42022337611) to clarify the clinical role of Aidi in MPE, reveal optimal combinations of Aidi and chemical agents, their indications, therapeutic route and usage, and demonstrate their clinical effectiveness and safety. METHODOLOGY: All randomized controlled trials (RCTs) about Aidi in controlling MPE were collected from Chinese and English databases (up to October 2022). We clustered them into multiple homogenous regimens, evaluated the risk-of-bias at outcome level using a RoB 2, extracted and pooled the data using meta-analysis or descriptive analysis, and finally summarized their evidence quality. RESULTS: All 56 studies were clustered into intrapleural administration with Aidi alone or plus chemical agents, and intravenous administration with Aidi for MPE. Intrapleural administration with Aidi alone displayed similar clinical responses on Cisplatin (DDP) alone. Only administration with Aidi plus DDP significantly improved complete response and quality of life, and displayed a low pleurodesis failure, disease progression, hematotoxicity, gastrointestinal and hepatorenal toxicity. For patients with moderate to massive effusion, Karnofsky Performance Status score ≥ 50 or anticipated survival time ≥3 months, Aidi (50 ml to 80 ml each time, one time each week and three to eight times) plus DDP (20 to 30 mg, 40 to 50 mg, or 60 to 80 mg each time) significantly improved clinical responses. Most results had moderate to low quality. CONCLUSIONS: Current evidences indicate that Aidi, a pleurodesis agent, plays an interesting clinical role in controlling MPE. Aidi plus DDP perfusion is a most commonly used regimen, which shows a significant improvement in clinical responses. These findings also provide an indication and possible optimal usage for rational drug use.

Aesculin offers increased resistance against oxidative stress and protective effects against Aß-induced neurotoxicity in Caenorhabditis elegans.

Aesculin, a coumarin compound, is one of the major active ingredients of traditional Chinese herbal medicine Qinpi (Cortex Fraxini), which has been reported to exhibit antioxidative, anti-inflammatory and neuroprotective properties against oxidative stress and cellular apoptosis. However, the regulatory mechanisms remain poorly characterized in vivo. This research was performed to explore the underlying molecular mechanisms behind aesculin response conferring oxidative stress resistance, and the protective effects on amyloid-ß (Aß)-mediated neurotoxicity in Caenorhabditis elegans. Study indicated that aesculin plays the protective roles for C. elegans against oxidative stress and Aß-mediated neurotoxicity and reduces the elevated ROS and MDA contents through enhancement of antioxidant defenses. The KEGG pathway analysis suggested that the differentially expressed genes are mainly involved in longevity regulating pathway, and the nuclear translocation of DAF-16 and the RNAi of daf-16 and hsf-1 indicated that DAF-16 and HSF-1 play critical roles in integrating upstream signals and inducing the expressions of stress resistance-related genes. Furthermore, the up-regulated expressions of their target genes such as sod-3 and hsp-16.2 were confirmed in transgenic GFP reporter strains CF1553 and CL2070, respectively. These results indicated that the regulators DAF-16 and HSF-1 elevate the stress resistance of C. elegans by modulating stress-responsive genes. Further experiments revealed that aesculin is capable of suppressing Aß-induced oxidative stress and apoptosis and improves chemosensory behavior dysfunction in Aß-transgenic nematodes. In summary, this study suggested that aesculin offers increased resistance against oxidative stress and protective effects against Aß-induced neurotoxicity through activation of stress regulators DAF-16 and HSF-1 in nematodes.

Achyranthes bidentata polypeptide k enhances the survival, growth and axonal regeneration of spinal cord motor neurons in vitro.

Achyranthes bidentata polypeptide k (ABPPk), a powerful active component from a traditional Chinese medicinal herb-Achyranthes bidentata Bl., has exhibited promising neuroprotective activity due to its multiple-targeting capability. However, the effect of ABPPk on the survival, growth and axonal regeneration of spinal cord motor neurons remains unclear. Here, a modified method, which is more optimized for embryonic cells in ambient carbon dioxide levels, was used for acquisition of rat embryonic spinal cord motor neurons with high survival and purity. ABPPk concentration-dependently enhanced the neuronal viability and promoted the neurite outgrowth. Co-culture of motor neurons and skeletal myocytes model indicated that ABPPk enhanced the neuromuscular junction development and maturation. A microfluidic axotomy model was further established for the axonal disconnection, and ABPPk significantly accelerated the axonal regeneration of motor neurons. Furthermore, we demonstrated that the upregulation of three neurofilament protein subunits in motor neurons might be relevant to the mechanisms of the growth-promoting effect of ABPPk. Our findings provide an experimental and theoretical basis for the development of ABPPk as a potential application in the development of treatment strategy for nerve injury diseases.

Intrathoracic infusion therapy with Lentinan and chemical irritants for malignant pleural effusion: a systematic review and meta-analysis of 65 randomized controlled trials.

BACKGROUND: Aderivative of Shiitake mushrooms, Lentinan is used to control malignant pleural effusion (MPE) through intrathoracic infusion. PURPOSE: To determine the clinical response, survival and safety of Lentinan plus chemical irritants, and the optimal combinations with chemical irritants, indication, threshold and optimal regimen for achieving the desired responses. STUDY DESIGN: We performed a new systematic review and meta-analysis following the PRISMA guidelines. METHODS: We collected all randomized controlled trials (RCTs) regarding Lentinan plus chemical irritants from Chinese and English electronic databases (from inception until March 2019). We evaluated their bias risk, synthesized data using meta-analysis, and summarized evidence quality following the Grades of Recommendation Assessment, Development and Evaluation approach. RESULTS: We included 65 RCTs involving 4,080 patients and nine chemical irritants. Most trials had unclear bias risk. Lentinan with cisplatin significantly improved complete response [Risk ratio (RR) = 1.68, 95% confidence intervals (CI) (1.51 to 1.87), p < 0.00001, Fig.3a] and quality of life [RR = 1.51 95% CI (1.41 to 1.62), p < 0.00001, Fig.4], and decreased the risk of treatment failure, myelosuppression, gastrointestinal reaction, and chest pain. For patients with moderate to large volume of the pleural effusion, primary treatment, KPS score ≥ 50-60, or anticipated survival time ≥ 3months, Lentinan (3-4 mg/time, once a week for three to four times) withcisplatin (30-40 mg/m2 or 50-60 mg/m2) significantly improved complete response and decreased failure. Most results were robust and moderate quality. CONCLUSION: The results suggest that Lentinan with chemical irritants, especially cisplatin is beneficial to the patient with MPE, and provide evidence for the indication, threshold, and optimal regimen that may achieve success and decrease failure.

The Hepatorenal Toxicity and Tumor Response of Chemotherapy With or Without Aidi Injection in Advanced Lung Cancer: A Meta-Analysis of 80 Randomized Controlled Trials.

PURPOSE: Chemotherapy-induced hepatorenal toxicity often decreases tolerance for further therapies and results in poor quality of life and prognosis for patients with lung cancer. In this meta-analysis, all related studies were systematically re-evaluated to determine whether Aidi injection relieves hepatorenal toxicity and improves tumor response, and to determine its threshold and the optimal treatment regimen for obtaining the desired responses. METHODS: All studies regarding Aidi injection with chemotherapy were gathered from Chinese and English databases (from inception until January 2019). Their bias risk was evaluated and the data were synthesized using meta-analysis; the quality of evidence of all outcomes was rated by using the Grades of Recommendation Assessment, Development, and Evaluation approach. FINDINGS: Eighty randomized controlled trials containing 6279 patients were included in the study. Most of the trials showed unclear risk of bias. Aidi injection with chemotherapy increased the objective response rate (risk ratio [RR], 1.32; 95% CI, 1.25-1.40) and the disease control rate (RR, 1.15; 95% CI, 1.12-1.17) and resulted in a lower incidence of hepatotoxicity (RR, 0.61; 95% CI, 0.55-0.69) and nephrotoxicity (RR, 0.62; 95% CI, 0.53-0.72) than that of chemotherapy alone. Subgroup analyses showed that treatment with 50 mL per time, 10 to 14 days per cycle, and 2 to 3 cycles of Aidi injection with chemotherapy resulted in a low incidence of hepatorenal toxicity. All of the results were robust, and their quality was moderate. IMPLICATIONS: The moderate evidence indicates that Aidi injection with chemotherapy may improve tumor response and result in a low incidence of hepatorenal toxicity in patients with lung cancer. Aidi injection may relieve hepatorenal toxicity and exhibit an important protective effect against chemotherapy-induced hepatorenal toxicity. Based on the subgroup analysis results, Aidi injection seems to lower the threshold for chemotherapy. Treatment with 50 mL per time, 10 to 14 days per cycle, and 2 to 3 cycles may be the optimal usage for attaining a decrease in hepatorenal toxicity.

Clinical efficacy and safety of aidi injection combination with vinorelbine and cisplatin for advanced non-small-cell lung carcinoma: A systematic review and meta-analysis of 54 randomized controlled trials.

The Aidi injection contains multiple active ingredients, including astragaloside (Re, Rb1, and Rg1), ginsenoside, cantharidin, elentheroside E, and syringin, and it is administered with vinorelbine and cisplatin (NP) to treat non-small-cell lung carcinoma (NSCLC). In this study, we performed a systematic review and meta-analysis to determine the clinical efficacy and safety of the Aidi injection with NP, and the optimal threshold and treatment regimen to produce the desired responses. We collected all studies regarding the Aidi injection with NP for NSCLC from Chinese and English databases (up to April 2019). Risk of methodological bias was evaluated for each study. Data for analysis were extracted using a standard data extraction form. Evidence quality was assessed following the Grading of Recommendations Assessment, Development and Evaluation approach. We included 54 trials containing 4,053 patients for analysis. Combining the Aidi injection with NP significantly increased the objective response rate (odds ratio [OR], 1.32; confidence interval [CI], 1.23, 1.42), disease control rate (OR, 1.14; CI, 1.11, 1.18), and quality of life (OR, 1.80; CI, 1.61, 1.98), with decreased risks of myelosuppression, neutropenia, thrombocytopenia, anemia, gastrointestinal reaction, and liver dysfunction. For patients with a Karnofsky Performance Status score of ≥60, the Aidi injection (50 mL/day, two weeks/cycle, with two to three cycles) treatment with vinorelbine (25 mg/m2) and cisplatin (30-35 mg/m2 or 40-50 mg/m2) might be the optimal regimen for producing the desired tumor response and achieving a good safety level. Most results were robust, and their quality was moderate. The results suggest that administration of the Aidi injection and concomitant NP is beneficial to NSCLC, and provide evidence for the optimal threshold and treatment regimen that may improve tumor response with a good safety level.

Achyranthes bidentata polypeptide k improves long-term neurological outcomes through reducing downstream microvascular thrombosis in experimental ischemic stroke.

Achyranthes bidentata Bl. (A. bidentata) occupies an important position in traditional Chinese medicine owing to the property of promoting the circulation of blood and removing stasis. Achyranthes bidentata polypeptide k (ABPPk) is one of the active components isolated from A. bidentata. We previously demonstrated that ABPPk has potent neuroprotective effects against neuronal apoptosis both in vitro and in vivo, but the roles and mechanisms of ABPPk on long-term functional recovery after ischemic stroke remain unknown. In the current study, we investigated the neuroprotective effects of ABPPk on filament transient middle cerebral artery occlusion (tMCAO) rats and found that ABPPk reduced the infarct volume and maintained the neuronal integrity in the ischemic penumbra. Moreover, we found that ABPPk might reduce the formation of downstream microthrombus through preventing ischemic-induced oxidative damage of brain endothelial cells and activation of tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1), and NF-κB. ABPPk also inhibited polymorphonuclear leukocytes (PMNs) infiltration and matrix metalloproteinase-2/-9 (MMP-2/-9) activation in the ischemic penumbra. Morris water maze, foot fault test, and modified neurological severity score were assessed for a period of 6 weeks following tMCAO. ABPPk improved long-term recognition abilities and neurological outcomes after stroke compared with saline-treated rats. Taken together, these results suggested that ABPPk is beneficial to the improvement of long-term outcomes after transient cerebral ischemia injury and can be used as a potential neuroprotective agent.

Curcumin-coordinated nanoparticles with improved stability for reactive oxygen species-responsive drug delivery in lung cancer therapy.

BACKGROUND: The natural compound curcumin (Cur) can regulate growth inhibition and apoptosis in various cancer cell lines, although its clinical applications are restricted by extreme water insolubility and instability. To overcome these hurdles, we fabricated a Cur-coordinated reactive oxygen species (ROS)-responsive nanoparticle using the interaction between boronic acid and Cur. MATERIALS AND METHODS: We synthesized a highly biocompatible 4-(hydroxymethyl) phenylboronic acid (HPBA)-modified poly(ethylene glycol) (PEG)-grafted poly(acrylic acid) polymer (PPH) and fabricated a Cur-coordinated ROS-responsive nanoparticle (denoted by PPHC) based on the interaction between boronic acid and Cur. The mean diameter of the Cur-coordinated PPHC nanoparticle was 163.8 nm and its zeta potential was -0.31 mV. The Cur-coordinated PPHC nanoparticle improved Cur stability in physiological environment and could timely release Cur in response to hydrogen peroxide (H2O2). PPHC nanoparticles demonstrated potent antiproliferative effect in vitro in A549 cancer cells. Furthermore, the viability of cells treated with PPHC nanoparticles was significantly increased in the presence of N-acetyl-cysteine (NAC), which blocks Cur release through ROS inhibition. Simultaneously, the ROS level measured in A549 cells after incubation with PPHC nanoparticles exhibited an obvious downregulation, which further proved that ROS depression indeed influenced the therapeutic effect of Cur in PPHC nanoparticles. Moreover, pretreatment with phosphate-buffered saline (PBS) significantly impaired the cytotoxic effect of Cur in A549 cells in vitro while causing less damage to the activity of Cur in PPHC nanoparticle. CONCLUSION: The Cur-coordinated nanoparticles developed in this study improved Cur stability, which could further release Cur in a ROS-dependent manner in cancer cells.

Can Aidi injection alleviate the toxicity and improve the clinical efficacy of radiotherapy in lung cancer?: A meta-analysis of 16 randomized controlled trials following the PRISMA guidelines.

BACKGROUND/INTRODUCTION: Aidi injection plus radiotherapy is widely used for lung cancer in China. Can Aidi injection alleviate the toxicity and improve the clinical efficacy of radiotherapy in lung cancer? Has Aidi injection the attenuation and synergistic efficacy to radiotherapy? There is lack of strong evidence to prove it. OBJECTIVES: To reveal its real attenuation and synergistic efficacy to radiotherapy and provide sufficient evidence for adjuvant chemotherapy strategies to lung cancer, we systematically evaluated all related studies. DATA SOURCES: We collected all studies about Aidi injection plus radiotherapy for lung cancer in Medline, Embase, Web of Science, China national knowledge infrastructure database (CNKI), Chinese scientific journals full-text database (VIP), Wanfang database, China biological medicine database (CBM) (established to June 2015), and Cochrane Central Register of Controlled Trials (June 2015), evaluated their quality according to the Cochrane evaluation handbook of randomized controlled trials (5.1.0), extracted data following the PICO principles and synthesized the data by Meta analysis. RESULTS: Sixteen randomized controlled trials (RCTs) with 1192 lung cancer patients were included, with general methodological quality in most trials. The merged relative risk (RR) values and their 95% CI of meta-analysis for objective response rate (ORR), disease control rate (DCR), and quality of life (QOL) were as follows: 1.54, (1.39,1.70), 1.10 (1.02, 1.19), and 2.13 (1.68, 2.68). The merged RR values and their 95% CI of meta-analysis for myelosuppression and neutropenia, radiation pneumonitis, and radiation esophagitis were as follows: 0.51 (0.38, 0.69), 0.53 (0.42, 0.65), 0.52 (0.41, 0.67), and 0.52 (0.40, 0.68). All were statistically significant. The possibility of publication bias was small which objectively reported the results. CONCLUSIONS: The evidence available indicates that Aidi injection plus radiotherapy can significantly improve the clinical efficacy and QOL of patients with lung cancer. Aidi injection can alleviate the myelosuppression, radiation pneumonitis, and radiation esophagitis of radiotherapy. It has the attenuation and synergistic efficacy to radiotherapy.

An active component of Achyranthes bidentata polypeptides provides neuroprotection through inhibition of mitochondrial-dependent apoptotic pathway in cultured neurons and in animal models of cerebral ischemia.

An active component has been isolated by reverse-phase high performance liquid chromatography (HPLC) from Achyranthes bidentata Blume polypeptides that are extracted from Achyranthes bidentata Blume, a Chinese medicinal herb. The active component is called ABPPk based on the order of HPLC elution. In this study, we used in vitro and in vivo experimental models of cerebral ischemia to investigate the possible neuroprotective effect of ABPPk. ABPPk treatment promoted neuronal survival and inhibited neuronal apoptosis in primary cortical neurons exposed to oxygen and glucose deprivation and in rats subjected to transient middle cerebral artery occlusion. The role of ABPPk in protection against ischemia-induced neuronal damage might be mediated by mitochondrial-dependent pathways, including modulation of apoptosis-related gene expression, regulation of mitochondrial dysfunction through restoring mitochondrial membrane potential, reducing release of mitochondrial apoptogenic factors, and inhibiting intracellular ROS production. The neuroprotective effect of ABPPk may suggest the possible use of this agent in the treatment and prevention of cerebral ischemic stroke.

Glucocorticoids sensitize rat placental inflammatory responses via inhibiting lipoxin A4 biosynthesis.

Inflammation dysregulation in placenta is implicated in the pathogenesis of numerous pregnancy complications. Glucocorticoids (GCs), universally considered anti-inflammatory, can also exert proinflammatory actions under some conditions, whereas whether and how GCs promote placental inflammation have not been intensively investigated. In this paper we report the opposing regulation of rat placental inflammation by synthetic GC dexamethasone (Dex). When Dex was subcutaneously injected 1 h after we administered an intraperitoneal lipopolysaccharide (LPS) challenge, neutrophil infiltration and proinflammatory Il1b, Il6, and Tnfa expression in rat placenta were significantly reduced. In contrast, Dex pretreatment for 24 h potentiated rat placental proinflammatory response to LPS and delayed inflammation resolution, which involved MAPKs and NF-kappaB activation. Mechanically, Dex pretreatment promoted 5-lipoxygenase (ALOX5) activation and increased leukotriene B4 production, whereas it inhibited the anti-inflammatory and proresolving lipid mediator lipoxin A4 (LXA4) biosynthesis in rat placenta via downregulating ALOX15 and ALOX15B expression. Moreover, LXA4 supplementation dampened Dex-potentiated placental inflammation and suppressed Dex-mediated ALOX5 activation in vivo and in vitro. Taken together, these findings suggest that GCs exposure could promote placental inflammation initiation and delay resolution via disrupting LXA4 biosynthesis.

Neurotrophic and neuroprotective actions of Achyranthes bidentata polypeptides on cultured dorsal root ganglia of rats and on crushed common peroneal nerve of rabbits.

We have isolated Achyranthes bidentata Blume polypeptides (ABPP) from the aqueous extract of A. bidentata Blume, a traditional Chinese medicine with multiple therapeutic applications. In this study, we aimed to investigate neurotrophic effects of ABPP on cultured dorsal root ganglia (DRGs) of rats and neuroprotective effects on crushed common peroneal nerve of rabbits. Immunochemistry and Western blot analysis indicated that ABPP (0.01, 0.1, and 1.0 µg/ml) encouraged neurite outgrowth from cultured DRG explants/neurons in a concentration-dependent manner through activation of ERK1/2. After crush injury to rabbit common peroneal nerve, animals received daily administration of ABPP for 5 weeks. Electrophysiological assessments and histomorphological evaluation showed that 6.0mg/kg ABPP significantly enhanced nerve regeneration and function restoration. Our findings suggest that ABPP could be used as a neurotrophic and neuroprotective agent to treat peripheral nerve crush injury.

The Achyranthes bidentata polypeptide k fraction enhances neuronal growth in vitro and promotes peripheral nerve regeneration after crush injury in vivo.

We have previously shown that Achyranthes bidentata polypeptides (ABPP), isolated from Achyranthes bidentata Blume (a medicinal herb), exhibit neurotrophic and neuroprotective effects on the nervous system. To identify the major active component of ABPP, and thus optimize the use of ABPP, we used reverse-phase high performance liquid chromatography to separate ABPP. We obtained 12 fractions, among which the fraction of ABPPk demonstrated the strongest neuroactivity. Immunocytochemistry and western blot analysis showed that ABPPk promoted neurite growth in cultured dorsal root ganglion explant and dorsal root ganglion neurons, which might be associated with activation of Erk1/2. A combination of behavioral tests, electrophysiological assessment, and histomorphometric analysis indicated that ABPPk enhanced nerve regeneration and function restoration in a mouse model of crushed sciatic nerve. All the results suggest that ABPPk, as the key component of ABPP, can be used for peripheral nerve repair to yield better outcomes than ABPP.

Protective effect of salidroside against H2O2-induced cell apoptosis in primary culture of rat hippocampal neurons.

Salidroside, a phenylpropanoid glycoside separated from a medicinal plant Rhodiola rosea, has been documented to have protective effects on neuronal cells in vitro. This study investigated whether salidroside was able to extend its unique neuroprotection to primary cultured rat hippocampal neurons against hydrogen peroxide (H(2)O(2))-induced cell damage. Cell viability tests and cell apoptosis assays confirmed that salidroside pretreatment attenuated H(2)O(2)-stimulated apoptotic cell death in primary culture of hippocampal neurons in a concentration-dependent manner. The measurements of caspase-3 activity, nitric oxide (NO) production, and NO synthase (NOS) activity suggest that the protection of salidroside, shown in this study, might be mediated by inhibiting caspase-3 activity, and antagonizing NO production and NOS activity during H(2)O(2) stimulation. Perhaps, this study might contribute to the development of salidroside as a broad-spectrum agent for preventing and/or treating neuronal damage in neurodegenerative disorders.

The repair effects of Achyranthes bidentata extract on the crushed common peroneal nerve of rabbits.

In this study the effect of the Achyranthes bidentata root aqueous extract on regeneration of the crushed common peroneal nerve in rabbits by using a combination of electrophysiological assessment and histological aspect were investigated. The examined functional and morphological parameters suggest that A. bidentata extract could accelerate peripheral nerve regeneration in a dose-dependent manner (10-20 microg/kg, i.v.).

Expression of bacterial hemoglobin genes to improve astaxanthin production in a methanotrophic bacterium Methylomonas sp.

Astaxanthin has been widely used as a feed supplement in poultry and aquaculture industries. One challenge for astaxanthin production in bacteria is the low percentage of astaxanthin in the total carotenoids. An obligate methanotrophic bacterium Methylomonas sp. 16a was engineered to produce astaxanthin. Astaxanthin production appeared to be dramatically affected by oxygen availability. We examined whether astaxanthin production in Methylomonas could be improved by metabolic engineering through expression of bacterial hemoglobins. Three hemoglobin genes were identified in the genome of Methylomonas sp. 16a. Two of them, thbN1 and thbN2, belong to the family of group I truncated hemoglobins. The third one, thbO, belongs to the group II truncated hemoglobins. Heterologous expression of the truncated hemoglobins in Escherichia coli improved cell growth under microaerobic conditions by increasing final cell densities. Co-expression of the hemoglobin genes along with the crtWZ genes encoding astaxanthin synthesis enzymes in Methylomonas showed higher astaxanthin production than expression of the crtWZ genes alone on multicopy plasmids. The hemoglobins likely improved the activity of the oxygen-requiring CrtWZ enzymes for astaxanthin conversion. A plasmid-free production strain was constructed by integrating the thbN1-crtWZ cassette into the chromosome of an astaxanthin-producing Methylomonas strain. It showed higher astaxanthin production than the parent strain.

Metabolic engineering for synthesis of aryl carotenoids in Rhodococcus.

Rhodococcus erythropolis naturally synthesizes monocyclic carotenoids: 4-keto-gamma-carotene and gamma-carotene. The genes and the pathway for carotenoid synthesis in R. erythropolis were previously described. We heterologously expressed a beta-carotene desaturase gene (crtU) from Brevibacterium in Rhodococcus to produce aryl carotenoids such as chlorobactene. Expression of the crtU downstream of a chloramphenicol resistance gene on pRhBR171 vector showed higher activity than expression downstream of a native 1-deoxyxylulose-5-phosphate synthase gene (dxs) on pDA71 vector. Expression of the crtU in the beta-carotene ketolase (crtO) knockout Rhodococcus host produced higher purity chlorobactene than expression in the wild-type Rhodococcus host. Growth of the engineered Rhodococcus strain in eight different media showed that nutrient broth yeast extract medium supplemented with fructose gave the highest total yield of chlorobactene. This medium was used for growing the engineered Rhodococcus strain in a 10-l fermentor, and approximately 18 mg of chlorobactene was produced as the almost exclusive carotenoid by fermentation.